Emergence of Extended-spectrum Beta-lactamase Producer and Colistin-resistant E. coli in Animal-origin Foods in Libya

597 To cite this paper: Sherif JA, Farag SAA, Abureema SF, Azwai SM, Garbaj AM, Gammoudi FT, El Salabi AA, and Eldaghayes IM (2025). Emergence of Extendedspectrum Beta-lactamase Producer and Colistin-resistant E. coli in Animal-origin Foods in Libya. World Vet. J., 15(3): 597-611. DOI: https://dx.doi.org/10.54203/scil.2025.wvj60 2025, Scienceline Publication World’s Veterinary Journal World Vet J, 15(3): 597-611. ISSN 2322-4568 Emergence of Extended-spectrum Beta-lactamase Producer and Colistin-resistant E. coli in Animalorigin Foods in Libya Jihan Ali Sherif1, Samira Abd Allateef Farag1, Salem Farhat Abureema1, Salah Mohamed Azwai2, Aboubaker Mohamed Garbaj1, Fatim Taher Gammoudi2, Allaaeddin Ali El Salabi3, and Ibrahim Mohamed Eldaghayes2* 1Department of Food Hygiene and Control, Faculty of Veterinary Medicine, University of Tripoli, Tripoli, Libya 2Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Tripoli, Tripoli, Libya 3Department of Public Health, Faculty of Medical Technology, University of Tripoli, Tripoli, Libya *Corresponding author's Email: [email protected] ABSTRACT The increasing prevalence of Escherichia coli (E. coli) infection poses significant health challenges worldwide. Understanding the genetic, pathogenic, and antimicrobial resistance profiles of E. coli is crucial for effective diagnosis and treatment. The present study aimed to assess the prevalence and antimicrobial susceptibility patterns of E. coli isolated from different samples of food products from animals, with specific attention to identifying and characterizing extended-spectrum beta-lactamase (ESBL)-producing isolates. The present study analyzed 92 E. coli isolates obtained from 1120 food samples, including milk, dairy products, meat, and meat products, collected randomly from retail markets in Libya. The isolates were tested for antimicrobial susceptibility, and the antibiotic resistance profiles were evaluated using 32 antibiotics from 12 different classes. Multiple antibiotic resistance (MAR) and antibiotic resistance index were calculated, with MAR ≥ 0.2 indicating high antibiotic resistance. Isolates were categorized as multidrug resistant (MDR), extensively drug-resistant (XDR), or pan drug-resistant (PDR) based on standard definitions. The ESBL production was assessed using the double-disc synergy test, and colistin resistance was tested using the agar diffusion method. Antimicrobial susceptibility testing of E. coli isolates revealed 100% resistance to penicillin and cloxacillin, with high resistance rates observed against neomycin (93.4%), rifampicin (86.9%), and methicillin (75%). However, all isolates were susceptible to chloramphenicol, whereas carbapenems (imipenem, meropenem, ertapenem) indicated the lowest resistance (3.2%). Cefepime demonstrated the highest effectiveness among cephalosporins, with a resistance rate of 1.08%. The MAR ranged from 0.09 to 0.6, with the highest MAR value (0.6) observed in isolates resistant to 20 antibiotics. All isolates were MDR, but no XDR or PDR strains were detected. Among the 92 isolates, 43 were confirmed as ESBL producers, primarily originating from raw milk, lben (fermented milk), and other dairy products. In addition, 83 isolates demonstrated phenotypic resistance to colistin. The present study highlighted the significant presence of MDR E. coli in food products of animal origin, particularly raw milk, fermented milk, and chicken meat in Libya, emphasizing the urgent need for antimicrobial stewardship, stronger regulatory frameworks, and integrated One Health surveillance approaches to combat AMR in Libya. Keywords: Antimicrobial resistance, Colistin, Escherichia coli, Extended-spectrum beta-lactamases, Food sample ORIGINAL ARTICLE Received: June 24, 2025 Revised: July 27, 2025 Accepted: August 30, 2025 Published: September 30, 2025 INTRODUCTION Food safety is a crucial component of public health and has been recognized as an effective measure for preventing foodborne diseases for over a century, owing to advancements in food production and the adoption of modern management philosophies, such as hazard analysis. However, several issues continue to persist, one of which is the high prevalence of foodborne illnesses caused by specific pathogens, which appear