Antimicrobial Resistance Profiles ofspp. Recovered from Chicken Farms in Two Districts of Bangladesh.

Abstract

The rapid emergence of antimicrobial resistance (AMR) inhas reinforced its status as a foodborne pathogen of significant public health concern. Resistantis typically transferred to humans via the consumption of contaminated animal products, particularly poultry. The genes associated with antimicrobial resistance inspp. are poorly understood. To address this knowledge gap, we conducted a prevalence survey of AMRacross 84 chicken farms in two districts of Bangladesh. Pooled cloacal swabs were collected from chickens and underwent bacteriological testing forspp. with PCR confirmation. Antimicrobial susceptibility was tested against 14 antibiotics by disk diffusion method, and 12 resistance genes were screened in-positive isolates using multiplex PCR. A total of 34 (40.5%) farms were-positive of which 73.5% of isolates were resistant to at least 10 antibiotics. The antimicrobial susceptibility results indicate a high level of resistance against streptomycin (97.1%), clindamycin (97.1%), ampicillin (94.1%), tetracycline (94.1%), erythromycin (91.2%), ciprofloxacin (88.2%), nalidixic acid (85.3%), and imipenem (82.4%), and comparatively a low frequency of resistance to chloramphenicol (47.1%), ceftazidime (44.1%), and colistin (35.3%). Multidrug-resistant (MDR) and extensively drug-resistantwere identified in 97.1%, and 50% of isolates, respectively. Ten resistance genes were identified including(in 97.1% of isolates),-(85.9%),(70.6%),(32.4%),(23.5%),(20.6%),(20.6%),(8.8%),(5.9%), and(2.9%). Our findings demonstrate that resistance to ampicillin, tetracycline, and ceftazidime inisolates was significantly ( ≤ 0.05) associated with the presence of,, andgenes, respectively. The high rates of AMR inisolates from our study are not surprising given the liberal use of antimicrobials and incomplete biosecurity provisions on farms. Of particular concern are resistance rates to those classes of antibiotics that should be reserved for human use (azithromycin, ciprofloxacin, and colistin). AMR was more prevalent in chicken farms that used multiple antibiotics, engaged in prophylactic treatment of the birds, and improperly disposed of antibiotic packages. The high prevalence of MDR in chicken-derivedisolates from the different regions of our study reinforces the need for more prudent use of antimicrobial compounds in Bangladeshi chicken farms.