젖소의 유방염 원인균 및 항생제 감수성의 변화 양상 조사

Patterns of mastitic pathogens and antibiotic susceptibility in milk of dairy cattle

The experiment described in this study was undertaken to investigate the incidence of bovine mastitis, and the distribution and antibiotic susceptibility of microorganisms isolated from milk of 2,073 dairy cattle during the period from May 1987 to September 1990. 1. A total of 119 (5.7%) of 2,073 cows were found to be infected with clinical mastitis. The incidence of subclinical mastitis was much higher, and the infection was found in 2,273 (28.8%) of 7,886 quarters. 2. Staphylococcus.(56.1%) and Streptococcus (14.8%) were the main two causative organisms of mastitis. Micrococcus (4.9%), coliforms (7.0%), corynebacterium (5.1%), yeast (1.3%) and others (10.6%) were also found to cause the infection. 3. The causative organisms isolated from milk were sensitive to gentamicin (64.7%), cephalothin (62.8%) and chloramphenicol (55.4%), and were very resistant to penicillin (10.4%), ampicillin (13.6%) and streptomycin (18.3%). The causative organisms isolated in 1990 showed a higher resistance to ampicillin, penicillin, streptomycin, tetracycline and vancomycin than the isolates of 1987.