to have increased in recent decades. Worldwide, foodborne diseases caused by contaminated food are rapidly spreading and can arise at any point in the food chain, from food production to delivery to consumption. Foodborne diseases may originate from a variety of environmental contaminants, such as unsafe or improper food processing, storage practices, and air, water, or soil pollution. According to the World Health Organization, 1 in 10 people falls ill each year due to contaminated food. Many of these illnesses are often linked to the consumption of contaminated undercooked meat and raw milk (Chaves et al., 2015). Furthermore, Faour-Klingbeil and Todd (2019) indicated that international commerce is impacted by food laws and regulations, which are implemented by nations as part of their control tactics against foodborne illnesses, which is a worldwide public health concern that affects people’s health, livelihoods, and healthcare systems. Listeria monocytogenes, Salmonella spp., Campylobacter spp., and Escherichia coli (E. coli) are some of the key bacterial DOI: https://dx.doi.org/10.54203/scil.2025.wvj60 PII: S232245682500060-15 Sherif et al., 2025 598 pathogens responsible for causing foodborne illnesses, according to Habib and Mohamed (2022). Although Africa bears the highest burden of foodborne disease, there is a lack of understanding of the disease’s prevalence in Africa due to the limited studies and surveillance programs (Desta, 2020), and Libya is not exceptional, where many cases are either dismissed as minor and self-limiting or go unconfirmed because of reporting, detection, and monitoring gaps. Escherichia coli is considered a dangerous pathogen in dairy farm operations worldwide because it leads to significant economic losses (Allocati et al., 2013). There are several strains of E. coli, most of which are not hazardous, but a few cause serious foodborne illnesses in humans. Additionally, E. coli has emerged as an essential model organism for researching the spread of drug resistance within bacterial populations and serves as an indicator of the selective pressure caused by the widespread and unregulated use of antibiotics in animal agriculture (Petty et al., 2014). This has positioned E. coli as a key reference in global drug resistance monitoring programs (Sheikh et al., 2012). The insights derived from drug resistance monitoring can contribute to the development of strategies aimed at reducing the risk of these infections among the population (Guiral et al., 2011). Currently, numerous antimicrobial drugs are utilized in food animal production to manage infections and serve as growth promoters, a practice that is increasingly contributing to the human food chain, raising substantial health concerns for both humans and animals (Hao et al., 2014). Common antibiotics such as tetracycline and amoxicillin are used to treat foodborne infections, but their overuse has led to rising resistance in bacteria such as E. coli (Miranda et al., 2014; Gwida and El-Gohary, 2015; Kapoor et al., 2017). Contributing factors to antibiotic resistance include misuse, incorrect prescription, extensive agricultural use, and inadequate regulation have been highlighted by Johnson et al. (2007) and Peterson and Kaur (2018). Developing nations, particularly those in Africa, do not have strong regulations for the use or management of antibiotics (Maron et al., 2013). According to the World Organization for Animal Health, many developing countries do not yet have legislation that addresses the proper use of antimicrobials in veterinary practices. Bacteria have evolved numerous resistance mechanisms to oppose the effects of antibiotics. Certain antibiotics contain chemical bonds, including amides and esters, that are susceptible to hydrolytic cleavage. Certain enzymes, such as extended-spectrum beta-lactamases (ESBLs), weaken antibiotic effectiveness by breaking key chemical bonds. The ESBLs confer resistance to all penicillins, third-generation cephalosporins, and aztreonam, but not to cephamycins or carbapenems (Ćirić et al., 2018). In India, the rise of ESBL-producing strains has led to increased carbapenem use, potentially accelerating the spread of carbapenem-resistant bacteria (Nagshetty et al., 2021). In addition to the consequences of bacterial infection, the susceptibility of the causative agent to antibiotics is