Prevalence and antibiogram of coliform bacteria, and occurrence of fungi in subclinical mastitis in small ruminants in Plateau State, Nigeria

Abstract

This study was conducted to determine the prevalence of coliform bacteria and fungi in ovine and caprine raw milk in Plateau State of Nigeria. In a cross sectional study, a total of 412 milk samples were collected aseptically and 206 questionnaires form where data such as breed, age, parity, lactation stage, floor type, and husbandry system were analyzed. Ewes and does without clinical mastitis were subjected to California Mastitis Test (CMT) to determine the presence of subclinical mastitis. Bacteriological assays and antibiotic susceptibility tests were performed according to standard guidelines. Fungal assays and identification were done according to standard protocol. The overall prevalence of subclinical mastitis for ewes and does were 28.2 and 35.8% respectively. Out of the risk factors examined, age and floor type showed statistically significant relationship with mastitis. Coliforms isolated from milk samples included Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter aerogenes, and Serratia marcescens. The highest coliform isolated among the ewes with 38% prevalence was E. coli and the least was S. marcescens with 2.5%. Among the does, E coli had the highest prevalence as well with 43.1% and E. aerogenes the least with 1.5%. Aspergillus species had 49 isolates out of the 94 fungal isolates (52.1%) of mycotic agents of mastitis in small ruminants. Most antibiotics used in this study showed extremely high level of antimicrobial resistance especially for Amoxicillin-clavulanic acid 45/79 (57.0%) and 53/65 (81.5%) in coliforms isolated from ewes and does respectively. The principle of one health approach which targets the environment, animals and humans should be considered important. Sensitization of pastoralists on good hygienic measures, and treatment of animals by qualified and registered veterinary personnel should be intensified.