Current microbiological challenges in drinking water

Cu en mic obiological challenges in d inking wa e
Ana C. A onso
a,b,c,d
, Ma ia J. Saa ed a
c
, Inˆ
es B. Gomes
a,b
, Manuel Sim˜
oes
a,b
,
Lúcia C. Sim˜
oes
d,e,*
a
LEPABE - Labo a o y o P ocess Enginee ing, En i onmen , Bio echnology and Ene gy, Facul y o Enginee ing, Uni e si y o Po o, Rua D Robe o F ias, 4200-465
Po o, Po ugal
b
ALiCE - Associa e Labo a o y in Chemical Enginee ing, Facul y o Enginee ing, Uni e si y o Po o, Rua D Robe o F ias, 4200-465 Po o, Po ugal
c
CITAB, Depa men o Ve e ina y Sciences, Uni e si y o T ´
as-os-Mon es e Al o Dou o, 5000-801 Vila Real, Po ugal
d
CEB – Cen e o Biological Enginee ing, Uni e si y o Minho, 4710-057 B aga, Po ugal
e
LABBELS - Associa e Labo a o y in Bio echnology and Bioenginee ing and Mic oelec omechanical Sys ems, B aga/Guima ˜
aes, Po ugal
ARTICLE INFO
Edi o : Rong Chen
Keywo ds:
Bio ilms
Disin ec ion by-p oduc s
Dis ibu ion sys ems
Public heal h
Wa e bo ne pa hogens
Wa e ea men
ABSTRACT
D inking wa e (DW) is pa amoun o human heal h, se ing as a co ne s one o public heal h wo ldwide.
Howe e , DW is no a s e ile p oduc and can ha bo a la ge di e si y o mic oo ganisms, including pa hogens.
This comp ehensi e e iew add esses he c i ical impo ance o DW o human heal h and he ongoing challenges
posed by mic obial pa hogens and bio ilms in wa e dis ibu ion sys ems. I u he analyzes he g owing chal-
lenges d i en by con empo a y ac o s such as an imic obial esis ance, bio ilms, clima e change, and mic o-
pollu an s. Bio ilms, in pa icula , emain unde es ima ed in con en ional wa e ea men p ocesses despi e
hei signi ican con ibu ion o mic obial con amina ion, he o ma ion o disin ec ion by-p oduc s, and disin-
ec an esis ance. Eme ging challenges, such as clima e change and mic opollu an s, ha e become signi ican
conce ns due o hei p o ound impac on mic obial communi ies and hei ole in shaping bio ilm o ma ion.
This e iew highligh s he key mic obiological h ea s o DW dis ibu ion sys ems, ocusing on he ole o bio-
ilms and he eme ging challenges posed by clima e change. I explo es he ac o s p omo ing bio ilm de el-
opmen , including wa e composi ion, pipe ma e ials, and ea men s a egies. I also explo es he limi a ions o
cu en wa e ea men s a egies, which o en ail o add ess bio ilms e ec i ely, and highligh s he need o
in eg a e mic obiological conside a ions in o wa e quali y managemen . This e iew aims o unde sco e he
u gen need o eassess wa e ea men and managemen p ac ices o add ess cu en mic obiological challenges
and ensu e he deli e y o sa e and sus ainable DW.
1. In oduc ion
Wa e , he essence o li e, is a undamen al esou ce indispensable
o human su i al and well-being [1]. Howe e , i s con amina ion by
mic obial pa hogens p esen s a pe sis en and igh ening challenge o
public heal h wo ldwide [2]. Wi hin he as a ay o pa hogens ha
inhabi wa e sou ces, eme ging and eeme ging pa hogens s and ou as
pa icula ly conce ning en i ies [3]. These pa hogens, spanning bac e-
ia, i uses, ungi, and pa asi es, ha e he po en ial o inci e widesp ead
illness and ou b eaks i no e ec i ely moni o ed and con olled [3].
No i iable diseases associa ed wi h wa e bo ne ansmission, unde sco e
he c i ical impo ance o obus disease su eillance and in e en ion
s a egies [4].
D inking wa e dis ibu ion sys ems (DWDS), while designed o
deli e po able wa e , o en ha bo complex mic obial communi ies,
namely bio ilms [5–7]. These bio ilms, consis ing o mic obial cells
embedded in a sel -p oduced ex acellula ma ix, adhe e o pipe su -
aces and signi ican ly impac wa e quali y. Some nega i e e ec s on
DWDS include bioco osion and inc eased ole ance o disin ec ion [8].
A po en ial consequence o he in e play be ween hese issues is he
o ma ion o disin ec ion by-p oduc s (DBPs). Speci ically, co osion
p oduc s om he piping ne wo k and o ganic ma e , including bio ilm
molecules, can signi ican ly a ec he e ec i eness o disin ec an s and
p omo e he o ma ion o DBPs [9–11]. While e idence o his ela-
ionship is s ill eme ging, cu en models p edic ing he o ma ion o
DBPs du ing wa e ea men o en unde es ima e he ole o bio ilms
[12,13].
Adding o hese challenges, clima e change exace ba es mic obial
* Co esponding au ho a : CEB – Cen e o Biological Enginee ing, Uni e si y o Minho, 4710-057 B aga, Po ugal.
E-mail add ess: [email p o ec ed] (L.C. Sim˜
oes).
Con en s lis s a ailable a ScienceDi ec
Jou nal o Wa e P ocess Enginee ing
jou nal homepage: www.else ie .com/loca e/jwpe
h ps://doi.o g/10.1016/j.jwpe.2025.107614
Recei ed 6 Feb ua y 2025; Recei ed in e ised o m 28 Ma ch 2025; Accep ed 29 Ma ch 2025
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
2214-7144/© 2025 The Au ho s. Published by Else ie L d. This is an open access a icle unde he CC BY-NC license ( h p://c ea i ecommons.o g/licenses/by-
nc/4.0/ ).
p oli e a ion in aqua ic en i onmen s. Rising empe a u es, al e ed
p ecipi a ion pa e ns, and ex eme wea he e en s c ea e a o able
condi ions o bio ilm o ma ion and he dissemina ion o an imic obial
esis ance (AMR) [14]. Also, mic opollu an s ha e inc easingly become
a majo conce n in DWDS. These ace con aminan s, o igina ing om
di e se sou ces, pe sis h ough con en ional ea men p ocesses and
can signi ican ly impac bio ilm o ma ion, al e mic obial di e si y, and
acili a e he sp ead o an imic obial esis ance genes [15,16]. Among
hem, mic oplas ics se e as no el su aces o mic obial coloniza ion,
u he p omo ing bio ilm de elopmen and po en ially ha bo ing
oppo unis ic pa hogens [17]. These in e ela ed issues demand a
deepe unde s anding o he en i onmen al and in as uc u al ac o s
d i ing mic obial dynamics in DWDS.
This e iew add esses he mul i ace ed challenges associa ed wi h
mic obiological s abili y and sa e y in DW, wi h a pa icula ocus on he
ole o bio ilms. I explo es bio ilm o ma ion and pe sis ence, hei
con ibu ions o bioco osion and DBP p oduc ion, and hei unc ion as
ese oi s o oppo unis ic pa hogens. Recognizing he complexi y o
hese issues, he e iew emphasizes he need o in e disciplina y
collabo a ion and adap i e managemen s a egies o sa egua d wa e
quali y and public heal h amid e ol ing en i onmen al p essu es. By
syn hesizing cu en knowledge and iden i ying esea ch gaps, his e-
iew seeks o inspi e inno a i e app oaches and echnological ad-
ancemen s o ensu e he sus ainable p o ision o sa e DW o all.
2. D inking wa e and public heal h
2.1. De ini ion, quali y c i e ia, and ea men
Wa e is he essen ial componen o li e, co e ing o e wo- hi ds o
he Ea h’s su ace. Howe e , <3 % o his wa e is eshwa e , and only
abou 1 % o i is accessible o use [18]. Gi en he g owing demand o
wa e and i s limi ed a ailabili y, sus ainable wa e use has become
c i ical o ensu e access o sa e d inking wa e (DW) o p esen and
u u e gene a ions [19]. The Uni ed Na ions ecognizes access o sa e
DW as a human igh [1], and he Wo ld Heal h O ganiza ion (WHO)
emphasizes he impo ance o main aining high s anda ds o DW
quali y o sa egua d public heal h [20]. By 2020, 5.8 billion people we e
using “sa ely managed” DW se ices, ye 771 million people s ill lacked
basic se ices, pa icula ly in low-income o in o mal u ban se lemen s
[2]. Add essing hese dispa i ies is cen al o he WHO/UNICEF Join
Moni o ing P og am’s Sus ainable De elopmen Goal 6, which aims o
ensu e he a ailabili y and sus ainable managemen o wa e and sani-
a ion o all by 2030 [21].
Sa e DW is gene ally de ined as wa e ha does no pose signi ican
heal h isks o e a li e ime o consump ion [22]. WHO guidelines se
comp ehensi e quali y c i e ia ac oss chemical, mic obiological, and
physical pa ame e s o ensu e he sa e y o DW [20]. Chemical c i e ia
limi con aminan s such as hea y me als, pes icides, and o ganic pol-
lu an s, while mic obiological c i e ia ocus on p e en ing pa hogens
ha can cause wa e bo ne diseases. Physical pa ame e s, including
colou , as e, and u bidi y, ensu e ha wa e is aes he ically accep able.
The WHO guidelines also s ess he impo ance o moni o ing and su -
eillance o main ain high s anda ds o wa e quali y and p e en isks
o public heal h [20].
DW ea men plan s (DWTPs) and DWDS unc ion collabo a i ely o
ensu e he chemical and biological sa e y o DW, sa egua ding public
heal h [23]. DWTPs u ilize a mul i-ba ie app oach o emo e con-
aminan s and inac i a e pa hogens h ough a sequence o physical,
chemical, and biological p ocesses [23]. The ea men p ocess ypically
begins wi h coagula ion and loccula ion, whe e chemical coagulan s
such as aluminum sul a e o e ic chlo ide a e added o des abilize
suspended pa icles and mic oo ganisms, o ming la ge agg ega es
called locs [24]. These locs a e hen emo ed in he sedimen a ion
s age, whe e g a i a ional se ling elimina es a signi ican po ion o
pa icula e ma e , including mic obial con aminan s [24]. Fil a ion
ollows, using ma e ials like sand, ac i a ed ca bon, o memb anes o
ap emaining pa icles and mic oo ganisms, u he enhancing wa e
cla i y and sa e y [25]. The inal and mos c i ical s ep is disin ec ion,
which employs chemical agen s such as chlo ine, chlo amines, o ozone,
as well as non-chemical me hods like ul a iole (UV) ligh o ad anced
oxida ion p ocesses (AOPs), o inac i a e bac e ia, i uses, and p o ozoa
[26]. Once ea ed, wa e en e s he DWDS, whe e main aining i s
chemical and biological in eg i y is i al o deli e ing sa e wa e o
consume s. Residual disin ec an s, such as ee chlo ine o monochlo -
amine, a e main ained h oughou he dis ibu ion sys em o p e en
mic obial eg ow h and p o ec agains con amina ion [27]. Howe e ,
while wa e ea men p ocesses a e e ec i e in ensu ing he sa e y and
quali y o DW, se e al limi a ions and d awbacks challenge hei e i-
cacy and sus ainabili y. Table 1 highligh s he challenges and limi a ions
a each s age o wa e ea men and dis ibu ion. These limi a ions
highligh he need o con inuous inno a ion in wa e ea men ech-
nologies, coupled wi h e ec i e moni o ing and main enance s a egies,
o add ess he g owing challenges o wa e sa e y and quali y.
2.2. Challenges o mic obial e iology in DW
Each yea , 1.5 million people wo ldwide die om wa e bo ne dis-
eases, wi h he majo i y being child en who die due o dehyd a ion
caused by dia hea [2]. Acco ding o he WHO, app oxima ely 1.7
billion cases o dia hea occu in child en annually, being he second
leading cause o dea h in child en unde 5 yea s o age [2].