considered a risk factor. Drug-resistant E. coli strains were found in humans and food in Salvador, Brazil, showing resistance to multiple antibiotics (Melo et al., 2015). Similarly, 65 strains of E. coli from animals and animal products in Tunisia demonstrated resistance to eight antibiotics, including kanamycin, gentamicin, and amoxicillin (Badi et al., 2022). These strains may spread to humans via direct contact, contaminated food, or the environment. Libya faces significant challenges in tackling bacterial food contamination due to limited awareness of food safety and security. Previous studies did not adequately cover the contamination of food from animal origin (meat and dairy) by pathogenic bacteria and their antibiotic resistance patterns. Infections and diseases caused by antimicrobial drug-resistant pathogens have led to increased morbidity and mortality rates in health care facilities (Alonso et al., 2017). As this problem has grown dramatically, standardized definitions that classify and explain bacteria resistant to different types of antimicrobial drugs are necessary so that epidemiological data can be gathered and analyzed reliably across countries. Since this issue has grown substantially, the term multidrug-resistant (MDR) refers to bacteria that are unsusceptible to at least one agent in three or more antimicrobial categories (Magiorakos et al., 2012; Al-Hasani et al., 2023). In Libya, data on antimicrobial resistance (AMR) of bacteria isolated from food and dairy products are lacking. Nevertheless, a key review article, conducted during the period from 1970 to 2011 and 2002 to 2021, revealed a scarcity of data on AMR, attributing it to the lack of surveillance studies (Ghenghesh et al., 2013; Atia et al., 2022). Another finding from a review of published data over 20 years is that urinary tract infection (UTI) is among the most frequently diagnosed clinical conditions. Notably, the predominant bacterial pathogen causing UTIs is E. coli, which displayed a significant resistance rate to commonly prescribed first-line treatments, such as nitrofurantoin and cotrimoxazole. This resistance raises a concern about potential complications, as patients with UTIs face an increased risk of developing renal damage (Hemolytic Uremic Syndrome) and future complications such as renal failure or hypertension, if their treatment is ineffective (Atia et al., 2022). Developed nations typically have stringent regulations and thorough documentation regarding antibiotic use. However, in many African countries, veterinary antimicrobials are readily available without prescription (Mainda et al., 2015). Recent studies have increasingly focused on the epidemiology of AMR bacteria, especially those producing plasmid-mediated AmpC β-lactamases, carbapenemases, and ESBLs and these studies centered on E. coli, a key World Vet. J., 15(3): 597-611, 2025 599 indicator of antibiotic resistance due to its wide host range and clinical relevance. Studying E. coli helped track resistance patterns across populations and the transfer of resistance between animals and humans (van den Bogaard and Stobberingh, 2000). Consumption of animal-derived food remains a significant pathway for spreading antibiotic-resistant pathogens. Therefore, the present study aimed to assess the antimicrobial susceptibility patterns of E. coli isolates obtained from different foods of animal origin, with particular focus on ESBL-producing isolates. MATERIALS AND METHODS Ethical approval The current study was conducted according to the guidelines of the Faculty of Veterinary Medicine, University of Tripoli, Tripoli, Libya. Sampling, isolation, and identification A total of 92 isolates of E. coli were utilized in the present study, which was a laboratory-based descriptive investigation conducted during the year 2024. Isolates of E. coli had been isolated previously from 1120 food samples and stored at -80oC (Garbaj et al., 2016, 2017, 2022; Eshamah et al., 2020). Among the 1120 food samples, 500 were milk and dairy products, and 620 were meat and meat products, as illustrated in Table 1. The samples of food from animal origin were collected randomly from several retail markets from different Libyan cities, including Tripoli, Sabha, Tobruk, and Regdalin. The isolates were revived from storage at -80°C by removing one cryobead from each cryovial, placing it in 5 mL