Helicobacter pylori oipA, vacA and dupA genetic diversity in individual hosts
Helicobacter pylori oipA, vacA and dupA genetic diversity in individual hosts
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DOI：
10.1099/jmm.0.011684-0
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Catalano, Mariana
中科院分区：
文献类型：
--
作者：
Jose Matteo, Mario;Ines Armitano, Rita;Catalano, Mariana
在慢性感染过程中，幽门螺杆菌推定的毒力因子作为细菌适应宿主环境变化的途径，可以经历一个不断进化的机制。研究了40例患者腔体多生态位分离的oipA、vacA和dupA的遗传多样性。共检测了229株菌株。对扩增片段进行直接DNA序列分析，研究oipA的“开/关”表达状态，以及产生连续dupA基因（jhp0917-jhp0918）的jhp0917中是否存在C或T插入。通过多重PCR鉴定vacA等位基因。9例患者观察到不同位间oipA CT重复模式；在其中的六个中，发现了“开”和“关”的混合模式。在这9例患者中的3例中，在单个宿主中也观察到不同的vacA等位基因。生态位间dupA差异涉及jhp0917和/或jhp0918或dupA突变的缺失和存在，包括那些可能起源于非功能性基因的突变，并且它们也存在于两名混合oipA CT模式的患者和另外七名患者中。混合感染的证据仅在两例患者中观察到。综上所述，oipA和dupA基因表现出相似的生态位间变异性，约有1/4的患者出现。相反，vacA等位基因微进化似乎是一个不太常见的事件，发生在大约1/10的患者中，可能是由于该基因“在体内”进化的机制。
Helicobacter pylori putative virulence factors can undergo a continuously evolving mechanism as an approach to bacterial adaptation to the host changing environment during chronic infection. oipA, vacA and dupA genetic diversity among isolates from multiple biopsies (niches) from the antrum and corpus of 40 patients was investigated. A set of 229 isolates was examined. Direct DNA sequence analysis of amplified fragments was used to study oipA 'on/off' expression status as well as the presence of C or T insertion in jhp0917 that originates a continuous (jhp0917-jhp0918) dupA gene. vacA alleles were identified by multiplex PCR. Different inter-niches oipA CT repeat patterns were observed in nine patients; in six of these, 'on' and 'off' mixed patterns were found. In three of these nine patients, different vacA alleles were also observed in a single host. Inter-niche dupA differences involved the absence and presence of jhp0917 and/or jhp0918 or mutations in dupA, including those that may originate a non-functional gene, and they were also present in two patients with mixed oipA CT patterns and in another seven patients. Evidence of mixed infection was observed in two patients only. In conclusion, oipA and dupA genes showed similar inter-niche variability, occurring in approximately 1/4 patients. Conversely, vacA allele microevolution seemed to be a less common event, occurring in approximately 1/10 patients, probably due to the mechanism that this gene evolves 'in vivo'.