Mic oo ganisms a e no mally p esen in DWDS a ela i ely high
concen a ions (10
3
o 10
6
cells/mL) bu wi hou comp omising public
heal h [28]. This sa e y is ensu ed by a combina ion o wa e ea men
p ocesses, s ingen egula o y o e sigh , he p edominan ly non-
pa hogenic na u e o hese mic oo ganisms, compe i i e mic obial
ecology ha inhibi s pa hogen g ow h, and he obus ness o he human
immune sys em [20,29–31]. Ne e heless, DWDS mus be mic obio-
logically sa e and s able. In o he wo ds, a mic obiologically s able
DWDS mus ha e a cons an concen a ion and bac e ial communi y
composi ion, om he poin o DW p oduc ion o he ap [28]. Howe e ,
unwan ed bac e ial g ow h inside he pipes can be esponsible o
ad e se changes in DW and DWDS quali y. The p esence o some mi-
c oo ganisms may be esponsible o some de e io a ion o he o gan-
olep ic p ope ies o he wa e [28], which ep esen s he main
consume complain o DWDS companies [32]. The wa e dis ibu ion
sys em i sel can also be a ec ed by he p esence o bac e ia, o
example, he p esence o bio ilms in pipe walls can accele a e i s
co osion [33]. In addi ion, bio ilms can also ha bo pa hogenic mi-
c oo ganisms ha can pose a dange o human heal h [8].
The quali y o wa e is inhe en ly shaped by i s geog aphic and
geological con ex , including ac o s like empe a u e, p ecipi a ion,
leaching, and he elease o elemen s om he c us o Ea h [34].
Ne e heless, human ac i i ies ha e a signi ican impac on su ace
wa e bodies globally [34]. In u al egions o de eloping na ions, in-
di iduals acing economic challenges equen ly ely on un ea ed su -
ace wa e o ba hing, laund y, cooking, and occasionally e en d inking
[34,35]. Simila ly, in bo h de eloped and de eloping coun ies, su ace
wa e s se e pu poses such as ec ea ional swimming, ishing, and
i iga ion [34,36]. Wa e bo ne diseases can be caused by a a ie y o
pa hogens including p o ozoa, pa asi es, bac e ia, and i uses [37,38].
Due o he imp ac icali y o es ing o all pa hogens in all loca ions,
moni o ing e o s o pollu ed wa e o en p io i ize he de ec ion o
speci ic indica o o ganisms ha signal he po en ial p esence o pa h-
ogens [38,39]. One o he mos employed indica o s is aecal coli o m
bac e ia [39]. While mos aecal coli o m bac e ia a e no inhe en ly
ha m ul, hey a e ypically associa ed wi h human and animal was e.
Fu he mo e, ele a ed le els o hese bac e ia o en indica e he p es-
ence o ha m ul pa hogens [20,40]. Nume ous coun ies ha e
acknowledged he co ela ion be ween aecal coli o m bac e ia and
heal h isks, leading hem o de elop guidelines dic a ing pe missible
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
2
le els o hese bac e ia in wa e sou ces. E alua ing he deg ee o
pa hogen pollu ion equi es a compa ison o he le els o aecal coli o m
bac e ia agains es ablished sa e y benchma ks [34]. The WHO has
es ablished hese benchma ks, d awing upon wa e quali y s anda ds
om 17 coun ies (Table 2). Howe e , h oughou he di e en phases
o DW sys ems, complex mic obial communi ies h i e, engaging in
in ica e ne wo ks o in e ac ions [41]. Addi ionally, as p e iously
men ioned, exis ing egula ions go e ning he mic obial sa e y o DWDS
p ima ily a ge he p obabili y o aecal con amina ion. These egula-
ions ely on con en ional cul u e-based me hodologies o de ec and
quan i y coli o ms, pa icula ly Esche ichia coli. Despi e hei cen u y-
long applica ion, hese echniques ha e emained la gely unal e ed.
C i ically, hese con en ional indica o s p esen se e al limi a ions: he
as majo i y o bac e ia, o e 99 %, e ade cul u ing [42,43]; he
eme gence o non- aecal pa hogens in DW; and he co ela ion be ween
o al coli o ms and o he pa hogenic ma ke s is weak [40,44,45].
The mic obiome o DW is in luenced by ac o s like sou ce wa e
quali y, ea men p ocesses, low dynamics, empe a u e, and he
p esence o bio ilms in he dis ibu ion sys em, among o he s [46].
Abka e al. [27] e iewed key s udies ha elucida e how ope a ional
condi ions shape mic obial communi ies wi hin DW sys ems. Lau-
enschlage e al. [47] p o ided ounda ional insigh s in o he e ec s o
s agna ion and low low a es, showing ha hese condi ions p omo e
mic obial eg ow h and bio ilm o ma ion, pa icula ly in dead-end
zones o he dis ibu ion ne wo k. They also obse ed ha p olonged
s agna ion os e s mic obial communi ies wi h inc eased me abolic ac-
i i y, which can deg ade wa e quali y. P es e al. [28] emphasized he
selec i e p essu es exe ed by disin ec an esiduals, demons a ing how
di e en concen a ions o chlo ine and chlo amine impac mic obial
di e si y, o en a o ing esis an axa like Ni ospi a and oppo unis ic
pa hogens. Fish e al. [48] u he explo ed he e ec s o empe a u e
inc eases, linking highe empe a u es o accele a ed mic obial ac i i y,
enhanced bio ilm g ow h, and shi s in mic obial communi y composi-
ion. The s udy highligh ed how empe a u e-d i en changes can in-
c ease he p e alence o P o eobac e ia and o he bio ilm-associa ed
axa, aising conce ns abou po en ial pa hogen p oli e a ion. Addi-
ionally, Abka e al. [27] highligh ed s udies ocusing on axa-speci ic
esponses, such as he dominance o Pseudomonas and Acine obac e
unde nu ien - ich and low-disin ec an condi ions, con ibu ing o
in as uc u e co osion and an imic obial esis ance. Collec i ely, hese
s udies e eal he complex in e play be ween physical, chemical, and
en i onmen al ac o s in DW sys ems, s essing he need o dynamic
managemen s a egies ha add ess mic obial p oli e a ion while
main aining wa e quali y. All o he a o emen ioned s udies unde sco e
he c i ical impo ance o in es iga ing he mic obiome o DW. Such
esea ch no only enhances he unde s anding o mic obial dynamics
wi hin DW sys ems bu also holds signi ican implica ions o public
heal h by elucida ing ac o s in luencing mic obial abundance, di-
e si y, and communi y s uc u e. The mic obiome o DW encompasses
a di e se a ay o mic oo ganisms ha can signi ican ly in luence wa e
quali y, ea men p ocesses, and human heal h. Unde s anding hese
changes is c ucial o wa e u ili ies o ensu e sa e DW by comp e-
hending hei impac on mic obiomes and pa hogen p e alence. By
elucida ing he mic obial ecology o wa e sys ems, one can iden i y
po en ial sou ces o con amina ion, ack he sp ead o pa hogens, and
de elop a ge ed s a egies o wa e ea men and dis ibu ion.
Mo eo e , s udying he DW mic obiome can also shed ligh on he
ecological ela ionships wi hin aqua ic ecosys ems, con ibu ing o
b oade e o s in en i onmen al conse a ion and esou ce manage-
men [46].
3. Wa e bo ne pa hogens
3.1. Pa hogens o conce n in d inking wa e
I is es ima ed ha he e a e 1407 human-in ec ing pa hogens, wi h
177 being conside ed eme ging o eeme ging [49]. These pa hogens
encompass bac e ia (538 species), i uses (208 ypes), ungi (317 spe-
cies), pa asi ic p o ozoa (57 species), and helmin hs (287 species) [50].
Wa e , was ewa e , ood, and soils can ha bo in ec ious agen s,
po en ially con amina ing DW [50]. Some po en ially ha m ul bac e ia
Table 1
Limi a ions and d awbacks o wa e ea men p ocesses in DWDS, highligh ing he challenges associa ed wi h each s age o ea men and dis ibu ion. Ve es e a igo
e comple a com in o de l´
a (Mic obial ecology o d inking wa e om sou ce o ap).
S age Desc ip ion Limi a ions and d awbacks Re e ences
Coagula ion and
Sedimen a ion
Coagula ion in ol es adding chemical coagulan s (e.g.,
aluminum sul a e) o des abilize and agg ega e pa icles,
ollowed by sedimen a ion o emo e locs
Gene a es signi ican quan i ies o sludge equi ing p ope disposal,
posing en i onmen al and logis ical challenges. E ec i eness can be
educed by luc ua ions in wa e chemis y (e.g., pH, empe a u e)
P es e al.
[28]
Fil a ion Fil e s, such as sand and ac i a ed ca bon, a e used o
physically emo e emaining pa icles and mic oo ganisms
Sand and ac i a ed ca bon il e s may become clogged o ouled o e
ime, educing e iciency and equi ing equen main enance. Memb ane
il a ion is cos ly and p one o ouling and damage, inc easing
ope a ional cos s
P es e al.
[28]
Chemical
Disin ec ion
Chemical agen s like chlo ine, chlo amines, and ozone a e used
o kill pa hogens and p o ide esidual p o ec ion
Chlo ine has educed e ec i eness agains p o ozoan cys s
(C yp ospo idium, Gia dia) and eac s wi h na u al o ganic ma e ,
o ming ha m ul DBPs. Chlo amines a e less e ec i e as p ima y
disin ec an s and p oduce ni osamines. Ozone lacks esidual ac i i y,
making wa e ulne able o econ amina ion and b oma e o ma ion
Oli ei a e al.
[26]
Non-Chemical
Disin ec ion
UV ligh o AOPs a e used o inac i a e mic oo ganisms
h ough non-chemical means
UV disin ec ion inac i a es mic oo ganisms bu does no p o ide esidual
p o ec ion, lea ing wa e suscep ible o eg ow h and con amina ion.
AOPs ha e high ene gy demands and ope a ional cos s, limi ing hei
widesp ead adop ion.
Abka e al.
[27]
Residual
Disin ec ion
Disin ec an (e.g., chlo ine) is added o main ain a esidual
concen a ion (0.2–2 mg/L, max. 5 mg/L) o inhibi mic obial
eg ow h
The e ec i eness o esidual disin ec an s can be in luenced by changes in
wa e quali y, such as luc ua ions in pH o empe a u e, and in e ac ions
wi h bio ilms, educing hei long- e m e icacy. Fo ma ion o DBPs. Does
no ully p e en mic obial g ow h and al e s mic obial communi y
s uc u e.
Abka e al.
[27]
Table 2
Classi ica ion o pa hogen wa e pollu ion based on i e concen a ions o
aecal coli o m bac e ia, u ilizing benchma ks de i ed om wa e quali y
s anda ds o 17 coun ies.
Classi ica ion o
wa e pollu ion
Faecal coli o m
(CFU/100 mL)
Explana ion
Low pollu ion ≤200 Gene ally sui able o con ac (e.g.
swimming and ba hing)
Mode a e pollu ion 200 <x ≤1000 App op ia e only o con ac du ing
i iga ion and ishing ac i i ies
Se e e pollu ion >1000 Unsui able o con ac
Adap ed om UNEP [34].
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
3
ha could be p esen in DW include Vib io chole ae, Salmonella Typhi,
Shigella spp., Campylobac e jejuni, E. coli, Ye sinia en e oli ica, Legionella
spp., Ae omonas spp., a ious species o Mycobac e ium (e.g. M. a ium,
M. ube culosis, M. o ui um M. abscessus, M. chelonae, M. kansasii. M.
ma inum, M. xenopi), and Pseudomonas ae uginosa [51,52]. One impo -
an ac o o disease de elopmen is he minimal in ec i e dose (MID)
which a ies widely wi h he ype o pa hogen [50]. The MID o hese
wa e bo ne pa hogens a e p esen ed in Table 3.
