Ben Zakour Nouri L, Sturdevant Daniel E, Even Sergine, Guinane Caitriona M, Barbey Corinne, Alves Priscila D, Cochet Marie-Françoise, Gautier Michel, Otto Michael, Fitzgerald J Ross, Le Loir Yves
INRA, UMR1253 STLO, F-35000 Rennes, France.
J Bacteriol. 2008 Oct;190(19):6302-17. doi: 10.1128/JB.01984-07. Epub 2008 Jun 20.
Staphylococcus aureus causes disease in humans and a wide array of animals. Of note, S. aureus mastitis of ruminants, including cows, sheep, and goats, results in major economic losses worldwide. Extensive variation in genome content exists among S. aureus pathogenic clones. However, the genomic variation among S. aureus strains infecting different animal species has not been well examined. To investigate variation in the genome content of human and ruminant S. aureus, we carried out whole-genome PCR scanning (WGPS), comparative genomic hybridizations (CGH), and the directed DNA sequence analysis of strains of human, bovine, ovine, and caprine origin. Extensive variation in genome content was discovered, including host- and ruminant-specific genetic loci. Ovine and caprine strains were genetically allied, whereas bovine strains were heterogeneous in gene content. As expected, mobile genetic elements such as pathogenicity islands and bacteriophages contributed to the variation in genome content between strains. However, differences specific for ruminant strains were restricted to regions of the conserved core genome, which contained allelic variation in genes encoding proteins of known and unknown function. Many of these proteins are predicted to be exported and could play a role in host-pathogen interactions. The genomic regions of difference identified by the whole-genome approaches adopted in the current study represent excellent targets for studies of the molecular basis of S. aureus host adaptation.
金黄色葡萄球菌可导致人类和多种动物发病。值得注意的是，包括奶牛、绵羊和山羊在内的反刍动物的金黄色葡萄球菌乳腺炎在全球范围内造成了重大经济损失。金黄色葡萄球菌致病克隆的基因组内容存在广泛差异。然而，感染不同动物物种的金黄色葡萄球菌菌株之间的基因组变异尚未得到充分研究。为了研究人类和反刍动物金黄色葡萄球菌基因组内容的变异，我们对来自人类、牛、羊和山羊的菌株进行了全基因组PCR扫描（WGPS）、比较基因组杂交（CGH）以及定向DNA序列分析。发现基因组内容存在广泛变异，包括宿主特异性和反刍动物特异性基因座。绵羊和山羊菌株在遗传上相关联，而牛菌株在基因内容上是异质的。正如预期的那样，诸如致病岛和噬菌体等可移动遗传元件导致了菌株之间基因组内容的变异。然而，反刍动物菌株特有的差异仅限于保守核心基因组区域，该区域在编码已知和未知功能蛋白质的基因中存在等位基因变异。预计这些蛋白质中的许多会被输出，并可能在宿主-病原体相互作用中发挥作用。本研究采用全基因组方法鉴定出的差异基因组区域是研究金黄色葡萄球菌宿主适应性分子基础的极佳靶点。
