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Distinct phenotypic and genomic signatures underlie contrasting pathogenic potential of Staphylococcus epidermidis clonal lineages

Espadinha, Diana,Sobral, Rita G.,Mendes, Catarina Inês,Méric, Guillaume,Sheppard, Samuel K.,Carrico, Joao Andre,de Lencastre, Hermínia,Miragaia, Maria

Abstract

Background: Staphylococcus epidermidis is a common skin commensal that has emerged as a pathogen in hospitals, mainly related to medical devices-associated infections. Noteworthy, infection rates by S. epidermidis have the tendency to rise steeply in next decades together with medical devices use and immunocompromized population growth. Staphylococcus epidermidis population structure includes two major clonal lineages (A/C and B) that present contrasting pathogenic potentials. To address this distinction and explore the basis of increased pathogenicity of A/C lineage, we performed a detailed comparative analysis using phylogenetic and integrated pangenome-wide-association study (panGWAS) approaches and compared the lineages's phenotypes in in vitro conditions mimicking carriage and infection. Results: Each S. epidermidis lineage had distinct phenotypic signatures in skin and infection conditions and differed in genomic content. Combination of phenotypic and genotypic data revealed that both lineages were well adapted to skin environmental cues. However, they appear to occupy different skin niches, perform distinct biological functions in the skin and use different mechanisms to complete the same function: lineage B strains showed evidence of specialization to survival in microaerobic and lipid rich environment, characteristic of hair follicle and sebaceous glands; lineage A/C strains showed evidence for adaption to diverse osmotic and pH conditions, potentially allowing them to occupy a broader and more superficial skin niche. In infection conditions, A/C strains had an advantage, having the potential to bind blood-associated host matrix proteins, form biofilms at blood pH, resist antibiotics and macrophage acidity and to produce proteases. These features were observed to be rare in the lineage B strains. PanGWAS analysis produced a catalog of putative S. epidermidis virulence factors and identified an epidemiological molecular marker for the more pathogenic lineage. Conclusion: The prevalence of A/C lineage in infection is probably related to a higher metabolic and genomic versatility that allows rapid adaptation during transition from a commensal to a pathogenic lifestyle. The putative virulence and phenotypic factors associated to A/C lineage constitute a reliable framework for future studies on S. epidermidis pathogenesis and the finding of an epidemiological marker for the more pathogenic lineage is an asset for the management of S. epidermidis infections.

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micb-10-01971 Augus 27, 2019 Time: 12:8 # 1 ORIGINAL RESEARCH published: 27 Augus 2019 doi: 10.3389/ micb.2019.01971 Edi ed by: Ludmila Chis ose do a, Uni e si y o Washing on, Uni ed S a es Re iewed by: Ka s en Becke , Uni e si y o Müns e , Ge many Vas i Chaudh y, Uni e si y o Tübingen, Ge many *Co espondence: Ma ia Mi agaia [email p o ec ed] Special y sec ion: This a icle was submi ed o E olu iona y and Genomic Mic obiology, a sec ion o he jou nal F on ie s in Mic obiology Recei ed: 02 Ap il 2019 Accep ed: 12 Augus 2019 Published: 27 Augus 2019 Ci a ion: Espadinha D, Sob al RG, Mendes CI, Mé ic G, Sheppa d SK, Ca iço JA, de Lencas e H and Mi agaia M (2019) Dis inc Pheno ypic and Genomic Signa u es Unde lie Con as ing Pa hogenic Po en ial o S aphylococcus epide midis Clonal Lineages. F on . Mic obiol. 10:1971. doi: 10.3389/ micb.2019.01971 Dis inc Pheno ypic and Genomic Signa u es Unde lie Con as ing Pa hogenic Po en ial o S aphylococcus epide midis Clonal Lineages Diana Espadinha1,2, Ri a G. Sob al3, Ca a ina Inês Mendes4, Guillaume Mé ic5, Samuel K. Sheppa d5,6, João A. Ca iço4, He mínia de Lencas e2,7 and Ma ia Mi agaia1* 1Labo a o y o Bac e ial E olu ion and Molecula Epidemiology, Ins i u o de Tecnologia Química e Biológica An ónio Xa ie , Uni e sidade No a de Lisboa, Oei as, Po ugal, 2Labo a o y o Molecula Gene ics, Ins i u o de Tecnologia Química e Biológica An ónio Xa ie , Uni e sidade No a de Lisboa, Oei as, Po ugal, 3Labo a o y o Molecula Mic obiology o Bac e ial Pa hogens, UCIBIO/REQUIMTE, Faculdade de Ciências e Tecnologia, Uni e sidade No a de Lisboa, Cos a de Capa ica, Po ugal, 4Molecula Mic obiology and In ec ion Uni , Ins i u o de Medicina Molecula , Faculdade de Medicina de Lisboa, Uni e sidade de Lisboa, Lisbon, Po ugal, 5The Milne Cen e o E olu ion, Uni e si y o Ba h, Ba h, Uni ed Kingdom, 6MRC CLIMB Conso ium, Ba h, Uni ed Kingdom, 7Labo a o y o Mic obiology and In ec ious Diseases, The Rocke elle Uni e si y, New Yo k, NY, Uni ed S a es Backg ound: S aphylococcus epide midis is a common skin commensal ha has eme ged as a pa hogen in hospi als, mainly ela ed o medical de ices-associa ed in ec ions. No ewo hy, in ec ion a es by S. epide midis ha e he endency o ise s eeply in nex decades oge he wi h medical de ices use and immunocomp omized popula ion g ow h. S aphylococcus epide midis popula ion s uc u e includes wo majo clonal lineages (A/C and B) ha p esen con as ing pa hogenic po en ials. To add ess his dis inc ion and explo e he basis o inc eased pa hogenici y o A/C lineage, we pe o med a de ailed compa a i e analysis using phylogene ic and in eg a ed pangenome-wide-associa ion s udy (panGWAS) app oaches and compa ed he lineages’s pheno ypes in in i o condi ions mimicking ca iage and in ec ion. Resul s: Each S. epide midis lineage had dis inc pheno ypic signa u es in skin and in ec ion condi ions and di e ed in genomic con en . Combina ion o pheno ypic and geno ypic da a e ealed ha bo h lineages we e well adap ed o skin en i onmen al cues. Howe e , hey appea o occupy di e en skin niches, pe o m dis inc biological unc ions in he skin and use di e en mechanisms o comple e he same unc ion: lineage B s ains showed e idence o specializa ion o su i al in mic oae obic and lipid ich en i onmen , cha ac e is ic o hai ollicle and sebaceous glands; lineage A/C s ains showed e idence o adap ion o di e se osmo ic and pH condi ions, po en ially allowing hem o occupy a b oade and mo e supe icial skin niche. In in ec ion condi ions, A/C s ains had an ad an age, ha ing he po en ial o bind blood-associa ed hos ma ix p o eins, o m bio ilms a blood pH, esis an ibio ics and mac ophage acidi y and o p oduce p o eases. These ea u es we e obse ed o be a e in he lineage B s ains. PanGWAS analysis p oduced a ca alog o pu a i e S. epide midis i ulence ac o s and iden i ied an epidemiological molecula ma ke o he mo e pa hogenic lineage. F on ie s in Mic obiology | www. on ie sin.o g 1Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 2 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y Conclusion: The p e alence o A/C lineage in in ec ion is p obably ela ed o a highe me abolic and genomic e sa ili y ha allows apid adap a ion du ing ansi ion om a commensal o a pa hogenic li es yle. The pu a i e i ulence and pheno ypic ac o s associa ed o A/C lineage cons i u e a eliable amewo k o u u e s udies on S. epide midis pa hogenesis and he inding o an epidemiological ma ke o he mo e pa hogenic lineage is an asse o he managemen o S. epide midis in ec ions. Keywo ds: S. epide midis, pan genome, GWAS, clonal lineages, pa hogen, commensal BACKGROUND S aphylococcus epide midis is one o he mos abundan commensal