Isolation and multidrug drug resistance profile of Listeria species in selected Dairy Farm's Operational stages in Oromia Regional State, Ethiopia

Abstract

Listeriosis occurs due to consumption of contaminated food including raw milk. This study was aimed to assess the occurrence of Listeria species along Haramaya University Dairy Farm's operational stages with antibiotic resistance test on the isolates in oromia-Ethiopia. Study involves 30 lactating cows and 170 randomly collected different types of dairy environmental samples. The samples were examined for Listeria species. The isolates were tested against eight antibiotics. Out of 200 samples, 10 (20%) were positive for Listeria species. Listeria was isolated from cow barn, milk supply, silage feed and milk from cow teat, milking operation and milk auditing at 30%, 26.7%, 20%, 18.6% and 10%, respectively. Listeria species including L. monocytogenes (5.5%), L. innocua (5%), L. gray (3%), L. ivanovii (2.5%), L. seeligeri (2%) and L. welshimeri (2%) were also isolated. High resistant L. monocytogene to tetracycline (54.5%), L. ivanovii to amoxicillin (40%), L. innocua to each of penicillin and tetracycline (60%), L. seeligeri to tetracycline (100%), L. welsheri to penicillin (75%) and L. gray to each of penicillin and tetracycline (66.7%) were observed. Of all the 40 Listeria species isolates, 35%, 25%, 17.5% and 5% isolates were resistant to single, two, three and four drugs, respectively. Detection of considerable proportion of, different species of and antibiotic resistant Listeria isolates in the studied dairy sampling location shows there rere risk for raw milk contamination. Thus application of basic hygiene along the studied dairy operational stages could reduce consumer infection.

Keywords

• Dairy
• Milk
• Operation stage
• Listeria species
• Silage