Role of Cattle Egrets in the Dissemination of Multi-drug Resistant Escherichia coli: A One Health Perspective

Abstract

This study was carried out to establish the role of cattle egrets that feed on a nearby animal farm as a possible source of MDR bacteria. A total of 50 faecal dropping samples of cattle egret were collected from cattle farm and processed in the laboratory for isolation of E. coli.  Total 45 isolates were recovered, of which 20 were identified and characterized as E. coli morphologically and biochemically. The antibiogram profile of all E. coli isolates recovered from cattle egret revealed 100% resistance to Ampicillin, Cloxacillin and Cefotaxime. Antibiotics such as Imipenem, Gentamycin, Trimethoprim, and Triple sulphas were found highly sensitive (100%) followed by Streptomycin (90%).  The Sensitivity of Norfloxacin and Kanamycin ranged between intermediate to high degree, while Polymyxin was found sensitive for 55% isolates. Multi antimicrobial resistance index of all the isolates was found to be more than 0.27 indicating a “high risk” for the community. These, MDR positive E. coli, were further subjected to phenotypic and genotypic confirmation of ESBL producers by DDST and PCR, respectively. Out of 20, 12 isolates (60%) were confirmed as ESBL producers by DDST and PCR.  PCR analysis of ESBL positive isolates revealed the predominance of bla CTX gene. All E. coli were also evaluated for pathogenicity using in vitro tests and 50% and 40% of the isolates were found to be pathogenic on the Congo red binding and hemolysis test, respectively. In the present study, the occurrence of MDR E. coli and ESBL producers in cattle egret is a cause of concern for public health and animal health.