Population genetic structure of the Staphylococcus intermedius group:: Insights into agr diversification and the emergence of methicillin-resistant strains
Population genetic structure of the Staphylococcus intermedius group:: Insights into agr diversification and the emergence of methicillin-resistant strains
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DOI：
10.1128/jb.01150-07
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发表时间：
2007-12-01
影响因子：
3.2
通讯作者：
Fitzgerald, J. Ross
中科院分区：
文献类型：
--
作者：
Bannoehr, Jeanette;Ben Zakour, Nouri L.;Fitzgerald, J. Ross
动物病原体中间葡萄球菌的群体遗传结构知之甚少。我们进行了多位点序列系统发育分析，从广泛的主机和地理来源的菌株，调查间和种内的多样性。我们发现，分离株表型鉴定为S。intermedius分化为3个密切相关的种，S.中间葡萄球菌、假中间葡萄球菌和海豚葡萄球菌。S. pseudintermedius，而不是S.中间体，是犬化脓的常见原因，偶尔也会引起人类的人畜共患感染。在S. pseudintermedius分离株，包括几个分布在不同大陆。由于葡萄球菌的agr群体感应系统被认为是在该属内沿着物种形成的沿着进化的，我们研究了编码自诱导肽（AIP）的agrD的等位基因变异。四个都是？变异体由S. pseudintermedius分离株，和相同的AIP变异体之间共享的三个物种，这表明一个共同的群体感应能力已被保存，尽管在很大程度上不同的生态位的物种分化。agr等位基因的克隆关联的缺乏表明连续重组可能有助于agr多样性的分布。最后，我们发现最近出现的耐甲氧西林菌株是由于不同的S.在不同的大陆上发现的pseudintermedius克隆。综合以上结果，初步解析了该群体的遗传结构。intermedius组，从而对其古代和近代的演变有了新的认识。
The population genetic structure of the animal pathogen Staphylococcus intermedius is poorly understood. We carried out a multilocus sequence phylogenetic analysis of isolates from broad host and geographic origins to investigate inter- and intraspecies diversity. We found that isolates phenotypically identified as S. intermedius are differentiated into three closely related species, S. intermedius, Staphylococcus pseudintermedius, and Staphylococcus delphini. S. pseudintermedius, not S. intermedius, is the common cause of canine pyoderma and occasionally causes zoonotic infections of humans. Over 60 extant STs were identified among the S. pseudintermedius isolates examined, including several that were distributed on different continents. As the agr quorum-sensing system of staphylococci is thought to have evolved along lines of speciation within the genus, we examined the allelic variation of agrD, which encodes the autoinducing peptide (AIP). Four All? variants were encoded by S. pseudintermedius isolates, and identical AIP variants were shared among the three species, suggesting that a common quorum-sensing capacity has been conserved in spite of species differentiation in largely distinct ecological niches. A lack of clonal association of agr alleles suggests that assortive recombination may have contributed to the distribution of agr diversity. Finally, we discovered that the recent emergence of methicillin-resistant strains was due to multiple acquisitions of the mecA gene by different S. pseudintermedius clones found on different continents. Taken together, these data have resolved the population genetic structure of the S. intermedius group, resulting in new insights into its ancient and recent evolution.