To evaluate the effect of antimicrobial susceptibility on outcomes, we compared the minimum inhibitory concentrations
(MICs) for Staphylococcus, Streptococcus, and the family Enterobacteriaceae from cured and uncured mastitis cases; milk
shipment for uncured cases could not be resumed within 3 weeks after initial clinical examination.
A higher MIC50 of ampicillin and a higher MIC90 of cefazolin for Enterobacteriaceae isolates were observed for cured
rather than uncured cases with differences in ≥2 tubes.
Endotoxins are generally released from Enterobacteriaceae upon antimicrobial treatment; their amounts are presumed to
be greater in mastitis cases resulting from β-lactam antibiotic-susceptible rather than -resistant microbes.
For staphylococcal and streptococcal isolates, the MIC50 and MIC90 of β-lactam antibiotics were similar for cured and
uncured cases.
乳房炎由来腸内細菌科のセファゾリン感受性
（Cefazolin susceptibility of Enterobacteriaceae isolated from bovine mastitis）
乳房炎由来ブドウ球菌および連鎖球菌のセファゾリン感受性
（Cefazolin susceptibility of Staphylococcus and Streptococcus isolated from bovine mastitis ）
