摘要 : The study was conducted to determine the dendrogram and antibiotic sensitivity of 40 <i>Escherichia coli</i> strains and 25 <i>Staphylococcus aureus</i> strains isolated from clinical and subclinical bovine mastitis in Bangalore, ... 展开 The study was conducted to determine the dendrogram and antibiotic sensitivity of 40 <i>Escherichia coli</i> strains and 25 <i>Staphylococcus aureus</i> strains isolated from clinical and subclinical bovine mastitis in Bangalore, India. The disk diffusion method was utilized to determine the sensitivity pattern and the dendrogram was analysed based on Ward's method of clustering. Results revealed that the <i>S. aureus</i> isolates were divided into two major clusters, A and B, while each cluster was divided into two subclusters A1, A2, B1 and B2. The subcluster A2 and B1 were further divided into subgroups A2.1 and A2.2, and B1.1 and B1.2, respectively. It was observed that <i>S. aureus</i> strains were highly sensitive against chloramphenicol and enrofloxacin, and moderately sensitive against tetracycline, gentamicin, amikacin, and penicillin. On the other hand, <i>E. coli</i> isolates were also divided into two major clusters A and B, and cluster A was divided into two subclusters A1 and A2. Subcluster A2 was divided to A2.1 and A2.2. It was observed that the strains were highly sensitive against chloramphenicol, enrofloxacin, amikacin and gentamicin, while least sensitive to tetracycline. All the isolates showed resistance to penicillin, ampicillin, cloxacillin, colistin, streptomycin and kanamycin. It is concluded that chloramphenicol and enrofloxacin are the most effective antibiotic against clinical and subclinical mastitis. 收起