Some o hese p e ious men ioned bac e ia a e also included in he
lis o no i iable in ec ious diseases, equi ing heal hca e p o ide s o
epo cases o public heal h au ho i ies. No i iable diseases, pa icula ly
hose associa ed wi h wa e bo ne ansmission, pose signi ican chal-
lenges o public heal h wo ldwide [53]. These diseases can apidly
sp ead h ough con amina ed wa e sou ces, leading o ou b eaks and
widesp ead illness [53]. Examples o such wa e bo ne diseases include
chole a caused by V. chole ae, yphoid e e caused by S. yphi, shigel-
losis caused by Shigella spp., lis e iosis caused by Lis e ia monocy ogenes,
and campylobac e iosis caused by C. jejuni. Timely epo ing o no i i-
able diseases is i al o e ec i e disease su eillance, enabling public
heal h au ho i ies ea ly de ec ion o ou b eaks and implemen a ion o
a ge ed in e en ions o con ol ansmission [4]. By moni o ing and
p omp ly no i ying heal h au ho i ies o suspec ed o con i med cases, i
becomes possible o implemen a ge ed in e en ions, such as wa e
ea men and sani a ion imp o emen s, o p e en u he sp ead and
p o ec communi y heal h [4].
Despi e he ema kable success o wa e ea men and sani a ion
p og ams in imp o ing public heal h, spo adic cases and poin -sou ce
ou b eaks o wa e bo ne diseases con inue o occu [54]. Acco ding o
he Cen e s o Disease Con ol and P e en ion (CDC), a wa e bo ne
disease ou b eak (WBDO) is an inciden in which wo o mo e
epidemiologically-linked pe sons expe ience a simila illness a e
exposu e o he same wa e sou ce and epidemiologic e idence impli-
ca es he wa e as he likely sou ce o he illness [55]. Table 4 shows he
WBDO, wi h bac e ial e iology, ha occu ed in Eu ope in he pe iod
be ween 2000 and 2023. A sea ch in SCOPUS (No embe 2024) il e ed
using he keywo ds “Wa e bo ne”, “Ou b eak” and “Eu ope” in he i le,
keywo ds and abs ac ; limi ed o English and he pe iod be ween 2000
and 2023, displayed 88 documen esul s. O hese, 64 co espond o
s udies on i uses (17), chemicals (2), clima e change (6), pa asi es (19),
o he con inen s (4) and o he subjec s (s udy ools, con ol s a egies,
p ojec ions, non-wa e bo ne, e c.) (29). Only 11 we e di ec ly ela ed o
wa e bo ne bac e ial ou b eaks. O he 11 eco ds ound, h ee we e
associa ed wi h he genus Campylobac e , h ee wi h L. pneumophila, one
wi h Salmonella ko bus, one wi h S. yphi and h ee wi h mul iple ae i-
ologies. In gene al, cases o campylobac e iosis and Legionnai es’ dis-
ease occu ed in milde seasons. Simila o wha was p e iously
desc ibed o Campylobac e spp., in ec ions end o occu mo e
equen ly in wa me mon hs, which co esponds o he ideal empe a-
u e ange o 25 o 42 ◦C o Legionella [56]. S udies ha e obse ed ha
empe a u e, ain all, and i e sys ems play signi ican oles in
in luencing he incidence o legionellosis in a ious loca ions [57–59].
In 2006, cases o S. ko bus in ec ions on G an Cana ia (Spain) we e
documen ed [60], p edominan ly a ec ing child en unde he age o
one, necessi a ing hospi aliza ion. Ins ances o ou b eaks a ibu ed o
his speci ic Salmonella species a e in equen in he li e a u e, wi h only
i e epo ed ou b eaks since 1959 [61–65]. Addi ionally, he ou b eak
on G an Cana ia ma ked he i s ins ance o S. ko bus associa ed wi h
comme cially bo led wa e in Eu ope. Also, in non-endemic coun ies,
occu ence o yphoid e e a e sca ce and ypically spo adic [66],
esul ing in limi ed public heal h ou comes. Typhoid e e , a se e e
sys emic illness, is caused by Salmonella en e ica subspecies en e ica,
se o a Typhi [66]. I s ansmission usually occu s h ough aecal
con amina ion o ood o wa e and is p e alen in egions wi h inade-
qua e sani a ion [66]. On Ap il 2022, a signi ican ou b eak o yphoid
e e eme ged in he Ne he lands among asylum seeke s housed on a
eno a ed essel. Ooms e al. [67] epo ed ha he con amina ion
o igina ed om a leakage o he was ewa e ank in o he DW ank
supply.
3.2. Eme ging and eeme ging pa hogens in d inking wa e
Eme ging and eeme ging pa hogens in DW e e o wo dis inc ye
in e ela ed ca ego ies. Eme ging pa hogens a e hose ha ha e only
ecen ly been iden i ied as wa e bo ne h ea s, ei he because hey a e
newly disco e ed o because ad ancemen s in de ec ion me hods ha e
e ealed hei p esence and signi icance. These may include p e iously
unknown mic oo ganisms o pa hogens ha we e no p e iously
ecognized as a conce n in DW bu ha e gained a en ion due o hei
public heal h implica ions. In con as , eeme ging pa hogens a e hose
ha we e once conside ed con olled o o limi ed conce n bu ha e
esu ged, leading o an inc ease in in ec ions o an expansion in hei
geog aphical dis ibu ion [3]. In ecen yea s, wa e bo ne pa hogens
ha e come o ligh , encompassing bo h known pa hogens o igina ing
om aecal con amina ion and no el pa hogens a ising om en i on-
men al ese oi s [54]. Va ious ac o s con ibu e o he esu gence o
eme gence o hese wa e bo ne pa hogens, including shi s in human
demog aphics, al e a ions in human habi s, de e io a ion o public
heal h in as uc u es, mic obial e olu ion, and modi ica ions in ag i-
cul u al me hods [68]. Fo ins ance, u baniza ion and popula ion
g ow h can lead o inc eased con amina ion o wa e sou ces, while
changes in ag icul u al p ac ices such as i iga ion echniques can
in oduce pa hogens in o wa e ese oi s. Addi ionally, clima e change
may in luence he dis ibu ion and su i al o pa hogens in wa e en-
i onmen s, u he complica ing e o s o mi iga e he isks associa ed
wi h wa e bo ne diseases [3,69].
The eme ging and eeme ging pa hogenic bac e ia highligh ed
he ein (Table 5) ha e he po en ial o be ansmi ed h ough DW;
howe e , hey do no necessa ily co ela e wi h he p esence o E. coli o
o he commonly used DW quali y indica o s. Typically, exis ing mic o-
biological indica o s used o assess DW quali y may no eliably de ec
he p esence o hese eme ging pa hogenic bac e ia, posing challenges
o hei iden i ica ion and moni o ing [54]. The species lis ed in Table 5
s and ou o hei ema kable p oli e a ion in wa e sys ems. Thei
abili y o o m bio ilms is a c i ical ac o in hei esis ance o disin-
ec ion e o s and en i onmen al s esses, enhancing hei pe sis ence
in wa e sys ems. Clima e change, human ac i i ies such as u baniza-
ion, ag icul u al uno , and imp ope was e managemen , u he
con ibu e o he sp ead and esilience o hese pa hogens [70]. The
inc easing p e alence o hese bac e ia in wa e sou ces unde sco es he
need o imp o ed wa e quali y moni o ing, e ec i e disin ec ion
p ac ices, and comp ehensi e s a egies o mi iga e hei impac on
public heal h [44].
Table 3
MID o ha m ul wa e bo ne pa hogens.
Pa hogen Minimal in ec i e dose (MID) (CFU/mL)
Vib io chole ae 10
3
Salmonella spp. 10
4
–10
7
Shigella spp. 10
1
–10
2
Campylobac e jejuni ≈500
Esche ichia coli 10
6
–10
8
Esche ichia coli O157:H7 <100
Ye sinia en e ocoli ica 10
6
Legionella spp. Unknown
Ae omonas spp. 10
4
Mycobac e ium a ium 10
4
–10
7
Pseudomonas ae uginosa Unknown
Based on Bi on [50], and Teunis and Figue as [168].
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
4
4. Bio ilms in d inking wa e sys ems
4.1. De ini ion and bio ilm-associa ed p oblems
Bio ilms a e well-o ganized s uc u es o mic oo ganisms o med
h ough a sequence o e en s, s a ing wi h he adhesion o plank onic
cells o a su ace, ollowed by subsequen eplica ion and p oduc ion o
an ex acellula ma ix o EPS [71]. Howe e , no all bio ilms de elop in
he same manne , especially wi hin li ing o ganisms, in medical and
indus ial se ings, and in na u e. In hese en i onmen s, bio ilms can be
obse ed as una ached agg ega es [72–74]. A clea example is he
o ma ion o clus e s o bac e ia, commonly called g anules, obse ed in
was ewa e ea men plan s (WWTPs) [75]. Simila ly, in ma ine, lake,
and i e ecosys ems, hese bio ilms a e o en e med “ma ine snow”
[76]. Fig. 1 illus a es an adap a ion o he bio ilm o ma ion model
p oposed by Saue e al. [74], whe e he s eps desc ibed abo e a e
inco po a ed.
The p esence o bio ilms in DW p esen s a mul i ude o challenges,
pa icula ly o wa e disin ec ion. Bac e ia in bio ilms a e ema kably
mo e esis an o con en ional disin ec ion me hods [77]. Assaidi e al.
[78] s udied he pe sis ence o L. pneumophila in wa e sys ems, ocusing
on he ole o bio ilms and he e ec i eness o sodium chlo ide disin-
ec ion. Assessing a ious concen a ions o sodium chlo ide on bo h
plank onic and sessile cells, hey ound ha while plank onic cells
showed suscep ibili y o sodium chlo ide, wi h su i al up o 2 % con-
cen a ion a 20 ◦C, bio ilms we e esilien , su i ing and eg owing
e en a e exposu e o a sodium chlo ide shock. In e es ingly, his
esilience was mo e p onounced in olde bio ilms compa ed o he
younge ones.
Mo eo e , bio ilms se e as ese oi s o a ious mic oo ganisms,
including pa hogens, aising conce ns abou mic obial con amina ion
and associa ed heal h isks [79]. Fo ins ance, esea ch on L. pneumo-
phila bio ilms has shown ha hey p o ec he colonize cells om
disin ec ion [5,7,78]. And eozzi e al. [80] used bac e ial cul u es and
ad anced molecula biology echniques o in es iga e how bio ilms
p o ec ed he eplica i e o m o L. pneumophila, ocusing on mip gene
exp ession. The mip gene and i s encoded p o ein, MIP, in Legionella is
c ucial o unde s anding i s ole as a i ulence ac o , elucida ing hos -
pa hogen in e ac ions, de eloping diagnos ic ma ke s, and iden i ying
po en ial he apeu ic a ge s o Legionnai es’ disease [81]. Resul s
showed an up- egula ion o mip gene unde nu ien deple ion, wi h
bio ilms p ese ing Legionella in he eplica i e o m. O he s udies ha e
shown ha bio ilms in DWDS can also se e as ese oi s o o he
oppo unis ic pa hogens [7,81].
Howe e , disin ec ion ole ance and pa hogen p o ec ion a e no he
only issues associa ed wi h he p esence o bio ilms in wa e sys ems.
Bio ilms also p omo e bioco osion, accele a ing he deg ada ion o he
piping in as uc u e [8]. Bioco osion, d i en by bio ilm- o ming mi-
c obes like bac e ia, a chaea, and ungi, accele a es pipe ma e ial
deg ada ion, comp omising wa e quali y and in as uc u e [82,83].