of peptone water, and then incubating it overnight at 35-37°C for further testing. Table 1. Samples cultured on agar media for the detection of Escherichia coli in Libya during 2024 Sample type No. of samples No. of positive samples Raw cows’ milk 139 21 Fermented milk (Lben) 86 28 White soft cheese (Massora) 57 13 White soft cheese (Ricotta) 36 4 Goats milk 8 2 She camels’ milk 15 2 Butter 4 3 Milk powder 36 2 Ice cream 24 4 Labanh 11 1 Skim milk powder 9 0 Cereal baby food 16 0 UHT milk 8 0 Yogurt 5 0 Growing up formula 18 0 Ready to feed baby formula 10 0 Full-cream milk powder 18 0 Chicken Meat 51 4 Chicken kabab 17 0 Chicken Burger 70 1 Chicken sausage 38 0 Ground chicken 42 0 Chicken liver 5 0 Ground beef 68 0 Beef 73 2 Camel’s meat 107 1 Beef Burger 84 2 Beef Sausage 47 1 Beef Kabab 18 1 Total 1120 92 Table 2. Different antibiotic categories used in the present study Categories Antibiotics Penicillin Amoxicillin 30 µg Ampicillin 30 µg Amoxicillin Clavunate Penicillin 10 µg Methicillin 5 µg Piperacillin/Tazobactam Cloxacillin 5 µg Ticarcillin + Clavunate Cephalosporins Cefepime 30 µg Cefoperazone75µg Cefotaxime 30 µg Ceftriaxone 30µ Cefoxitin 30 µg Carbapenems Imipenem 10 µg Meropenem 10µ Ertapenem 10 µg Aminoglycosides Neomycin 10 µg Kanamycin 30 µg Gentamycin 10 µg Tobramycin 10 µg Strepromycin 10 µg Tetracyclines Tetracycline 30 µg Doxycycline 30 µg Oxytetracycline 30 µg Fluoroquinolones Levofloxacin 5µ Ciprofloxacin 5 µg Glycopeptides Polymixin 300units Phenicols Chloramphenicol 30 µg Sulfonamides Sulphamethoxazole/Trimethoprim Monobactum Aztreonam 30 µg Nitrofurantoin Nitrofurantoin 300 µg Rifampicin Rifampicin 5 µg Sherif et al., 2025 600 Antimicrobial susceptibility profile Antibiotic susceptibility of the E. coli isolates was assessed using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar (MHA), following the guidelines established by the Clinical and Laboratory Standards Institute (CLSI, 2024). Thirty-two antibiotics from 12 classes (Antrim Technology Park, Antrim BT41, England) were tested, as described in Table 2. A sterile nutrient broth was first inoculated with 3-5 colonies from each isolate and then incubated at 37°C for 2-4 hours until it reached an optimum log phase. The suspension was standardized to a 0.5 McFarland turbidity level, then evenly spread onto an MHA plate. After allowing it to dry and absorb for five minutes, the plate was inoculated with a range of commercially available antibiotic discs. Multiple antibiotic resistance index and antibiotic resistance index The multiple antibiotic resistance (MAR) index and antibiotic resistance index (ARI) indices were estimated and interpreted according to Hinton and Linton (1983) as follows. MAR index = a/b, Antibiotic resistance index (ARI) = y / nx, Where a is the number of antibiotics to which the isolates are resistant, b is the total number of antibiotics exposed, y is the number of resistant isolates, n is the number of isolates, and x is the number of antibiotics. A MAR value ≥ 0.2 indicated that antibiotics were ineffective. Identification of multidrug resistance, extensively drug-resistant, and pan-drug-resistant The isolates were considered as multidrug resistant (MDR) if they appeared resistant to at least one antimicrobial agent in three or more antimicrobial different classes, extensively drug-resistant (XDR) was defined as resistance to at least one agent in all except two or fewer antimicrobial categories, and pan drug-resistant (PDR) was defined as nonsusceptibility to all agents in all antimicrobial categories according to Magiorakos et al. (2012). Detection of extended-spectrum beta-lactamase producers The incidence of antimicrobial resistance and ESBL-producing E. coli was phenotypically assessed by culture and antibiotic susceptibility testing of the isolates. The ESBL-producing E. coli was determined by double-disc synergy tests using amoxicillin-clavulanate, cefotaxime, ceftazidime, ceftriaxone, and cefoxitin (Amare et al., 2022). Colistin susceptibility testing Colistin resistance was phenotypically assessed using the agar diffusion method, with 4 mg/dL of colistin incorporated into the culture medium (Tartor et al., 2021). RESULTS Antimicrobial susceptibility profile of Escherichia coli isolates A total of 32 commonly used antibiotics from 12 categories, including