bac e ia o heal hy human skin and mucosa. This o ganism has eme ged in ecen decades as an impo an oppo unis ic pa hogen, being he main cause o nosocomial in ec ions associa ed o indwelling medical de ices such as pe iphe al o cen al in a enous ca he e s (CVCs) (O o, 2009). In ec ions by S. epide midis usually occu due o a b each in he skin ba ie esul ing om he inse ion o he medical de ices, allowing S. epide midis o pene a e he hos issues. The p og ession o in ec ion a e skin pene a ion depends on he abili y o S. epide midis o apidly change om a commensal o a pa hogenic s a e. As skin commensals, S. epide midis su i e and g ow unde nu ien limi a ion, a a low empe a u e (<37◦C) and pH (∼4.5–6.4) (Schmid- Wend ne and Ko ing, 2006) and a di e se osmo ic p essu es esul ing om he p oduc ion/e apo a ion o swea and luc ua ions in en i onmen al humidi y (Wilson, 2005). Fu he mo e, hey ha e o cope wi h cell desquama ion, and oxida i e s ess esul ing om UV exposu e (Kammeye and Lui en, 2015). Once in he bloods eam, upon skin ba ie b each, he en i onmen al landscape changes d ama ically and S. epide midis suddenly ace a nu ien - ich and alkaline en i onmen wi h a highe empe a u e, p o-in lamma o y molecules and eac i e oxygen species (ROS) gene a ed by immune cells (Aki a e al., 2006;Weiss and Schaible, 2015) and e en ual an ibio ic p essu e (Cio u e al., 2017). Howe e , he ac o s o S. epide midis ha con ibu e o he ansi ion om heal h o disease s a e a e no comple ely unde s ood. One o he ac o s hough o be c ucial o ansi ion om skin o blood is he o ma ion o bio ilms on he su ace o medical de ices, which can be composed o a mesh o p o eins, exopolysaccha ides and ex acellula DNA (Qin e al., 2007; O o, 2009). These bio ilms can con e p o ec ion agains he hos immune sys em (Vuong e al., 2004) and esis ance o an ibio ics (Fa be e al., 1990;Kha do i e al., 1995;Singh e al., 2010), making in ec ions ex emely di icul o ea (O o, 2009). O he mechanisms ha ha e been shown o be impo an o S. epide midis pa hogenici y include he abili y o e ade human inna e immuni y, namely h ough p ocesses in ol ed in esis ance o an imic obial pep ides (AMP) (Cheung e al., 2010). Besides he ica ope on, which is di ec ly in ol ed in bio ilm o ma ion (Heilmann e al., 1996) and he inse ion sequence IS256, shown o modula e bio ilm o ma ion and an ibio ic esis ance (Kozi skaya e al., 2004), o he i ulence ac o s ha e been p oposed. These include he p ima y a achmen o hos ex acellula ma ices and in e cellula agg ega ion, oxins, p o eases and lipases, all sugges ed o be implica ed in in asi e po en ial (O o, 2012). Whole genome sequence analysis (Conlan e al., 2012;Me ic e al., 2015) has shown ha he S. epide midis popula ion was composed o wo main phylogene ic clus e s: lineage A/C, con aining mos o he isola es om coloniza ion and in ec ion and lineage B, comp ising mainly coloniza ion isola es. In spi e o hei clinical ele ance, he ac o s associa ed o he success o A/C s ains, bo h as colonize s and pa hogens, a e no ully unde s ood. He e we hypo hesize ha he success o A/C s ains as colonize s and as pa hogens is associa ed wi h an inc eased abili y o adap o en i onmen al cons ain s imposed by bo h coloniza ion and in ec ion s a es. To add ess his, we analyzed he genomes o ep esen a i e isola es om A/C and B clus e s and cha ac e ized hei pheno ypic ai s in condi ions ha mimic he coloniza ion and in ec ion scena ios. RESULTS AND DISCUSSION S. epide midis Popula ion S uc u e Is Composed o Two Clus e s Wi h Di e en Pa hogenic Po en ial In p e ious s udies we ha e cha ac e ized a collec ion o 1714 S. epide midis om di e en isola ion da es, geog aphic and clinical o igins (Mi agaia e al., 2007;Rolo e al., 2012). Based on mul ilocus sequence yping (MLST) da a we selec ed a collec ion o 83 isola es ha ep esen he di e si y o s ains in e ms o gene ic backg ounds (71 sequence ypes, be ween 1996 and 2001). To unde s and how isola es o di e en o igins we e ela ed, we gene a ed a pan genome based on he anno a ed genomes om 82 S. epide midis s ains unde s udy (one genome was excluded om he genomic analysis due o possible con amina ion, see Ma e ials and Me hods) and compa ed he genomic con en o he s ains acco ding o hei isola ion sou ce. The pangenome ob ained had a o al size o 5.0 Mbp wi h 31.3% o GC con en , encoding a o al o 6682 genes. F om hese, app oxima ely one hi d (n= 1653) comp ised he co e genome (p esen in all s ains in his s udy), wi h he emainde (5029) comp ising he accesso y genome. Gene accumula ion cu es ha plo pan genome size as a unc ion o he numbe o genomes sequenced, sugges an open pan genome ha is cha ac e is ic o popula ions F on ie s in Mic obiology | www. on ie sin.o g 2Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 3 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y FIGURE 1 | Maximum-likelihood ee o he 82 S. epide midis s ains. The ee was gene a ed by RaxML (S ama akis e al., 2012) embedded in Gubbins (C ouche e al., 2015), based on he co e gene alignmen wi h emo al o he ecombining egions. In blue a e depic ed he coloniza ion isola es, in ed he in ec ion isola es and in g ay a e he isola es o which no epidemiological in o ma ion was a ailable. (A–C) Co espond o S. epide midis clonal clus e s, acco ding o Me ic e al. (2015). ha unde go equen ho izon al gene ans e (HGT) (Me ic e al., 2015) (Supplemen a y Figu e S1). Phylogene ic econs uc ion, based on he Maximum- likelihood (ML) ee de i ed om he co e genome co ec ed o ecombining egions, con i med ha he S. epide midis popula ion is di ided in o h ee clus e s (Figu e 1). Consis en wi h p e ious s udies (Me ic e al., 2015), Clus e s A (66%) and C (6%) we e joined in a single clus e and we e analyzed oge he in u he analysis. The emainde o he isola es belonged o clus e B (28%). The A/C clus e con ained mainly nosocomial isola es (n= 49/59, 83%) whe eas he B clus e con ained a highe p opo ion o isola es om heal hy people in he communi y (n= 13/23, 56%) (p= 0.0007), con i ming p e ious indings by Conlan e al. (2012) o a much smalle and geog aphically delimi ed isola e collec ion. A/C clus e isola es almos equally o igina ed om in ec ion (n= 28/59, 47%) and coloniza ion (n= 31/59, 53%) sou ces, while B clus e isola es we e mos ly om coloniza ion (17/23, 70%) (p= 0.127) e en hough his di e en dis ibu ion did no each s a is ical signi icance. These esul s sugges ha al hough bo h A/C and B s ains a e ca ied asymp oma ically, A/C s ains a e, appa en ly, mo e implica ed in in ec ion e en s. This obse a ion is co obo a ed by mul iple s udies whe ein S. epide midis om in ec ion we e in hei majo i y om A/C clus e (which comp ises clonal complex 2 as de ined by MLST) (Mi agaia e al., 2007;Wide s om e al., 2009; Go don e al., 2012;Hellma k e al., 2013;Che i i e al., 2014). E idence o he Clonal Dissemina ion o A/C Clus e Isola es An impo an cha ac e is ic o some oppo unis ic pa hogens is he abili y o dissemina e in di e en hos s and en i onmen s. This can lead o b oad dis ibu ion o closely ela ed s ains. The mean numbe o SNP di e ences be ween he co e genomes o A/C and B clus e s was 39889, which co espond o 1.6% o he a e age genome size o S. epide midis. Wi hin each clus e , he a e age numbe o SNPs was simila o s ains o clus e B (a e age numbe o SNP di e ences = 16786, anging be ween 31 and 36796) and o s ains o clus e A/C (a e age numbe o SNP di e ences = 17696 nucleo ides, anging be ween 1 and 37617). The lowe numbe o di e ences (<100 SNPs) we e ound be ween 11 pai s o A/C isola es and only one pai in clus e B, sugges ing ha A/C