The clonality of Staphylococcus aureus nasal carriage
The clonality of Staphylococcus aureus nasal carriage
复制标题
DOI：
10.1086/427240
复制
发表时间：
2005-02-01
影响因子：
6.4
通讯作者：
Lowy, FD
中科院分区：
文献类型：
--
作者：
Cespedes, C;Sa誰d-Salim, B;Lowy, FD
鼻腔携带金黄色葡萄球菌通常是同一菌株感染的前奏。普遍的假设是，被殖民的个体携带单一菌株。本研究调查了多种金黄色葡萄球菌菌株同时鼻腔携带的频率。最初通过脉冲场凝胶电泳比较来自定植受试者的平板样品的三个细菌菌落。 148 个金黄色葡萄球菌阳性样本中的 14 个至少表现出单条带的差异；这14个样本中有7个含有不同的菌株，这7个样本中的3个也属于不同的辅助基因调节因子（agr）类型。其余 7 个样本含有克隆相关分离株；这 7 对中的 3 对因是否存在 IV 型葡萄球菌染色体盒而有所不同。我们开发的数学模型预测，大约有 6.6% 的金黄色葡萄球菌定植个体携带 >1 个菌株。本研究表明，鼻腔定植个体中经常携带不一致的金黄色葡萄球菌菌株，这表明鼻孔可能是菌株之间水平遗传交换的场所。
Nasal carriage of Staphylococcus aureus is often a prelude to infection with the same strain. The prevailing assumption has been that colonized individuals carry a single strain. The present study investigated the frequency of simultaneous nasal carriage of multiple strains of S. aureus. Three bacterial colonies from plated samples from colonized subjects were initially compared by pulsed-field gel electrophoresis. Fourteen of 148 S. aureus-positive samples demonstrated at least a difference of a single band; 7 of these 14 samples contained different strains, and 3 of these 7 also belonged to different accessory gene regulator (agr) types. The remaining 7 samples contained clonally related isolates; 3 of these 7 contained pairs that differed by the presence or absence of the staphylococcal chromosomal cassette mec type IV. A mathematical model that we developed predicted that similar to6.6% of S. aureus-colonized individuals carry >1 strain. The present study demonstrates that carriage of discordant S. aureus strains in individuals with nasal colonization occurs regularly and suggests that the nares are likely sites for horizontal genetic exchange among strains.