Antimicrobial drug resistance among Enterococci from broilers and poultry abattoir workers

Abstract

Poultry abattoir workers who carry out eviscerate do pick up resistance from broiler enteric organisms. To test this hypothesis, the prevalence of and the association of antimicrobial drug resistance between enterococci from broilers and workers who carry out evisceration, washing and packing of broiler intestines were investigated. Broiler caecae (n = 240) from 6 farms were collected after slaughter. Caecal content as well as faeces from 29 abattoir workers and 28 human controls were selectively cultured for E. faecium and E. faecalis. The micro-dilution broth method was used to determine MICs for selected antimicrobials. Broilers carried higher levels of resistance for certain antimicrobials compared to the two human groups. Percent resistance and MIC90 for enrofloxacin and bacitracin and MIC50 for doxycycline showed that abattoir workers carried higher levels of resistance compared to the control group for antimicrobials used in poultry production. Resistance levels in the isolates from broilers and abattoir workers exhibited an association for certain drugs. Overall, the level of resistance in the two human populations did not exhibit a significant difference (p>0.05). Usage of antimicrobials as feed additives fuels resistance among broiler isolates. Abattoir workers are more likely to carry higher levels of resistance than the general public. However, this study did not demonstrate that carrying out evisceration, washing and packing of intestines of broilers fed antimicrobial feed additives significantly influences the level of resistance in abattoir workers.