MOLECULAR IDENTIFICATION OF PATHOGENS CAUSING CLINICAL AND SUBCLINICAL MASTITIS IN NILI-RAVI BUFFALOES

Abstract

Mastitis is the leading cause of substantial economic losses due to decreased milk yield and treatment costs in buffaloes. It occurs in two forms; clinical symptoms and subclinical without symptoms but affects the milk yield caused by a wide range of pathogens including bacteria and fungi. Identification of causative agents is important for management and treatment. In this study milk samples from 30 buffaloes of Nili-Ravi breed were collected from different dairy farms and investigated for clinical and subclinical mastitis (CMT). Subclinical mastitis cases are followed by biochemical tests (catalase, oxidase, coagulase, etc.) to identify different microorganisms. DNA was extracted and the 16S rRNA (1500 bp) gene was amplified by PCR using universal primers. Amplicons were sequenced and analyzed for identification.

Out of 30 milk samples 13 (43.3%) were positive for clinical mastitis and 09 positive for subclinical mastitis (30%) while other 08 (26.7%) were negative samples having no growth. Out of 22 positive samples the most predominant bacteria were E.coli (31.8%) followed by Staphylococcus spp. (9.1%), Pseudomonas aeruginosa (9.1%), Pseudomonas spp. (9.1%), Enterobacter spp. (9.1%), Staphylococcus aureus (4.5%), Klebsiella pneumonia (4.5%), Klebsiella spp. (4.5%), Stenotrophomonas sp. (4.5%), Aeromonas spp. (4.5%) and Fungal spp. (9.1%). Our findings highlight the significant prevalence of clinical (43.3%) and subclinical (30%) mastitis in buffaloes, with E. coli being the most common pathogen (31.8%) alongside a diverse range of bacterial and fungal species. The use of 16S rRNA sequencing provided precise pathogen identification, emphasizing the polymicrobial nature of mastitis. These findings underline the importance of regular monitoring and targeted management strategies to control mastitis and maintain dairy farm productivity.