Ampicillin Resistance and Transferable β-Lactamase Plasmids of Gram Negative Rods Isolated from Bovine Mastitis

Park, Cheong-kyu

Korean Journal of Veterinary Research 1985;25(1):61-67.

Cheong-kyu Park

Department of Veterinary Medicine, College of Agriculture, Gyeongbug National University

젖소 유방염유래(乳房炎由來) Gram 음성간균(陰性桿菌)의 Ampicillin 내성(耐性) 및 전달성(傳達性) β-Lactamase Plasmids

박청규

경북대학교 농과대학 수의학과

Abstract

One hundred and twenty seven strains of Gram-negative rods (72 E. coli, 45 Klebsieila pneumoniae, 8 Enterobacter spp. and 2 Pseudomonas aeruginosa) isolated from bovine mastitis were examined for resistance to ampicilin, carbenicillin and cefazolin, ${eta}$-lactamase activity and transferable ${eta}$-lactamase plasmids. Stains resistant to ampicillin were 13.9% in E. coli, 93.3% in Klebsiella pneumoniae, 87.5% in Enterobacter. spp. and all in Pseudomonas aeruginosa, Resistance of E. coli, Klebsiella pneumoniae and Enterobacter spp. to ampicillin was due to the ${eta}$-lactamases, but all Pseudomonas aeruginosa exhibited a high level of the non-enzymic resistance. Transferable plasmid-mediated ${eta}$-lactamase synthesis was demonstrated in 61.9% of Klebsiella pneumoniae, 50% of E. coli and 42.9% of Enterobacter spp. The same ${eta}$-lactamase plasmids specified different resistance levels to various ${eta}$-lactam antibiotics in different recipients.