isola es a e mo e clonal han B isola es. Fu he mo e, hese pai s included isola es om di e en coun ies, isola ed ei he om he hospi al o he communi y, demons a ing he dissemina ion o his clus e h ough hese se ings. In con as wi h o he known nosocomial pa hogens, including S. au eus (Ruimy e al., 2009;G undmann e al., 2010), we ound no e idence o geog aphic clus e ing in S. epide midis, since each b anch in he ML ee, co esponding ei he o A/C o B clus e s (conside ing a maximum o 50 SNPs di e ence), con ained isola es om mul iple coun ies (see Supplemen a y Table S1). Fu he mo e, he e we e eigh pai s o s ains om di e en coun ies ha , wi h one excep ion, belonged o he A/C clus e ha di e ged in less han 100 SNPs and ha we e isola ed wi hin he same yea . This was he case o s ains om Denma k and Po ugal (68 SNPs; DEN161, 966N), Denma k and Iceland (60 SNPs; DEN116, ICE122) and A gen ina and Hunga y (17 SNPs; AGT24, HUR105), among o he s (see Supplemen a y Table S1). These examples sugges ex ensi e and apid geog aphic dissemina ion o s ains belonging o he A/C clus e , likely p omo ed by skin- o-skin con ac be ween a ele s. This is consis en wi h p e ious s udies ha hypo hesized b oad geog aphic dissemina ion o his species (Mi agaia e al., 2002; Wide s om e al., 2006). E idence o Ecological Isola ion and Dis inc Biological Func ions o A/C and B Clus e s The success o a bac e ial clone may be in luenced by i s capaci y o adap o di e en en i onmen s and his is equen ly accomplished by he acquisi ion o exogenous gene ic elemen s F on ie s in Mic obiology | www. on ie sin.o g 3Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 4 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y (Uhlemann e al., 2012;Wal he e al., 2018), which will compose he accesso y genome. To assess di e ences in gene con en o he wo S. epide midis clus e s, we analyzed and quan i ied accesso y genome a ia ion. The ma ix o p esence/absence o all he genes in he genomes is ep esen ed in Supplemen a y Table S2. The majo i y o A/C and B pan genomes was composed o accesso y genes (A/C: 74%, 3723/5029; B: 67%, 3381/5029). Among his accesso y genome, 1648 genes we e exclusi e o A/C clus e and hese genes a ied in equency om 93% o 2% and 1306 genes we e exclusi e o clus e B and anged om 100 o 4%, sugges ing high genome plas ici y and clus e -speci ic unc ions. The numbe o accesso y genes sha ed be ween s ains o he same clus e (3723 in A/C and 3381 genes in B) is 1.8–1.6 highe han he numbe o genes sha ed be ween he wo clus e s (2075 genes). This di e ence could be due o he exis ence o a ba ie o gene ic ans e be ween hem. Howe e , in con as o S. au eus, his appa en ly low equency o gene ic ans e is no e iden ly associa ed wi h he p esence o Res ic ion/Modi ica ion (R-M) sys ems (Wald on and Lindsay, 2006;Co aglia e al., 2010) and/o he clus e ed egula ly in e spaced sho palind omic epea s (CRISPR) (Ma a ini and Son heime , 2008). The e was no clea associa ion o a hsdR/hsdM sys em o any o he clus e s and cas and csm genes we e equally dis ibu ed among s ains o he wo clus e s [A/C: 12% and B: 17% (p>0.05)] (Supplemen a y Table S2). An al e na i e explana ion o he lowe le el o gene ic exchange be ween he clus e s, in his appa en ly ecombinogenic species (Mi agaia e al., 2007;Me ic e al., 2015), migh be he exis ence o opism o each o hese lineages o speci ic skin niches (G ice e al., 2009;Oh e al., 2014) ha could ha e lead o some ecological isola ion o he wo gene ic clus e s. Ac ually, skin mic obio a composi ion was p e iously shown o a y acco ding o he en i onmen al cha ac e is ics o he skin ecological niche sampled (Cos ello e al., 2009;G ice e al., 2009). To es he hypo hesis o ecological isola ion we ha e examined he se en MLST genes, which cons i u e a good ep esen a ion o he co e genes, ei he in e ms o genome dis ibu ion and gene ic di e si y (Gomes e al., 2005;Mi agaia e al., 2007). Da a showed an appa en allelic seg ega ion, whe e a oE gene p esen ed no common alleles be ween he clus e s and he emaining genes (a cC, g ,mu S, py R, pi,yqiL), comp ising be ween 11 and 20 alleles, had a maximum o wo alleles sha ed by he wo clus e s. Fu he mo e, we looked o genes ha we e signi ican ly associa ed o each clus e using a pan genome wide-associa ion app oach, ha sco es genes o associa ions wi h speci ic epidemiological ea u es. In pa icula , 166 genes we e iden i ied o ha e a s ong posi i e associa ion (Benjamini–Hochbe g p<0.05) wi h clus e A/C (see Supplemen a y Table S3) and 244 genes wi h a s ong associa ion wi h clus e B (see Supplemen a y Table S4). Tables 1,2include he genes among hese, which ha e unc ions ha we e ei he p esen exclusi ely in one o he clus e s o ha we e p esen in bo h bu in signi ican ly di e en equencies. S ains o he A/C clus e we e en iched o genes in ol ed in p ocesses such as bio ilm o ma ion and adhesion o hos ma ix p o eins, p o eolysis, esis ance o an ibio ics and adap a ion o low pH. Con e sely, s ains om clus e B we e en iched o genes in ol ed in he de oxi ica ion o o ma e and o maldehyde, oxida i e s ess esponse, hos in e ac ion h ough ype VII sec e ion sys em, lipid me abolism and cell wall biosyn hesis. This is consis en wi h S. epide midis clus e s A/C and B pe o ming dis inc biological unc ions and possibly occupying di e en skin niches. S. epide midis o A/C and B Clus e s Ha e Adap ed o Skin En i onmen Condi ions Using Di e en S a egies Skin is he i s ba ie o he human body agains ex e nal agg essions and con ains molecules ha de i e om he me abolism o skin cells and ou mic obio a, bu also om he en i onmen (Wilson, 2005). On he skin, S. epide midis ha e o deal wi h nu ien limi a ion, ha sh and a iable en i onmen al condi ions and mechanic s esses. Pe spi a ion is one o he cen al con ibu o s o he composi ion o skin milieu and a majo physiological unc ion ha assis s in he mo egula ion, skin su ace hyd a ion and immune de ense. Pe spi a ion is composed mainly o wa e , bu con ains se e al o he me aboli es ha con ibu e o i s mul iple unc ions, such as an imic obial pep ides (AMP), immunoglobulins, na u al mois u izing ac o s (lac a e, u ea, elec oly es, amino acids), i amins, me als and sal s (Wilson, 2005). To unde s and i he S. epide midis clus e s di e in hei abili y o adap o skin we ha e compa ed hei abili y o g ow and p oduce bio ilm in condi ions ha mimic he skin en i onmen (acidic pH and inc eased sal concen a ions). Mo eo e , we looked in mo e de ail o he genes ha we e associa ed by he pan genomic wide-associa ion app oach o each lineage and ha could p o ide an ad an age in he skin en i onmen al condi ions. G ow h and Bio ilm Fo ma ion a Acidic pH S aphylococcus epide midis belonging o A/C clus e appea o ha e a dis inc i e abili y o adap o he wo acidic pH alues es ed (pH 4.5 and pH 5.5), as s ains om he A/C clus e eached, in a e age, highe cell densi ies in s a iona y phase (∼12% highe in bo h cases) and p esen ed ei he a g ea e (pH4.5: µA/C= 0.335; µB= 0.274, p= 0.043) o simila a e age g ow h a e (pH 5.5: µA/C= 0.626; µB= 0.594, p= 0.273) when compa ed o s ains om he B clus e (see Figu e 2A and Table 3). Addi ionally, s ains belonging o he A/C clus e we e associa ed o a gene in ol ed in he a ginine deiminase me abolism (a cD, an a ginine/o ni hine an ipo e ) (see Table 1) usually ca ied by he a ginine ca abolic mobile elemen (ACME). Al hough a genomic copy o a cD gene wi h a simila unc ion is known o be ubiqui ous in he S. epide midis genome, his ex a copy oge he wi h he emaining a c ope on wi hin ACME was p e iously sugges ed o be impo an o pH homeos asis