Antibiotic Sensitivity and Antibiotic Resistance Genes in Extended Spectrum Beta Lactamases (ESBL) Producing Strains of Escherichia coli Recovered from Small Ruminants

Abstract

This study was conducted at Animal Health Program of National Agricultural Research Center Islamabad (NARC), and Zoology Department of Quaid-i-Azam University, Islamabad. The aim of the study was to find out prevalence of ESBL producing E.coli among the ESBL screened E. coli isolates recovered from small ruminants. The study was also performed to know their antibiotic susceptibility pattern and to detect bla genes in these ESBL producing E.coli isolates. A total of 112 samples of E.coli isolated from Pakistani sheep and goats were processed for the confirmation of E.coli and ESBL producing E.coli isolates. Out of these 112 samples, 84 were found to be positive for E.coli and 39 (46.4%) were confirmed to be ESBL E.coli by colonial morphology on specific media, biochemical and phenotypic testing as well as through the bla genes PCR. The 39 confirmed ESBL E.coli isolates were subjected to antibiotic sensitivity testing. Highest resistance (100%) against Penicillin and Lincosamides, (90%) against Cefixime and Cefotaxime while relatively low insensitivity was observed against Flouroquinolones (69%) and Tetracycline (54%) in the ESBL E.coli isolates. The most efficacious drugs were found to be Aminoglycosides and Ceftazidime against which 77% and 64% of the isolates were noted to be sensitive respectively. Results of PCRs for bla antibiotic resistance genes revealed that TEM gene was highly prevalent and found in 37 out of a total of 39 ESBL E.coli (94.8%). Bla CTX-M was present in 84.6% of the isolates, however, the blaSHV gene was not found in any of the isolated ESBL E.coli. A prevalence of 46.4% of ESBL producing E.coli in small ruminants depicts an alarming situation both for the livestock as well as public health perspectives.