Mic obes such as i on-oxidizing bac e ia (IOB), sul a e- educing bac e ia
(SRB), and manganese-oxidizing bac e ia (MOB) con ibu e o co osion
by al e ing local chemis y. IOB oxidize e ous i on, o ming e ic
hyd oxide deposi s ha c ea e anae obic condi ions o SRB, which
p oduce co osi e sul ides [84,85]. MOB oxidize manganese, deposi ing
oxides ha u he co osion [86]. Bio ilms, s abilized by an EPS ma ix,
ap nu ien s and co osion p oduc s, es ablish edox g adien s, and
c ea e di e en ial ae a ion cells, exace ba ing co osion [11,87]. These
p ocesses accele a e disin ec an decay, des abilize wa e quali y, and
inc ease ha m ul DBP p oduc ion, posing heal h isks [11]. This opic
will be u he discussed in Sec ion 5.1, as i is conside ed one o he
eme ging key issues associa ed wi h bio ilm o ma ion.
4.2. Bio ilms as a sou ce o wa e bo ne mic obiological diseases
Bio ilms a e belie ed o be he p ima y sou ce o mic oo ganisms in
DWDS, wi h an es ima ed 95 % o he o al biomass in he wa e being
a ached o he pipe walls, while only 5 % is in he wa e phase [6]. In
ac , a e ea men p ocedu es like chlo ina ion, bac e ia le els in
wa e anks a e a hei lowes , bu hey inc ease in ap wa e due o
bio ilms in plumbing sys ems [88]. The le els o colony o ming uni s
(CFU) a y, anging om up o 10
6
CFU/mL in g oundwa e o be ween
10
2
and 10
5
CFU/mL in household ap wa e [88,89]. Fig. 2 p esen s he
bac e ial concen a ions a key s ages o he wa e ea men p ocess.
These s ages encompass he wa e sou ce, he ea ed wa e immedia ely
pos -disin ec ion wi hin he holding ank, he s o age ank be o e dis-
ibu ion, and inally, he wa e as i eaches he ap o consump ion.
Mo eo e , i p o ides a b eakdown o he p edominan and commonly
ound bac e ial classes and gene a iden i ied wi hin a household en i-
onmen ac oss a ious loca ions. Each a ea exhibi s dis inc mic obial
composi ions, e lec ing localized en i onmen al condi ions and usage
pa e ns. In ac , bac e ial di e si y is in luenced by ac o s like disin-
ec an ype, empe a u e, low a e, and building ma e ials [90]. Fo
example, in lowe pa s o plumbing sys ems, Alphap o eobac e ia a e
dominan o e Be ap o eobac e ia in bio ilms, especially in sys ems
wi h egula wa e consump ion and high low a es [91]. This domi-
nance was also obse ed in coppe pipes [91], while c oss-linked poly-
e hylene (PEX) pipes, pa icula ly in conjunc ion wi h ho wa e , end o
a o Be ap o eobac e ia, Gammap o eobac e ia, Ac inobac e ia, and
Bacilli [89,91,92].
The lack o epo ing and su eillance on wa e bo ne ou b eaks
associa ed wi h bio ilms ep esen s a signi ican de iciency in public
heal h moni o ing. Recen indings om he CDC unde sco e he
magni ude o his issue, wi h hei epo on “Su eillance o Wa e -
bo ne Disease Ou b eaks Associa ed wi h D inking Wa e ” in he Uni ed
S a es e ealing ala ming s a is ics. Be ween 2015 and 2020, 87 % o
epo ed ou b eaks we e linked o bio ilms, accoun ing o 187 cases ou
o 214. These ou b eaks we e p edominan ly a ibu ed o Legionella,
comp ising 98 % o bio ilm- ela ed cases, wi h isola ed ins ances
in ol ing non ube culous mycobac e ia and Pseudomonas spp. [93].
Such da a highligh s he u gen need o enhanced su eillance and
epo ing mechanisms globally o e ec i ely add ess bio ilm-associa ed
Table 4
Bac e ial- ela ed ou b eaks caused by wa e bo ne ansmission in Eu ope be ween 2000 and 2020.
Yea Coun y Pa hogenic bac e ia Numbe o cases Sou ce Re e ence
2000 F ance Mul iple 202 G oundwa e sys em con amina ion [169]
2002–2003 Sweden Campylobac e jejuni 101 Communal wa e [170]
2006 Spain Salmonella ko bus 41 Bo led wa e [60]
2007 No way Campylobac e spp. 105 Vulne abili y o he DW sys em [171]
2007 Denma k Mul iple 140 DW [210]
2010 Belgium Mul iple 222 DW [172]
2012 Uni ed Kingdom Legionella pneumophila 21 Spa pool de ice [173]
2014 Po ugal Legionella pneumophila 550 Indus ial we cooling sys ems [174]
2019 No way Campylobac e jejuni 2000 Municipal DW sys em [175]
2020–2021 Finland Legionella pneumophila 12 Tap wa e [176]
2022 Ne he lands Salmonella Typhi 72 Was ewa e leak in DW ank [67]
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
5

Table 5
Eme ging and eeme ging wa e bo ne pa hogenic bac e ia o public heal h conce n.
Bac e ia P e alence in
wa e sou ces
Resis ance o
disin ec ion
Bio ilm o ma ion Impac o clima e
change
Human ac i i ies
impac
Eme ging o eeme ging
s a us
Heal h e ec s Re e ences
Acine obac e spp. 28 % o es ed DW
samples
Resis an o
chlo ine
Bio ilm o ma ion
enhances
esis ance o
disin ec an s and
an ibio ics
Inc eased su i al
and dissemina ion
in wa me wa e
An ibio ic o e use,
imp ope was e
disposal, un ea ed
was ewa e
Eme ging pa hogen due o
mul id ug esis ance (MDR)
and su i al in di e se
en i onmen s
Nosocomial in ec ions;
meningi is, pneumonia,
endoca di is, bac e emia, skin
and u ina y ac in ec ions in
immunocomp omised pa ien s
[99,177–180]
A cobac e spp. 35 % o su ace
wa e samples
Mode a e
esis ance o
chlo ine and
ozone
Bio ilm o ma ion
enhances
esis ance o
disin ec an s and
en i onmen al
s esses
Inc eased isk o
wa e bo ne
ansmission due o
al e ed wa e
empe a u es and
p ecipi a ion
pa e ns
In ensi e li es ock
a ming, inadequa e
was ewa e
ea men , and
ag icul u al uno
Eme ging pa hogens due o
ising de ec ion in wa e
sou ces and esis ance o
common disin ec ion
me hods
Dia hea [181–184]
Ae omonas
hyd ophila
18 % o DW
samples
Resis an o
chlo ina ion and
oxida i e s ess
Bio ilm o ma ion
enhances
esis ance o
en i onmen al
s esses and
disin ec an s
Inc eased p esence
and i ulence in
wa me wa e s
Ag icul u al uno ,
u baniza ion,
indus ial discha ges
Reeme ging pa hogen due o
pe sis en wa e p esence
and esis ance o
disin ec an s and an ibio ics
Gas oen e i is [44,185,186]
Campylobac e
(including
C. jejuni, C. coli,
and ela ed
species)
Su ace wa e ,
g oundwa e ,
u al wa e shed
uno , ma ine
wa e , ainwa e ,
i e s, and lakes
Sensi i e o
chlo ina ion bu
pe sis s in
bio ilms and low-
nu ien
en i onmen s
Bio ilm o ma ion
enhances
esis ance o
chlo ina ion and
en i onmen al
s esses
Highe
empe a u es and
in ense ain all
inc ease cases,
while hea wa es
and win e
p ecipi a ion
dec ease cases
Sp ead by imp ope
was e managemen ,
ag icul u al uno ,
ec ea ional wa e
ac i i ies, and
occupa ional
exposu e in poul y
a ms
Eme ging pa hogens due o
inc easing incidence,
en i onmen al adap abili y,
wa e sou ce p esence, and
clima e and human ac i i y
impac s
Acu e gas oen e i is [69,190,191,187–189,209,211]
Helicobac e pylo i 30 % o es ed DW
samples
Su i es in wa e
o ex ended
pe iods,
esis ance o
chlo ine is
unce ain
Bio ilm o ma ion
p o ec s agains
en i onmen al
s esses and
disin ec ion
Inc eased su i al
in wa me wa e s
due o clima e
change
Imp ope
was ewa e
managemen and
con amina ed wa e
supplies
Eme ging pa hogen due o
associa ion wi h wa e bo ne
ansmission and esilience
in en i onmen al condi ions
Gas oduodenal disease
including ch onic ac i e
gas i is; pep ic and duodenal
ulce disease; gas ic cance
[44,192,208]
Legionella
pneumophila
High p e alence
in wa e sys ems
Resis an o
s anda d
disin ec ion,
equi es he mal
ea men
Bio ilm o ma ion
p o ides p o ec ion
agains
disin ec an s
Inc eased isk due
o highe wa e
empe a u es
Use o cooling
sys ems, inadequa e
wa e sys em
main enance,
u baniza ion
Eme ging pa hogen due o
associa ion wi h mode n
wa e sys ems and ising
incidence
Legionnai e’s disease and
Pon iac e e
[56,191,193,194]
Mycobac e ium
a ium complex
40 % o municipal
wa e samples
Resis an o
chlo ine and
common
disin ec an s
Bio ilm o ma ion
p o ides a
p o ec i e niche o
pe sis ence and
g ow h
Enhanced su i al
in wa me wa e
U baniza ion,
ag icul u al uno ,
ea ed wa e sys em
use
Eme ging pa hogens due o
inc easing incidence in
immunocomp omised
popula ions and esilience in
ea ed wa e sys ems
Pulmona y disease [44,195,196]
Lis e ia
monocy ogenes
25 % o es ed DW
sou ces
Resis ance o
chlo ine and
o he
disin ec an s
Bio ilm o ma ion
enhances su i al
and esis ance o
en i onmen al
s esses and
disin ec an s
Inc eased
p e alence due o
wa me
empe a u es and
ex eme wea he
e en s
Sp ead by imp ope
was ewa e
managemen ,
ag icul u al uno ,
and ood p ocessing
en i onmen s
Eme ging pa hogen due o i s
esilience in a ious
en i onmen s, bio ilm
o ma ion, and inc easing
de ec ion in wa e sou ces
Lis e iosis, abo ion, human
meningi is, in ec ion du ing
he pe ina al pe iod,
g anuloma osis in an isep ica,
sepsis, dia hea, pyeli is, and
“ lu-like” symp oms
[197–199]
Pseudomonas
ae uginosa
42 % o hospi al
wa e sys ems
Resis an o
chlo ine and
o he
disin ec an s
Bio ilm o ma ion
enhances
esis ance o
an ibio ics and
disin ec an s
Inc eased
p e alence in
wa me wa e and
highe ain all
An ibio ic misuse,
poo hospi al
sani a ion, imp ope
was ewa e
ea men
Eme ging pa hogen due o
high esis ance o an ibio ics
and disin ec an s,
associa ion wi h heal hca e-
associa ed in ec ions
In ec ions in
immunocomp omised pa ien s
and pa ien s wi h unde lying
diseases (i.e. wound and
u ina y ac in ec ions and
[191,200,201]
(con inued on nex page)
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
6
wa e bo ne illnesses and mi iga e public heal h isks.
4.3. Impac o ma e ials and ea men s on bio ilm o ma ion
Bio ilm o ma ion in DW sys ems is highly a iable and in luenced by
nume ous ac o s, including wa e composi ion, ma e ials in use, ea -
men me hods, and he p esence o esidual disin ec an s.