in S. epide midis and o con ibu e o addi ional ole ance o low-pH in communi y-associa ed S aphylococcus au eus USA300 clone (Thu low e al., 2013;Lindg en e al., 2014). O he unc ions associa ed o A/C clus e s ains ha can e en ually con ibu e o he obse ed inc eased g ow h a e is he la in-con aining oxido educ ase (YwqN), he YdjH suga kinase; and he hexose- 6-phospha e:phospha e an ipo e (UhpT) (Pa k e al., 2015), F on ie s in Mic obiology | www. on ie sin.o g 4Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 5 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y TABLE 1 | Genes posi i ely associa ed o clus e A/C (Benjamini–Hochbe g p<0.05 and OR >1). Pu a i e unc ions Gene anno a ion Func ional anno a ion F equency in clus e A/C % F equency in clus e B % Hyd olysis g oup_1452 Pu a i e hyd olase 92 35 Adhesion and Bio ilm sd F Se ine-aspa a e epea -con aining p o ein F 68 9 sd I Pu a i e su ace p o ein 63 9 icaA∗∗ Poly-be a-1,6-N-ace yl-D-glucosamine syn hase 37 4 icaB∗∗ Poly-be a-1,6-N-ace yl-D-glucosamine N-deace ylase 37 4 icaC∗∗ Pu a i e poly-be a-1,6-N-ace yl-D-glucosamine expo p o ein 37 4 icaD∗∗ Poly-be a-1,6-N-ace yl-D-glucosamine syn hesis 37 4 icaR∗∗ Bio ilm ope on icaADBC HTH- ype nega i e ansc ip ional egula o 37 4 Nickel and Cobal up ake nm R∗HTH- ype ansc ip ional egula o Nm R 37 0 A ginine deiminase a cD∗∗ A ginine/o ni hine an ipo e 55 4 Penicillin esis ance blaI Penicillinase ep esso 68 17 blaZ Be a-lac amase 60 22 Coppe esis ance mco∗∗ Mul icoppe oxidase mco 68 30 P o eolysis splF∗∗ Se ine p o ease SplF 78 35 Ca bohyd a e me abolism gno∗∗ Glucona e 5-dehyd ogenase 62 22 ywqN∗∗ Pu a i e NAD(P)H-dependen FMN-con aining oxido educ ase YwqN 37 4 ydjH∗Pu a i e suga kinase YdjH 37 4 g oup_1735 Hexose-6-phospha e:phospha e an ipo e uhpT 34 0 Thiamine up ake hiQ Thiamine impo ATP-binding p o ein ThiQ 80 30 Cys eine biosyn hesis cysL HTH- ype ansc ip ional egula o CysL 88 43 ∗Only one gene/allele o ha unc ion and unc ion is exclusi e in clus e ; ∗∗Only one gene/allele o ha unc ion and is en iched in he clus e bu he unc ion is no exclusi e in clus e . which lead ei he o he p oduc ion o educing powe (NADH) o he biosyn hesis o majo cell componen s o o he escue o al e na i e suga sou ces. The wo g oups could no be dis inguished by hei abili y o p oduce bio ilm a pH 5.5 (ODA/C= 1.538 s. ODB= 1.536, p= 0.994), since almos all s ains, i espec i e o hei gene ic backg ound, p oduced bio ilm in his condi ion, sugges ing ha bio ilm is impo an o he g ow h o his commensal a he su ace o he skin (see Table 3 and Figu e 2C). G ow h in Osmo ic S ess Condi ions The be e capaci y o he s ains om he A/C clus e o wi hs and pe spi a ion, osmo ic s ess and desicca ion condi ions equen ly imposed a he skin su ace was appa en om hei capaci y o g ow a sodium chlo ide concen a ions cha ac e is ic o he skin (0.15M NaCL) (Schi ek e al., 2001) and in high salini y s ess (2M NaCl) (P ice-Whelan e al., 2013). Whe eas a a physiological concen a ion (0.15M NaCl), s ains om clus e A/C and B had equi alen a e age g ow h a es (µA/C= 0.701 s. µB= 0.670, p= 0.411) (see Table 3), a osmo ic s ess condi ions (2M NaCl), he medium g ow h a e o A/C clus e s ains was signi ican ly highe (µA/C= 0.339 s. µB= 0.298, p= 0.011; see Figu e 2B). Fu he mo e, hey showed a much sho e lag phase (A/C: 361 min s. B: 404 min), and eached highe inal ODs (14% highe ) (see Table 3). The esul s sugges ha , in con as o S. epide midis s ains o B clus e , s ain om A/C clus e a e well adap ed o a ange o salini y concen a ions sugges ing imp o ed su i al in a b oade ange o niches. We ound ha di e en genes indi ec ly in ol ed on esis ance o osmo ic s ess we e speci ically associa ed o ei he clus e A/C o B. This is he case o genes which we e associa ed o A/C clus e ha a e in ol ed in he p oduc ion o polysaccha ide in e cellula adhesion (PIA) (icaADBCR ope on), which h ough he p oduc ion o bio ilm induce p o ec ion agains as osmo ic changes by dec easing he a e o wa e loss and ehyd a ion (Robe son and Fi es one, 1992;de Go au e al., 2009) (see Table 1). Fu he mo e, genes associa ed o B clus e ha could induce osmop o ec ion include hose in ol ed in: pep idoglycan c oss-linking (dacA - a pbp4 homolog, yodJ) ha p o ides ex a igidi y o he bac e ial cell wall (Wyke e al., 1981;Loskill e al., 2014); and he up ake o manni ol (m lA, m lR), a known osmoly e (Ke s e al., 1996;Zahid e al., 2015). The absence o m lD, esponsible o manni ol deg ada ion, sugges s ha s ains o B clus e use manni ol mainly as an osmoly e a he han as a ca bon o ene gy sou ce (da Cos a e al., 1998). F on ie s in Mic obiology | www. on ie sin.o g 5Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 6 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y TABLE 2 | Genes posi i ely associa ed o clus e B (Benjamini–Hochbe g p<0.05 and OR >1). Pu a i e unc ions Gene anno a ion Func ional anno a ion F equency in clus e B % F equency in clus e A/C % Fo ma e de oxi ica ion g oup_862 g oup_863 Pu a i e o ma e dehyd ogenase Pu a i e o ma e dehyd ogenase 91 22 0 0 Fo maldehyde assimila ion/de oxi ica ion hxlR_1 HTH- ype ansc ip ional ac i a o HxlR 22 0 Coppe esis ance cueR∗HTH- ype ansc ip ional egula o 22 0 Oxida i e s ess esponse g oup_3122 (c O)∗∗(?) Glycosyl-4,40-diaponeu ospo enoa e acyl ans e ase 22 0 c P∗∗ Diapolycopene oxygenase 22 0 c Q∗∗ 4,40-diaponeu ospo enoa e glycosyl ans e ase 22 0 c M∗∗ Dehyd osqualene syn hase 22 0 c N∗∗ Dehyd osqualene desa u ase 22 0 Hos -in e ac ion and Vi ulence esaA∗ESAT-6 sec e ion accesso y ac o 65 0 esaB∗ESAT-6 sec e ion accesso y ac o 65 0 essC∗∗ ESAT-6 sec e ion machine y p o ein 65 0 esxA∗ESAT-6 sec e ion sys em ex acellula p o ein A 65 0 essB∗∗ g oup_2414∗∗ ESAT-6 sec e ion machine y p o ein ESAT-6 sec e ion machine y p o ein 39 30 0 0 yezG_1 yezG_2 yezG_3 yezG_5 Pu a i e an i oxin Pu a i e an i oxin Pu a i e an i oxin Pu a i e an i oxin 52 48 43 26 0 0 0 2 Ca bohyd a e me abolism eA∗T ehalose-6-phospha e hyd olase 26 0 m lR∗T ansc ip ional egula o M lR 22 0 m lA∗PTS sys em manni ol-speci ic EIICB componen 22 0 Lipid me abolism g oup_3907∗NADP-dependen 7-alpha-hyd oxys e oid dehyd ogenase 48 0 Benzoa e deg ada ion ligI∗2-py one-4,6-dica baxyla e hyd olase 26 0 T anspo sys ems g oup_1444 ABC anspo e ATP-binding p o ein Na A 43 0 Cell wall biosyn hesis dacAD-alanyl-D-alanine ca boxypep idase DacA 39 2 yodJ∗∗∗ Pu a i e ca boxypep idase YodJ 35 2 T ansposable elemen s bin3_3 Tn552 DNA-in e ase 43 0 in - n Tn916 ansposase In -Tn 87 34 ∗Only one gene/allele o ha unc ion and unc ion is exclusi e in clus e ; ∗∗Mo e han one gene/allele o ha unc ion bu unc ion is exclusi e in clus e ; ∗∗∗Only one gene/allele o ha unc ion and is en iched in he clus e bu he unc ion is no exclusi e in clus e . Al hough s ains o bo h clus e s ca y genes ha a e associa ed o esis ance o osmo ic s ess, o e all, he p ocesses used by s ains o he A/C clus e appea o be mo e e icien han hose o s ains om he B clus e , as illus a ed by i s highe g ow h a e in i o. Gene ic T ai s Associa ed o E asion o Skin Inna e Immuni y Skin is con inuously exposed o commensal mic oo ganisms and challenged o de end he human body om in asion by pa hogens. To deal wi h his ex ensi e mic obial exposu e, skin issues p oduce an imic obial pep ides (AMPs) and ee a y acids ha a ge he bac e ial cell wall o cell memb ane s uc u es (Kenny e al., 2009;Gallo and Hoope , 2012). To su i e, bac e ia ha e de eloped mul iple s a egies, including he p oduc ion o ca o enoid pigmen s ha p o ec om ee a y acids and he inac i a ion o AMPs by p o eolysis. We ound ha s ains