Li J, Musser J M, Beltran P, Kline M W, Selander R K
Institute of Molecular Evolutionary Genetics, Mueller Laboratory, Pennsylvania State University, University Park 16802.
J Clin Microbiol. 1990 Aug;28(8):1760-5. doi: 10.1128/jcm.28.8.1760-1765.1990.
Genetic diversity and relationships among 42 strains of Citrobacter diversus recovered from the cerebrospinal fluid of human infants with meningitis and from other clinical sources in the United States were estimated on the basis of electrophoretically detectable allelic variation in 20 genes encoding metabolic enzymes. Sixteen distinctive multilocus enzyme genotypes were identified, among which the mean genetic diversity per locus was 0.244. The recovery of isolates of the same genotype in several regions of the United States and over periods as long as 20 years indicates that the population structure of C. diversus is clonal. There was little association between multilocus enzyme genotype and biotype, piliation, or presence of a 32-kilodalton outer membrane protein. The observation that the 32-kilodalton outer membrane protein, which is expressed predominantly by strains recovered from infants with meningitis, occurs in a variety of genotypically diverse clones belonging to several phylogenetic lineages supports the hypothesis that this protein confers virulence.
基于对20种编码代谢酶的基因进行电泳检测的等位基因变异，对从美国患脑膜炎的人类婴儿脑脊液及其他临床来源中分离出的42株差异柠檬酸杆菌的遗传多样性及亲缘关系进行了评估。共鉴定出16种独特的多位点酶基因型，每个位点的平均遗传多样性为0.244。在美国多个地区以及长达20年的时间里均分离出相同基因型的菌株，这表明差异柠檬酸杆菌的种群结构是克隆性的。多位点酶基因型与生物型、菌毛或32千道尔顿外膜蛋白的存在之间几乎没有关联。从患脑膜炎婴儿中分离出的菌株主要表达32千道尔顿外膜蛋白，该蛋白存在于属于几个系统发育谱系的各种基因型不同的克隆中，这一观察结果支持了该蛋白赋予毒力的假说。
