Bai Ying, Hayman David T S, McKee Clifton D, Kosoy Michael Y
Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
Molecular Epidemiology and Public Health Laboratory, Infectious Disease Research Centre, Massey University, Palmerston North, New Zealand.
PLoS Negl Trop Dis. 2015 Jan 30;9(1):e0003478. doi: 10.1371/journal.pntd.0003478. eCollection 2015 Jan.
Bartonellae are facultative intracellular bacteria and are highly adapted to their mammalian host cell niches. Straw-colored fruit bats (Eidolon helvum) are commonly infected with several bartonella strains. To elucidate the genetic diversity of these bartonella strains, we analyzed 79 bartonella isolates from straw-colored fruit bats in seven countries across Africa (Cameroon, Annobon island of Equatorial Guinea, Ghana, Kenya, Nigeria, Tanzania, and Uganda) using a multi-locus sequencing typing (MLST) approach based on nucleotide sequences of eight loci (ftsZ, gltA, nuoG, ribC, rpoB, ssrA, ITS, and 16S rRNA). The analysis of each locus but ribC demonstrated clustering of the isolates into six genogroups (E1 - E5 and Ew), while ribC was absent in the isolates belonging to the genogroup Ew. In general, grouping of all isolates by each locus was mutually supportive; however, nuoG, gltA, and rpoB showed some incongruity with other loci in several strains, suggesting a possibility of recombination events, which were confirmed by network analyses and recombination/mutation rate ratio (r/m) estimations. The MLST scheme revealed 45 unique sequence types (ST1 - 45) among the analyzed bartonella isolates. Phylogenetic analysis of concatenated sequences supported the discrimination of six phylogenetic lineages (E1 - E5 and Ew) corresponding to separate and unique Bartonella species. One of the defined lineages, Ew, consisted of only two STs (ST1 and ST2), and comprised more than one-quarter of the analyzed isolates, while other lineages contained higher numbers of STs with a smaller number of isolates belonging to each lineage. The low number of allelic polymorphisms of isolates belonging to Ew suggests a more recent origin for this species. Our findings suggest that at least six Bartonella species are associated with straw-colored fruit bats, and that distinct STs can be found across the distribution of this bat species, including in populations of bats which are genetically distinct.
巴尔通体属兼性胞内菌，高度适应其哺乳动物宿主细胞生态位。淡黄色果蝠（锤头果蝠）通常感染多种巴尔通体菌株。为阐明这些巴尔通体菌株的遗传多样性，我们采用多位点测序分型（MLST）方法，基于8个基因座（ftsZ、gltA、nuoG、ribC、rpoB、ssrA、ITS和16S rRNA）的核苷酸序列，分析了来自非洲7个国家（喀麦隆、赤道几内亚的安诺本岛、加纳、肯尼亚、尼日利亚、坦桑尼亚和乌干达）的79株淡黄色果蝠巴尔通体分离株。除ribC外，对每个基因座的分析均显示分离株聚类为6个基因群（E1 - E5和Ew），而属于Ew基因群的分离株中不存在ribC。总体而言，每个基因座对所有分离株的分组相互支持；然而，nuoG、gltA和rpoB在几个菌株中与其他基因座存在一些不一致，提示可能存在重组事件，网络分析和重组/突变率比（r/m）估计证实了这一点。MLST方案在分析的巴尔通体分离株中揭示了45种独特的序列类型（ST1 - 45）。串联序列的系统发育分析支持区分对应于不同且独特的巴尔通体物种的6个系统发育谱系（E1 - E5和Ew）。定义的谱系之一Ew仅由两个ST（ST1和ST2）组成，占分析分离株的四分之一以上，而其他谱系包含更多数量的ST，每个谱系的分离株数量较少。属于Ew的分离株等位基因多态性数量较低，表明该物种起源较晚。我们的研究结果表明，至少有6种巴尔通体物种与淡黄色果蝠有关，并且在这种蝙蝠物种的分布范围内，包括在基因不同的蝙蝠种群中，都可以发现不同的ST。
