Characterization of morphological conversion of Helicobacter pylori under anaerobic conditions
Characterization of morphological conversion of Helicobacter pylori under anaerobic conditions
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DOI：
10.1111/1348-0421.12582
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发表时间：
2018-04-01
影响因子：
2.6
通讯作者：
Mimuro, Hitomi
中科院分区：
文献类型：
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作者：
Hirukawa, Sayaka;Sagara, Hiroshi;Mimuro, Hitomi
幽门螺杆菌 (H. pylori) 是一种革兰氏阴性微需氧细菌病原体，寄居在一半以上人类的胃中，与慢性胃炎、消化性溃疡和胃癌有关。当螺旋形幽门螺杆菌从微需氧胃转移到厌氧肠道时，它们会经历形态转变为可存活但不可培养的球状形式。然而，人们对幽门螺杆菌在长时间厌氧条件下的形态和致病特征知之甚少。在这项研究中，使用扫描电子显微镜记录了厌氧引起的幽门螺杆菌的形态变化，从螺旋状到球状，再到新定义的碎片形式。蛋白质印迹分析表明，所有三种形式几乎均等地表达某些致病蛋白，包括细菌细胞毒素相关基因 A (CagA)、cag IV 型分泌系统 (TFSS) 成分、血型抗原结合粘附素 BabA 和 UreA（脲酶脱辅基酶）。在所有三种形式的幽门螺杆菌中也检测到类似的脲酶活性。然而，与螺旋形式相反，在厌氧诱导的球状和碎片形式的幽门螺杆菌中，发现细菌运动性和 TFSS 活性被消除。值得注意的是，事实证明，一些厌氧诱导的碎片状态细胞可以在体外转化为具有增殖能力的螺旋细菌。这些结果表明，长时间暴露于厌氧肠道可能无法消除幽门螺杆菌恢复螺旋致病状态的可能性。
Helicobacter pylori (H. pylori), a gram-negative microaerophilic bacterial pathogen that colonizes the stomachs of more than half of all humans, is linked to chronic gastritis, peptic ulcers and gastric cancer. Spiral-shaped H. pylori undergo morphologic conversion to a viable but not culturable coccoid form when they transit from the microaerobic stomach into the anaerobic intestinal tract. However, little is known about the morphological and pathogenic characteristics of H. pylori under prolonged anaerobic conditions. In this study, scanning electron microscopy was used to document anaerobiosis-induced morphological changes of H. pylori, from helical to coccoid to a newly defined fragmented form. Western blot analysis indicated that all three forms express certain pathogenic proteins, including the bacterial cytotoxin-associated gene A (CagA), components of the cag-Type IV secretion system (TFSS), the blood group antigen-binding adhesin BabA, and UreA (an apoenzyme of urease), almost equally. Similar urease activities were also detected in all three forms of H. pylori. However, in contrast to the helical form, bacterial motility and TFSS activity were found to have been abrogated in the anaerobiosis-induced coccoid and fragmented forms of H. pylori. Notably, it was demonstrated that some of the anaerobiosis-induced fragmented state cells could be converted to proliferation-competent helical bacteria in vitro. These results indicate that prolonged exposure to the anaerobic intestine may not eliminate the potential for H. pylori to revert to the helical pathogenic state.