Epidemiology and antimicrobial resistance of Escherichia coli in broiler chickens, farmworkers, and farm sewage in Bangladesh

Abstract

Background: Antimicrobial resistance (AMR) has become an emerging threat worldwide, and developing countries such as Bangladesh are considered to be at greater risk of disseminating the resistant bacteria between human-animal interfaces.

Objectives: The present study was carried out to determine the prevalence and AMR profile of Escherichia coli isolated from broiler chickens, the environment, and farmworkers. This study also aimed to identify the risk factors associated with multidrug-resistant (MDR) E. coli infection in broiler chickens. In addition, the presence of carbapenem resistance gene (NDM-1) was assessed.

Methods: A total of 114 E. coli isolates, recovered from 150 samples (cloacal swabs = 50, farm sewage = 50, and hand washed water of farmworkers = 50) collected from 50 broiler farms, were identified by biochemical examination and polymerase chain reaction (PCR) assay. Antimicrobial susceptibility test was performed for 10 antibiotics by disk diffusion test. Carbapenem resistance gene (NDM-1) was detected by PCR. Risk factors were identified through multivariable logistic regression.

Results: The highest prevalence of E. coli was recorded in broiler chickens (86%) and the lowest in farmworkers (66%). For MDR E. coli infection, 'winter season', 'absence of specific shoes for staff', and 'use of antibiotics without veterinarian's prescription' were the significant risk factors. High resistance of the E. coli isolates was observed against levofloxacin (81.6%), doxycycline (78.1%), cefotaxime (78.1%), and ciprofloxacin (70.2%). About 76% of the isolates demonstrated MDR. None of the isolates were positive for the NDM-1 gene.

Conclusions: The high level and similar pattern of antibiotic resistance in E. coli isolates from broiler chickens, farmworkers, and sewage in poultry farms indicates a good possibility of spreading the antibiotic-resistant E. coli in such settings.

Keywords: Bangladesh; E. coli; antimicrobial resistance; broiler chickens; multidrug resistance.