Smaoui H, Amri J, Hajji N, Kechrid A
Laboratoire de microbiologie, hôpital d'enfants de Tunis Bab-Saadoun, 1006 Tunis, Tunisie.
Arch Pediatr. 2009 Mar;16(3):220-6. doi: 10.1016/j.arcped.2008.12.015. Epub 2009 Feb 11.
Streptococcus pneumoniae is a major causative agent of severe infectious diseases. More than 90 pneumococcal serotypes are known, although most invasive and noninvasive diseases are associated with a much smaller number of serotypes. The aim of this study was to determine the antimicrobial susceptibility of S. pneumoniae isolates in children, the distribution of serogroups and serotypes, and the coverage by the serotypes included in the seven-valent pneumococcal conjugate vaccine toward pneumococcal disease. This study investigated 210 nonrepetitive isolates of S. pneumoniae isolated between 1998 and 2004. Antimicrobial susceptibility was tested using the disk diffusion method as determined by the CA-SFM guidelines. Penicillin susceptibility was determined using the oxacillin 5-microg disk screening test. The MICs of penicillin G, amoxicillin, and cefotaxime were determined using the E-test (ABBIODISK). Serotype was determined using rapid latex agglutination (Pneumotest Latex) and the capsular reaction test used antisera from the Staten Serum Institute. The evaluation of susceptibility to ss-lactamins showed that 52.8% of the strains were penicillin non susceptible strains (PNSs), 16.6% had decreased susceptibility to amoxicillin, and 8.5% to cefotaxime. Among noninvasive isolates, 55.2% were PNSs and 50.4% were invasive PNSs. The PNS strains were more frequently resistant to other antibiotics, with 68.4% resistance to erythromycin, 44.1% to trimethoprim-sulfamethoxazole, and 9.9% to chloramphenicol versus 32.3, 11.1, and 1%, respectively, in penicillin-susceptible strains. The predominant serogroups/serotypes of our study were 14 (22%), 23 (14.3%), 19 (11.9%), and 4 (8.5%). The study of the vaccine serotype distribution showed that the theoretical vaccinal coverage of the seven valent vaccines was 62.8% for all the isolates, 55.2% for the invasive isolates, and 67.9% for the PNSs.
肺炎链球菌是严重传染病的主要病原体。已知有90多种肺炎球菌血清型，尽管大多数侵袭性和非侵袭性疾病与数量少得多的血清型有关。本研究的目的是确定儿童肺炎链球菌分离株的抗菌药敏性、血清群和血清型的分布，以及七价肺炎球菌结合疫苗中所含血清型对肺炎球菌疾病的覆盖范围。本研究调查了1998年至2004年间分离出的210株非重复性肺炎链球菌分离株。按照CA-SFM指南采用纸片扩散法检测抗菌药敏性。使用5μg苯唑西林纸片筛选试验确定青霉素敏感性。使用E-test（ABBIODISK）测定青霉素G、阿莫西林和头孢噻肟的最低抑菌浓度（MIC）。使用快速乳胶凝集法（肺炎球菌检测乳胶）确定血清型，荚膜反应试验使用丹麦国家血清研究所的抗血清。对β-内酰胺类药物的敏感性评估显示，52.8%的菌株为青霉素不敏感菌株（PNSs），16.6%对阿莫西林敏感性降低，8.5%对头孢噻肟敏感性降低。在非侵袭性分离株中，55.2%为PNSs，50.4%为侵袭性PNSs。PNS菌株对其他抗生素的耐药性更高，对红霉素的耐药率为68.4%，对甲氧苄啶-磺胺甲恶唑的耐药率为44.1%，对氯霉素的耐药率为9.9%，而青霉素敏感菌株的耐药率分别为32.3%、11.1%和1%。本研究中主要的血清群/血清型为14型（22%）、23型（14.3%）、19型（11.9%）和4型（8.5%）。对疫苗血清型分布的研究表明，七价疫苗对所有分离株的理论疫苗覆盖率为62.8%，对侵袭性分离株为55.2%，对PNSs为67.9%。