belonging o he B clus e mo e commonly con ained he ope on in ol ed in s aphyloxan hin biosyn hesis (c OPQMN) ha was desc ibed o con e esis ance o ee a y acids p oduced by skin cells (Chambe lain e al., 1991). The p oduc ion o he ca o enoid was con i med pheno ypically o he g oup o i e s ains ca ying his ope on h ough he obse a ion o p oduc ion o a yellow colo by colonies g own on aga g ow h medium. O he pigmen s had been ound o be syn hesized by S. epide midis (Ogo, 1985), bu his is he i s ime ha s aphyloxan hin ope on is desc ibed in his species. We also ound a se ine-p o ease (SplF) posi i ely associa ed o s ains om clus e A/C (Table 1). S aphylococcal p o eases ha e al eady been implica ed in he mechanism o de ense agains he human inna e immune sys em, as some o hese p o eases ha e he abili y o clea e and inac i a e human AMPs, namely de mcidin (Lai e al., 2007) and LL-37 (Siep awska-Lupa e al., 2004) ha a e p oduced by epi helial cells F on ie s in Mic obiology | www. on ie sin.o g 6Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 7 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y FIGURE 2 | Pe o mance o clus e A/C and B s ains in he g ow h and bio ilm assays. (A) A e age g ow h a es o A/C and B s ains g own in liquid medium a pH 4.5; (B) A e age g ow h a es o A/C and B s ains g own in liquid medium wi h 2M NaCl; (C) A e age bio ilm o ma ion capaci y o A/C and B s ains a pH 5.5; (D) A e age bio ilm o ma ion capaci y o A/C and B s ains a pH 7. and al hough his could be he case also o S. epide midis SplF, his has ye o be p o en. Al oge he , he esul s sugges ha bo h S. epide midis o A/C and B clus e a e equipped o e ade he hos immune sys em and ha could be a majo ad an age o su i al in bo h skin and blood. In e ac ion Wi h he Hos and Pa hogens Commensal bac e ia a e in cons an in e ac ion wi h he su ounding en i onmen and he hos . Sec e ion sys ems a e cen al elemen s in hese in e ac ions bu ha e been in es iga ed mos ly om he pe spec i e o pa hogen-hos in e ac ions. Recen da a sugges ha hese sys ems may play a ole in mu ualis ic ela ionships be ween bac e ia and he hos (Sil e e al., 2007) o in media ion o bac e ial in e ac ions (Basle e al., 2013). We ound ha S. epide midis s ains belonging o B clus e we e associa ed o genes ela ed o ype VII sec e ion sys em (T7SS) (Lai e al., 2007). In pa icula , all he conse ed T7SS s uc u al genes (esaA, esaB, essA, essB, essC) we e co- loca ed in he ch omosome. Mo eo e , he e was conside able s ain- o s ain a ia ion in he numbe and ype o sec e ed oxin/an i oxin-homologs downs eam his ope on (see Table 2). T7SS we e p e iously desc ibed in S. epide midis and we e p oposed o sec e e an inhibi o y oxin agains P opionibac e ium acnes (Ch is ensen e al., 2016), ano he common commensal o he skin. Ye , in S. au eus, he unc ions o T7SS a e b oade , in ol ing no only in aspecies compe i ion (Cao e al., 2016), bu also pe sis ence and pa hogenici y (Bu s e al., 2008;Kneupe e al., 2014;Ko ea e al., 2014). The iden i ica ion o a T7SS in S. epide midis belonging o B clus e is consis en wi h he hypo hesis ha S. epide midis o clus e B and P opionibac e ium may sha e a simila niche in he skin. S. epide midis Gene ic Con en Re lec s Adap a ion o An h opogenic Ac i i ies P e ious s udies ha e shown ha human skin composi ion is also de ined by ou daily ou ines (Bouslimani e al., 2015), including ac i i ies ha imply equen con ac wi h he skin, like hygiene habi s and he applica ion o skin ca e p oduc s and clo hing. Mo eo e , swea has been conside ed o long as a cleanse , allowing he exc e ion o oxic subs ances ha could ha e been abso bed due o acu e o ch onic exposu e o con amina ed en i onmen (ai , wa e , ood) o o consumed p oduc s. We ound ha S. epide midis o ei he A/C o B clus e we e associa ed o six loci ela ed o he up ake, de oxi ica ion o egula ion o me aboli es (glucona e, ehalose, coppe , and o maldehyde) ha acco ding o he Human Me abolome Da abase1(Wisha e al., 2018) a e p esen in he skin issues and ha a e known o be simul aneously p esen in he composi ion o ood, pha maceu ical p oduc s, de e gen s/disin ec an s and/o cosme ics (see Tables 1,2). Deg ada ion o Suga and Suga De i a i es Genes in ol ed in he deg ada ion o suga s o suga de i a i es, namely ehalose ( eA) and glucona e (gno), we e associa ed wi h B and A/C clus e s espec i ely, sugges ing ha s ains om he wo clus e s use hese al e na i e suga s as ca bon and ene gy 1www.hmdb.ca F on ie s in Mic obiology | www. on ie sin.o g 7Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 8 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y TABLE 3 | Pe o mance o clus e A/C and clus e B s ains in skin and blood condi ions. Condi ions es ed Clus e A/C Clus e B p- alue Skin G ow h a pH 5.5 G ow h a e (h−1) 0.626 0.594 0.273 Lag phase (min) 234 212 – Final OD (nm) 1.369 1.231 – G ow h a 2M NaCl G ow h a e (h−1) 0.339 0.298 0.011 Lag phase (min) 361 404 – Final OD (nm) 1.231 1.08 – Bio ilm a pH 5.5 (OD595 nm) 1.538 1.536 0.994 Blood G ow h a pH 7.4 G ow h a e (h−1) 0.788 0.728 0.122 Lag phase (min) 191 212 – Final OD (nm) 1.456 1.389 – Bio ilm a pH 7 (OD595 nm) 1.475 0.377 0.0003 Adhesion o collagen (OD595 nm) 0.185 0.175 0.671 Skin and Blood G ow h a pH 4.5 G ow h a e (h−1) 0.335 0.274 0.043 Lag phase (min) 234 276 – Final OD (nm) 0.591 0.528 – G ow h a 0.15 M NaCl G ow h a e (h−1) 0.701 0.670 0.411 Lag phase (min) 212 212 – Final OD (nm) 1.476 1.470 – An ioxidan capaci y (nmol/µL) 10.20 10.79 0.428 Cell wall cha ge (OD410 nm) 20.10 27.09 0.084 P o eolysis High (no isola es) 29 4 Medium (no isola es) 21 14 0.032 Low (no isola es) 10 5 Penicillin esis ance no. esis an isola es (%) 52 (87%) 12 (48%) no. suscep ible isola es (%) 8 (13%) 11 (9%) 0.002 Oxacillin esis ance no. esis an isola es (%) 37 (62%) 10 (43%) n . suscep ible isola es (%) 23 (38%) 13 (57%) 0.147 Gen amicin esis ance no. esis an isola es (%) 21 (35%) 2 (9%) no. suscep ible isola es (%) 39 (65%) 21 (91%) 0.026 sou ces. The use o glucona e as a ca bon sou ce and i s cen al ole in bac e ial cell di ision and coloniza ion was p e iously desc ibed o o he bac e ia like S ep ococcus suis (Shi e al., 2014) and Esche ichia. coli (Sweeney e al., 1996). T ehalose is no commonly used by S. epide midis as a ca bon sou ce. Ac ually, he absence o ehalose e men a ion has been conside ed a signa u e o S. epide midis used o dis inguish i om o he bac e ial species (Kloos and Schlei e , 1975). A possible o igin o ehalose ound in he skin, besides ood and cosme ics (Oh ake and Wang, 2011), a e bac e ia o he genus P opionibac e ium (also pa o skin na u al lo a), which a e desc ibed o be capable o syn hesizing his suga (Piwowa ek e al., 2018). The esul s sugges once mo e ha P opionibac e ium and S. epide midis o B clus e migh sha e he same niche, possibly hai ollicles and sebaceous egions whe ein P opionibac e ium a e en iched (Scha schmid and Fischbach, 2013) and he ehalose p oduced by P opionibac e ium can be used by S. epide midis as a ca bon and ene gy sou ce. Ha ing he capaci y o me abolize glucona e and ehalose, ei he om an h opogenic o mic obial o igin, can be highly ad an ageous o S. epide midis in an en i onmen o nu ien limi a ion like he skin. Resis ance and Modula ion o Coppe S aphylococcus epide midis s ains belonging o A/C clus e and B clus e we e associa ed o genes in ol ed in coppe egula ion, al hough using di e en mechanisms. While s ains om he A/C clus e we e associa ed o mul icoppe oxidase (mco), an enzyme in ol ed in he oxida ion o Cu+ o Cu2+ (Si hisak e al., 2005), B clus e s ains we e associa ed