The louse-borne human pathogen Bartonella quintana is a genomic derivative of the zoonotic agent Bartonella henselae
The louse-borne human pathogen Bartonella quintana is a genomic derivative of the zoonotic agent Bartonella henselae
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DOI：
10.1073/pnas.0305659101
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发表时间：
2004-06-29
影响因子：
11.1
通讯作者：
Andersson, SGE
中科院分区：
文献类型：
--
作者：
Alsmark, CM;Frank, AC;Andersson, SGE
我们提出了两种人类病原体，quintana巴尔通体（1,581,384 bp）和henselae巴尔通体（1,931,047 bp）的完整基因组。这两种病原体在通过昆虫媒介传播、利用哺乳动物宿主、感染相似的细胞类型（内皮细胞和红细胞）以及在免疫功能低下的宿主中引起血管增生性变化等方面保持若干相似之处。这两种病原体的主要区别在于它们的宿主生态。而B. quintana是一种专家，只把人类作为宿主，B. henselae则更滥交，经常与猫和人类分离。基因组比较揭示了高度的整体相似性，主要差异是B. henselae特有的编码丝状血凝素的基因组岛，以及B. quintana基因组大量减少的证据，这让人想起了在普氏立克次体中发现的。这两个基因组都是来自高度相关的梅利氏布鲁氏菌的1号染色体的简化版本。在两个rRNA操纵子的两侧，有一个片段与B. melitensis第2号染色体上的基因相似，这表明它是通过整合两个巴尔通体物种共同祖先的megareplicon DNA获得的。对这些生物的媒介-宿主生态的比较表明，利用受宿主限制的媒介与基因组降解速度加快有关，这可能解释了为什么由专门媒介传播的人类病原体数量少于使用广泛宿主媒介的人畜共患媒介。
We present the complete genomes of two human pathogens, Bartonella quintana (1,581,384 bp) and Bartonella henselae (1,931,047 bp). The two pathogens maintain several similarities in being transmitted by insect vectors, using mammalian reservoirs, infecting similar cell types (endothelial cells and erythrocytes) and causing vasculoproliferative changes in immunocompromised hosts. A primary difference between the two pathogens is their reservoir ecology. Whereas B. quintana is a specialist, using only the human as a reservoir, B. henselae is more promiscuous and is frequently isolated from both cats and humans. Genome comparison elucidated a high degree of overall similarity with major differences being B. henselae specific genomic islands coding for filamentous hemagglutinin, and evidence of extensive genome reduction in B. quintana, reminiscent of that found in Rickettsia prowazekii. Both genomes are reduced versions of chromosome I from the highly related pathogen Brucella melitensis. Flanked by two rRNA operons is a segment with similarity to genes located on chromosome II of B. melitensis, suggesting that it was acquired by integration of megareplicon DNA in a common ancestor of the two Bartonella species. Comparisons of the vector-host ecology of these organisms suggest that the utilization of host-restricted vectors is associated with accelerated rates of genome degradation and may explain why human pathogens transmitted by specialist vectors are outnumbered by zoonotic agents, which use vectors of broad host ranges.