The chemical and mic obiological composi ion o wa e plays a
pi o al ole; high le els o o ganic ma e , nu ien s (e.g., ca bon, ni-
ogen, phospho us), and ions such as calcium and magnesium o en
p omo e bio ilm g ow h, p o iding subs a es o mic obial me abolism
[6]. In con as , low-nu ien condi ions may limi bio ilm densi y bu
a o mic oo ganisms adap ed o oligo ophic en i onmen s [94]. Fo
ins ance, a s udy by Dang e al. [95] highligh s ha nu ien a ailabili y
no only in luences bio ilm biomass bu also al e s mic obial communi y
composi ion, wi h oligo ophic en i onmen s a o ing slowe -g owing,
esou ce-e icien o ganisms. O ganic ca bon is o en he mos c i ical
g ow h-limi ing nu ien due o i s ole as he p ima y ene gy sou ce o
he e o ophic bac e ia. Bioa ailable o ganic ma e (BOM), comp ising
simple suga s, o ganic acids, and complex humic subs ances, ep esen s
only a ac ion o he dissol ed o ganic ca bon (DOC) in wa e , ypically
be ween 1 and 30 % [96]. E en small concen a ions o BOM, such as 1
μ
g C/L, can suppo bac e ial g ow h, highligh ing he sensi i i y o
mic obial communi ies o nu ien a ailabili y [97]. Addi ionally, he
balance o ino ganic nu ien s like ni ogen and phospho us is essen ial,
as de iciencies in hese elemen s can limi bac e ial p oli e a ion e en in
he p esence o su icien o ganic ca bon [98]. These nu ien dynamics
shape mic obial communi ies, whe e compe i ion o subs a es in-
luences he di e si y and esilience o bac e ia in wa e sys ems.
The ma e ials used in dis ibu ion sys ems also signi ican ly impac
bio ilm o ma ion. Fo example, ough o po ous su aces like unlined
cas i on acili a e mic obial adhesion mo e han smoo he ma e ials
such as polye hylene o s ainless s eel [99]. Poly inyl chlo ide (PVC)
pipes gene ally show educed bio ilm o ma ion compa ed o coppe
pipes, whe e ion elease may a ec mic obial communi ies [100].
Howe e , ma e ial choice alone does no de e mine bio ilm g ow h;
ac o s such as pipe ageing, main enance, and ope a ional condi ions
also play c i ical oles. Poo ly main ained sys ems can exace ba e bio-
ilm o ma ion, leading o aes he ic issues (e.g., discolo a ion, odo ),
echnical p oblems (e.g., pipe co osion), and po en ial public heal h
isks om wa e bo ne diseases. S udies indica ed ha high-densi y
polye hylene (HDPE) and unplas icized poly inyl chlo ide (PVC-U)
ha e been inc easingly p e e ed in mode n ne wo ks due o hei
esis ance o co osion and cos -e ec i eness, hough bio ilm g ow h on
hese ma e ials can s ill occu unde ce ain condi ions [101]. Ye ,
bio ilm composi ion and biomass a y ac oss ma e ials. Despi e i s
smoo h su ace, esea ch has shown ha s ainless s eel can suppo
signi ican bio ilm g ow h unde low-nu ien condi ions, al hough
elec opolished su aces educe ini ial bac e ial adhesion [102]. Coppe
pipes, known o eleasing an imic obial ions, ypically ha bo ewe
bac e ia, especially when combined wi h chlo amine disin ec ion [103].
Con e sely, plas ic ma e ials like PVC-P may exhibi highe biomass and
mic obial di e si y compa ed o PVC-C, which is mo e e ec i e in
minimizing bac e ial accumula ion [104].
T ea men me hods, such as il a ion and coagula ion, play a i al
ole in educing o ganic loads, which can help mi iga e bio ilm o ma-
ion. Howe e , disin ec ion me hods, such as chlo ina ion, while e ec-
i e agains plank onic mic oo ganisms, can inad e en ly al e
mic obial communi y s uc u es and p omo e he selec ion o esis an
species, po en ially con ibu ing o bio ilm pe sis ence [105]. Ad anced
disin ec ion echniques, such as ozona ion and UV i adia ion, e ec-
i ely inac i a e mic oo ganisms bu lack esidual disin ec ion capaci y,
lea ing sys ems suscep ible o bio ilm eg ow h and econ amina ion
[106]. The choice o disin ec ion s a egy signi ican ly impac s bio ilm
o ma ion and composi ion. Con en ional disin ec an s like chlo ine and
chlo amine ha e been shown o lowe bio ilm di e si y while selec ing
Table 5 (con inued)
Bac e ia P e alence in
wa e sou ces
Resis ance o
disin ec ion
Bio ilm o ma ion Impac o clima e
change
Human ac i i ies
impac
Eme ging o eeme ging
s a us
Heal h e ec s Re e ences
pneumonia); acheob onchi is
in cys ic ib osis pa ien s
S eno ophomonas
mal ophilia
30 % o hospi al
wa e sou ces
Resis an o
chlo ine and
se e al
disin ec an s
Bio ilm o ma ion
enhances
esis ance o
disin ec an s and
en i onmen al
s esses
Facili a ed sp ead
and pe sis ence in
changing wa e
a ailabili y
An ibio ic o e use,
inadequa e wa e
ea men
Eme ging pa hogen due o
inc easing p e alence in
hospi al se ings and MDR
Nosocomial in ec ions, mainly
espi a o y ac in ec ions
[202–204]
Ye sinia
en e ocoli ica
27 % o su ace
wa e samples
Resis an o
chlo ine,
especially in cold
wa e
Bio ilm o ma ion
enhances su i al
in cold and
chlo ina ed wa e
Inc eased
pe sis ence in cold
wa e due o
clima e a iabili y
Ag icul u al uno ,
un ea ed
was ewa e , and
imp ope was e
disposal
Eme ging pa hogen due o
cold wa e pe sis ence and
mode a e esis ance o
disin ec ion
Gas oin es inal in ec ions [69,191,205–207]
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
7
o oppo unis ic pa hogens, highligh ing he impo ance o main aining
e ec i e esidual concen a ions o inhibi bio ilm-associa ed isks [26].
Howe e , he inabili y o cu en s a egies o ully e adica e bio ilms
unde sco es he need o inno a i e app oaches. Eme ging echnologies,
including mul i-ba ie disin ec ion, bac e iophages, and nanopa icle-
based ea men s, o e p omising solu ions o limi bio ilm de elop-
men and con ol mic obial eg ow h [26]. Fu he mo e, he in e ac ion
be ween esidual disin ec an s and pipe ma e ials, along wi h he
deg ada ion o chlo amines, poses addi ional challenges o bio ilm
managemen . Add essing hese ac o s h ough op imized ea men
p o ocols and ad anced ma e ials, such as ca bon quan um do s and
me al-o ganic amewo ks-based sys ems, could signi ican ly imp o e
bio ilm p e en ion [107].
Residual disin ec an s, pa icula ly chlo ine and chlo amines, a e
essen ial o main aining mic obial con ol wi hin DWDS. F ee chlo ine
is he mos widely used esidual disin ec an wo ldwide, whe eas
monochlo amine is a o ed in some sys ems due o i s abili y o limi
disin ec ion by-p oduc (DBP) o ma ion in high o ganic load en i on-
men s [108]. Howe e , coun ies such as he Ne he lands, Ge many,
Aus ia, and Swi ze land a oid esidual disin ec an s due o conce ns
abou DBPs, which a e inc easingly ecognized o hei po en ial ca -
cinogenici y [108,109]. In e es ingly, esea ch indica es ha sys ems
using chlo ine esiduals, like hose in he USA, epo en imes mo e
o al coli o m ailu es compa ed o sys ems wi hou esiduals, such as in
he Ne he lands, a e adjus ing o popula ion di e ences [110]. This
sugges s ha ac o s beyond disin ec ion esiduals, including in a-
s uc u e age and wa e quali y, signi ican ly a ec wa e sa e y ou -
comes. Al hough chlo ine gene ally a enua es bac e ial bio ilm cell
concen a ions [111–113], bio ilm-bound mic oo ganisms exhibi
g ea e esis ance o disin ec an s compa ed o plank onic cells, la gely
due o he p o ec i e EPS ma ix. Fish e al. [48] in es iga ed how e-
sidual chlo ine in luences bio ilm ecology and o e all wa e quali y. The
s udy highligh ed ha while esidual chlo ine is e ec i e in con olling
plank onic bac e ia, i can inad e en ly selec o chlo ine- ole an
species wi hin bio ilms, po en ially al e ing mic obial communi y
s uc u es and educing ea men e icacy. The EPS laye no only
shields bio ilm cells bu also plays a ole in mechanical s abili y and
in luences DBP o ma ion [114–116]. The s udy o Xu e al. [117]
examined he in e play be ween bio ilms and chlo ine decay, showing
ha bio ilms no only con ibu e o he deple ion o esidual chlo ine bu
also acili a e he o ma ion o DBPs such as ihalome hanes (THMs).
Addi ionally, s udies ha e shown ha inc easing chlo ine concen a-
ions do no necessa ily educe EPS o o he bio ilm componen s,
meaning isks o wa e quali y pe sis i bio ilms a e mobilized [116].
The e o e, bio ilm o ma ion in DW sys ems is shaped by wa e
composi ion, ma e ials, and ea men me hods, highligh ing he need
o in eg a ed s a egies ha add ess mic obial dynamics, ma e ial in-
e ac ions, and he limi a ions o cu en disin ec ion app oaches.
4.4. Role o me als in bio ilm o ma ion
In wa e sys ems, bio ilm o ma ion is no only in luenced by o ganic
nu ien s, mic obial communi ies, and wa e composi ion bu also by he
accumula ion o ino ganic deposi s such as me als like i on (Fe), man-
ganese (Mn), and aluminum (Al). Fo example, discolo ed wa e e en s
emain a pe sis en challenge o he DW indus y, o en leading o
cus ome dissa is ac ion [118]. Ginige e al. [119] in es iga ed he
con ibu ion o pipe wall bio ilms owa d Fe and Mn deposi ion, and
discolo ed wa e e en s. Using bio ilm eac o s and ield bio ilm moni-
o s designed iden ically, he s udy compa ed Fe and Mn accumula ion
Fig. 1. Schema ic ep esen a ion o bio ilm o ma ion highligh ing bac e ial agg ega ion. In he “Agg ega ion and A achmen ” phase, plank onic single cells,
au oagg ega es, o coagg ega es adhe e di ec ly o he su ace o coadhe e wi h p ima y colonize s, la e pa icipa ing in he coadhesion p ocess. Du ing he “G ow h
and Accumula ion” phase, ac i e mic obial g ow h and he ec ui men o seconda y colonize s lead o mic ocolony o ma ion and EPS exc e ion. This phase also
in ol es he o ma ion o coagg ega ion/coadhesion b idges be ween ea ly colonize s. In he “Disagg ega ion and De achmen ” phase, bac e ia can lea e he bio ilm
as agg ega es o single cells, depending on he mechanism, and may in eg a e in o o he bio ilms.
Based on Saue e al. [74].
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
8
on glass su aces in he p esence and absence o bio ilms. In non-
chlo ina ed eac o s, bio ilms signi ican ly enhanced Mn deposi ion,
wi h bio ilm-co e ed su aces accumula ing 33 imes mo e Mn han
hose exposed o lowe Mn concen a ions. Con e sely, Fe deposi ion
was only abou wice as high unde high Fe condi ions, sugges ing ha
Mn accumula ion is mo e in luenced by bio ilm ac i i y. Chlo ina ed
eac o s exhibi ed a 95 % educ ion in bio ilm biomass, ye Mn depo-
si ion emained 17 imes highe in eac o s wi h ele a ed Mn concen-
a ions, indica ing abio ic deposi ion mechanisms. Upon chlo ina ion o
p e iously bio ilm- ich sys ems, Fe and Mn concen a ions in e luen
wa e inc eased six- old, demons a ing ha bio ilm de achmen could
lead o me al elease and po en ial wa e discolo a ion e en s.