o cueR, a Me R- amily me allo egula o y ansc ip ional ac i a o ha senses in acellula Cu+and up egula es copA and cueO, wo genes in ol ed in coppe e lux and oxida ion in esponse o inc easing coppe concen a ions (Cha u edi and Hende son, 2014). Coppe is u ilized by bac e ia o se e al essen ial me abolic p ocesses, bu is also c i ical o he main enance o a heal hy skin, namely o he syn hesis and s abiliza ion o ex acellula ma ix skin p o eins and angiogenesis (Raju e al., 1982;Philips e al., 2012). Al hough an impo an enzyme co ac o and signaling molecule, he in acellula le els o ee coppe can be damaging o bac e ia, leading o ROS- ela ed oxida i e s ess de i ed om i s educ ion and oxida ion cycles, eason by which i is equen ly added o cosme ics as a biocide. Coppe oxida ion pe o med by sys ems like Mco and Cue p obably help S. epide midis o igh ly egula e and main ain coppe homeos asis in he skin (Fes a and Thiele, 2012; Cha u edi and Hende son, 2014). De oxi ica ion o Fo maldehyde S aphylococcus epide midis belonging o B clus e we e addi ionally associa ed wi h a gene (hxlR) in ol ed in de oxi ica ion o o maldehyde, a me aboli e ha can be highly dele e ious o human cells. The o maldehyde- esponsi e ansc ip ional ac o hxlR is pa o he o maldehyde de oxi ica ion/assimila ion ia a ibulose monophospha e (RuMP)-dependen pa hway, h ough which o maldehyde is con e ed in o uc ose-6 phospha e and subsequen ly inco po a ed in o he usual ca bon me abolism pa hway (Chen e al., 2016). Fo maldehyde, is ubiqui ously ound in na u e and is an impo an me aboli e o bo h bac e ia and human cells (Bu gos-Ba agan e al., 2017), bu is also one o he mos syn hesized compounds as he esul o an h opogenic ac i i ies. Toxici y o o maldehyde o animals, humans and bac e ia (Tang e al., 2009;Chen e al., 2016) is due o he as eac ion o o maldehyde wi h ee hiol (−SH) and amine g oups (−NH2) on p o eins and DNA (Feldman, 1973;Page and Bu ne , 2003), F on ie s in Mic obiology | www. on ie sin.o g 8Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 9 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y making o maldehyde one o he mos po en p o ein and DNA c oss-linking agen s. The p esence o genes o he de oxi ica ion in S. epide midis s ains belonging o B clus e p obably allowed hem o adap o o maldehyde esul ing ei he om human and bac e ial cells me abolism o om con inuous exposu e o o maldehyde con aining p oduc s (dyes, syn he ic ex iles, disin ec an s, and cosme ics). In his ega d, S. epide midis migh be unc ioning no only o i s own bene i bu also in he bene i o he hos by a oiding ha hese compounds each oxic concen a ions o human cells. S ains o A/C Clus e Ha e a Highe Capaci y o Su i al in Hospi al and In ec ion En i onmen al Condi ions Du ing in ec ion S. epide midis has o adap o a new en i onmen , he bloods eam, whe ein he pH is s abilized a 7.4, he concen a ion o sal is s eady (0.15 M), speci ic hos ma ix p o eins a e p oduced, he immune esponse is exace ba ed, and inhibi o y concen a ions o an ibio ics may be p esen . One o he s a egies o deal wi h such s esses is he a achmen o he su ace o a de ice, ollowed by he de elopmen o he bio ilm, whe e bac e ial cells a e p o ec ed. To e alua e i S. epide midis belonging o A/C and B clus e s ha e de eloped di e en capaci ies o adap o an in ec ion en i onmen , we compa ed hei abili y o bind collagen I, o g ow and p oduce bio ilm in blood-simila pH and sal condi ions (g ow h: pH 7.4; 0.15 M NaCl; bio ilm: pH 7), o esis oxida i e s ess and o e ade he immune sys em (by measu ing he su ace cha ge and p o eoly ic ac i i y). Mo eo e , we sea ched o speci ic genes wi hin hese lineages ha could be associa ed o a highe in ec ious capaci y. Binding o Hos Ma ix P o eins and Bio ilm Fo ma ion a Blood pH When a medical de ice is in oduced in o he human body, i s su ace becomes coa ed wi h a laye o hos p o eins (Vaudaux e al., 1995; on Ei e al., 2002;A ecubie a e al., 2007;Singh e al., 2012). Fo eign-body associa ed in ec ions a e a ibu ed o he a achmen o bac e ia o hese hos p o eins, such as collagen I om issues, and ib onec in and ib inogen om blood, h ough binding o su ace p o eins (Pa i e al., 1994; Fos e and Hook, 1998) ollowed by he p oduc ion o bio ilm. To unde s and i S. epide midis belonging o he wo gene ic lineages di e ed in hei abili y o cause de ice-associa ed in ec ion, we es ed hei abili y o bind collagen I (see Table 3), he collagen ype mo e abundan in human issues (Singh e al., 2012), a he han he skin. Howe e , ou esul s showed ha binding o collagen was no a dis inc i e ac o con ibu ing o hei di e en in ec ious capaci y (ODA/C= 0.185 s. ODB= 0.175, p= 0.067) (see Supplemen a y Figu e S2A). Mo eo e , we iden i ied wo adhesins o mic obial su ace componen s ecognizing adhesi e ma ix molecules (MSCRAMMs), namely Sd F and Sd I, ha we e associa ed o A/C s ains and ha ha e been desc ibed o be in ol ed in binding o collagen I and ib onec in (Ha o d e al., 2001;Sakinc e al., 2005;A ecubie a e al., 2007), espec i ely. In spi e o he iden i ied associa ion be ween Sd F and A/C clus e , his did no impac di ec ly he pheno ype o collagen binding, p obably due o he exis ence o known edundancy o p o eins o he han Sd F ha bind collagen I. On he o he hand, he compa ison o he wo lineages ega ding he abili y o o m bio ilm a pH 7 (simila o blood’s pH) showed ha A/C s ains p oduced signi ican ly mo e bio ilm (ODA/C= 1.475; ODB= 0.377, p= 0.0003) (see Table 3 and Figu e 2D) and we e simul aneously associa ed o he p esence o he ica ope on, in ol ed in he p oduc ion o polysaccha ide in e cellula adhesion (PIA) (Benjamini–Hochbe g p= 0.029). These esul s sugges ha upon skin dis up ion he s ains ha a e able o p oduce bio ilm and ha su i e be e in blood en i onmen a e hose belonging o A/C clus e ha in addi ion o he abili y o binding collagen I ha e he po en ial o bind ib onec in (mainly ound in he blood a e inju y) and o p oduce PIA-dependen bio ilms a blood’s pH. Resis ance o Hos Immune Sys em Du ing In ec ion Once in he bloods eam, bac e ia a e immedia ely ecognized by monocy es and neu ophils h ough se e al Pa e n ecognizing ecep o s (such as Toll-Like ecep o s, Nod-Like ecep o s and C- ype lec in ecep o s), leading o he exp ession o AMPs, phagocy osis, deg anula ion, espi a o y bu s and killing and he o ma ion o neu ophil ex acellula aps ha cap u e bac e ia inducing a apid in lamma o y esponse (cy okines and chemokines) (Aki a e al., 2006). Bac e ial phagocy osis by mac ophages occu s ia he o ma ion o a memb ane-enclosed phagosome con aining he mic obe in an acidic en i onmen (can be as low as pH 4.5), ex emely ich in bac e icidal enzymes and oxic compounds ( eac i e oxygen and ni ogen species and coppe ) (Weiss and Schaible, 2015). Acco ding o ou da a, S. epide midis s ains ha e de eloped se e al mechanisms ha allow hem o su i e wi hin mac ophages. In pa icula , we obse ed ha al hough A/C s ains had a signi ican ly highe medium g ow h a e a pH 4.5 (pH o mac ophages milieu) (µA/C= 0.335; µB= 0.274, p= 0.043) han B s ains, hey did no a y signi ican ly in hei o al an ioxidan capaci y (see Supplemen a y Figu e S2B). The lack o di e ence in an ioxidan capaci y migh be due o he ac ha bo h A/C and B clus e s we e associa ed o genes ha p o ide esis ance o oxida i e s ess (A/C clus e : mco; B clus e : c OPQMN ope on) and ole ance o coppe (A/C clus e : mco; B clus e : cueR) (see Tables 1,2). Especially, s aphyloxan hin p oduced by c OPQMN was desc ibed in S. au eus o pa icipa e in he sca enging o ee adicals and o ha e impac in i ulence (Claudi z e al., 2006;Mish a e al., 2011). We ha e also compa ed he su ace cha ge and p o eoly ic ac i i y o he wo clus e s, as a measu e o he capaci y o e ade he hos immune sys em. Acco ding o ou da a, s ains o he A/C and B clus e s showed a simila a e age alue o su ace cha ge measu ed by he ela i e pe cen age o unbound cy och ome C, bu he alues ob ained a ied om 0 and 78% among s ains (see Supplemen a y Figu e S2C and Supplemen a y Table S5). In pa icula , closely ela ed s ains in he phylogene ic ee (DEN116 and ICE21, 101 SNPs) showed comple ely dis inc ela i e su ace cha ges (72 and F on ie s in Mic obiology | www. on ie sin.o g 9Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 16 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y Ma a ini, L. A., and Son heime , E. J. (2008). CRISPR in e e ence limi s ho izon al gene ans e in s aphylococci by a ge ing DNA. Science 322, 1843– 1845. doi: 10.1126/science.1165771 May, L., Klein, E. Y., Ro hman, R. E., and Laxmina ayan, R. (2014). T ends in an ibio ic esis ance in coagulase-nega i e s aphylococci in he Uni ed S a es, 1999 o 2012. An imic ob. Agen s Chemo he . 