Plasmids, drug resistance, and gene transfer in the genus Streptococcus.
Plasmids, drug resistance, and gene transfer in the genus Streptococcus.
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链球菌属的质粒、耐药性和基因转移。
DOI：
10.1128/mr.45.3.409-436.1981
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Clewell,DB
中科院分区：
文献类型：
--
作者：
Clewell,DB
链球菌代表一大群具有显着异质性的挑剔的革兰氏阳性微生物。大多数链球菌是兼性厌氧菌且不活动，它们倾向于以可变长度的链生长，特别是在体外培养期间。链球菌在化脓性疾病中的作用是众所周知的，例如咽炎（链球菌性咽喉炎）、猩红热、丹毒、皮肤蜂窝组织炎、脓疱疮和淋巴管炎。相关的非化脓性疾病包括急性肾小球肾炎和急性风湿热。大多数这些疾病与化脓性链球菌（兰斯菲尔德 A 组）感染有关，但有时也涉及其他链球菌种类。草绿色群（例如血链球菌、变形链球菌、唾液链球菌和轻度链球菌）栖息在口腔中，通常与亚急性细菌性心内膜炎有关。龋齿是人类最普遍的细菌感染之一，据信与变形链球菌有关 (91)。粪链球菌（D 组）是肠道的正常居民，可能与心内膜炎有关，并且通常与尿路感染有关。 D 组菌株也经常与根管感染有关 (76, 235)，并且某些菌株对无菌大鼠具有致龋性 (18, 88, 181, 227)。近年来，无乳链球菌（B 族）已成为新生儿脑膜炎的常见原因之一 (6, 244)。作为大叶性肺炎的病原体，肺炎链球菌是人类的主要杀手，尽管其致命性常常是作为先前的衰弱疾病的并发症而出现的。除了其医学重要性外，链球菌在乳制品工业中也发挥着非常重要的作用。乳酸链球菌、乳脂链球菌和其他链球菌与奶酪和奶油的生产密切相关。链球菌中质粒脱氧核糖核酸 (DNA) 的首次报道来自两项独立的研究，这两项研究均在大约 9 年前进行了描述。首先，Courvalin 和同事 (52) 报告了粪链球菌耐药菌株裂解物中的卫星 DNA，该菌株在含有溴化乙锭的 CsCl 梯度中离心至平衡。在该菌株的药物敏感变体中没有观察到卫星（质粒）DNA。其次，Dunny 等人鉴定了变形链球菌中的小质粒(68)；在这种情况下，对质粒进行了物理表征。从那时起，在许多链球菌菌株中都鉴定出了质粒。表 1 给出了至少部分表征和命名的质粒列表。一般来说，质粒在链球菌中与在革兰氏阴性肠道细菌中一样常见；然而，在某些物种中比在其他物种中更容易发现它们。就粪链球菌（B. Brown、Y. Yagi 和 DB Clewell，未发表数据）和乳酸链球菌 (116, 129) 而言，含有 5 个或更多质粒的菌株并不罕见，无质粒分离株为 o09
The streptococci represent a large group of fastidious gram-positive microorganisms of remarkable heterogeneity. Most streptococci are facultative anaerobes and nonmotile, and they tend to grow in chains of variable length, espe-cially during cultivation in vitro. The role of streptococci in suppurative diseases, such as pharyngitis (strep throat), scarlet fever, erysipelas, cellulitis of the skin, impetigo, and lymphangitis, is well known. Related non-suppurative diseases include acute glomerulonephritis and acute rheumatic fever. Most of these illnesses are associated with infections by Streptococcus pyogenes (Lancefield group A), although other streptococcal species are sometimes involved. The viridans group (eg, Strep-tococcus sanguis, Streptococcus mutans, Streptococcus salivarius, and Streptococcus mitior) inhabit the oral cavity and commonly are involved in cases of subacute bacterial endocarditis. Dental caries, one of the most widespread bacterial infections in humans, is believed to involve S. mutans (91). Streptococcus faecalis (group D), a normal inhabitant of the gut, can be involved in endocarditis and is commonly involved in urinary tract infections. Group D strains are also frequently implicated in root canal infections (76, 235), and some strains are cariogenic in germfree rats (18, 88, 181, 227). In recent years, Streptococcus agalactiae (group B) has become one of the common causes of meningitis in newborn infants (6, 244). As the etiological agent of lobar pneumonia, Strepto-coccuspneumoniae is a major killerofhumans, albeit its lethality frequently arises as a complication of a preceding debilitating illness. In addition to their medical importance, the streptococci play highly significant roles in the dairy industry; Streptococcus lactis, Streptococcus cremoris, and other streptococci are intimately involved in the production of cheeses and creams.The first reports of plasmid deoxyribonucleic acid (DNA) in streptococci came from two in-dependent studies, both of which were described about 9 years ago. First, Courvalin and co-work-ers (52) reported satellite DNA in lysates of a drug-resistant strain of S. faecalis centrifuged to equilibrium in CsCl gradients containing ethidium bromide. No satellite (plasmid) DNA was observed in a drug-sensitive variant of this strain. Second, a smallplasmid in S. mutans was identified by Dunny et al.(68); in this case, the plasmid was physically characterized. Since then, plasmids have been identified in numerous strains of streptococci; a list of the plasmids that have been at least partially characterized and named is given in Table 1. In general, plasmids are as common in streptococci as they are in gram-negative enteric bacteria; however, they are found more easily in some species than in others. In the case of S. faecalis (B. Brown, Y. Yagi, and DB Clewell, unpublished data) and S. lactis (116, 129), it is not uncommon to find strains containing five or more plasmids, and plasmid-free isolates are o09