ANTIBIOTIC RESIDUES AND PREVALENCE OF RESISTANT SALMONELLA SPECIES IN BEEF OBTAINED FROM WA ABATTOIR

Abstract

Beef contamination with Salmonella and their resistance to antibiotics is a concern and a threat to the public health. This study determined the knowledge of ruminant farmers and veterinary officers in antibiotic usage, and the presence of antibiotic residues in beef samples in the Wa Municipality of Ghana. The microbiological quality and prevalence of resistant Salmonella spp. in the beef samples were also determined. Two hundred and fifty ruminant farmers and six veterinary officers were interviewed on their knowledge and usage of antibiotics administration in ruminant production using semi structured questionnaire. Snowball sampling was used to select the farmers for this research. Forty-eight meat samples from sixteen cattle were tested for antibiotic residues using Premi®Test Kit by following the manufacturer’s instructions. One hundred and fifty beef swab samples, taken from Wa abattoir were examined for the prevalence of Salmonella spp. Isolation of Salmonella, and enumeration of coliforms and total aerobic bacteria were done according to the procedures in the USA-FDA Bacteriological Analytical Manual. Antibiotic susceptibility test was performed using the disc diffusion method and the results interpreted using the CLSI guidelines. The commonly used antibiotics were ciprofloxacin (32%), amoxicillin/clavulanic (27%), trimethoprim/ sulfamethoxazole (17.1%), azithromycin (5.4%), gentamicin (1.8%), ceftriaxone (0.9%), tetracycline (0.9%) and chloramphenicol (0.9%). Majority (63.6%) of the farmers had some knowledge on the antibiotics administered to their animals. They acquired the knowledge from veterinary officers (51%), colleague farmers (29%) and extension officers (20%). Majority (51%) also relied on veterinary officers to administer drugs to their animals. Out of the 48 meat samples examined, 14 (29.17%) were positive for antibiotic residues. The prevalence of antibiotic residues in the kidney, liver and muscles were 43.75%, 37.50% and 6.25%, respectively. And of 150 beef swab samples examined, 36 (24%) were positive for Salmonella spp. Total aerobic count was 3.57 logcfu/cm2, 3.39logcfu/cm2 and 3.23 logcfu/cm2 for muscle, liver and kidney, respectively. Forty-two (42) Salmonella isolates were tested against 9 different antibiotics. The results revealed a high resistance to teicoplanin (97.62%). Resistant to azithromycin was 30.95%. The Salmonella isolates were highly susceptible to chloramphenicol (100%), ciprofloxacin (100%), suphamethoxazole/trimethoprim (100%), tetracycline (100%), ceftriaxone (95.24%), amoxycillin/clavulanic acid (90.48%) and gentamicin (78.57%). Out of 42 Salmonella isolates, 29 were resistant to one antibiotic, 6 were resistant to two antibiotics and 1 was resistant to four antibiotics Some of the beef samples in the area contained antimicrobial residue which were above acceptable daily intake. The result also revealed that beef samples in Wa municipality were contaminated with Salmonella spp some of which were resistant to some antibiotics. Therefore, consumers of beef in this municipality are at risk of harboring antibiotic residues and resistant Salmonella spp.