58, 1404–1409. doi: 10.1128/aac. 01908-13 Me ic, G., Mi agaia, M., de Been, M., Yaha a, K., Pascoe, B., Magei os, L., e al. (2015). Ecological o e lap and ho izon al gene ans e in S aphylococcus au eus and S aphylococcus epide midis.Genome Biol. E ol. 7, 1313–2138. Mi agaia, M., Cou o, I., Pe ei a, S. F., K is insson, K. G., Wes h, H., Ja lo m, J. O., e al. (2002). Molecula cha ac e iza ion o me hicillin- esis an S aphylococcus epide midis clones: e idence o geog aphic dissemina ion. J. Clin. Mic obiol. 40, 430–438. doi: 10.1128/jcm.40.2.430-438.2002 Mi agaia, M., Thomas, J. C., Cou o, I., En igh , M. C., and de Lencas e, H. (2007). In e ing a popula ion s uc u e o S aphylococcus epide midis om mul ilocus sequence yping da a. J. Bac e iol. 189, 2540–2552. doi: 10.1128/jb.01484-06 Mish a, N. N., Liu, G. Y., Yeaman, M. R., Nas , C. C., P oc o , R. A., McKinnell, J., e al. (2011). Ca o enoid- ela ed al e a ion o cell memb ane luidi y impac s S aphylococcus au eus suscep ibili y o hos de ense pep ides. An imic ob. Agen s Chemo he . 55, 526–531. doi: 10.1128/aac.00680-10 Ogo, K. (1985). P ope ies o pigmen s p oduced by S. epide midis. J. Okayama Med. Assoc. 97, 749–759. doi: 10.4044/joma1947.97.7-8_749 Oh, J., By d, A. L., Deming, C., Conlan, S., NISC Compa a i e Sequencing P og am, Kong, H. H., e al. (2014). Biogeog aphy and indi iduali y shape unc ion in he human skin me agenome. Na u e 514, 59–64. doi: 10.1038/ na u e13786 Oh ake, S., and Wang, Y. J. (2011). T ehalose: cu en use and u u e applica ions. J. Pha m. Sci. 100, 2020–2053. doi: 10.1002/jps.22458 O o, M. (2009). S aphylococcus epide midis– he “acciden al” pa hogen. Na . Re . Mic obiol. 7, 555–567. doi: 10.1038/n mic o2182 O o, M. (2012). Molecula basis o S aphylococcus epide midis in ec ions. Semin. Immunopa hol. 34, 201–214. doi: 10.1007/s00281-011-0296-2 Page, A. J., Cummins, C. A., Hun , M., Wong, V. K., Reu e , S., Holden, M. T., e al. (2015). Roa y: apid la ge-scale p oka yo e pan genome analysis. Bioin o ma ics 31, 3691–3693. doi: 10.1093/bioin o ma ics/b 421 Page , M. S., and Bu ne , M. J. (2003). Thiol-based egula o y swi ches. Annu. Re . Gene ics 37, 91–121. doi: 10.1146/annu e .gene .37.110801.142538 Paha ik, A. E., Salgado-Pabon, W., Meye holz, D. K., Whi e, M. J., Schlie e , P. M., and Ho swill, A. R. (2016). The spl se ine p o eases modula e S aphylococcus au eus p o ein p oduc ion and i ulence in a abbi model o pneumonia. mSphe e 1:e00208-16. Pa k, J. Y., Kim, J. W., Moon, B. Y., Lee, J., Fo in, Y. J., Aus in, F. W., e al. (2015). Cha ac e iza ion o a no el wo-componen egula o y sys em, Hp RS, he egula o o he hexose phospha e anspo sys em in S aphylococcus au eus. In ec . Immun. 83, 1620–1628. doi: 10.1128/iai.03109-14 Pa i, J. M., Allen, B. L., McGa in, M. J., and Hook, M. (1994). MSCRAMM- media ed adhe ence o mic oo ganisms o hos issues. Annual Re iew o Mic obiology.;48:585–617. doi: 10.1146/annu e .mic o.48.1.585 Peschel, A., O o, M., Jack, R. W., Kalbache , H., Jung, G., and Go z, F. (1999). Inac i a ion o he dl ope on in S aphylococcus au eus con e s sensi i i y o de ensins, p o eg ins, and o he an imic obial pep ides. J. Biol. Chem. 274, 8405–5410. Philips, N., Samuel, P., Pa akandi, H., Gopal, S., Siomyk, H., Minis o, A., e al. (2012). Bene icial egula ion o ib illa collagens, hea shock p o ein-47, elas in ibe componen s, ans o ming g ow h ac o -be a1, ascula endo helial g ow h ac o and oxida i e s ess e ec s by coppe in de mal ib oblas s. Connec . Tissue Res. 53, 373–378. doi: 10.3109/03008207.2012.665970 Piwowa ek, K., Lipinska, E., Hac-Szymanczuk, E., Kieliszek, M., and Scibisz, I. (2018). P opionibac e ium spp.-sou ce o p opionic acid, i amin b12, and o he me aboli es impo an o he indus y. Appl. Mic obiol. Bio echnol. 102, 515–538. doi: 10.1007/s00253-017-8616-7 P ice, M. N., Dehal, P. S., and A kin, A. P. (2010). Fas T ee 2–app oxima ely maximum-likelihood ees o la ge alignmen s. Plos One. 5:e9490. doi: 10.1371/ jou nal.pone.0009490. P ice-Whelan, A., Poon, C. K., Benson, M. A., Eidem, T. T., Roux, C. M., Boyd, JM, e al. (2013). T ansc ip ional p o iling o S aphylococcus au eus du ing g ow h in 2 M NaCl leads o cla i ica ion o physiological oles o Kdp and K K+ up ake sys ems. mBio 4:e00407-13. Qin, Z., Ou, Y., Yang, L., Zhu, Y., Tolke -Nielsen, T., Molin, S., e al. (2007). Role o au olysin-media ed DNA elease in bio ilm o ma ion o S aphylococcus epide midis.Mic obiology 153(P 7), 2083–2092. doi: 10.1099/mic.0.2007/ 006031-0 Raju, K. S., Alessand i, G., Ziche, M., and Gullino, P. M. (1982). Ce uloplasmin, coppe ions, and angiogenesis. J. Na . Cance Ins . 69, 1183–1188. Reed, S. B., Wesson, C. A., Liou, L. E., T umble, W. R., Schlie e , P. M., Bohach, G. A., e al. (2001). Molecula cha ac e iza ion o a no el S aphylococcus au eus se ine p o ease ope on. In ec . Immun. 69, 1521–1527. doi: 10.1128/iai.69.3. 1521-1527.2001 Robe son, E. B., and Fi es one, M. K. (1992). Rela ionship be ween Desicca ion and exopolysaccha ide p oduc ion in a soil Pseudomonas sp. Appl. En i on. Mic obiol. 58, 1284–1291. Rolo, J., de Lencas e, H., and Mi agaia, M. (2012). S a egies o adap a ion o S aphylococcus epide midis o hospi al and communi y: ampli ica ion and di e si ica ion o SCCmec. J. An imic ob. Chemo he . 67, 1333–1341. doi: 10. 1093/jac/dks068 Ruimy, R., A mand-Le e e, L., Ba bie , F., Ruppe, E., Cocoja u, R., Mesli, Y., e al. (2009). Compa isons be ween geog aphically di e se samples o ca ied S aphylococcus au eus.J. Bac e iol. 191, 5577–5583. doi: 10.1128/jb.00493-09 Sakinc, T., Woznowski, M., Ebsen, M., and Ga e mann, S. G. (2005). su ace- associa ed p o ein o S aphylococcus sap ophy icus is a lipase. In ec . Immun. 73, 6419–6428. doi: 10.1128/iai.73.10.6419-6428.2005 San os Sanches, I., Ma o, R., de Lencas e, H., Tomasz, A., CEM/NET Collabo a o s and he In e na ional Collabo a o s, (2000). Pa e ns o mul id ug esis ance among me hicillin- esis an hospi al isola es o coagulase- posi i e and coagulase-nega i e s aphylococci collec ed in he in e na ional mul icen e s udy RESIST in 1997 and 1998. Mic ob. D ug Res. 6, 199–211. doi: 10.1089/md .2000.6.199 Sawe s, R. G. (2005). Fo ma e and i s ole in hyd ogen p oduc ion in Esche ichia coli.Biochem. Soc. T ans. 33(P 1), 42–46. doi: 10.1042/bs 0330042 Scha schmid , T. C., and Fischbach, M. A. (2013). Wha li es on ou skin: ecology, genomics and he apeu ic oppo uni ies o he skin mic obiome. D ug Disco . Today Dis. Mech. 10, e83–e89. doi: 10.1016/j.ddmec.2012.12.003 Schi ek, B, Hip el, R, Saue , B, Baue , J, Kalbache , H, S e ano ic, S, e al. (2001). De mcidin: a no el human an ibio ic pep ide sec e ed by swea glands. Na . Immunol. 