Genome and virulence determinants of high virulence community-acquired MRSA
Genome and virulence determinants of high virulence community-acquired MRSA
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DOI：
10.1016/s0140-6736(02)08713-5
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发表时间：
2002-05-25
期刊：
影响因子：
168.9
通讯作者：
Hiramatsu, K
中科院分区：
文献类型：
--
作者：
Baba, T;Takeuchi, F;Hiramatsu, K
一种新型的耐甲氧西林金黄色葡萄球菌（MRSA），称为社区获得性MRSA，在社区中变得越来越引人注目，其中一些菌株在其他健康个体中引起致命感染。与医院获得性MRSA相比，社区获得性MRSA对非β-内酰胺类抗生素更敏感。我们调查了高毒力潜力的某些菌株的bacterios.Methods，我们确定了全基因组序列的MW 2，一株社区获得性MRSA，鸟枪克隆和测序，MW 2引起致命的败血症和脓毒性关节炎的一个16个月大的女孩在北达科他州，美国，在1998年。结果MW 2中的甲氧西林耐药基因（mecA）由葡萄球菌盒式染色体mec（SCCmec）的一种新等位基因（IVa型）携带，而N315和Mu 50中的mecA基因为II型。IVa型SCCmec不携带II型SCCmec中报告的任何多种抗生素耐药基因。相比之下，MW 2基因组中记录了19个额外的毒力基因。MW 2的7个基因组岛中，除2个外，其余4个都有毒力基因。MW 2携带的毒力和耐药基因与现存金黄色葡萄球菌染色体上的毒力和耐药基因不同。大多数基因由MW 2染色体中基因组岛的特定等位基因形式携带。基因组岛的等位基因形式的组合是决定金黄色葡萄球菌的医学重要表型的致病性的遗传基础，包括社区获得性MRSA菌株的致病性。
Background A new type of meticillin-resistant Staphylococcus aureus (MRSA), designated community-acquired MRSA, is becoming increasingly noticeable in the community, some strains of which cause fatal infections in otherwise healthy individuals. By contrast with hospital-acquired MRSA, community-acquired MRSA is more susceptible to non beta-lactam antibiotics. We investigated the high virulence potential of certain strains of this bacterium.Methods We ascertained the whole genome sequence of MW2, a strain of community-acquired MRSA, by shotgun cloning and sequencing, MW2 caused fatal septicaemia and septic arthritis in a 16-month-old girl in North Dakota, USA, in 1998. The genome of this strain was compared with those of hospital-acquired MRSA strains, including N315 and Mu50.Findings Meticillin resistance gene (mecA) in MW2 was carried by a novel allelic form (type IVa) of staphylococcal cassette chromosome mec (SCCmec), by contrast with type II in N315 and Mu50. Type IVa SCCmec did not carry any of the multiple antibiotic resistance genes reported in type II SCCmec. By contrast, 19 additional virulence genes were recorded in the MW2 genome. All but two of these virulence genes were noted in four of the seven genomic islands of MW2.Interpretation MW2 carried a range of virulence and resistance genes that was distinct from those displayed on the chromosomes of extant S aureus strains. Most genes were carried by specific allelic forms of genomic islands in the MW2 chromosome. The combination of allelic forms of genomic islands is the genetic basis that determines the pathogenicity of medically important phenotypes of S aureus, including those of community-acquired MRSA strains.