Genotyping and Antibiotic Resistance Profile of Klebsiella pneumoniae and Corynebacterium bovis Isolates Recovered from Clinical and Subclinical Mastitis Milk Samples

Mastitis is an inflammation of the mammary gland caused in dairy cows due to bacterial infections causing high economic losses. Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) is an effective genotyping tool for tracing the infection by different bacteria. One hundred milk samples were collected (50 from clinical mastitis and 50 from subclinical mastitis) from different dairy farms at different regions of El-Gharbia Governorate in Egypt. The samples were examined bacteriologically for the isolation and identification of Klebsiella pneumoniae and Corynebacterium bovis. Antibiotic sensitivity testing for the isolates and genotyping by ERIC-PCR were performed. Our results showed that the prevalence of K. pneumoniae was 41% from total samples and C. bovis strains was18% from subclinical mastitis milk samples. All the examined isolates were multi drug resistant with higher resistance to ampicillin, amoxicillin-clavulanate and cefotaxime for K. pneumoniae and to penicillin, erythromycin and tetracycline for C. bovis. Discriminatory index of ERIC-PCR was 0.984 and 1 for K. pneumoniae and C. bovis isolates, respectively. The dendrogram analysis for K. pneumoniae showed three clusters and two separate isolates, while for C. bovis 1 cluster with 2 sub clusters and three separate isolates were observed. It was concluded that ERIC-PCR is proven to be effective genotyping technique with high discriminatory index and is a good epidemiological tool for mastitis in cows as there was a genetic relatedness between strains collected from different regions at El-Gharbia Government in Egypt. This indicated the possibility of infection transmission between these regions and necessitates the need to increase control measures.