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Authors: Sultana, Nasreen
Keywords: Chicken farm, Antimicrobial resistance, E. coli, Broth micro-dilution method, Risk factors.
Issue Date: Jun-2022
Publisher: Chattogram Veterinary and Animal Sciences University Khulshi, Chattogram-4225, Bangladesh
Abstract: Antimicrobial resistance (AMR) is a major health problem, particularly in developing countries like Bangladesh, where there is a paucity of information on the status of AMR at different levels and the associated potential factors. The emergence and spread of multi-resistance to several first-line antimicrobial drugs has made the health management more difficult. The main threat to the poultry industry is AMR and the growth of multidrug resistant bacteria, which endangers food safety. Risk factors associated with the occurrence of AMR in E. coli in poultry included the excessive use of antimicrobials, insufficient farm density, poor hygiene standards, and contamination of feeds and eggs, which favors the selection of antimicrobial resistant E. coli. There were available studies on the prevalence of AMR in E. coli at an individual level (i.e., isolate level) isolated from commercial chicken farms in Bangladesh. But, farm level AMR prevalence and associated risk factors were not identified in any previous study in commercial chicken farms in Bangladesh. Hence, the present study attempted to fill these scientific gaps. A total of 152 E. coli isolates obtained from swab pool samples (cloacal and environmental swabs) of the studied farms (83 broiler and 57 layer farms) through a cross-sectional study conducted in Chattogram between February and July 2019 were evaluated at the UK AMR reference Lab. Broth micro-dilution assay was used to determine the susceptibility of the isolates to a panel of 14 antimicrobials. Farm and farmers’ demography and farm bio-security data obtained were used to assess the AMR status with their association at farm level. Descriptive analysis was performed to calculate the prevalence of AMR in E. coli in chickens at farm and individual isolate level. Logistic regression was conducted to determine potential risk factors associated with the occurrence AMR in E. coli in chickens at farm level (min/6 antimicrobials per farm vs.7/max antimicrobials per farm) in Chattogram, Bangladesh. Overall farm AMR prevalence was respectively 75% (42.1% in broiler and 32.9% at layer farms. Overall isolate (individual) AMR prevalence was 100% (51.3% from broiler and 48.7% from layer farms. Regardless of production type, multidrug resistant in E. coli (3-11 antimicrobials per farm) were identified, as well as farm size was found to have a significant relationship with the x increase level of resistance occurrence. In this study, E. coli isolates were more frequently resistant to ciprofloxacin and tetracycline (98.7% in broiler and 97.3% and 100% in layer, respectively), trimethoprim (92.3% and 81.1%), ampicillin (91% and 79.7%) and nalidixic acid (83.3% and 66.2%), whereas colistin (25.6% and 13.5%), cefotaxime (3.9% and 8.1%) and ceftazidime (3.9% and 8.1%) were less frequently resistant antimicrobials. The findings of high level of AMR prevalence emphasized the development of guidelines for curbing AMR challenge through prudent use of critically important antimicrobials (CIAs) to human, which were revealed as sensitive and stopped the use of highly resistant antimicrobials in commercial chicken. Enhanced veterinarian supervision, strong monitoring systems, farm bio-security management, and increased diagnostic facilities could mitigate the burden of AMR in farms while also reducing public health risk.
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