Genetic and phenotypic characterization of intestinal spirochetes colonizing chickens and allocation of known pathogenic isolates to three distinct genetic groups
Genetic and phenotypic characterization of intestinal spirochetes colonizing chickens and allocation of known pathogenic isolates to three distinct genetic groups
复制标题
DOI：
10.1128/jcm.35.2.412-417.1997
复制
发表时间：
1997-02-01
影响因子：
9.4
通讯作者：
Hampson, DJ
中科院分区：
文献类型：
--
作者：
McLaren, AJ;Trott, DJ;Hampson, DJ
肠道螺旋体感染最近已被认为是家禽业产量损失的原因。对这些生物体知之甚少，因此检查了源自澳大利亚、美国、荷兰和英国商业鸡群中的56个分离物的集合，血琼脂上的β-溶血强度、吲哚产生、API ZYM酶谱、对分离株进行了形态学和细胞学观察，并采用多位点酶电泳技术分析了分离株间的遗传多样性程度，并与已报道的猪肠道螺旋体的遗传多样性进行了比较。它们被分为40个电泳类型，分布在6个不同的遗传群（群B至g），平均遗传多样性为0.587。两组（d组和e组）中的菌株可能代表Serpulina的新种，并且该组仅包含从鸡中分离的菌株。三个遗传组包含先前被证明对鸡具有致病性的分离株，这些菌株对应于提议的种“中间Serpulina”，对应于未命名的组（e组），并且对应于Serpulina pilosicoli，其中两个鸡分离株（一个"S. intermedius“和一个S. pilosicoli分离物）是强β-溶血性的，两个（均为S.中间型）具有中等水平的β-溶血，其余为弱β-溶血。14个分离的S。intermedius“产生吲哚，d组的一个分离物也产生吲哚，鉴定为S. pilosicoli类似于该物种的猪分离物，具有4至6个周质鞭毛，在细胞的每一端插入近末端的单排中，并且具有锥形的细胞末端。所有其他螺旋体在形态上相似，具有7个或更多个周质鞭毛和钝的细胞末端，鉴定出三个含有致病性分离株的基因组，为更详细地研究这些病原体的流行病学提供了机会，用于开发改进的诊断测试。
Infection with intestinal spirochetes has recently been recognized as a cause of lost production in the poultry industry, Little is known about these organisms, so a collection of 56 isolates originating from chickens in commercial flocks in Australia, the United States, The Netherlands, and the United Kingdom was examined, Strength of beta-hemolysis on blood agar, indole production, API ZYM enzyme profiles, and cellular morphology were determined, and multilocus enzyme electrophoresis was used to analyze the extent of genetic diversity among the isolates, The results were compared with those previously obtained for well-characterized porcine intestinal spirochetes, The chicken isolates were genetically heterogeneous, They were divided into 40 electrophoretic types distributed among six diverse genetic groups (groups b to g), with a mean genetic diversity of 0.587. Strains in two groups (groups d and e) may represent new species of Serpulina, and the groups contained only strains isolated from chickens, Three genetic groups contained isolates previously shown to be pathogenic for chickens, These corresponded to the proposed species ''Serpulina intermedius,'' to an unnamed group (group e), and to Serpulina pilosicoli, Two of the chicken isolates (one ''S. intermedius'' and one S. pilosicoli isolate) were strongly beta-hemolytic, two (both ''S. intermedius'') had an intermediate level of beta-hemolysis, and the rest were weakly beta-hemolytic. Fourteen isolates of ''S. intermedius'' produced indole, as did one isolate from group d, Isolates identified as S. pilosicoli resembled porcine isolates of this species, having four to six periplasmic flagella inserted subterminally in a single row at each end of the cell, and had tapered cell ends, All other spirochetes were morphologically similar, having seven or more periplasmic flagella and blunt cell ends, The identification of three genetic groups containing pathogenic isolates provides an opportunity for more detailed epidemiologic studies with these pathogens and for the development of improved diagnostic tests.