Multiple infection and microdiversity among Helicobacter pylori isolates in a single host in India.
Multiple infection and microdiversity among Helicobacter pylori isolates in a single host in India.
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DOI：
10.1371/journal.pone.0043370
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Mukhopadhyay AK
中科院分区：
文献类型：
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作者：
Patra R;Chattopadhyay S;De R;Ghosh P;Ganguly M;Chowdhury A;Ramamurthy T;Nair GB;Mukhopadhyay AK
幽门螺杆菌是最多样化的细菌种类之一，慢性感染超过70%的印度人口。有趣的是，显示特定胃生态位内幽门螺杆菌菌株微多样性的数据仍然很少。为了了解给定宿主内幽门螺杆菌菌株的遗传多样性程度，对30例胃-十二指肠疾病患者进行了内窥镜检查，并从每位患者中分离出10个单个菌落。对这10个单菌落进行DNA指纹鉴定，并对cagA、vacA、iceA、vapD、cag PAI空位点、IS605、RFLP等重要遗传标记进行基因分型，结果表明30例患者均感染了1种以上的菌株，有时菌株存在5 ~ 6种遗传变异。对某些遗传位点的分析表明，单个患者的菌落之间存在微多样性，这可能是由于病原体长期携带过程中的重组事件。这些结果表明，大多数患者由于反复接触这种具有不同基因组成的病原体而获得幽门螺杆菌，这可能增加了超级感染的可能性。这些不相关的幽门螺杆菌菌株之间的遗传交换可能支持某些幽门螺杆菌变体在给定宿主中比亲本菌株生长得更好，从而增加了感染严重程度的可能性。
Helicobacter pylori is one of the most diverse bacterial species that chronically infects more than 70% of Indian population. Interestingly, data showing microdiversity of the H. pylori strains within a particular gastric niche remained scarce. To understand the extent of genetic diversity among H. pylori strains within a given host, 30 patients with gastro-duodenal problems were subjected to endoscopy and from each patient 10 single colonies were isolated. Characterization of each of these 10 single colonies by DNA fingerprinting as well as genotyping of several important genetic markers viz. cagA, vacA, iceA, vapD, cag PAI empty site, IS605, RFLP and two other genetic segments within cag PAI revealed that all of the 30 patients were infected with more than one strain and sometimes strains with 5 to 6 types of genetic variants. Analyses of certain genetic loci showed the microdiversity among the colonies from single patient, which may be due to the recombination events during long-term carriage of the pathogen. These results suggest that most of the patients have acquired H. pylori due to repeated exposure to this pathogen with different genetic make-up, which may increase the possibility of super infections. Genetic exchanges between these unrelated H. pylori strains may support certain H. pylori variant to grow better in a given host than the parental strain and thereby increasing the possibility for the severity of the infection.