Exfoliatin-producing strains define a fourth agr specificity group in Staphylococcus aureus
Exfoliatin-producing strains define a fourth agr specificity group in Staphylococcus aureus
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DOI：
10.1128/jb.182.22.6517-6522.2000
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发表时间：
2000-11-01
影响因子：
3.2
通讯作者：
Novick, RP
中科院分区：
文献类型：
--
作者：
Jarraud, S;Lyon, GJ;Novick, RP
葡萄球菌的葡萄球菌素被一个短肽自身诱导的密度敏感AGR系统激活（自诱导肽[AIP]）由agrD编码的前肽加工而成，agr基因座的中心片段，由AgrB的C末端三分之二组成（推定的加工酶），AgrD和AgrC的N-末端一半这一发现导致金黄色葡萄球菌分离株分为三个不同的agr特异性组，并将非金黄色葡萄球菌分为许多其他组。AIPs交叉抑制组间agr反应。我们以前已经表明，大多数月经中毒性休克菌株属于agr特异性第三组，但没有强有力的临床身份已与其他两组菌株。在本报告中，我们证明了第四agr特异性组之间的S。金黄色葡萄球菌菌株，并显示大多数脱落素生产菌株属于这一组。组IV菌株的一个显著的共同特征是在指数期早期激活agr反应，比其他组的菌株早至少2小时。这一发现提出了agr自诱导阈值的生物学意义的问题。
The staphylococcal virulon is activated by the density-sensing agr system, which is autoinduced by a short peptide (autoinducing peptide [AIP]) processed from a propeptide encoded by agrD, A central segment of the agr locus, consisting of the C-terminal two-thirds of AgrB (the putative processing enzyme), AgrD, and the N-terminal half of AgrC (the receptor), shows striking interstrain variation, This finding has led to the division of Staphylococcus aureus isolates into three different agr specificity groups and to the division of non-aureus staphylococci into a number of others. The AIPs cross-inhibit the agr responses between groups. We have previously shown that most menstrual toxic shock strains belong to agr specificity group III but that no strong clinical identity has been associated with strains of the other two groups. In the present report, we demonstrate a fourth agr specificity group among S. aureus strains and show that most exfoliatin-producing strains belong to this group. A striking common feature of group IV strains is activation of the agr response early in exponential phase, at least 2 h earlier than in strains of the other groups. This finding raises the question of the biological significance of the agr autoinduction threshold.