Drug Sensitivity of Microorganisms Causing Subclinical Mastitis in Buffaloes


University of Forestry, Faculty of Veterinary Medicine, BG-1000 Sofia, Bulgaria


PARVANOV, P. and T. POPOVA, 2000. Drug sensitivity of microorganisms causing subclinical mastitis in buffaloes. Bulg. J. Agric. Sci., 6: 111-118.

Microbiological studies of milk samples from buffaloes with subclinical mastitis have been performed in order to determine the bacterial aetiology and the sensitivity of isolates to antibacterial drugs. The leading role of Gram-positive bacteria was evidenced, most oftenly in mixed infections.
The isolated causative agents showed the highest in vitro sensitivity to tetracycline, kanamycin and gentamicin. The determination of the minimal inhibitory concentrations (MIC's) chloramphenicol, streptomycin, penicillin and ampicillin showed that the inhibition of most microbial agents, especially of Gram-negative bacteria, was achieved following the application of medium (8-16 mg/ml) and higher (64-128 mg/ml) antibiotic concentrations.
The inhibitory action of Levamisoli hydrochloridum was determined in vitro. Its minimal inhibitory concentrations were higher than those of tested antibiotics.

Key words: buffalo, subclinical mastitis, causative microorganisms, antibiotic sensitivity, minimal inhibitory concentrations (MIC's)