广州地区老年人肺炎链球菌临床分离株的青霉素耐药研究与分子分型

目的调查广州地区老年患者肺炎链球菌分离株对青霉素的敏感性，并分析其亲缘关系。方法K—B纸片法对33株分离自老年住院病人的肺炎链球菌进行青霉素药敏试验；应用PCR技术检测青霉素结合蛋白基因pbp1a，pbp2x，pbp2b；用盒式PCR（BOX—PCR）分析菌株间亲缘关系。用多位点测序分型技术（multilocus sequence typing，MLST）检测青霉素耐药菌株的分子分型。结果青霉素的耐药率为3．03％（1／33）：用PCR方法鉴定PSSP的准确率为68．75％；BOX-PCR可将这33株肺炎链球菌分为21型。MIST分型显示，青霉素耐药菌株属ST271型。结论广州地区老年患者肺炎链球菌对青霉素耐药率较低．用PCR方法检测PSSP有一定的可行性。BOX—PCR显示了较高的分辨率，能快速可靠地检测菌株间的亲缘关系。广州地区流行的耐药克隆与Taiwan^19F-14株同源。

Penicillin-Resistance and Molecular Typing of Streptococcus pneumoniae Isolated in Guangzhou from Elderly Patients

Objective To investigate penicillin-resistance and sequence type of Streptcoccus pneumoniae of clinical isolates from elders in Guangzhou. Method 33 clinical isolates of S.pneumoniae were obtained from the elders in Guangzhou and determined the susceptibility to penicillin by K-B disk method. The pbp1a, pbp2x and pbp2b genes were amplified by PCR. BOX-PCR was used to analyze the homology among strains. Multilocus sequence typing （MIST） was undertaken on the PRSP isolate to determine the sequence type （ST）. Result Among these isolates, 1/ 33（3.03%） is resistant to penicillin. PCR result shows that 22/32 （68.75%） are possible of PSSP isolates. 21 BOX- PCR clusters are identified from these isolates. The isolate, which is resistant to penicillin belongs to ST271. Conclusion The penicillin resistant rate of S.pneumoniae is low in the elders of Guangzhou. The PCR methods based on PBPs can be used for testing clinical samples. BOX-PCR typing is a suitable technique to type S.pneumoniae. The isolate resistant to penicillin may belong to the major international clone Taiwan619F-14.