Study of the mechanism of uneven distrlbudon of leucocytolytic toxin in Staphylococcus aureus-Phage conversion and regulation of PVL expression-

金黄色葡萄球菌溶白细胞毒素分布不均的机制研究-噬菌体转化及PVL表达调控-

基本信息

批准号：
13660075
负责人：
KANEKO Jun
金额：
$ 2.3万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13660075/
关键词：
Staphylococcus aureus Panton -Valentine Leukocidin Phage conversion regulation Panton -Valentine Leukocidim

项目摘要

Staphylococcus aureus is known as community-accuired, nosocominal pathogen. It produces bi-component toxin, called Panton-Valentine leukocidin (PVL) which acts to polymorphonuclear lukocytes and macrophages. The epidemiological studies of PVL shows that PVL producing strains were isolated from limited clinical samples, most of cotenous necrotic lesions, such as furuncles, however, PVL cluster was seen only few % of clinical isolated strain while almost all S. aureus has hlg/luk cluster. The aim of this study is clarification of the mechanism of these uneven distribution of PVL producing strains among the clinical isolated S. aureus.(1) Phage conversion of PVLP Previously, we found that gene cluster of two components for PVL are encoded in the prophages φPVL and φSLT. Therefore we assumed that phage conversion of PVL is related to the uneven distribution of PVL gemes. In this *y, we isolated 10 novel PVL-carrying phages and whole genome sequence of three of them were determined. We showed that these PVL carrying phages are divided into two groups, φPVL and φSLT types. In addition, each type phage divided into several subtypes by difference of lysogenic and replication regions. These data shows that PVL genes are carried by several different temperate phases and these deference were reflected to host ranges of PVL converting phages. We tested 257 S. aureus isolates from food poisoning origins, and only few percent of strains were infected by these phages.(2) Regulation of PVL expression. Regulation of expression of PVL is important factor for the infection of S. aureus in the high-level PVL producer related lesions. We found several indicator strains which could not produce PVL components when PVL genes were transduced by φSLT. Now we are studying about the effect of the well known global regulators, such as agr and sigB to the expression of PVL.

金黄色葡萄球菌被称为社区获得的肿瘤病原体。它产生双成分毒素，称为Panton-Valentine Liukocidin（PVL），该白细胞素（PVL）作用于多形核Lukocytes和巨噬细胞。 PVL的流行病学研究表明，从有限的临床样本中分离出PVL的产生菌株，大多数型型坏死病变（例如兽医），但是，仅几乎所有的临床分离菌株都只能看到PVL簇，而几乎所有的金黄色葡萄球菌都具有HLG/LUK簇。这项研究的目的是阐明临床分离的金黄色葡萄球菌中PVL产生菌株的这些不均匀分布的机制。（1）先前PVLP的噬菌体转化率，我们发现PVL两个成分的基因簇被编码在先知φpvl和φslt中。因此，我们假设PVL的噬菌体转化与PVL宝石的不均匀分布有关。在此 *y中，我们分离了10个新型PVL携带噬菌体，并确定了其中三个的整个基因组序列。我们表明，这些携带噬菌体的PVL分为两组φpvl和φslt类型。另外，每种类型的噬菌体都通过溶菌发生和复制区域的差异分为几种亚型。这些数据表明，PVL基因通过几个不同的温度阶段携带，这些定义反映为托管PVL转换噬菌体的范围。我们从食物中毒的起源中测试了257个金黄色葡萄球菌分离株，只有少量的菌株被这些噬菌体感染。（2）调节PVL表达。 PVL表达的调节是高水平PVL生产者相关病变中金黄色葡萄球菌感染的重要因素。我们发现了几个指标菌株，这些指标菌株在通过φSLT翻译PVL基因时无法产生PVL成分。现在，我们正在研究众所周知的全球调节剂的影响，例如AGR和SIGB对PVL的表达。