儿童侵袭性与非侵袭性肺炎链球菌耐药性的对照研究

Control study on antimicrobial resistance of invasive and non-invasive Streptococcus pneumoniae in children

目的检测儿童侵袭性与非侵袭性肺炎链球菌(SP)的耐药性,为合理使用抗菌药物治疗不同部位SP感染提供依据。方法选取2009年1月至2013年12月诊断为侵袭性肺炎链球菌疾病(IPD)的70例患儿为研究对象,同期随机选取因SP所致下呼吸道感染住院的164例患儿为对照组。采集IPD患儿无菌部位(血液、脑脊液等)标本和对照组患儿痰液标本行细菌培养,并对分离的SP行药敏分析。结果 70例IPD患儿无菌部位中共分离到82株侵袭性SP,其中分离自血液49株(60%),脑脊液19株(23%)。5年间侵袭性SP菌株的检出率呈下降趋势(P<0.01);侵袭性与非侵袭性菌株中青霉素不敏感SP(PNSP)的总检出率(27%vs17%)及各年度检出率差异均无统计学意义(P>0.05)。侵袭性PNSP对头孢噻肟、头孢曲松、头孢吡肟的不敏感率明显高于青霉素敏感SP(PSSP)(P<0.01)。侵袭性和非侵袭性SP对头孢噻肟、头孢曲松、美罗培南的不敏感率差异有统计学意义(P<0.05)。侵袭性和非侵袭性SP的多重耐药率分别为89%和93%,差异无统计学意义(P>0.05)。结论侵袭性SP易侵入患儿血液,总检出率呈逐年下降趋势;药敏分析结果对于不同类型SP感染的抗菌药物合理应用具有指导意义。

Objective To investigate the antimicrobial resistance of invasive and non-invasive Streptococcus pneumoniae（SP） strains in children and to provide a basis for proper use of antimicrobial drugs in the treatment of SP infection. Methods Seventy children who were diagnosed with invasive pneumococcal diseases（IPD） between January 2009 and December 2013 were enrolled, and 164 children with lower respiratory tract infection caused by SP were randomly selected as the control group. The samples from sterile sites（blood, cerebrospinal fluid, etc） of children with IPD, as well as the sputum samples of children in the control group, were collected for bacterial culture, and the drug susceptibility tests for isolated SP strains were conducted. Results A total of 82 invasive strains of SP were isolated from sterile sites of 70 children with IPD; 49 strains（60%） were isolated from blood, and 19 strains（23%） from cerebrospinal fluid. The detection rate of invasive SP strains decreased from 2009 to 2013（P〈0.01）. The total detection rates of penicillin-nonsusceptible SP from the invasive and non-invasive strains were 27% and 17% respectively（P〈0.05）. Among invasive strains, the penicillin-nonsusceptible SP strains had significantly higher rates of insusceptibility to cefotaxime, ceftriaxone, and cefepime than the penicillin-susceptible SP（P〈0.01）. There were significant differences in the rates of insusceptibility to cefotaxime, ceftriaxone, and meropenem between the sensitive and non-sensitive SP strains（P〈0.05）. The multidrug resistance rates of the invasive and non-invasive SP strains were 89% and 93% respectively（P〉0.05）. Conclusions Invasive SP can easily invade the blood in children, but the total detection rate has decreased year by year. The results of drug sensitivity tests have guiding significance for proper use of antimicrobial drugs for different SP infections.