Quinolone Resistance in Bacterial Isolates from Chicken Carcasses in Abeokuta, Nigeria: A Retrospective Study from 2005-2011

Quinolone resistance in bacteria from food animals is now globally recognized as a serious veterinary and public health problem. To determine the rate of quinolone resistance in pathogenic bacteria isolated from samples from dead chickens submitted for microbiological examination, a six-year retrospective study (April, 2005 – March, 2011) was carried out. Data from records of bacteriological investigations at a Veterinary Teaching Hospital in Nigeria were evaluated. Two hundred bacterial isolates including Escherichia coli (95; 47.5%), Salmonella serotypes (78; 38.0%), Klebsiella (17; 8.5%) and Staphylococcus aureus (12; 6.0%) were isolated from chicken carcasses within the six-year period. On the overall, the isolates were resistant to ciprofloxacin (40.5%), enrofloxacin (21.0%), nalidixic acid (9.5%) and norfloxacin (44.0%). Overall, resistance to quinolones (except nalidixic acid) was highest in S. aureus (ciprofloxacin, 58.3%; enrofloxacin, 33.3%; and norfloxacin, 83.3%) followed by Klebsiella spp (ciprofloxacin, 41.2%; enrofloxacin, 29.4%; and norfloxacin, 64.7%), E. coli (ciprofloxacin, 40.0%; enrofloxacin, 23.2%; and norfloxacin, 41.1%) and least in Salmonella (ciprofloxacin, 38.6%; enrofloxacin,14.5%; and norfloxacin, 36.8%). However, resistance to nalidixic acid was highest in Klebsiella spp (23.5%) followed by S. aureus (16.7%), E. coli (9.5%) and least in Salmonella (5.3%). There was a general decline in quinolone resistance in the last three years (2009-2011) of this investigation. Quinolone resistance in avian pathogenic bacteria could lead to increase in economic loss from bacterial infection and refractory to treatment. Their possible transmission to humans is of public health significance.