Aluminum, o en in oduced h ough wa e ea men p ocesses o he
use o aluminum-based coagulan s [120], can also in luence bio ilm
o ma ion. I has been shown o p omo e mic obial adhesion o su aces
and s eng hen he s uc u al s abili y o he bio ilm ma ix by in e -
ac ing wi h EPS and bac e ial cell su aces [121]. Cui e al. [121]
examined he e ec s o low concen a ions o esidual Al(III) on bio ilm
o ma ion, explo ing mechanisms po en ially ele an o bio ouling in
WTPs and euse sys ems. A concen a ions below 2.0 mg/L, Al(III)
s imula ed bac e ial g ow h by app oxima ely 3.7 imes and enhanced
EPS p oduc ion, p omo ing bio ilm de elopmen . Al(III)-induced loc-
cula ion acili a ed bac e ial agg ega ion, leading o apid bio ilm o -
ma ion, wi h bio ilm hickness inc easing o 103.0 ±7.1
μ
m and 112.0
±5.7
μ
m a 0.6 and 2.0 mg-Al/L, espec i ely, compa ed o 61 ±4.24
μ
m in con ol condi ions. The ze a po en ial o bac e ial cells dec eased
wi h inc easing Al(III) concen a ions, indica ing cha ge neu aliza ion
and educed elec os a ic epulsion, he eby enhancing mic obial
adhesion. No ably, Al(III) in e ac ed s ongly wi h bac e ial ou e
memb anes, causing s uc u al damage, p o ein leakage, and ATP
deple ion by up o 55.91 %, leading o a dis inc double-laye bio ilm
s uc u e wi h inac i a ed cells and p o eins a he bo om and poly-
saccha ides wi h ac i e cells a he op. The p esence o ino ganic de-
posi s can also al e he mic obial composi ion wi hin bio ilms,
p omo ing he g ow h o speci ic me al- ole an mic oo ganisms ha
can h i e in he al e ed chemical en i onmen . Recen ly, Li e al. [122]
in es iga ed he impac o ace me als on wa e quali y and mic obial
isks by conduc ing a 168-hou expe imen al simula ion, whe e bio ilms
de eloped on glass beads in ap wa e supplemen ed wi h Fe(III) and Al
(III), ollowed by me agenomic analysis. The s udy e ealed ha Fe(III)
signi ican ly inc eased u bidi y, while bo h Fe(III) and Al(III) p omo ed
bio ilm g ow h and enhanced he p oduc ion o EPS. Bac e ial commu-
ni ies, domina ed by Pseudomonado a, exhibi ed adap i e mechanisms in
esponse o me al-induced s ess, wi h Al(III) ha ing a mo e p onounced
e ec on bac e ial p oli e a ion han Fe(III). The p esence o Al(III) also
inc eased he ela i e abundance o pa hogenic bac e ia, such as
S. en e ica and P. ae uginosa, aising conce ns abou po en ial heal h
isks. Mo eo e , Fe(III) acili a ed he co-occu ence o an ibio ic esis-
ance genes and pa hogens, inc easing he o e all isk o an ibio ic-
esis an bac e ia in DW sys ems.
These s udies collec i ely unde sco e he signi ican ole o ino ganic
deposi s in shaping bio ilm o ma ion and s abili y by no only
enhancing he accumula ion o me als bu also con ibu ing o hei
emobiliza ion. The indings highligh how bio ilms acili a e me al
deposi ion and in luence me al elease du ing disin ec ion, as well as
how accele a e bio ilm o ma ion h ough mic obial adhesion, EPS
p oduc ion, and cha ge neu aliza ion. Fu he mo e, he syne gis ic e -
ec s o hese ino ganic deposi s p omo e bio ilm de elopmen while
inc easing he abundance o pa hogenic bac e ia and an ibio ic esis-
ance genes. Addi ionally, he edox p ocesses associa ed wi h me al
Fig. 2. DW mic obial dynamics om he sou ce o household consump ion.
1
Pina -M´
endez e al. [166];
2
Ko mas e al. [88];
3
Moa e al. [92];
4
Inkinen e al. [91];
5
Moen e al. [167].
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
9
simula ed d inking wa e con aining co osion inhibi o s, Sci. To al En i on. 815
(2022), h ps://doi.o g/10.1016/J.SCITOTENV.2021.152763.
[126] Z. Wang, L. Li, R.W. A iss, K.M. Cobu n, M. Behbahani, Z. Xue, Y. Seo, The ole o
bio ilms on he o ma ion and decay o disin ec ion by-p oduc s in chlo (am)
ina ed wa e dis ibu ion sys ems, Sci. To al En i on. 753 (2021) 141606,
h ps://doi.o g/10.1016/J.SCITOTENV.2020.141606.
[127] R. Sadiq, M.J. Rod iguez, Disin ec ion by-p oduc s (DBPs) in d inking wa e and
p edic i e models o hei occu ence: a e iew, Sci. To al En i on. 321 (2004)
21–46, h ps://doi.o g/10.1016/J.SCITOTENV.2003.05.001.
[128] M.B. Heeb, J. C ique , S.G. Zimme mann-S e ens, U. Von Gun en, Oxida i e
ea men o b omide-con aining wa e s: o ma ion o b omine and i s eac ions
wi h ino ganic and o ganic compounds—a c i ical e iew, Wa e Res. 48 (2014)
15–42, h ps://doi.o g/10.1016/J.WATRES.2013.08.030.
[129] S.T. Khu, X. Changchun, T. Wang, E ec s o low eloci y on bio ilm composi ion
and mic obial molecula ecological ne wo k in eclaimed wa e dis ibu ion
sys ems, Chemosphe e 341 (2023) 140010, h ps://doi.o g/10.1016/J.
CHEMOSPHERE.2023.140010.
[130] X. Ren, S. Zhang, M. Wu, B. Xiao, H. Miao, H. Chen, E ec and in luence
mechanism o bio ilm o ma ion on he biological s abili y o eclaimed wa e ,
Sci. To al En i on. 906 (2024) 167735, h ps://doi.o g/10.1016/J.
SCITOTENV.2023.167735.
[131] H. Wang, Y. Zhu, C. Hu, Impac s o bac e ia and co osion on emo al o na u al
o ganic ma e and disin ec ion byp oduc s in di e en d inking wa e
dis ibu ion sys ems, In . Biode e . Biodeg . 117 (2017) 52–59, h ps://doi.o g/
10.1016/J.IBIOD.2016.11.023.
[132] Y. Chen, H. Zhou, H. Gao, Z. Su, X. Li, P. Qi, T. Li, C. Hu, Z. Li, Z. Bi, X. Xing,
J. Yang, C. Chen, K. Ma, J. Chen, Comp ehensi e compa ison o wa e quali y isk
and mic obial ecology be ween new and old cas i on pipe dis ibu ion sys ems,
J. En i on. Sci. 146 (2024) 55–66, h ps://doi.o g/10.1016/J.JES.2023.05.020.
[133] Y. Luo, C. Liu, Y. Wang, Y. Yang, S. Mish a, Occu ence, dis ibu ion and hei
co ela ion wi h di e en pa ame e s o an ibio ics and an ibio ic esis ance genes
in lakes o China: a e iew, Ma . Pollu . Bull. 193 (2023) 115189, h ps://doi.o g/
10.1016/J.MARPOLBUL.2023.115189.
[134] A.K. Singh, R. Kau , S. Ve ma, S. Singh, An imic obials and an ibio ic esis ance
genes in wa e bodies: pollu ion, isk, and con ol, F on . En i on. Sci. 10 (2022)
830861, h ps://doi.o g/10.3389/FENVS.2022.830861/BIBTEX.
[135] F. Cos a, T. Ca alho-Pe ei a, M. Begon, L. Riley, J. Childs, Zoono ic and ec o -
bo ne diseases in u ban slums: oppo uni ies o in e en ion, T ends Pa asi ol. 33
(2017) 660–662, h ps://doi.o g/10.1016/J.PT.2017.05.010.
[136] I.D. Ola u, B. Wal he , F. Schaumbu g, Zoono ic sou ces and he sp ead o
an imic obial esis ance om he pe spec i e o low and middle-income
coun ies, In ec . Dis. Po e y 12 (2023) 1–15, h ps://doi.o g/10.1186/S40249-
023-01113-Z.
[137] H.E.J. Kaba, E. Kuhlmann, S. Schei haue , Thinking ou side he box: associa ion
o an imic obial esis ance wi h clima e wa ming in Eu ope - a 30 coun y
obse a ional s udy, In . J. Hyg. En i on. Heal h 223 (2020) 151–158, h ps://
doi.o g/10.1016/J.IJHEH.2019.09.008.
[138] M. C uz-Loya, T.M. Kang, N.A. Lozano, R. Wa anabe, E. Tekin, R. Damoiseaux, V.
M. Sa age, P.J. Yeh, S esso in e ac ion ne wo ks sugges an ibio ic esis ance
co-op ed om s ess esponses o empe a u e, ISME J. 13 (2018) 12–23, h ps://
doi.o g/10.1038/s41396-018-0241-7.
[139] P. Nikolic, P. Mudgil, The cell wall, cell memb ane and i ulence ac o s o
S aphylococcus au eus and hei ole in an ibio ic esis ance, Mic oo ganisms 11
(2023), h ps://doi.o g/10.3390/MICROORGANISMS11020259.
[140] A. Rod íguez-Ve dugo, N. Lozano-Hun elman, M. C uz-Loya, V. Sa age, P. Yeh,
Compounding e ec s o clima e wa ming and an ibio ic esis ance, iScience 23
(2020) 101024, h ps://doi.o g/10.1016/J.ISCI.2020.101024.
[141] A.J. Lopa kin, S.C. Bening, A.L. Manson, J.M. S okes, M.A. Kohanski, A.H. Bad an,
A.M. Ea l, N.J. Cheney, J.H. Yang, J.J. Collins, Clinically ele an mu a ions in
co e me abolic genes con e an ibio ic esis ance, Science 371 (2021), h ps://doi.
o g/10.1126/SCIENCE.ABA0862.
[142] W. Zhao, C. Ye, J. Li, X. Yu, Inc eased isk o an ibio ic esis ance in su ace wa e
due o global wa ming, En i on. Res. 263 (2024) 120149, h ps://doi.o g/
10.1016/J.ENVRES.2024.120149.
[143] J.P. Bu nham, Clima e change and an ibio ic esis ance: a deadly combina ion,
The . Ad . In ec . Dis. 8 (2021), h ps://doi.o g/10.1177/2049936121991374.
[144] H. Goossens, M. Fe ech, R. Vande S ichele, M. Else ie s, Ou pa ien an ibio ic
use in Eu ope and associa ion wi h esis ance: a c oss-na ional da abase s udy,
Lance (London, England) 365 (2005) 579–587, h ps://doi.o g/10.1016/S0140-
6736(05)17907-0.
[145] T.R. Walsh, J. Weeks, D.M. Li e mo e, M.A. Toleman, Dissemina ion o NDM-1
posi i e bac e ia in he New Delhi en i onmen and i s implica ions o human
heal h: an en i onmen al poin p e alence s udy, Lance In ec . Dis. 11 (2011)
355–362, h ps://doi.o g/10.1016/S1473-3099(11)70059-7.
[146] W. Li, C. Liu, H.C. Ho, L. Shi, Y. Zeng, X. Yang, Q. Huang, Y. Pei, C. Huang,
L. Yang, Associa ion be ween an ibio ic esis ance and inc easing ambien
empe a u e in China: an ecological s udy wi h na ionwide panel da a, Lance
Reg. Heal. Wes . Paci ic 30 (2022), h ps://doi.o g/10.1016/J.
LANWPC.2022.100628.
[147] R. Pechous, N. Ledala, B.J. Wilkinson, R.K. Jayaswal, Regula ion o he exp ession
o cell wall s ess s imulon membe gene ms A1 in me hicillin-suscep ible o
- esis an S aphylococcus au eus, An imic ob. Agen s Chemo he . 48 (2004) 3057,
h ps://doi.o g/10.1128/AAC.48.8.3057-3063.2004.
[148] J. Dawan, J. Ahn, Bac e ial s ess esponses as po en ial a ge s in o e coming
an ibio ic esis ance, Mic oo ganisms 10 (2022), h ps://doi.o g/10.3390/
MICROORGANISMS10071385.
