摘要
目的 了解和分析中国幽门螺杆菌（ Ｈｅｌｉｃｏｂａｃｔｅｒ ｐｙｌｏｒｉ， Ｈｐ）菌株细胞毒素相关基因Ａ（ｃａｇＡ） 的核苷酸序列特性．方法 从两位患胃溃疡儿童的胃粘膜中分离两株 Ｈｐ 菌株，用ＰＣＲ方法扩增ｃａｇＡ 基因的５○端和３○端的两个片段并作克隆和序列分析．结果 两株中国 Ｈｐ 菌株ｃａｇＡ 基因之间的同源性为９４ ％ ～９５ ％ ． 中国Ｈｐ 菌株与国外菌株相同区段比较，５○端的同源性为８９ ％ ～９２ ％ ，３○端的同源性为６９ ％ ．结论 中国Ｈｐ 菌株与国外Ｈｐ 菌株ｃａｇＡ 基因５○端序列部分区域的同源性较好，可以作为分子检测 Ｈｐ 感染的靶基因序列，而ｃａｇＡ 基因３○端序列部分区域的同源性较差，可以作为Ｈｐ 分子流行病学研究的靶基因序列．
AIM To investigate the sequence characterization of Hp cag A gene from Chinese strains. METHODS Two Hp strains derived from two Chinese pediatric patients with gastric ulcer were isolated. Two DNA fragments of Hp cag A gene 5 and 3 regions of each strain were PCR amplified, cloned and sequenced. RESULTS The nucleotide homology between two Chinese Hp strains was 94%. However, the nucleotide homology of cag A gene 5 and 3 regions between Chinese and American strains and between Chinese and Italian strains were 89% and 69%-71%, respectively. CONCLUSION The nucleotide sequences of Hp cag A gene 5 region among the strains showed a better homology, this region could be chosen as a target gene for molecular diagnosis of Hp infection, while that of cag A gene 3 region between Chinese and American strains or between Chinese and Italian strains showed a poorer homology, this region could be chosen as a target gene for Hp molecular epidemiological study.
出处
《世界华人消化杂志》
CAS
1999年第8期669-672,共4页
World Chinese Journal of Digestology
关键词
幽门螺杆菌
细胞毒素
相关基因A
序列分析
Helicobacter pylori infection
cag A
gene cloning
cag A gene
sequencing
