Antibiotic resistance of Staphylococcus and Streptococcus Spp as determinedby milk somatic cell count in healthy cows

摘要

In vitro antibiotic resistance of bacteriaisolated from 100 clinically normal lactating cows was determined by somatic cell count. Milksamples were taken aseptically from all quarters. Twelve genus of bacteria were isolated from133 (33.25%) quarters and 48 (48%) cows. Most frequent isolates were Staphylococcus Spp.,37.61% and Streptococcus spp., 36.69%, both highly resistant to penicillin 39% and cloxacillin22.5%, respectively. Minimum inhibitory concentrations of the various antibiotics used to treatmastitis for Staphylococcus Spp was < 8 and < 2 μg/ml based on the percentage of bacterialresistance.