penicillin, cephalosporins, carbapenems, monobactams, aminoglycosides, tetracyclines, fluoroquinolones, glycopeptides, phenicols, sulfonamides, nitrofurantoin, and rifampicin, were used to evaluate the susceptibility of the isolates. The overall isolated E. coli susceptibility profiles are shown in Table 3. All E. coli isolates showed complete resistance (100%) to penicillin and cloxacillin. A high resistance rate was also observed for neomycin (93.4%), followed by rifampicin (86.9%) and methicillin (75%). In contrast, all isolates were fully susceptible to chloramphenicol. The lowest resistance was noted against carbapenems, imipenem, meropenem, and ertapenem, with a combined resistance rate of only 3.2%. Among the tested cephalosporins, cefepime was the most effective, exhibiting a resistance rate of just 1.08%. Additionally, low resistance was observed against the piperacillin/tazobactam combination (3.2%) and cefoxitin (4.3%). Resistance to nitrofurantoin, levofloxacin, ticarcillin/clavulanate, and kanamycin was similarly low, each at 5.4% (Figures 1, 2, and 3). Multiple antibiotic resistance index and antibiotic resistance index All tested isolates exhibited resistance to the antibiotics administered. Table 4 displays the MAR index values. The MAR index for E. coli isolates ranged from 0.09 to 0.6. The minimum MAR index value for E. coli was 0.09, corresponding to three antimicrobial agents. Conversely, the maximum MAR index value of 0.6 was associated with twenty antimicrobial agents. The calculated ARI values are provided in Table 3. World Vet. J., 15(3): 597-611, 2025 601 Multidrug resistance patterns of Escherichia coli The prevalence of MDR bacteria was high based on the antibiotic classification. In the present study, all E. coli isolates were resistant to three or more antibiotic categories. For instance, E. coli isolate number E315 derived from raw milk was resistant to three categories (Figure 4). The current results indicated that E260 isolated from lben (fermented milk) and E52 isolated from chicken meat were resistant to nine antibiotic categories (Figures 5 and 6). However, XDR and PDR were not detected in E. coli isolates. Phenotypic detection of extended-spectrum beta-lactamase production in Escherichia coli Among the 92 isolates, 43 were phenotypically confirmed to be positive for ESBL. Among all types of food, 17 isolates were detected in raw milk, 10 were isolated from lben, and nine isolates were from dairy products. A total of 7 isolates were detected from meat and its products. All phenotypically ESBL-positive isolates are listed in Table 5. Colistin-resistant isolates A total of 83 E. coli were identified as phenotypically colistin-resistant isolates using the agar diffusion method. Table 3. Antibiotic susceptibility profile and antibiotic resistance index of Escherichia coli isolates in Libya during 2024 Antibiotic Susceptible (n)% Intermediate (n)% Resistant (n)% ARI Imipenem 10 µg (63) 68.5 (26)28.2 (3) 3.2 0.0010 Meropenem 10 µg (71) 77.2 (18)19.5 (3) 3.2 0.0010 Ertapenem 10 µg (67) 72.8 (22)23.9 (3) 3.2 0.0010 Cefepime 30 µg (64) 69.5 (27) 29.3 (1)1.08 0.0003 Cefoperazone 75 µg (66) 71.7 (12) 13 (14) 15.2 0.0047 Cefotaxime 30 µg (25) 27.1 (24) 26 (43) 46.7 0.0146 Ceftriaxone 30 µg (49) 53.2 (29) 31 (14) 15.2 0.0047 Cefoxitin 30 µg (76) 82.6 (12) 13 (4) 4.3 0.0013 Amoxicillin 30 µg (41) 44.5 (32) 34.7 (19) 20.6 0.0064 Ampicillin 30 µg (17) 18.4 (51) 55.4 (24) 26 0.0081 Amoxicillin Clavunate20/10 µg (39) 42.3 (41) 44.5 (12) 13 0.0040 Ticarcillin + Clavunate75/10 µg (58) 63 (29) 31 (5) 5.4 0.0016 Penicillin 10 µg (0) 0 (0) 0 (92) 100 0.0312 Cloxacillin 5 µg (0) 0 (0) 0 (92) 100 0.0312 Methicillin 5 µg (2) 2.1 (21) 22.8 (69) 75 0.0234 Piperacillin/Tazobactam100/10µg (51) 55.4 (38) 41.3 (3) 3.2 0.0010 Aztreonam 30 µg (64) 69.5 (10)10.8 (18) 19.5 0.0061 Neomycin 10 µg (1)1.08 (5) 5.4 (86) 93.4 0.0292 Kanamycin 30 µg (38) 41.3 (49) 53.2 (5) 5.4 0.0016 Gentamycin 10 µg (72) 78.2 (13) 14.1 (7) 7.6 0.0023 Tobramycin 10 µg (46) 50 (36) 39.1 (10) 10.8 0.0033 Streptomycin 10 µg (36) 39.1 (45) 48.9 (11) 11.9 0.0037 Levofloxacin 5 µg (83) 90.2 (4) 4.3 (5) 5.4 0.0016 Ciprofloxacin 5 µg (70) 76 (12) 13 (10) 10.8 0.0033 Oxytetracycline 30 µg (1)1.08 (62) 67.3 (29) 31.5 0.0089 Tetracycline 30 µg (74) 80 (1) 1.08 (17) 18.4 0.0057 Doxycycline 30 µg (63) 68.4 (21) 22.8 (8) 8.6 0.0027 Sulphamethoxazole/Trimethoprim 25 µg (80) 86.9 (1) 1.08 (11) 