Risk of multi-drug resistant Campylobacter spp. and residual antimicrobials at poultry farms and live bird markets in Bangladesh

Background: This study systematically examined potential risks and associated socio-environmental factors of MDR Campylobacter spp. in poultry farms and live bird markets (LBMs) of Bangladesh.

Methods: Microbial culture and PCR-based methods were applied to examine the occurrence and MDR patterns of Campylobacter spp. at hatcheries (n = 33), broiler farms (n = 122) and LBMs (n = 69). Antimicrobial residues in broiler meat and liver samples (n = 50) were detected by advanced chromatographic techniques. A questionnaire based cross-sectional survey was conducted on socio-environmental factors.

Results: In poultry farms, Campylobacter spp. was primarily found in cloacal swab (21/49, 43%), followed by drinking water (8/24, 33%), and meat (8/28, 29%) samples of broilers. Remarkably, in live bird markets, Campylobacter spp. was detected in higher prevalence in broiler meat (14/26, 54%), which could have an association with bacterial contamination in drinking water sources (11/21, 52%) and floor (9/21, 43%). Representative isolates (n = 71) were differentiated into two species: Campylobacter jejuni (66%) and Campylobacter coli (34%). Majority of C. jejuni (33/47, 70%) and C. coli (14/24, 58%) strains were observed to be MDR, predominantly showing resistance to amoxycilin, tetracycline and erythromycin, and additionally to ciprofloxacin, norfloxacin, streptomycin, and azithromycin. Residual antimicrobials, including oxytetracycline, ciprofloxacin and enrofloxacin, were detected in majority of broiler liver (79%) and meat (62%) samples. Alarmingly, 33% and 19% of the liver and meat samples, respectively, contained residual antimicrobial concentration above acceptable limit. Inadequate personal and environmental hygiene, unscrupulously use of antimicrobials, improper waste disposal, and lack of health surveillance and quarantine facilities of diseased birds were distinguishable anthropogenic risk factors, with local diversity and compound influences on MDR pathogens.

Conclusion: The observed large-scale occurrence of MDR C. jejuni and C. coli and residual antimicrobials in poultry value chain reflects an alarming situation for public health in Bangladesh. Potential contamination sources of MDR Campylobacter and the combined influences of diverse socio-environmental risk factors, noted in this study, would aid in developing interventions to minimize the increasing risks of poultry-associated MDR pathogens under 'One Health' banner that includes poultry, human and environment perspectives.