[149] K.N. Kind achuk, L. Fe n´
andez, M. Bains, R.E.W. Hancock, In ol emen o an
ATP-dependen p o ease, PA0779/As A, in inducing hea shock in esponse o
ob amycin in Pseudomonas ae uginosa, An imic ob. Agen s Chemo he . 55 (2011)
1874, h ps://doi.o g/10.1128/AAC.00935-10.
[150] M. Pepi, S. Foca di, An ibio ic- esis an bac e ia in aquacul u e and clima e
change: a challenge o heal h in he Medi e anean a ea, In . J. En i on. Res.
Public Heal h 18 (2021), h ps://doi.o g/10.3390/IJERPH18115723.
[151] F. Chiappo i, M. Fumian, L. Milanesi, I. Me elli, DnaK as an ibio ic a ge : ho spo
esidues analysis o di e en ial inhibi ion o he bac e ial p o ein in compa ison
wi h he human HSP70, PloS One 10 (2015), h ps://doi.o g/10.1371/JOURNAL.
PONE.0124563.
[152] D.F. Cha on, M.K. Thomas, D. Wal ne -Toews, J.J. A amini, T. Edge, R.A. Ken ,
A.R. Maa ou , J. Wilson, Vulne abili y o wa e bo ne diseases o clima e change
in Canada: a e iew, J. Toxicol. En i on. Heal h A 67 (2004) 1667–1677, h ps://
doi.o g/10.1080/15287390490492313.
[153] A.M. Pedneka , S.B. G an , Y. Jeong, Y. Poon, C. Oancea, In luence o clima e
change, idal mixing, and wa e shed u baniza ion on his o ical wa e quali y in
Newpo Bay, a sal wa e we land and idal embaymen in sou he n Cali o nia,
En i on. Sci. Technol. 39 (2005) 9071–9082, h ps://doi.o g/10.1021/
ES0504789.
[154] F.C. Cu ie o, J.A. Pa z, J.B. Rose, S. Lele, The associa ion be ween ex eme
p ecipi a ion and wa e bo ne disease ou b eaks in he Uni ed S a es, 1948–1994,
Am. J. Public Heal h 91 (2001) 1194–1199, h ps://doi.o g/10.2105/
AJPH.91.8.1194.
[155] I. Sla ik, D. Kos owski, W. Uhl, E ec o sola adia ion on na u al o ganic
ma e composi ion in su ace wa e s and esul ing impac s on d inking wa e
ea men , En i on. Technol. 44 (2023) 1549–1565, h ps://doi.o g/10.1080/
09593330.2021.2007289.
[156] B. Le eque, J.B. Bu ne , S. Do ne , F. Bichai, Impac o clima e change on he
ulne abili y o d inking wa e in akes in a no he n egion, Sus ain. Ci ies Soc.
66 (2021) 102656, h ps://doi.o g/10.1016/J.SCS.2020.102656.
[157] Y. Huang, T. Hu, B. Lin, Y. Ke, J. Li, J. Ma, Mic oplas ics-bio ilm in e ac ions in
bio ilm-based was ewa e ea men p ocesses: a e iew, En i on. Pollu . 361
(2024) 124836, h ps://doi.o g/10.1016/J.ENVPOL.2024.124836.
[158] R. Kuma , M. Qu eshi, D.K. Vishwaka ma, N. Al-Ansa i, A. Ku iqi, A. Elbel agi,
A. Sa aswa , A e iew on eme ging wa e con aminan s and he applica ion o
sus ainable emo al echnologies, Case S ud. Chem. En i on. Eng. 6 (2022)
100219, h ps://doi.o g/10.1016/J.CSCEE.2022.100219.
[159] T. aus de Beek, F.-A. Webe , A. Be gmann, Pha maceu icals in he En i onmen :
Global Occu ence and Po en ial Coope a i e Ac ion Unde he S a egic
App oach o In e na ional Chemicals Managemen (SAICM): P ojec No. (FKZ)
3712 65 408, Repo No. (UBA-FB) 002331/ENG. Ge many, 2015.
[160] S. Khan, M. Naushad, M. Go a hanan, J. Iqbal, S.M. Al adul, Eme ging
con aminan s o high conce n o he en i onmen : cu en ends and u u e
esea ch, En i on. Res. 207 (2022) 112609, h ps://doi.o g/10.1016/J.
ENVRES.2021.112609.
[161] N. G oss, J. Muh ich, C. Ching, B. Gomez, E. Ho a h, Y. Nahum, M.H. Zaman,
E ec s o mic oplas ic concen a ion, composi ion, and size on Esche ichia coli
bio ilm-associa ed an imic obial esis ance, Appl. En i on. Mic obiol. (2025),
h ps://doi.o g/10.1128/AEM.02282-24.
[162] R. Saba ino, R. Zullo, A. Di Cesa e, R. Piscia, S. Musazzi, G. Co no, P. Vol a,
S. Gala assi, T adi ional and biodeg adable plas ics hos dis inc and po en ially
mo e haza dous mic obes when compa ed o bo h na u al ma e ials and
plank onic communi y, J. Haza d. Ma e . 465 (2024) 133166, h ps://doi.o g/
10.1016/J.JHAZMAT.2023.133166.
[163] A. Bo eca, S. Vuilleumie , G. Im eld, Combined e ec s o mic opollu an s and
hei deg ada ion on p oka yo ic communi ies a he sedimen -wa e in e ace,
Sci. Rep. 14 (2024), h ps://doi.o g/10.1038/S41598-024-67308-Y.
[164] A.R. Pe ei a, L.M. Rooney, I.B. Gomes, M. Sim˜
oes, G. McConnell, The impac o
me hylpa aben and chlo ine on he a chi ec u e o S eno ophomonas mal ophilia
bio ilms, Sci. To al En i on. 951 (2024) 175646, h ps://doi.o g/10.1016/J.
SCITOTENV.2024.175646.
[165] B. Ho emans, J. Ho kens, E. Smolde s, D. Sp ingael, Bio ilm o ma ion o a
bac e ial conso ium on linu on a mic opollu an concen a ions in con inuous
low chambe s and he impac o dissol ed o ganic ma e , FEMS Mic obiol. Ecol.
88 (2014) 184–194, h ps://doi.o g/10.1111/1574-6941.12280.
[166] A. Pina -M´
endez, O.S. Wangens een, K. P æbel, B. Galo ´
e, J. M´
endez, A.
R. Blanch, C. Ga cía-Alja o, Moni o ing bac e ial communi y dynamics in a
d inking wa e ea men plan : an in eg a i e app oach using me aba coding and
mic obial indica o s in la ge wa e olumes, Wa e 14 (2022) 1435, h ps://doi.
o g/10.3390/W14091435/S1.
[167] B. Moen, S. Langs ud, I. Be ge , T. Mauges en, T. Mø e ø, Mapping he ki chen
mic obio a in i e eu opean coun ies e eals a se o co e bac e ia ac oss
coun ies, ki chen su aces, and cleaning u ensils, Appl. En i on. Mic obiol. 89
(2023) e0026723, h ps://doi.o g/10.1128/AEM.00267-23.
[168] P. Teunis, M.J. Figue as, Reassessmen o he en e opa hogenici y o mesophilic
Ae omonas species, F on . Mic obiol. 7 (2016) 1395, h ps://doi.o g/10.3389/
FMICB.2016.01395.
[169] A. Gallay, H. De Valk, M. Cou no , B. Ladeuil, C. Heme y, C. Cas o , F. Bon,
F. M´
eg aud, P. Le Cann, J.C. Desenclos, A la ge mul i-pa hogen wa e bo ne
communi y ou b eak linked o aecal con amina ion o a g oundwa e sys em,
F ance, 2000, Clin. Mic obiol. In ec . 12 (2006) 561–570, h ps://doi.o g/
10.1111/J.1469-0691.2006.01441.X.
[170] S. Ma in, P. Pen inen, G. Hedin, M. Ljungs ¨
om, G. Alles am, Y. Ande sson,
J. Giesecke, A case-coho s udy o in es iga e concomi an wa e bo ne ou b eaks
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
16

o Campylobac e and gas oen e i is in S¨
ode hamn, Sweden, 2002-3, J. Wa e
Heal h 4 (2006) 417–424.
[171] I. Jakopanec, K. Bo gen, L. Vold, H. Lund, T. Fo se h, R. Hannula, K. Nygå d,
A la ge wa e bo ne ou b eak o campylobac e iosis in No way: he need o ocus
on dis ibu ion sys em sa e y, BMC In ec . Dis. 8 (2008) 128, h ps://doi.o g/
10.1186/1471-2334-8-128.
[172] T. B aeye, K. De Sch ij e , E. Wollan s, M. Van Rans , J. Ve haegen, A la ge
communi y ou b eak o gas oen e i is associa ed wi h consump ion o d inking
wa e con amina ed by i e wa e , Belgium, 2010, Epidemiol. In ec . 143 (2015)
711–719, h ps://doi.o g/10.1017/S0950268814001629.
[173] N. Coe zee, H. Duggal, J. Hawke , S. Ibbo son, T.G. Ha ison, N. Phin, V. Laza-
S anca, R. Johns on, Z. Iqbal, Y. Rehman, E. Knappe , S. Robinson, N. Aigbogun,
An ou b eak o Legionnai es’ disease associa ed wi h a display spa pool in e ail
p emises, S oke-on-T en , Uni ed Kingdom, July 2012, Eu o Su eill. 17 (2012)
20271.
[174] T. Shi aji, C. Sousa Pin o, A. San-Ben o, L.A. Oli ei a Se a, J. Valen e,
J. Machado, T. Ma ques, L. Ca alho, P.J. Noguei a, B. Nunes, P. Vasconcelos,
A la ge communi y ou b eak o Legionnai es disease in Vila F anca de Xi a,
Po ugal, Oc obe o No embe 2014, Eu o Su eill. 19 (2014) 20991, h ps://
doi.o g/10.2807/1560-7917.ES2014.19.50.20991.
[175] L. Pa uch, A.M. Pa uch, R. Sø heim, DNA-based aecal sou ce acking o
con amina ed d inking wa e causing a la ge Campylobac e ou b eak in No way
2019, In . J. Hyg. En i on. Heal h 224 (2020) 113420, h ps://doi.o g/10.1016/
J.IJHEH.2019.113420.
[176] S. Men ula, S. K¨
a¨
a i¨
ainen, S. Jaakola, M. Nii ynen, P. Ai aksinen, I. Koi ula,
M. Leh ola, E. Mau anen, I. Mononen, R. Sa olainen, S. Haa ainen,
O. Lyy ik¨
ainen, Tap wa e as he sou ce o a Legionnai es’ disease ou b eak
sp ead o se e al esiden ial buildings and one hospi al, Finland, 2020 o 2021,
Eu o Su eill. 28 (2023), h ps://doi.o g/10.2807/1560-7917.
ES.2023.28.11.2200673.
[177] J.M. Bi ulco, J.J. Shi ey, G.K. Bissonne e, De ec ion o Acine obac e spp. in u al
d inking wa e supplies, Appl. En i on. Mic obiol. 55 (1989) 2214–2219, h ps://
doi.o g/10.1128/AEM.55.9.2214-2219.1989.
[178] A. Ca alhei a, J. Sil a, P. Teixei a, Acine obac e spp. in ood and d inking wa e
- a e iew, Food Mic obiol. 95 (2021) 103675, h ps://doi.o g/10.1016/J.
FM.2020.103675.
[179] M.J. McConnell, A. P´
e ez-O d´
o˜
nez, P. P´
e ez-Rome o, R. Valencia, J.A. Lepe,
I. V´
azquez-Ba ba, J. Pach´
on, Quan i a i e eal- ime PCR o de ec ion o
Acine obac e baumannii coloniza ion in he hospi al en i onmen , J. Clin.
Mic obiol. 50 (2012) 1412, h ps://doi.o g/10.1128/JCM.06566-11.
