Heterogeneity of pneumococcal phase variants in invasive human infections
Heterogeneity of pneumococcal phase variants in invasive human infections
复制标题
DOI：
10.1186/1471-2180-6-67
复制
发表时间：
2006-07-26
期刊：
影响因子：
4.2
通讯作者：
Ramirez, M.
中科院分区：
文献类型：
--
作者：
Serrano, I.;Melo-Cristino, J.;Ramirez, M.
背景资料：肺炎链球菌可以在其人类宿主的鼻咽中无症状地携带，但也可以引起广泛的感染。在不同的生活方式，这种细菌的肺炎球菌相变异的作用已被建议，但没有系统的调查与人类infections.Results相关的分离株的殖民地表型：我们报告的殖民地不透明表型的遗传多样性的304个侵入性分离株代表10个血清型。超过一半的分离株（52%）呈现不透明表型，而透明变体仅占总数的26%。然而，每个相变异的恢复频率是不均匀的，而血清型1，4，12 B和23 F呈现不透明的表型比预期的机会，血清型3和14不经常与此表型。结论：不透明的表型是最常见的表型中发现的侵袭性分离株。一个意想不到的和同样重要的发现是在血清型中发现的显性不透明表型的变异性。这一观察结果突出了不透明表型的异质性在侵入性菌株，并进一步支持的建议，其他因素，除了网站的隔离，确定一个给定的隔离的不透明表型。血清型和菌落混浊之间的关联可以帮助解释在肺炎球菌血清型之间观察到的流行病学差异，例如更高的侵袭性疾病潜力。
Background: Streptococcus pneumoniae can be carried asymptomatically in the nasopharynx of its human host but can also cause a wide range of infections. A role for pneumococcal phase variants in the different lifestyles of this bacterium has been suggested but no systematic survey of the colony phenotypes of isolates associated with human infections has been undertaken.Results: We report the colony opacity phenotypes of a genetically diverse set of 304 invasive isolates representing 10 serotypes. Over half of the isolates (52%) presented the opaque phenotype whereas transparent variants accounted for only 26% of the total. However, the frequency of recovery of each phase variant was not uniform, while serotypes 1, 4, 12B and 23F presented the opaque phenotype more frequently than expected by chance, serotypes 3 and 14 where less frequently associated with this phenotype.Conclusion: The opaque phenotype was the most frequent phenotype found among invasive isolates. An unexpected and equally important finding is the variability of the dominant opacity phenotype found among serotypes. This observation highlights the heterogeneity of opacity phenotypes in invasive isolates and lends further support to the proposal that other factors, in addition to the site of isolation, determine the opacity phenotype of a given isolate. The association between serotype and colonial opacity could help explain epidemiological differences observed among pneumococcal serotypes such as a higher invasive disease potential.