The emergence and spread of multidrug resistant Escherichia coli (MDR- E. coli) among food producing animals is a challenging public health concern, globally. E. coli is an opportunist pathogen having zoonotic potential that causes several infections among animals and humans. Currently, there is limited data about the distribution of antibiotics resistance genes in E. coli sequence types from commercial broilers. Hence, in this study, cloacal swab samples (n=200) were collected for the isolation and molecular identification of E. coli based on uidA gene and multi-locus sequence type analysis followed by determination of antimicrobial resistance (colistin, gentamicin, streptomycin, tetracycline & quinolones) along with identification of antimicrobial resistance genes (ARGs) using specific primers. A total of 153/200 (76.5%) E. coli were identified and resistance was observed among 49, 54, 62, 77 and 24% of the E. coli isolates against colistin, gentamicin, streptomycin, tetracycline and ciprofloxacin, respectively. Minimum inhibitory concentration data showed 49, 54, 50 and 23% of E. coli isolates were resistant to colistin, gentamicin, tetracycline and ciprofloxacin, respectively. Further, ARGs data showed detection of aac(3)-IV, aadA1, mcr-1, tetA and qnrA as 47, 56, 43, 61 and 12% of the isolates, respectively. Virulence genes amplification data showed that one isolate encodes maximum virulence genes i.e. adhesins (fimH, papC, and papG), tissue invasion (hlyA and KpsMTII) and immune evasion (traT and capU). Whereas other isolates were identified to encode few virulent genes. MLST data of E. coli harboring multiple ARGs showed the detection of ST1035, ST131, ST1650 as (mcr-1, qnrA, tetA) ST1035 (n=10), (qnrA, aadA1, tetA) ST1035 (n=3), (qnrA, aac(3)-IV, aadA1) ST131 (n=7) and (aac(3)-IV, tetA) ST1650 (n=3). Altogether, it was concluded that ST131 and ST1035 were predominant MDR- E. coli strains (harboring qnrA gene) isolated from commercial broilers which can potentially spread multidrug resistant E. coli to humans.

To Cite This Article: Madni WA, Zahoor MA, Nawaz Z and Khurshid M, 2025. Prevalence and Sequence Analysis of Escherichia Coli Harboring Colistin, Gentamicin, Streptomycin, Tetracycline and Quinolones Resistant Genes from Commercial Broilers. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.010