Kim K S, Morrison J O, Bayer A S
Infect Immun. 1982 May;36(2):582-5. doi: 10.1128/iai.36.2.582-585.1982.
To define the mechanism(s) of penicillin tolerance in lactobacilli, one nontolerant and two tolerant strains were examined for autolytic enzyme activity. When incubated with 14C-labeled cell wall preparations, autolysin extracts of tolerant lactobacilli released significantly less radioactivity than did extracts of nontolerant lactobacilli (p less than 0.02). These differences in the release of radioactivity by nontolerant and tolerant strains were maximal during the logarithmic growth phase. Moreover, this activity was greatest at pH 8, was heat labile, and was inhibited by the addition of magnesium, suggesting characteristics of an enzyme. This study illustrates that autolytic enzyme activity is deficient in strains of antibiotic-tolerant lactobacilli and suggests that this may be partially responsible for the delayed killing effect of penicillins against such strains.
为了确定乳酸杆菌中青霉素耐受性的机制，对一株非耐受性菌株和两株耐受性菌株进行了自溶酶活性检测。当与14C标记的细胞壁制剂一起孵育时，耐受性乳酸杆菌的自溶素提取物释放的放射性明显低于非耐受性乳酸杆菌的提取物（p小于0.02）。非耐受性和耐受性菌株在放射性释放上的这些差异在对数生长期最大。此外，这种活性在pH 8时最强，对热不稳定，并被镁的添加所抑制，表明具有酶的特性。这项研究表明，抗生素耐受性乳酸杆菌菌株的自溶酶活性不足，并表明这可能部分是青霉素对这类菌株延迟杀伤作用的原因。
