Prevalence of antibiotic resistance in Campylobacter isolates from commercial poultry suppliers in KwaZulu-Natal, South Africa.

OBJECTIVES Campylobacter jejuni isolated from broiler and layer chickens from registered abattoirs in KwaZulu-Natal, South Africa, were tested for their susceptibility to eight antibiotics. METHODS Using agar dilution, susceptibility to eight antibiotics was determined for C. jejuni recovered from the caeca. RESULTS A total of 155 isolates were collected of which 77 were identified as C. jejuni (broilers n = 56 and layers n = 21). Resistance was highest to tetracycline (broilers 98.2% and layers 100%) and ceftriaxone (broilers 96.4% and layers 100%). High susceptibility was found to ciprofloxacin (broilers 91% and layers 76%) and gentamicin (broilers 98% and layers 81%). Susceptibilities to each of the antibiotics for the broilers and layers, respectively, were: 50% and 57% for erythromycin, 45% and 24% for clarithromycin, 68% and 43% for ampicillin and 64% and 48% for nalidixic acid. Statistically significant differences were detected for the MIC(50) of gentamicin, ciprofloxacin and tetracycline between broilers and layers (P < 0.001) with the MIC(90) of gentamicin also of significant difference (P = 0.01). Multiresistance was detected in 23% and 43% of the isolates from broiler and layer chickens, respectively. CONCLUSIONS Mass therapy procedures used in animal husbandry have a potential impact on antibiotic resistance development in C. jejuni.