Structure and distribution of an unusual chimeric genetic element encoding macrolide resistance in phylogenetically diverse clones of group A Streptococcus
Structure and distribution of an unusual chimeric genetic element encoding macrolide resistance in phylogenetically diverse clones of group A Streptococcus
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DOI：
10.1086/379897
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发表时间：
2003-12-15
影响因子：
6.4
通讯作者：
Musser, JM
中科院分区：
文献类型：
--
作者：
Banks, DJ;Porcella, SF;Musser, JM
A组链球菌对大环内酯类抗生素的耐药是一个世界性的问题。对导致宾夕法尼亚州匹兹堡I市咽炎爆发的红霉素耐药血清型M6克隆的基因组进行初步测序，以确定含有mefA基因的遗传元件的结构，该基因编码大环内酯外排蛋白。mefA基因与由插入原噬菌体的转座子组成的58.8-kb嵌合遗传元件相关。该元件还编码一个假定的细胞外蛋白，其羧基末端具有细胞壁锚定基序（LPKTG）。mefA元件存在于美国各地分离的遗传多样性GAS菌株中。丝裂霉素C处理后制备的代表爆发克隆的菌株的培养上清液含有呈DNAse抗性形式的mefA元件DNA。总之，这些数据提供了新的信息，大环内酯类耐药的分子遗传基础和传播的GAS菌株。
The resistance of group A Streptococcus(GAS) to macrolide antibiotics is now a worldwide problem. Preliminary sequencing of the genome of an erythromycin-resistant serotype M6 clone that was responsible for a pharyngitis outbreak in I Pittsburgh, Pennsylvania, was conducted to determine the structure of the genetic element containing the mefA gene, which encodes a macrolide efflux protein. The mefA gene is associated with a 58.8-kb chimeric genetic element composed of a transposon inserted into a prophage. This element also encodes a putative extracellular protein with a cell-wall anchoring Motif (LPKTG) located at the carboxyterminus. The mefA element was present in phylogenetically diverse GAS strains isolated throughout the United States. Culture supernatants, prepared after mitomycin C treatment, of a strain representing the outbreak clone contained mefA element DNA in a DNAse-resistant form. Together, these data provide new information about the molecular genetic basis of macrolide resistance and dissemination in GAS strains.