Comparative molecular analysis of community- or hospital-acquired methicillin-resistant Staphylococcus aureus
Comparative molecular analysis of community- or hospital-acquired methicillin-resistant Staphylococcus aureus
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DOI：
10.1128/aac.47.1.196-203.2003
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发表时间：
2003-01-01
影响因子：
4.9
通讯作者：
Schlievert, PM
中科院分区：
文献类型：
--
作者：
Fey, PD;Saïd-Salim, B;Schlievert, PM
社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）是一个日益严重的公共卫生问题，与儿科死亡有关。据推测，CA-MRSA的演变是最近的事件，由于收购的mec DNA由以前的甲氧西林敏感菌株，在社区中流传。本研究调查了CA-MRSA、医院相关MRSA（HA-MRSA）和非月经中毒性休克综合征（nmTSS）分离株之间的遗传相关性。32株CA-MRSA中有31株与32株HA-MRSA高度相关，但可与32株HA-MRSA区分开来。31株相关CA-MRSA分离株产生葡萄球菌肠毒素B（n = 5）或C（n = 26），无一株产生TSS毒素1。所有检测的CA-MRSA分离株均含有IV型葡萄球菌盒式染色体mec（SCCmec）元件。相比之下，HA-MRSA分离株（n = 32）均不表达这三种超抗原。CA-MRSA和HA-MRSA分离株的抗生素敏感性模式不同; CA-MRSA通常仅对β-内酰胺类抗生素耐药。21株nmTSS分离株中有6株与CA-MRSA分离株无法区分或高度相关。MnCop是1986年在亚拉巴马获得的一种nmTSS分离株，与CA-MRSA分离株高度相关，但不含SCCmec元件。这些数据表明，CA-MRSA菌株可能代表了在先前能够引起nmTSS的易感遗传背景中新获得的SCCmec DNA。CA-MRSA构成严重的健康风险，不仅因为它对社区获得性葡萄球菌感染的抗生素具有耐药性，而且还因为它能够通过超抗原产生引起nmTSS。
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a growing public health concern that has been associated with pediatric fatalities. It is hypothesized that the evolution of CA-MRSA is a recent event due to the acquisition of mec DNA by previously methicillin-susceptible strains that circulated in the community. This study investigated the genetic relatedness between CA-MRSA, hospital-associated MRSA (HA-MRSA), and nonmenstrual toxic shock syndrome (nmTSS) isolates. Thirty-one of 32 CA-MRSA isolates were highly related as determined by pulsed-field gel electrophoresis and spa typing yet were distinguishable from 32 HA-MRSA strains. The 31 related CA-MRSA isolates produced either staphylococcal enterotoxin B (n = 5) or C (n = 26), and none made TSS toxin 1. All CA-MRSA isolates tested contained a type IV staphylococcal cassette chromosome mec (SCCmec) element. In comparison, none of the HA-MRSA isolates (n = 32) expressed the three superantigens. Antibiotic susceptibility patterns were different between the CA-MRSA and HA-MRSA isolates; CA-MRSA was typically resistant only to beta-lactam antibiotics. Six of twenty-one nmTSS isolates were indistinguishable or highly related to the CA-MRSA isolates. MnCop, an nmTSS isolate obtained in Alabama in 1986, was highly related to the CA-MRSA isolates except that it did not contain an SCCmec element. These data suggest that CA-MRSA strains may represent a new acquisition of SCCmec DNA in a previously susceptible genetic background that was capable of causing nmTSS. CA-MRSA poses a serious health risk not only because it is resistant to the antibiotics of choice for community-acquired staphylococcal infections but also because of its ability to cause nmTSS via superantigen production.