Abstract
Background and Aim: The extended-spectrum beta-lactamases (ESBLs), as well as carbapenemases, are considered as the foremost resistance determinants throughout the world. However, the relevant data especially related to the sequence types of ESBL and carbapenemases producing Escherichia coli from the poultry is limited from Pakistan. Here, we present the data on the genetic diversity of E. coli strains isolated from the poultry birds from the poultry farms located in Islamabad, Pakistan, and the underlying resistance mechanisms to beta-lactam agents.
Methods: Of 250 broilers from 25 different farms (10 birds from each farm), the cecal samples were obtained and analyzed for the presence of ESBLs producing E. coli (ESBL-Ec) as well as carbapenemases producing E. coli (CPEc) strains using selective agar for ESBL and carbapenemases screening. The susceptibility profiling of the ESBL-Ec and CPEc isolates was evaluated followed by multi-locus sequence typing.
Results: A total of 119 strains were positive for ESBL production whereas 37 strains were found positive to produce carbapenemases in addition to ESBLs. The MLST analysis has shown a diversity of isolates as the E. coli isolates from poultry birds correspond to a total of 16 sequence types (STs). The ST131 (22/48, 46%) followed by ST8051 (10/48, 21%) were the main STs in this study. The bla(CTX-M) gene was detected in all the poultry E. coli strains whereas the bla(TEM) was found in 45.5% of strains. The bla(VIM) was found in all 37 CPEc isolates whereas the bla(NDM) and bla(IMP) were found in 31/37 (83.8%) and 16/37 (43.2%) CPEc isolates respectively.
Conclusion: The overall results have shown the prevalence of diverse genotypes among the ESBL-Ec and carbapenemase-producing E. coli (CPEC) from poultry. Furthermore, the study documents poultry birds as a persisting reservoir of extensively antimicrobial-resistant E. coli ST131 in Pakistan, suggesting a potential threat to public health.