The origin of a methicillin-resistant Staphylococcus aureus isolate at a neonatal ward in Sweden-possible horizontal transfer of a staphylococcal cassette chromosome mec between methicillin-resistant Staphylococcus haemolyticus and Staphylococcus aureus
The origin of a methicillin-resistant Staphylococcus aureus isolate at a neonatal ward in Sweden-possible horizontal transfer of a staphylococcal cassette chromosome mec between methicillin-resistant Staphylococcus haemolyticus and Staphylococcus aureus
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DOI：
10.1111/j.1469-0691.2008.02090.x
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发表时间：
2008-11-01
影响因子：
14.2
通讯作者：
Soderquist, B.
中科院分区：
文献类型：
--
作者：
Berglund, C.;Soderquist, B.
第一个耐甲氧西林金黄色葡萄球菌（MRSA）菌株起源于带有mecA基因的葡萄球菌盒式染色体mec（SCCmec）整合到敏感的S.金黄色细胞SCCmec元件在凝固酶阴性葡萄球菌中很常见，例如溶血葡萄球菌，当MRSA的新克隆出现时，这些被认为是潜在的SCCmec供体。MRSA爆发发生在新生儿重症监护室，分离株均为序列型（ST）45，其特征在于多位点序列分型，但无法分型SCCmec I、II、III或IV型。在同一时期，耐甲氧西林的S。通过脉冲场凝胶电泳发现，在同一病房的血培养物中鉴定的溶血性链球菌（MRSH）分离株的基因型是均一的，并且也不携带I、II、III或IV型SCCmec。因此，提出了MRSH的SCCmec已经转移到甲氧西林敏感的S.金黄色葡萄球菌菌株，从而创造了一个新的克隆MRSA，导致爆发。这项研究表明，来自爆发的MRSA携带ccrC和C类mec复合物，这些复合物也在MRSH分离株中发现。部分测序的mec复合物显示超过99%的同源性，表明一个共同的V型SCCmec。这一发现可能为最近SCCmec从MRSH水平转移到已确定的潜在受体（ST 45甲氧西林敏感S）提供证据。金黄色葡萄球菌菌株，从而创造了一个新的克隆MRSA，导致爆发。
The first methicillin-resistant Staphylococcus aureus (MRSA) strain originated when a staphylococcal cassette chromosome mec (SCCmec) with the gene mecA was integrated into the chromosome of a susceptible S. aureus cell. The SCCmec elements are common among the coagulase-negative staphylococci, e.g. Staphylococcus haemolyticus, and these are considered to be potential SCCmec donors when new clones of MRSA arise. An outbreak of MRSA occurred at a neonatal intensive-care unit, and the isolates were all of sequence type (ST) 45, as characterized by multilocus sequence typing, but were not typeable with respect to SCCmec types I, II, III or IV. During the same time period, methicillin-resistant S. haemolyticus (MRSH) isolates identified in blood cultures at the same ward were found to be genotypically homogenous by pulsed-field gel electrophoresis, and did not carry a type I, II, III or IV SCCmec either. Thus, the hypothesis was raised that an SCCmec of MRSH had been transferred to a methicillin-susceptible S. aureus strain and thereby created a new clone of MRSA that caused the outbreak. This study showed that MRSA from the outbreak carried a ccrC and a class C mec complex that was also found among MRSH isolates. Partial sequencing of the mec complexes showed more than 99% homology, indicative of a common type V SCCmec. This finding may provide evidence for a recent horizontal transfer of an SCCmec from MRSH to an identified potential recipient, an ST45 methicillin-susceptible S. aureus strain, thereby creating a new clone of MRSA that caused the outbreak.