Comparison of transformation frequencies among selected Streptococcus pneumoniae serotypes
Comparison of transformation frequencies among selected Streptococcus pneumoniae serotypes
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DOI：
10.1016/j.ijantimicag.2010.03.024
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发表时间：
2010-08-01
影响因子：
10.8
通讯作者：
Jacobs, Michael R.
中科院分区：
文献类型：
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作者：
Joloba, Moses L.;Kidenya, Benson R.;Jacobs, Michael R.
尽管肺炎链球菌有超过 90 种血清型，但抗菌药物耐药性主要存在于有限数量的血清型/血清组中，即 6、9、14、19 和 23。没有令人信服的机制来解释这种限制。我们的目的是确定通常与耐药性相关的血清型是否比对抗菌药物敏感的血清型具有更高的转化频率。在合成能力刺激肽的影响下，对耐药血清型与敏感血清型的遗传转化频率进行了体外研究。转化DNA是携带Tn916样转座子的基因组DNA，该转座子含有赋予红霉素抗性的mefE基因。据观察，与耐药性高度相关的血清型6、9、14、19和23并未表现出比其他血清型更高程度的转化效率。这些发现表明，血清型与耐药性的关联可能是由于鼻咽运输时间较长而导致长时间暴露于转化DNA，以及抗菌药物的更大选择压力，特别是在儿童中。这是第一项使用携带复合 Tn916 样元件的基因组 DNA 比较肺炎球菌临床分离株转化频率的研究。 (C) 2010 Elsevier B.V. 和国际化疗协会。版权所有。
Although there are over 90 serotypes of Streptococcus pneumoniae, antimicrobial resistance is predominantly found in a limited number of serotypes/serogroups, namely 6, 9, 14, 19 and 23. There is no compelling mechanism to account for this restriction. We aimed to determine whether serotypes commonly associated with drug resistance have higher transformation frequencies than those that are susceptible to antimicrobial agents. An in vitro investigation of the genetic transformation frequency of drug-resistant serotypes compared with that of susceptible serotypes under the influence of synthetic competence-stimulating peptides was performed. The transforming DNA was genomic DNA carrying a Tn916-like transposon containing the mefE gene that confers resistance to erythromycin. It was observed that serotypes 6, 9, 14, 19 and 23, which are highly associated with drug resistance, do not exhibit a higher degree of transformation efficiency than other serotypes. These findings suggest that the association of serotype with drug resistance is likely due to prolonged exposure to transforming DNA resulting from longer nasopharyngeal carriage and to a greater selective pressure from antimicrobials, particularly in children. This is the first study to compare the transformation frequencies of pneumococcal clinical isolates using genomic DNA that carries the composite Tn916-like element. (C) 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.