Prevalence, Antibiogram, and Resistance Profile of Extended-Spectrum ß-Lactamase-Producing Escherichia coli Isolates from Pig Farms in Luzon, Philippines.

This cross-sectional study was conducted to determine the prevalence, antibiogram, and resistance profile of extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) isolates from healthy pigs and pig farms in Luzon, Philippines. A total of 162 rectal samples from healthy finisher and breeder pigs and boot swab samples from pig houses were collected from 54 randomly selected pig farms. Bacteria were isolated and screened using MacConkey agar plate supplemented with 1 mg/L cefotaxime. Identification of bacteria and antimicrobial susceptibility test were carried out through Vitek® 2 and combined disk test. PCR amplifications were carried out in all isolates targeting blaCTX-M and its five major groupings, blaTEM, and blaSHV. The farm prevalence of ESBL-EC was 57.41% (95% confidence interval [CI] = 43.21-70.77). A total of 48 (29.63%) ESBL-EC isolates were isolated from samples that showed 14 different phenotypic multidrug resistance patterns. The prevalence of blaCTX-M gene was 91.67% (95% CI = 80.02-97.68). All major blaCTX-M-groups except blaCTX-M-25group were detected. The blaCTX-M-1 was the most prevalent blaCTX-M gene, 75.0% (95% CI = 60.40-86.36). The prevalence of blaTEM and blaSHV genes was 91.67% (95% CI = 80.02-97.68) and 60.42% (95% CI = 45.27-74.23), respectively. Coexistence of different blaCTX-M, blaTEM, and blaSHV genes was observed in 44 isolates with 20 different genotypic patterns. High prevalence, diverse antibiogram profile, and genotypic resistance pattern of ESBL-EC isolates from healthy pigs and pig farms were observed in this study that could result in possible transmission to farm workers, susceptible bacteria, and the environment.

Prevalence and distribution of blaCTX-M, blaSHV, blaTEM genes in extended- spectrum ß- 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 ß-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 ß-lactamase (ESBL)-encoding genes, blaCTX-M, blaSHV, and blaTEM, 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 blaCTX-M groups except blaCTX-M-25 group were identified in the isolates. The most prevalent group was blaCTX-M-1, 72.46% (CI: 60.38-82.54%), followed by blaCTX-M-2, blaCTX-M-9 group and blaCTX-M-8. The blaTEM and blaSHV genes were identified in 57.97 and 27.54% of isolates, respectively. The blaCTX-M and blaTEM were the most common gene combinations (33.33%). Coexistence of blaCTX-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.