ANTIBIOTIC PROPHYLAXIS AND CLOACAL CARRIAGE OF RESISTANT ZOONOTIC BACTERIA IN COMMERCIALLY-BRED POULTRY

Abstract

Purpose: The aim of this study was to determine the relationship between the use of antibiotic prophylactics in commercial poultry breeding and cloacal carriage of antibiotic-resistant zoonotic bacteria.

Methodology: Biodata was collected on poultry from 11 selected farms.  Cloacal swabs were collected from 10 birds from each farm for culture, isolation and biochemical identification of bacteria isolates. Antibiotic susceptibility of 96 Enterobacteriaceae and 24 Staphylococcus aureus isolates were determined by disk diffusion.

Findings: Antibiotics prophylaxis administered to the birds were chloramphenicol (40/110), penicillin (20/110), doxycycline (20/110), gentamicin (10/110), neomycin (10/100) and a combination of chloramphenicol, ampicillin, penicillin and cloxacillin (10/100).  These were administered either weekly (90/110), every 3 days (10/110) or monthly (10/100). Two hundred and fifty six (256) different bacteria isolates were recovered. These were Escherichia coli (31.6%), Staphylococcus aureus (14.5%), Staphylococcus epidermidis (12.1%), Proteus sp. (12.1%), Citrobacter sp. (9%), Proteus vulgaris (5.1%), Salmonella enterica (4.7%), Citrobacter koseri (4.3%), Klebsiella sp. (2.8%), Klebsiella pneumoniae (2.3%), Shigella sp. (2.3%), Enterobacter sp. (0.8%) and Klebsiella oxytoca (0.4%). Of 96 Enterobacteriaceae, 60 (63%) were multidrug resistant. Enterobacteriaceae were resistant to ampicillin (54%), tetracycline (52%), cotrimoxazole (54%), gentamicin (22%), cefuroxime (44%), vancomycin (19%), chloramphenicol (39%), ceftriaxone (29%), cefotaxime (71%), ciprofloxacicn (21%), amikacin (10%) and meropenem (23%). Of 24 Staphylococcus aureus, 17 (71%) were multidrug resistant. Staphylococcus aureus were resistant to ampicillin (89%), cotrimoxazole (59%), gentamicin (24%), vancomycin (67%), ciprofloxacin (18%), meropenem (33%), tetracycline (85%), cloxacillin (100%), penicillin (81%), erythromycin (71%), cefuroxime (43%) and augmentin (45%). Doxycycline-prophylaxis was significantly related (0.001) to tetracycline-nonsusceptible isolates but chloramphenicol-prophylaxis and penicillin-prophylaxis were not significantly related (<0.05) to resistance to their corresponding antibiotics.

Unique contribution to theory, practice and policy: Occurrence of multidrug resistant zoonotic bacteria was high as was the frequency of administering antibiotic prophylactics. Amikacin was the most effective antibiotic against Enterobacteriaceae whereas gentamicin and ciprofloxacin were the most effective against both Enterobacteriaceae and Staphylococcus aureus. To safeguard high-priority class antibiotics regulations to adhere to the WHO statement on the use of antibiotics in animal husbandry should be enforced. Alternative measures should also be applied to reduce dependence on antibiotics in poultry farming