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首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Clonal success of piliated penicillin nonsusceptible pneumococci
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Clonal success of piliated penicillin nonsusceptible pneumococci

机译：毛状青霉素非敏感性肺炎球菌的克隆成功

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Antibiotic resistance in pneumococci is due to the spread of strains belonging to a limited number of clones. The Spain~(9v)-3 clone of sequence type (ST)156 is one of the most successful clones with reduced susceptibility to penicillin [pneumococci nonsusceptible to penicillin (PNSP)]. In Sweden during 2000-2003, a dramatic increase in the number of PNSP isolates was observed. Molecular characterization of these isolates showed that a single clone of sequence type ST156 increased from 40% to 80% of all serotype 14, thus causing the serotype expansion. Additionally, during the same time period, we examined the clonal composition of two serotypes 9V and 19F: all 9V and 20% of 19F isolates belonged to the clonal cluster of ST156, and overall ≈50% of all PNSP belonged to the ST156 clonal cluster. Moreover, microarray and PCR analysis showed that all ST156 isolates, irrespective of capsular type, carried the rlrA pilus islet. This islet was also found to be present in the penicillin-sensitive ST162 clone, which is believed to be the drug-susceptible ancestor of ST156. Competitive experiments between related ST156 serotype 19F strains confirmed that those containing the rlrA pilus islet were more successful in an animal model of carriage. We conclude that the pilus island is an important biological factor common to ST156 isolates and other successful PNSP clones. In Sweden, a country where the low antibiotic usage does not explain the spread of resistant strains, at least 70% of all PNSP isolates collected during year 2003 carried the pilus islet.
机译：肺炎球菌中的抗生素耐药性归因于属于有限数量克隆的菌株的传播。序列类型（ST）156的Spanish〜（9v）-3克隆是最成功的克隆之一，对青霉素[对青霉素不敏感的肺炎球菌（PNSP）]的敏感性降低。在2000年至2003年期间，瑞典的PNSP分离株数量急剧增加。这些分离物的分子特征表明，序列类型为ST156的单个克隆从所有血清型14的40％增至80％，从而引起血清型扩展。此外，在同一时间段内，我们检查了两种血清型9V和19F的克隆组成：所有19V分离株的9V和20％都属于ST156的克隆群，而所有PNSP的约50％都属于ST156克隆的群。此外，微阵列和PCR分析显示，所有ST156分离株，不论荚膜类型如何，均携带rlrA菌毛胰岛。还发现该胰岛存在于对青霉素敏感的ST162克隆中，该克隆被认为是ST156的药物敏感性祖先。在相关ST156血清型19F菌株之间进行的竞争性实验证实，含有rlrA菌毛胰岛的菌株在运输动物模型中更为成功。我们得出的结论是，菌毛岛是ST156分离株和其他成功的PNSP克隆共有的重要生物因子。在瑞典，抗生素使用率低不能解释耐药菌株的扩散，该国在2003年收集的所有PNSP分离株中至少有70％带有菌毛胰岛。

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