Prevalence and distribution of bla CTX-M, bla SHV, bla TEM genes in extended- spectrum β- lactamase- producing E. coli isolates from broiler farms in the Philippines

Background Antimicrobial resistance is a worldwide problem causing serious health threats. Escherichia coli is one of the most important bacteria that causes resistance problem. These bacteria produce an enzyme called extended-spectrum β-lactamase (ESBL) that allows it to become resistant to a wide variety of penicillins and cephalosporins. Currently, no information or published studies on ESBL-producing E.coli in broilers are available in the Philippines. This cross-sectional study was conducted to determine the prevalence and distribution of extended-spectrum β-lactamase (ESBL)-encoding genes, bla CTX-M, bla SHV, and bla TEM , among E. coli isolates from broiler farms in Luzon, Philippines. Results Results showed a farm prevalence of 66. 67%. A total of 69 (44.23%) ESBL-producing E. coli were isolated from boot swabs and cloacal swab samples from broiler farms. All major bla CTX-M groups except bla CTX-M-25 group were identified in the isolates. The most prevalent group was bla CTX-M-1, 72.46% (CI: 60.38–82.54%), followed by bla CTX-M-2, bla CTX-M-9 group and bla CTX-M-8. The bla TEM and bla SHV genes were identified in 57.97 and 27.54% of isolates, respectively. The bla CTX-M and bla TEM were the most common gene combinations (33.33%). Coexistence of bla CTX-M types was observed in 50 (73.53%) isolates. Conclusion This study shows the high prevalence, diversity of patterns and coexistence of ESBL genes in the E. coli isolates from cloacal and boot swabs from broiler farms which pose risks of possible transmission to the environment, other animals and human.