不同类型慢性胃炎患者幽门螺杆菌的分离培养、耐药与毒力基因研究

目的 研究不同类型慢性胃炎患者幽门螺杆菌（Helicobacter pylori，Hp）的感染情况，检测分离株的耐药性与毒力基因。方法 采集患者胃黏膜，分离Hp并进行药敏试验。PCR扩增克拉霉素、左氧氟沙星耐药相关基因23S rRNA、gyrA及毒力基因cagA、vacA、iceA，测序并分析23S rRNA和gyrA扩增产物的突变位点。分析慢性胃炎类型与Hp的分离率、耐药性和毒力基因的关系。结果 120例患者共分离获得45株Hp（37.5%）。Hp对甲硝唑、克拉霉素、左氧氟沙星、阿莫西林、呋喃唑酮和四环素的耐药率分别为97.8%、28.9%、28.9%、4.4%、0和0。在克拉霉素和左氧氟沙星耐药菌株中，23S rRNA、gyrA基因最常见的突变位点分别为A2143G（76.9%）和N87K（38.5%）。cagA、vacA s1a、vacA s1b、vacA s1c、vacA s2、vacA m1、vacA m2、iceA1、iceA2阳性率分别为97.8%、97.8%、0、95.6%、0、37.7%、62.2%、71.1%、24.4%。在不同类型慢性胃炎组间，Hp的分离率差异有统计学意义（χ2 = 13.299，P＜0.05），分离株的耐药率差异均无统计学意义（均P＞0.05），iceA1、iceA2的分布差异有统计学意义（均P＜0.05）。结论 不同类型慢性胃炎患者Hp的分离率不同，Hp感染治疗可选呋喃唑酮和四环素，iceA1和iceA2毒力基因可能与胃炎类型有关。

Study on isolation,drug resistance and virulence genes of Helicobacter pylori from patients with different types of chronic gastritis

Objective To study the infection of Helicobacter pylori (Hp) in gastric mucosa of patients with different types of chronic gastritis, and to detect the drug resistance and virulence genes of the isolates. Methods Gastric mucosa of patients with different types of chronic gastritis were collected for Hp isolation and drug sensitivity test. The 23S rRNA and gyrA of CLA and LVX resistance related genes and cagA, vacA and iceA virulence genes were amplified by PCR. The 23S rRNA and gyrA gene PCR products were sequenced and analyzed. The relationship between chronic gastritis types and Hp isolation rate, drug resistance and virulence genes were analyzed. Results A total of 45 strains of Hp were isolated from 120 patients (37.5%). The resistance rates of MTZ, CLA, LVX, AMX, FZ and TE were 97.8%, 28.9%, 28.9%, 4.4%, 0, and 0, respectively. In CLA and LVX resistant strains, the most common mutation sites of 23S rRNA and gyrA genes were A2143G (76.9%) and N87K (38.5%) respectively. The positive rates of cagA, vacA s1a, vacA s1b, vacA s1c, vacA s2, vacA m1, vacA m2, iceA1 and iceA2 were 97.8%, 97.8%, 0, 95.6%, 0, 37.7%, 62.2%, 71.1%, and 24.4%, respectively. Among different types of chronic gastritis groups, the difference in the isolation rates of Hp was statistically significant (χ2=13.299, P<0.05), the drug resistance rates of the isolates were not statistically significant (P>0.05), and the distribution of iceA1 and iceA2 virulence genes was statistically significant (P<0.05). Conclusion The isolation rates of Hp in patients with different types of chronic gastritis are different. Furazolidone and tetracycline should be the first choice for treatment of Hp infection. IceA1 and iceA2 virulence genes may be related to the type of chronic gastritis.