Sensitivity of Pathogens of Bovine Udder Origin to Antibiotics

Chung, Jong Sig; Cho, Sung Whan; Cho, Yoong Jun; Park, Cheong Kyu

Korean Journal of Veterinary Research 1979;19(1):75-83.

Jong Sig Chung¹, Sung Whan Cho¹, Yoong Jun Cho¹, Cheong Kyu Park²

¹Cyeongbug Animal Health Laboratory
²Department of Veterinary Medicine, College of Agriculture, Gyeongbug National University

젖소 유방원(乳房源) 병원세균(病原細菌)의 항생물질(抗生物質)에 대(對)한 감수성(感受性)

정종식¹, 조성환¹, 조용준¹, 박청규²

¹경상북도가축보건소
²경북대학교 농과대학

Abstract

The sensitivities of 270 pathogens (124 Streptococci, 118 Staphylococci, 10 Corynebacterium pyogenes and 18 Escherichia coli) isolated from clinical or subclinical cases of bovine mastitis during lactation to 11 antibiotics were determined by the agar plate dilution method. All cultures of Streptococci were inhibited at $1.56{mu}g/ml$ of ampicillin and 1.56 units/ml of penicillin G. Most of the cultures were inhibited at $3.125{mu}g/ml$ of leukomycin, but were resistant to kanamycin, streptomycin, chloramphenicol, erythromycin and colistin at concentration of $12.5{mu}g/ml$. More than 93% of the Staphlococcal cultures were sensitive to kanamycin, leukomycin, ampicillin, tetracycline, ledermycin and minocycline at concentrations of $12.5{mu}g/ml$ or less, and sensitive to penicillin at concentration of 3.125 units/ml, but for more than 71% of the cultures to chloramphenicol, erythromycin and colistin the concentrations required to inhibit growth were 100 ${mu}g/ml$ or higher. All 10 cultures of Corynebacterium pyogenes were inhibited by leucomycin, ampicillin and minocycline at concentration of $1.56{mu}g/ml$ and by penicillin G at concentration of 0.78 units/ml, but all the cultures required at least $400{mu}g/ml$ or higher of streptomycin, erythromycin and colistin for inhibition. More than 83% of E. coli cultures were sensitive to erythromycin and minocycline at concentration of $12.5{mu}g/ml$, but resistant to leucomycin and chloramphenicol at concentration of $100{mu}g/ml$.