Antimicrobials serve as crucial treatments in both veterinary and human medicine, aiding in the control and prevention of infectious diseases. However, their misuse or overuse has led to the emergence of antimicrobial resistance, posing a significant threat to public health. This review focuses on extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in animals and their associated food products, which contribute to the proliferation of antimicrobial-resistant strains. Recent research has highlighted the presence of ESBL-producing E. coli in animals and animal-derived foods, with some studies indicating genetic similarities between these isolates and those found in human infections. This underscores the urgent need to address antimicrobial resistance as a pressing public health issue. More comprehensive studies are required to understand the evolving landscape of ESBLs and to develop strategic public health policies grounded in the One Health approach, aiming to control and mitigate their prevalence effectively.

Escherichia coli is part of the normal microflora of the intestines of mammals. However, among the enteric pathogens, it is one of the leading causes of intestinal diseases, especially Shiga toxigenic E. coli, which can cause diarrhoea, haemorrhagic colitis and complications like haemolytic uraemic syndrome and thrombotic thrombocytopaenic purpura. Escherichia coli is considered a serious public health problem. Water and fish samples were subjected to biochemical tests to confirm the presence of E. coli and by PCR to verify the presence of pathogenic strains (O157, enteropathogenic and shiga toxigenic) in water and fish (skin, gastrointestinal tract and muscles) from pay‐to‐fish ponds located in the Córrego Rico watershed in the northeastern region of the state of São Paulo, Brazil. Of the 115 E. coli isolates from fish or water, five (4·34%) contained eae and stx2 genes, one had only the eae gene and two had the stx1 gene. An isolate containing the stx2 gene was also found in the water sample. In addition, eight isolates (6·95%) from the fish gastrointestinal tract contained rfbEO157:H7 (O157 gene), and three (2·61%) contained stx2 and eae genes, demonstrating the potential risk to the environment and public health. The results provide useful basic information for the proper management of these environments and animals in order to prevent faecal pollution, reducing health risks to the Brazilian population. Significance and Impact of the Study Pay‐to‐fish ponds are a common commercial activity in Brazil. Samples of water and Oreochromis niloticus were examined by PCR to detect the presence of pathogenic strains of Escherichia coli (O157, enteropathogenic and shiga toxigenic). Several pathogenic strains were detected in this study, providing useful epidemiological information for the proper management of these environments and animals in order to prevent faecal pollution, reducing health risks to the Brazilian population.

This study focused on detecting diarrheagenic Escherichia coli, enteropathogenic E. coli (EPEC), Shiga-toxin-producing E. coli (STEC), enterohemorrhagic E. coli (EHEC or STEC:EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) in raw milk, water, and cattle feces sampled from non-technified dairy farms located in the northeastern São Paulo State, Brazil. Thirty-six water samples were collected at different points, namely, water wells (8 samples), water intended for human consumption (8 samples), water from milking parlor (8 samples), and water intended for animal consumption (7 samples), headwaters (1 sample), rivers (3 samples), and reservoirs (1 sample). Three raw milk samples were taken directly from bulk tanks in each farm, totalizing 24 samples. Feces samples were collected using rectal swabs from 160 bovines (20 animals per farm). E. coli was detected in 128 feces samples (80%), 16 raw milk samples (66.67%), and 20 water samples (55.56%). STEC (26 samples, 16.25%), EPEC (10 samples, 6.25%), STEC: EPEC (5 samples, 3.13%), and STEC: ETEC (1 sample, 0.63%) were the most prevalent strains detected in samples from cattle feces. EPEC, STEC, and STEC: EPEC strains were detected in 4.17% (1 sample), 16.67% (4 samples), and 4.17% (1 sample) of raw milk samples, respectively. STEC strains were detected in water used in the milking parlor, while no EAEC strain was detected. As a conclusion, cattle feces are important contamination sources of pathogenic E. coli in non-technified dairy farms and, consequently, cross-contamination among feces, water, and/or raw milk can occur. The use of quality water and hygienic practices during milking are recommended to avoid contamination since pathogens can be transmitted to humans via raw milk or raw milk cheese ingestion.

This study aimed to identify contamination sources in raw milk and cheese on small farms in Brazil by isolating Escherichia coli at various stages of milk production and cheese manufacturing. The study targeted EAEC, EIEC, ETEC, EPEC, STEC, and ExPEC pathotypes, characterizing isolates for the presence of virulence genes, phylogroups, antimicrobial susceptibility, and phylogenetic relationships using PFGE and MLST. The presence of antimicrobial resistance genes and serogroups was also determined. Three categories of E. coli were identified: pathogenic, commensal, and ceftriaxone-resistant (ESBL) strains. Pathogenic EPEC, STEC, and ExPEC isolates were detected in milk and cheese samples. Most isolates belonged to phylogroups A and B1 and were resistant to antimicrobials such as nalidixic acid, ampicillin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. Genetic analysis revealed that E. coli with identical virulence genes were present at different stages within the same farm. The most frequently identified serogroup was O18, and MLST identified ST131 associated with pathogenic isolates. The study concluded that E. coli was present at multiple points in milk collection and cheese production, with significant phylogroups and high antimicrobial resistance. These findings highlight the public health risk posed by contamination in raw milk and fresh cheese, emphasizing the need to adopt hygienic practices to control these microorganisms.

Methicillin-resistant Staphylococcus spp. (MRS) have been identified in several foods, including dairy products. Studies are needed about their occurrence and genetic diversity in the dairy production chain in order to gain a better understanding of their epidemiology and control. This study therefore focuses on isolating and characterizing MRS strains detected in milk used in the production of Brazilian artisanal unpasteurized cheeses. To this end, samples were collected from bovine feces, the hands of milkmen, milking buckets, sieves, unpasteurized milk, whey, water, artisanal unpasteurized cheeses, cheese processing surfaces, cheese handlers, cheese trays, cheese molds, and skimmers at five dairy farms located in the state of São Paulo, Brazil. Colonies suggestive of Staphylococcus spp. were subjected to multiplex PCR to confirm the presence of Staphylococcus aureus and to detect the mecA gene. Sixteen isolates containing mecA gene were detected in samples from unpasteurized cheese and from cheese handlers. None of these isolates were positive to enterotoxin genes. These 16 isolates were subjected to antimicrobial susceptibility tests, which revealed they were resistant to oxacillin, penicillin, and cefepime. Using gene sequencing, the MRS isolates were identified as S. haemolyticus, S. hominis, and S. epidermidis. Furthermore, isolates from cheese handlers’ hands and artisanal unpasteurized cheese presented high genetic similarity by random amplified polymorphic DNA (RAPD-PCR) analysis, which indicates cross contamination during cheese production. Thus, we found that people directly involved in milking and cheese processing activities at small dairy farms are a potential source of contamination of MRS strains in unpasteurized milk and cheese, representing a risk to public health.

Foodborne diseases pose a major threat to global public health and contribute substantially to economic losses, increased healthcare expenses, negative effects on child development, reduced productivity, and losses in international trade