Brook I, Gillmore J D
Naval Medical Research Institute, Bethesda, Md.
Chemotherapy. 1994 Jan-Feb;40(1):16-20. doi: 10.1159/000239164.
The antimicrobial susceptibility and in vitro growth curve of 4 nonencapsulated and 4 encapsulated isolates of Bacteroides fragilis were determined for clindamycin. The MIC of the nonencapsulated isolates was 1-2 dilutions less (0.062-0.25 microgram/ml) than the MIC for their encapsulated counterparts (0.25-0.5 microgram/ml). No difference was noted in the bacterial growth of the nonencapsulated or encapsulated isolates when incubated without clindamycin. The decline in the number of nonencapsulated isolates was significantly lower (p < 0.05) as compared to the encapsulated isolates when incubated with 0.1 or 0.4 microgram/ml of clindamycin. These results illustrate the higher susceptibility of nonencapsulated B. fragilis isolates to clindamycin as compared to their encapsulated counterparts. Since B. fragilis becomes more encapsulated during the infectious process, this finding underscores the advantage of early antimicrobial prophylaxis and therapy.
测定了4株脆弱拟杆菌非荚膜菌株和4株荚膜菌株对克林霉素的药敏性及体外生长曲线。非荚膜菌株的最低抑菌浓度（MIC）比其荚膜对应菌株低1 - 2个稀释度（0.062 - 0.25微克/毫升），而荚膜对应菌株的MIC为0.25 - 0.5微克/毫升。在不添加克林霉素的情况下孵育时，未观察到非荚膜或荚膜菌株的细菌生长有差异。当与0.1或0.4微克/毫升的克林霉素一起孵育时，非荚膜菌株数量的下降明显低于荚膜菌株（p < 0.05）。这些结果表明，与荚膜对应菌株相比，非荚膜脆弱拟杆菌菌株对克林霉素更敏感。由于脆弱拟杆菌在感染过程中会形成更多的荚膜，这一发现强调了早期抗菌预防和治疗的优势。
