Antimicrobial Susceptibility Profile of Coliforms from Bovine Mastitis Cases among Pastoral Herds in Parts of Kaduna State, Nigeria: Curbing the Environmental Health Risk

Consumption of raw milk from pastoral bovines have been identified as a major source of public and environmental health risk in developing countries. Antimicrobial resistance is a global health challenge threatening the lives of humans and animals. The indiscriminate use of antimicrobial agents among the pastoralists on commercial animals, especially for non-therapeutic purposes has been linked to the development of resistant strains of potentially pathogenic bacteria which are being transferred from animals to humans. This study investigated the antimicrobial susceptibility profile of coliform bacteria isolated from mastitis milk of pastoral herds. Out of 147 milk samples collected and screened for subclinical mastitis, 29 (19.7%) were positive. Out of the 29 mastitis positive samples, 13 (8.8%) were positive for coliforms (6 E. coli and 7 K. pneumoniae). All the coliform isolates showed 100% resistance to Penicillin and Tetracycline, and were all 100% susceptible to Imipenem. High multidrug resistance was expressed by all the isolates to Penicillin, Tetracycline and Erythromycin. All the isolates (100%) had Multiple Antibiotic Resistance Index (MARI) of 0.2 and above which is an indication of gross abuse of antibiotics within the studied population. However, antibiotics still effective against the coliform species tested were Imipenem (100%), Ciprofloxacin (92.3%), Gentamycin (92.3%), Chloramphenicol (84.6%), Amoxicillin/ Clavulanic acid (84.6%) and Sulfamethoxazole/Trimethoprim (69.2%).