2, 1133–1137. doi: 10.1038/ni732 Schmid-Wend ne , M. H., and Ko ing, H. C. (2006). The pH o he skin su ace and i s impac on he ba ie unc ion. Skin Pha macol. Physiol. 19, 296–302. doi: 10.1159/000094670 Seemann, T. (2014). P okka: apid p oka yo ic genome anno a ion. Bioin o ma ic 30, 2068–2069. doi: 10.1093/bioin o ma ics/b u153 Shi, Z., Xuan, C., Han, H., Cheng, X., Wang, J., Feng, Y., e al. (2014). Glucona e 5- dehyd ogenase (Ga5DH) pa icipa es in S ep ococcus suis cell di ision. P o ein Cell 5, 761–769. doi: 10.1007/s13238-014-0074-8 Siep awska-Lupa, M., Mydel, P., K awczyk, K., Wojcik, K., Puklo, M., Lupa, B., e al. (2004). Deg ada ion o human an imic obial pep ide LL-37 by S aphylococcus au eus-de i ed p o einases. An imic ob. Agen s Chemo he . 48, 4673–4679. doi: 10.1128/aac.48.12.4673-4679.2004 Sil e , A. C., Kikuchi, Y., Fadl, A. A., Sha, J., Chop a, A. K., and G a , J. (2007). In e ac ion be ween inna e immune cells and a bac e ial ype III sec e ion sys em in mu ualis ic and pa hogenic associa ions. P oc. Na . Acad. Sci. U.S.A. 104, 9481–6948. Singh, B., Fleu y, C., Jalal and, F., and Riesbeck, K. (2012). Human pa hogens u ilize hos ex acellula ma ix p o eins laminin and collagen o adhesion and in asion o he hos . FEMS Mic obiol. Re . 36, 1122–1180. doi: 10.1111/j.1574- 6976.2012.00340.x Singh, R., Ray, P., Das, A., and Sha ma, M. (2010). Pene a ion o an ibio ics h ough S aphylococcus au eus and S aphylococcus epide midis bio ilms. J. An imic ob. Chemo he . 65, 1955–1958. doi: 10.1093/jac/dk q257 Si hisak, S., Howieson, K., Amezola, C., and Jayaswal, R. K. (2005). Cha ac e iza ion o a mul icoppe oxidase gene om S aphylococcus au eus. Applied and En i onmen al Mic obiology. 71, 5650–5653. doi: 10.1128/aem.71.9.5650-5653.2005 F on ie s in Mic obiology | www. on ie sin.o g 16 Augus 2019 | Volume 10 | A icle 1971 micb-10-01971 Augus 27, 2019 Time: 12:8 # 17 Espadinha e al. S. epide midis Clonal Lineages Pa hogenici y S ama akis, A., Abe e , A. J., Goll, C., Smi h, S. A., Be ge , S. A., and Izquie do- Ca asco, F. (2012). RAxML-Ligh : a ool o compu ing e aby e phylogenies. Bioin o ma ics 28, 2064–2066. doi: 10.1093/bioin o ma ics/b s309 S en zel, S., Teu elbe ge , A., No deng un, M., Kola a, J., Schmid , F., an C omb uggen, K., e al. (2017). S aphylococcal se ine p o ease-like p o eins a e pacemake s o alle gic ai way eac ions o S aphylococcus au eus.J. Alle gy Clin. Immunol. 139:492-500.e8. Sweeney, N. J., Klemm, P., McCo mick, B. A., Molle -Nielsen, E., U ley, M., Schemb i, M. A., e al. (1996). The Esche ichia coli K-12 gn P gene allows E. coli -18 o occupy a dis inc nu i ional niche in he s ep omycin- ea ed mouse la ge in es ine. In ec . Immun. 64, 3497–3503. Tang, X., Bai, Y., Duong, A., Smi h, M. T., Li, L., and Zhang, L. (2009). Fo maldehyde in China: p oduc ion, consump ion, exposu e le els, and heal h e ec s. En i on. In . 35, 1210–1224. doi: 10.1016/j.en in .2009.06.002 Thu low, L. R., Joshi, G. S., Cla k, J. R., Spon ak, J. S., Neely, C. J., Maile, R., e al. (2013). Func ional modula i y o he a ginine ca abolic mobile elemen con ibu es o he success o USA300 me hicillin- esis an S aphylococcus au eus. Cell Hos Mic obe 13, 100–107. doi: 10.1016/j.chom.2012. 11.012 Uhlemann, A. C., Po cella, S. F., T i edi, S., Sulli an, SB., Ha e , C., Kennedy, AD., e al. (2012). Iden i ica ion o a highly ansmissible animal-independen S aphylococcus au eus ST398 clone wi h dis inc genomic and cell adhesion p ope ies. mBio 3:e00027-12. an de Bel , H., Neu , D., Schenk, W., an Ho n, J. R., an de Mei, H. C., and Bussche , HJ. (2001). In ec ion o o hopedic implan s and he use o an ibio ic-loaded bone cemen s. Re . Ac a O hop. Scand. 72, 557–751. Vaudaux, P. E., F ancois, P., P oc o , R. A., McDe i , D., Fos e , T. J., Alb ech , R. M., e al. (1995). Use o adhesion-de ec i e mu an s o S aphylococcus au eus o de ine he ole o speci ic plasma p o eins in p omo ing bac e ial adhesion o canine a e io enous shun s. In ec . Immun. 63, 585–590. on Ei , C., Pe e s, G., and Heilmann, C. (2002). Pa hogenesis o in ec ions due o coagulase-nega i e s aphylococci. Lance In ec . Dis. 2, 677–685. Vuong, C., Voyich, J. M., Fische , E. R., B augh on, K. R., Whi ney, A. R., DeLeo, F. R., e al. (2004). Polysaccha ide in e cellula adhesin (PIA) p o ec s S aphylococcus epide midis agains majo componen s o he human inna e immune sys em. Cell. Mic obiol. 6, 269–275. doi: 10.1046/j.1462-5822.2004. 00367.x Wald on, D. E., and Lindsay, J. A. (2006). Sau1: a no el lineage-speci ic ype I es ic ion-modi ica ion sys em ha blocks ho izon al gene ans e in o S aphylococcus au eus and be ween S. Au eus isola es o di e en lineages. J. Bac e iol. 188, 5578–85. Wal he , B., Klein, K. S., Ba on, A. K., Semmle , T., Hube , C., Me le, R., e al. (2018). Equine me hicillin- esis an sequence ype 398 S aphylococcus au eus (MRSA) ha bo mobile gene ic elemen s p omo ing hos adap a ion. F on . Mic obiol. 9:2516. doi: 10.3389/ micb.2018.02516. Weiss, G., and Schaible, U. E. (2015). Mac ophage de ense mechanisms agains in acellula bac e ia. Immunol. Re . 264, 182–203. doi: 10.1111/im .12266 Wide s om, M., Monsen, T., Ka lsson, C., and Wis om, J. (2006). Molecula epidemiology o me icillin- esis an coagulase-nega i e s aphylococci in a Swedish coun y hospi al: e idence o in a- and in e hospi al clonal sp ead. J. Hosp. In ec . 64, 177–83 Wide s om, M., Monsen, T., Ka lsson, C., Edeb o, H., Johansson, A., and Wis om, J. (2009). Clonali y among mul id ug- esis an hospi al-associa ed S aphylococcus epide midis in no he n Eu ope. Scand. J. In ec . Dis. 41, 642–649. doi: 10.1080/00365540903146987 Wilson, M. (2005). Mic obial Inhabi an s o Humans: Thei Ecology and Role in Heal h and Disease. Camb idge: Camb idge Uni e si y P ess Wisha , D. S., Feunang, Y. D., Ma cu, A., Guo, A. C., Liang, K., Vazquez-F esno, R., e al. (2018). HMDB 4.0: he human me abolome da abase o 2018. Nucleic Acids Res. 46, D608–D617. Wyke, A. W., Wa d, J. B., Hayes, M. V., and Cu is, N. A. (1981). A ole in i o o penicillin-binding p o ein-4 o S aphylococcus au eus. Eu . J. Biochem. 119, 389–933. Zahid, N., Schweige , P., Galinski, E., and Deppenmeie , U. (2015). Iden i ica ion o manni ol as compa ible solu e in Gluconobac e oxydans.Appl. Mic obiol. Bio echnol. 99, 5511–5521. doi: 10.1007/s00253-015-6626-x Zdzalik, M., Ka im, AY, Wolski, K, Buda, P, Wojcik, K, B ueggemann, S, e al. (2012). P e alence o genes encoding ex acellula p o eases in S aphylococcus au eus - impo an a ge s igge ing immune esponse in i o. FEMS Immunol. Med. Mic obiol. 66, 220–229. doi: 10.1111/j.1574-695x.2012.01005.x Con lic o In e es S a emen : The au ho s decla e ha he esea ch was conduc ed in he absence o any comme cial o inancial ela ionships ha could be cons ued as a po en ial con lic o in e es . Copy igh © 2019 Espadinha, Sob al, Mendes, Mé ic, Sheppa d, Ca iço, de Lencas e and Mi agaia. This is an open-access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion License (CC BY). The use, dis ibu ion o ep oduc ion in o he o ums is pe mi ed, p o ided he o iginal au ho (s) and he copy igh owne (s) a e c edi ed and ha he o iginal publica ion in his jou nal is ci ed, in acco dance wi h accep ed academic p ac ice. No use, dis ibu ion o ep oduc ion is pe mi ed which does no comply wi h hese e ms. F on ie s in Mic obiology | www. on ie sin.o g 17 Augus 2019 | Volume 10 | A icle 1971