小儿肺炎链球菌的耐药性及其血清学特征

目的　了解小儿肺炎链球菌的耐药性及其血清型分布情况 ,为小儿上呼吸道感染的临床抗生素合理治疗提供依据。　方法　肺炎链球菌自小儿上呼吸感染者的鼻咽拭子标本分离取得 ,并用标准 E- test法和琼脂稀释法测定其耐药性 ;采用 Quellung反应方法对其血清分型 ;采用 BOX- PCR和琼脂糖电泳技术对其进行基因特征分析。　结果　研究了 1999年至 2 0 0 1年期间从患儿鼻咽拭子标本中分离出来的 84株肺炎链球菌。 78.6% ( 66株 )的菌株对青霉素敏感 ,也同时对其他的 β-内酰胺类抗生素敏感。仅有 2 1.4 % ( 18株 )的菌株对青霉素耐药 ,其中 ,88.9% ( 16株 )的是低度耐药 ,11.1% ( 2株 )是高度耐药。几乎所有的菌株对利福平和万古霉素是敏感的。但大多数菌株对四环素、氯霉素、复方新诺明、红霉素表现出多重耐药性。占 60 .6%的肺炎链球菌其血清型是 6A( 14 .3 % )、2 3 F( 13 .1% )、19F( 11.9% )、15 B( 7.1% )、14( 7.1% ) ,不能分型 ( 7.1% ) ,而 18株青霉素耐药菌株的血清型是 2 3 F、19F、6B、14不能分型 ,以 2 3 F为主 ,它们有相似的BOX基因指纹图谱和耐药谱。　结论　本研究小儿肺炎链球菌对青霉素的耐药率较其他地区高 ,耐药模式以四环素、氯霉素、复方新诺明、红霉素、氯林可霉素为主。 2 3 F血清型是

Antimicrobial Resistance of Streptococcus Pneumoniae among Children and Molecular Serotype of Penicillin-resistant Strains

Objective This study designed to determine the antimicrobial resistance of streptococcus pneumoniae(S. pneumoniae) among children, and investigate the prevalence of molecular serotypes of penicillin-resistant strains. The aim is to offer adequate clinical antimicrobial therapy to upper respiratory infection. Methods Antimicrobial resistance of 84 S. pneumoniae stains isolated from the Nasopharyneal specimens of children patients with upper respiratory infection from 1999 to 2001 were studied by E-test and agar dilution method according to NCCLS, and S. pneumoniae strain was identified by optochin sensitivity and bile solubility. Serotyping of the S.pneumoniae strains was performed by using Quelling Reaction, and DNA of the S.pneumoniae strains resistant to penicillin was detected by BOX fingerprint PCR technique and pulsed-field gel electrophoresis. Results Among 84 S. pneumoniae strains,78.6% of them were susceptible to penicillin and also to other tested beta-lactams. Only 21.4% of them were resistant to penicillin with 16 strains were low-level resistant to penicillin and 2 strains was high-level resistant to penicillin. Almost all of them were susceptible to vancomycin and rifampin. Serotype of most of S. pneumoniae were multiresistant to tetracyline, chloramphenicol and trimethoprim-sulfamethoxazole?erythromycin. Serotype 6A(14.3%)?23F(13.1%)?19F(11.9%)?15B(7.1%)?14(7.1%),NT(7.1%) were most common, and also most of penicillin non-susceptible strain were serotype 23F and had similar multiresistance and BOX patterns. Conclusions Penicillin-resistant pneumococci remains uncommon but higher incidence in our area than others. Widespread resistance to tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole?erythromycin was found. Almost all of the strains were susceptible to vancomycin and rifampin. The epidemic multiresistant 23F clones, a majority of serotypes, have similar BOX fingerprint. It is important to monitor Betalactam resistance every year.