Porat Nurith, Soley Carolina, Marengolciene Marija M, Greenberg David, Givon-Lavi Noga, Trefler Ronit, Arguedas Adriano, Dagan Ron
Pediatric Infectious Disease Unit, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Pediatr Infect Dis J. 2008 Aug;27(8):709-12. doi: 10.1097/INF.0b013e31816fca86.
Serotype 3 is known for its ability to cause invasive diseases worldwide. In the United States, after introduction of the 7-valent pneumococcal conjugate vaccine (PCV7), the prevalence of a serotype 3 clone (Netherlands-31/ST180) increased. The present study was aimed to evaluate the importance of serotype 3 clones in noninvasive infections in Israel, Costa Rica, and Lithuania.
Molecular typing and antibiotic resistance were performed on 77 serotype 3 strains recovered from pediatric noninvasive infections during 2003-2005, and on 50 carried strains from healthy carriers.
Serotype 3 ranked second among isolates from noninvasive infections in Costa Rica and Lithuania, and seventh among the Israeli isolates. Pulsed field gel electrophoresis (PFGE) analysis revealed the presence of 1 major cluster (64/77, 83%); this cluster comprised 60/64 fully susceptible strains that corresponded to the Netherlands-31/ST180 clone, and 4/64 multidrug-resistant strains, all from Lithuania, that corresponded to ST505, a double locus variant of ST180. Two additional fully susceptible clones, ST458 (11/77, 14%) and ST1116 (2/77, 3%), were found among the Israeli and Costa Rican strains, respectively. The same PFGE clusters identified among noninvasive infections were found among 50 isolates from carriers, with the same molecular characteristics.
Serotype 3 accounts for a large proportion of mucosal disease in children, even before the introduction of PCV7. The data presented here describe for the first time the importance of a multidrug-resistant serotype 3 clone, ST505, in noninvasive infections.
3型血清型以其在全球范围内引发侵袭性疾病的能力而闻名。在美国，引入7价肺炎球菌结合疫苗（PCV7）后，一种3型血清型克隆（荷兰-31/ST180）的流行率有所上升。本研究旨在评估3型血清型克隆在以色列、哥斯达黎加和立陶宛非侵袭性感染中的重要性。
对2003年至2005年期间从儿童非侵袭性感染中分离出的77株3型血清型菌株以及50株来自健康携带者的携带菌株进行分子分型和抗生素耐药性检测。
在哥斯达黎加和立陶宛，3型血清型在非侵袭性感染分离株中排名第二，在以色列分离株中排名第七。脉冲场凝胶电泳（PFGE）分析显示存在1个主要簇（64/77，83%）；该簇包含60/64株对所有检测抗生素均敏感的菌株，与荷兰-31/ST180克隆相对应，以及4/64株多重耐药菌株，均来自立陶宛，与ST505相对应，ST505是ST180的双位点变体。在以色列和哥斯达黎加的菌株中分别发现了另外两个对所有检测抗生素均敏感的克隆，即ST458（11/77，14%）和ST1116（2/77，3%）。在50株来自携带者的分离株中也发现了与非侵袭性感染中相同的PFGE簇，且具有相同的分子特征。
即使在引入PCV7之前，3型血清型在儿童黏膜疾病中也占很大比例。此处呈现的数据首次描述了多重耐药的3型血清型克隆ST505在非侵袭性感染中的重要性。
