Methods British Society for Antimicrobial Chemotherapy ( BSAC) disk diffusion test and agar dilution test were taken to determine minimal inhibition concentration ( MIC) and antibiotic resistance of Mc strains Nitrocefin disk test was used to detect beta-lactamase producing. 方法采用英国抗生素化疗学会(BSCA)琼脂稀释法进行抗生素最小抑菌浓度测定;用Nitrocefin纸片琼脂扩散法检测β-内酰胺酶;