Prevalence of subclinical mastitis in cows, isolation of agents and determination of their antibiotic susceptibility

Abstract

Aim: To investigate bacterial agents causing subclinical mastitis in cow husbandry in Kars province, Turkey. Materials and Methods: Subclinical mastitis was identified in 120 (24%) of 500 dairy cows screened by CMT. Within the scope of the study, it was taken milk samples from 120 dairy cows and evaluated in the laboratory. For bacterial isolation, the milk samples were mixed with vortex and 100 μl of milk were streaked on Blood Agar (with 7% sheep blood) and Eosin Methylene Blue Agar. For Mycoplasma spp. isolation, milk samples were transferred to PPLO broth and PPLO agar. For phenotypic identification, cultures were evaluated according to the colony morphology, hemolysis on BA and Gram staining properties, and then were subjected to biochemical tests. Antibiotic susceptibilities of isolates were determined by Kirby Bauer Disc Diffusion Test. Results: As a result of bacteriological studies, 229 Staphylococcus spp., 7 Corynebacterium spp., 16 Bacillus spp., 5 Acinetobacter spp., 2 Escherichia coli, and 2 Mycoplasma spp. were isolated from milk samples of 120 cows. As a result of antibiogram, the majority of isolates have found sensitive to cefoxitin (30 μg) and imipenem (10 μg) and the highest resistance among the isolates was determined against to penicillin (10 μg). Conclusion: The screening of subclinical mastitis at certain periods in enterprises, the proper characterization to be determined by isolation and identification of agent are crucial for the profitability and sustainability of dairy farming.

Keywords

• subclinical mastitis
• dairy cow
• prevalence
• bacteria
• antibiotic susceptibility