[180] S. Roy, G. Chowdhu y, A.K. Mukhopadhyay, S. Du a, S. Basu, Con e gence o
bio ilm o ma ion and an ibio ic esis ance in Acine obac e baumannii in ec ion,
F on . Med. 9 (2022) 793615, h ps://doi.o g/10.3389/FMED.2022.793615.
[181] T.T.D. Hsu, J. Lee, Global dis ibu ion and p e alence o A cobac e in ood and
wa e , Zoonoses Public Heal h 62 (2015) 579–589, h ps://doi.o g/10.1111/
ZPH.12215.
[182] T.P. Ramees, K. Dhama, K. Ka hik, R.S. Ra ho e, A. Kuma , M. Samina han,
R. Tiwa i, Y.S. Malik, R.K. Singh, A cobac e : an eme ging ood-bo ne zoono ic
pa hogen, i s public heal h conce ns and ad ances in diagnosis and con ol - a
comp ehensi e e iew, Ve . Q. 37 (2017) 136–161, h ps://doi.o g/10.1080/
01652176.2017.1323355.
[183] S. Scio ino, P. A culeo, V. Alio, C. Ca damone, L. Nicas o, M. A culeo,
R. Alduina, A. Cos a, Occu ence and an imic obial esis ance o A cobac e spp.
eco e ed om aqua ic en i onmen s, An ibio ics 10 (2021) 10, h ps://doi.o g/
10.3390/ANTIBIOTICS10030288.
[184] D. ˇ
Silha, S. Si o ko ´
a, K. ˇ
S a co ´
a, L. Ho meis e o ´
a, K. Ko yˇ
cano ´
a, L. ˇ
Silho ´
a,
Bio ilm o ma ion abili y o A cobac e -like and Campylobac e s ains unde
di e en condi ions and on ood p ocessing ma e ials, Mic oo ganisms 9 (2021)
2017, h ps://doi.o g/10.3390/MICROORGANISMS9102017.
[185] M. Ashiku Rahman, S. Ak e , M. Ash a udoulla, M. Anamul Hasan Chowdhu y,
A.G.M.S. Uddin Mahamud, S. Hong Pa k, S. Do Ha, Insigh s in o he mechanisms
and key ac o s in luencing bio ilm o ma ion by Ae omonas hyd ophila in he
ood indus y: a comp ehensi e e iew and bibliome ic analysis, Food Res. In .
175 (2024) 113671, h ps://doi.o g/10.1016/J.FOODRES.2023.113671.
[186] J. Ca usi, D.Y. Kabuki, P.M. de Seixas Pe ei a, L. Cab al, Ae omonas spp. in
d inking wa e and ood: occu ence, i ulence po en ial and an imic obial
esis ance, Food Res. In . 175 (2024) 113710, h ps://doi.o g/10.1016/J.
FOODRES.2023.113710.
[187] S.M. Die gaa d , S.N. Ven e , A. Sp ee h, J. The on, V.S. B ¨
ozel, The occu ence o
campylobac e s in wa e sou ces in Sou h A ica, Wa e Res. 38 (2004)
2589–2595, h ps://doi.o g/10.1016/J.WATRES.2004.03.004.
[188] L.M. G as, J.H. Smid, J.A. Wagenaa , M.G.J. Koene, A.H. Ha elaa , I.H.
M. F iesema, N.P. F ench, C. Flemming, J.D. Galson, C. G aziani, L. Busani,
W. Van Pel , Inc eased isk o Campylobac e jejuni and C. coli in ec ion o pe
o igin in dog owne s and e idence o gene ic associa ion be ween s ains causing
in ec ion in humans and hei pe s, Epidemiol. In ec . 141 (2013) 2526–2535,
h ps://doi.o g/10.1017/S0950268813000356.
[189] B. Guzman-He ado , A. Ca lande , S. E helbe g, B.F. De Blasio, M. Kuusi,
V. Lund, M. L¨
o dahl, E. MacDonald, G. Nichols, C. Sch¨
onning, B. Sud e,
L. T ¨
onnbe g, L. Vold, J.C. Semenza, K. Nygå d, Wa e bo ne ou b eaks in he
No dic coun ies, 1998 o 2012, Eu o Su eill. 20 (2015) 1–10, h ps://doi.o g/
10.2807/1560-7917.ES2015.20.24.21160.
[190] J. Moo e, P. Caldwell, B. Milla , Molecula de ec ion o Campylobac e spp. in
d inking, ec ea ional and en i onmen al wa e supplies, In . J. Hyg. En i on.
Heal h 204 (2001) 185–189, h ps://doi.o g/10.1078/1438-4639-00096.
[191] U. Szewzyk, R. Szewzyk, W. Manz, K.H. Schlei e , Mic obiological sa e y o
d inking wa e , Ann. Re . Mic obiol. 54 (2000) 81–127, h ps://doi.o g/
10.1146/ANNUREV.MICRO.54.1.81.
[192] R.K. Aziz, M.M. Khali a, R.R. Sha a , Con amina ed wa e as a sou ce o
Helicobac e pylo i in ec ion: a e iew, J. Ad . Res. 6 (2015) 539, h ps://doi.
o g/10.1016/J.JARE.2013.07.007.
[193] NAS, NAE, NAM, Regula ions and guidelines on Legionella con ol in wa e
sys ems, in: Managemen o Legionella in Wa e Sys ems, Na ional Academies
P ess (US), Washing on, DC, 2019, h ps://doi.o g/10.17226/25474.
[194] E.L. Sciu o, P. Lagan`
a, S. Filice, S. Scalese, S. Libe ino, D. Co so, G. Fa o, M.
A. Coniglio, En i onmen al managemen o Legionella in domes ic wa e sys ems:
consolida ed and inno a i e app oaches o disin ec ion me hods and isk
assessmen , Mic oo ganisms 9 (2021) 1–22, h ps://doi.o g/10.3390/
MICROORGANISMS9030577.
[195] J.O. Falkinham, Mycobac e ium a ium Complex (MAC) in wa e dis ibu ion
sys ems and household plumbing in he Uni ed S a es, Wa e 12 (2020) 3338,
2020. 12, 3338, h ps://doi.o g/10.3390/W12123338.
[196] L. Lande, J. Geo ge, T. Plush, Mycobac e ium a ium complex pulmona y disease:
new epidemiology and managemen concep s, Cu . Opin. In ec . Dis. 31 (2018)
199–207, h ps://doi.o g/10.1097/QCO.0000000000000437.
[197] S. Ga ley, B. Ande son-Coughlin, M. Sha ma, K.E. Kniel, Lis e ia monocy ogenes
in i iga ion wa e : an assessmen o ou b eaks, sou ces, p e alence, and
pe sis ence, Mic oo ganisms 10 (2022) 1319, h ps://doi.o g/10.3390/
MICROORGANISMS10071319.
[198] C.D. Kap chouang Tcha chouang, J. F i, P.K. Mon so, G. Amagliani, G.
F. Schia ano, M.C. Manganyi, G. Baldelli, G. B andi, C.N. A eba, E idence o
i ulen mul i-d ug esis an and bio ilm- o ming Lis e ia species isola ed om
a ious sou ces in Sou h A ica, Pa hogens 11 (2022) 843, h ps://doi.o g/
10.3390/PATHOGENS11080843.
[199] G. Pando e, P. Saho a, N. Ga g, Lis e ia species: eeme ging pa hogen in d inking
wa e u ili ies, in: Mic obes in Food and Heal h, Sp inge In e na ional
Publishing, 2016, pp. 317–332, h ps://doi.o g/10.1007/978-3-319-25277-3_16/
COVER.
[200] P.M. T ibelli, N.I. L´
opez, Insigh s in o he empe a u e esponses o Pseudomonas
species in bene icial and pa hogenic hos in e ac ions, Appl. Mic obiol.
Bio echnol. 106 (2022) 7699–7709, h ps://doi.o g/10.1007/S00253-022-
12243-Z/METRICS.
[201] J. Walke , G. Moo e, Pseudomonas ae uginosa in hospi al wa e sys ems: bio ilms,
guidelines, and p ac icali ies, J. Hosp. In ec . 89 (2015) 324–327, h ps://doi.
o g/10.1016/J.JHIN.2014.11.019.
[202] J.S. B ooke, S eno ophomonas mal ophilia: an eme ging global oppo unis ic
pa hogen, Clin. Mic obiol. Re . 25 (2012) 2–41, h ps://doi.o g/10.1128/
CMR.00019-11.
[203] I. Gomes, M. Que ido, J. Teixei a, C. Pe ei a, L. Sim˜
oes, M. Sim˜
oes, P olonged
exposu e o S eno ophomonas mal ophilia bio ilms o ace le els o clo ib ic
acid al e s an imic obial ole ance and i ulence, Chemosphe e 235 (2019)
327–335, h ps://doi.o g/10.1016/j.chemosphe e.2019.06.184.
[204] I. Gomes, M. Sim˜
oes, L. Sim˜
oes, The e ec s o sodium hypochlo i e agains
selec ed d inking wa e -isola ed bac e ia in plank onic and sessile s a es, Sci.
To al En i on. 565 (2016) 40–48, h ps://doi.o g/10.1016/j.
sci o en .2016.04.136.
[205] B.M. Cheyne, M.I. Van Dyke, W.B. Ande son, P.M. Huck, The de ec ion o Ye sinia
en e ocoli ica in su ace wa e by quan i a i e PCR ampli ica ion o he ail and
yadA genes, J. Wa e Heal h 8 (2010) 487–499, h ps://doi.o g/10.2166/
WH.2009.215.
[206] A. Rahman, T.S. Bonny, S. S onsao apak, C. Ananchaipa ana, Ye sinia
en e ocoli ica: epidemiological s udies and ou b eaks, J. Pa hog. 2011 (2011)
1–11, h ps://doi.o g/10.4061/2011/239391.
[207] R. Vi o, D. Sanz, I. ´
Al a ez, S. Condon, J. Raso, Compa ison o he chlo ine
inac i a ion o Ye sinia en e ocoli ica in chlo ine demand and demand- ee
sys ems, J. Food P o . 68 (2005) 1816–1822, h ps://doi.o g/10.4315/0362-
028X-68.9.1816.
[208] P. San iago, Y. Mo eno, M.A. Fe ús, Iden i ica ion o iable Helicobac e pylo i in
d inking wa e supplies by cul u al and molecula echniques, Helicobac e 20
(2015) 252–259, h ps://doi.o g/10.1111/HEL.12205.
[209] E. Ve een, R.R. Low ance, D.J. Cole, E.K. Lipp, Dis ibu ion and ecology o
campylobac e s in coas al plain s eams (Geo gia, Uni ed S a es o Ame ica),
Appl. En i on. Mic obiol. 73 (2007) 1395–1403, h ps://doi.o g/10.1128/
AEM.01621-06.
[210] L.S. Ves e gaa d, K.E. Olsen, R. S ens old, B.E. B¨
o ige , M. Adelha d , M. Lisby,
L. Mø k, K. Mølbak, Ou b eak o se e e gas oen e i is wi h mul iple ae iologies
caused by con amina ed d inking wa e in Denma k, Janua y 2007, Eu o Su eill.
12 (2007) E070329.1, h ps://doi.o g/10.2807/ESW.12.13.03164-EN.
[211] M.W. LeChe allie , M. Abbaszdegan, A.K. Campe , G. Izagui e, M. S ewa ,
D. Naumo i z, C.R. Ma dhall, C.R. S e ling, P. Paymen , E.W. Rice, C.J. Hu s ,
S. Schaub, T.R. Sli ko, J.B. Rose, H.V. Smi h, D.B. Smi h, Eme ging pa hogens:
names o know and bugs o wa ch ou o , J. Am. Wa e Wo ks Assoc. 91 (1999)
136–172.
A.C. A onso e al.
Jou nal o Wa e P ocess Enginee ing 72 (2025) 107614
17