Urease activity and urea gene sequencing of coccoid forms of H-Pylori induced by different factors
Urease activity and urea gene sequencing of coccoid forms of H-Pylori induced by different factors
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DOI：
10.1007/s00284-007-9047-y
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发表时间：
2008-02-01
影响因子：
2.6
通讯作者：
Arslan, Hande
中科院分区：
文献类型：
--
作者：
Can, Fusun;Karahan, Ceren;Arslan, Hande
幽门螺杆菌有两种形态：螺旋形和球形。长期以来，不可培养的球形体被认为是细胞死亡的形态学表现。然而，最近的研究表明这种形式的可行性。这种形式的H。现在人们怀疑幽门螺杆菌在细菌的传播中发挥了作用，并且是抗菌治疗后感染复发的部分原因。尿素酶活性测定结果表明，H. pylori是一个重要的维持因子。因此，确定尿素酶的活性和可能的突变的球菌的DNA序列将有助于了解感染的发病机制，这些形式可能是负责。本研究的目的是分析球孢H.幽门螺杆菌的形成是由不同的因素引起的。为此，本文测定了H. pylori NCTC 11637标准菌株和两个临床分离株在通过不同方法如暴露于阿莫西林、需氧、冷饥饿和老化将细胞转化为球形形式之前和之后进行了检测。通过PCR技术扩增411-bp的ureA基因和115-bp的ureB基因区域，并对ureA基因进行测序，研究了这些条件对脲酶基因的影响。球形细胞的脲酶活性低于螺旋形细胞。通过PCR扩增所有球形细胞中的ureA和ureB基因区域。通过不同方法诱导转化为球形体，发现对ureA基因的核苷酸序列没有影响。这些结果表明，球孢H.幽门螺杆菌在各种温和的环境条件下受到高度保护。
Helicobacter pylori exists in two morphologic forms: spiral shaped and coccoid. The nonculturable coccoid forms were believed to be the morphologic manifestations of cell death for a long time. However, recent studies indicate the viability of such forms. This form of H. pylori is now suspected to play a role in the transmission of the bacteria and is partly responsible for relapse of infection after antimicrobial treatment. Urease activity of H. pylori is an important maintenance factor. Determination of urease activity and possible mutations in the DNA sequences of coccoid bacteria will hence contribute to the understanding of pathogenesis of infections, which these forms might be responsible for. In this study, our aim was to analyze the urease activity and investigate the urease gene sequences of coccoid H. pylori forms induced by different factors with respect to the spiral form. For this purpose, the urease activities of H. pylori NCTC 11637 standard strain and two clinical isolates were examined before and after transformation of the cells to coccoid forms by different methods such as exposure to amoxicillin, aerobiosis, cold starvation, and aging. The effects of these conditions on the urease gene were examined by the amplification of 411-bp ureA gene and 115-bp ureB gene regions by PCR technique and sequencing of the ureA gene. The urease activities of coccoid cells were found to be lower than those of the spiral form. ureA and ureB gene regions were amplified in all coccoid cells by PCR. Inducing the change to coccoid form by different methods was found to have no effect on the nucleotide sequence of the ureA gene. These results show that the urease gene region of coccoid H. pylori is highly protected under various mild environmental conditions.