11.9 0.0037 Chloramphenicol 30 µg (89) 96 (3) 3.2 0 0 Nitrofurantoin 300 µg (73) 79.3 (14) 15.2 (5) 5.4 0.0016 Rifampicin 5 µg (9) 9.7 (3) 3.2 (80) 86.9 0.0271 Polymixin 300units (6) 6.5 (23) 25 (63) 68.4 0.0213 Colistin (9) 9.7 0 (83) 90 0.0281 ARI: Antibiotic resistance index. Sherif et al., 2025 602 Table 4. Multiple antibiotic-resistant index of E. coli isolates in Libya during 2024 Antibiotics Resistant isolates MARI 20 1 0.6 16 2 0.5 15 1 0.4 14 5 0.4 12 3 0.3 11 4 0.3 10 5 0.3 9 7 0.2 8 17 0.2 7 15 0.2 6 16 0.1 5 4 0.1 4 2 0.1 3 4 0.09 MAR: Multiple antibiotic-resistant index Table 5. Extended-spectrum beta-lactamase-positive isolates ESBL-positive E. coli isolates Sources of isolates E49 Minced meat E55 Beef kebab E56 Beef burger E57 Chicken burger E59 Goats milk E61 Maasorra E63 Cow’s milk E65 Lben E66 Lben E67 Lben E75 Beef burger E166 Cow’s milk E168 Cow’s milk E169 Cow’s milk E170 Cow’s milk E171 Cow’s milk E173 Lben E174 Maasorra E180 Lben E182 Lben E188 Cow’s milk E189 Cow’s milk E194 Cow’s milk E195 Cow’s milk E199 Ricotta E202 Cow’s milk E203 Cow’s milk E204 Butter E209 Lben E213 Lben E221 Chicken meat E222 Chicken meat E223 Milk powder E228 Cow’s milk E238 Ricotta E250 Camels’ milk E252 Cow’s milk E253 Cow’s milk E260 Lben E299 Maasorra E317 Lben E321 Ricotta E323 Milk powder ESBL: Extended-spectrum beta-lactamase. World Vet. J., 15(3): 597-611, 2025 603 Figure 1. Antimicrobial resistance profiles of Escherichia coli isolates against 32 antimicrobial agents in Libya during 2024 Figure 2. Antimicrobial resistance profiles of all Escherichia coli isolates against cephalosporins in Libya during 2024 Figure 3. Antimicrobial resistance profiles of all Escherichia coli isolates against aminoglycosides in Libya during 2024 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Antibiotic susceptibility profile of E. coli Resistant Intermediate Susceptible Sherif et al., 2025 604 Figure 4. Antimicrobial resistance profiles of Escherichia coli isolated from raw milk in Libya during 2024 Figure 5. Antimicrobial resistance profiles of Escherichia coli isolated from Lben (fermented milk) in Libya during 2024 Figure 6. Antimicrobial resistance profiles of Escherichia coli isolated from chicken meat in Libya during 2024 World Vet. J., 15(3): 597-611, 2025 605 Figure 7. Antimicrobial resistance profiles of Escherichia coli isolated from processed meat in Libya during 2024 Figure 8. Antimicrobial resistance profiles of Escherichia coli isolated from dairy products in Libya during 2024 DISCUSSION The isolation, antibiotic susceptibility, and molecular sequencing of foodborne bacteria such as E. coli from milk, meat, and their products have been the subject of several studies worldwide. Microbes are becoming an increasingly serious problem, and understanding their transmission, resistance mechanisms, and genetic relationships requires a holistic approach to public health. However, there has been a dearth of studies into the prevalence of E. coli-resistant strains in animal-origin foods such as milk and meat in Libya. Thus, the present study investigated the incidence of E. coli in milk, meat, and their associated products, in addition to examining their antibiotic susceptibility. It should be mentioned that this investigation is part of a series of studies carried out in Libya (Garbaj et al., 2016, 2017; Naas et al., 2017, 2019; Azwai et al., 2016, 2024) on locally isolated microorganisms, probably for the first time, aiming to establish the Libyan Integrated Program for Antimicrobial Resistance Surveillance. The association of E. coli contamination between milk, meat, and their products is primarily due to shared sources and similar handling practices throughout the food production chain (Oliver et al., 2005). Since E. coli is a common inhabitant of the intestinal tract of animals, contamination can easily occur during milking or slaughter if fecal matter comes into contact with the product (Callaway et al., 2003). Cross-contamination is also common during processing, especially when hygiene practices are poor or equipment is shared between raw products. Environmental factors such as contaminated water, feed, or farm surroundings, along with inadequate refrigeration and storage, can further promote bacterial growth and spread (Wang et al., 2017). In many cases, small-scale or backyard farming systems where animals