Boyanova Lyudmila, Markovska Rumiana, Yordanov Daniel, Marina Maya, Ivanova Katusha, Panayotov Stephan, Gergova Galina, Mitov Ivan
Chair of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria.
Diagn Microbiol Infect Dis. 2009 Aug;64(4):374-80. doi: 10.1016/j.diagmicrobio.2009.04.005.
The aim of the study was to evaluate the prevalence of main virulence genes in Helicobacter pylori strains from 116 patients with peptic ulcers (41 cases) and nonulcer diseases (75) by polymerase chain reaction (PCR) with pure cultures and to compare the results with those by multiplex PCR in 39 H. pylori-positive gastric biopsies in another center in Sofia, Bulgaria. Strain susceptibility to amoxicillin, metronidazole, and clarithromycin was determined by agar dilution method. By PCR with pure cultures, coinfections with multiple H. pylori strains were found in 8 (6.9%) patients who were excluded from the statistical analysis. Prevalence of toxigenic type vacA s1 was higher (91.7%) than that usually reported in Europe. cagA-positive genotype was detected in most (81.5%) strains, and almost all of them harbored vacA s1 genotype. Strains with cagA+/vacA s1a genotype were more common (80.6%) than the other genotypes (19.4%, P = 0.0001). The ulcer patients had more often virulent strains than the other patients (92.3% versus 75.4% for cagA+, 100.0% versus 87.0% for vacA s1, 100% versus 84.0% for vacA s1a, and 92.3% versus 73.9% for cagA+/vacA s1a, respectively). The prevalence of H. pylori virulence-associated genes was not associated with patients' sex and age or with the antibacterial resistance of strains. The most common H. pylori genotype was cagA+/vacA s1a. Similar prevalence of cagA-positive (82.1%), vacA s1 (97.4%), and cagA+/vacA s1 strains (79.5%) was found by multiplex PCR in gastric biopsies in the 2nd center. In conclusion, H. pylori strains with virulent genotypes are widespread in symptomatic Bulgarian patients.
本研究旨在通过对116例消化性溃疡患者（41例）和非溃疡疾病患者（75例）的幽门螺杆菌菌株进行纯培养，采用聚合酶链反应（PCR）评估主要毒力基因的流行情况，并将结果与保加利亚索非亚另一中心对39例幽门螺杆菌阳性胃活检组织进行多重PCR的结果进行比较。通过琼脂稀释法测定菌株对阿莫西林、甲硝唑和克拉霉素的敏感性。通过对纯培养物进行PCR，在8例（6.9%）患者中发现了多种幽门螺杆菌菌株的混合感染，这些患者被排除在统计分析之外。产毒型vacA s1的流行率较高（91.7%），高于欧洲通常报道的水平。在大多数（81.5%）菌株中检测到cagA阳性基因型，并且几乎所有这些菌株都携带vacA s1基因型。cagA+/vacA s1a基因型的菌株比其他基因型更为常见（80.6%比19.4%，P = 0.0001）。溃疡患者比其他患者更常携带毒力菌株（cagA+分别为92.3%对75.4%，vacA s1分别为100.0%对87.0%，vacA s1a分别为100%对84.0%，cagA+/vacA s1a分别为92.3%对73.9%）。幽门螺杆菌毒力相关基因的流行率与患者的性别、年龄或菌株的抗菌耐药性无关。最常见的幽门螺杆菌基因型是cagA+/vacA s1a。在第二个中心的胃活检组织中，通过多重PCR发现cagA阳性（82.1%）、vacA s1（97.4%）和cagA+/vacA s1菌株（79.5%）的流行率相似。总之，具有毒力基因型的幽门螺杆菌菌株在有症状的保加利亚患者中广泛存在。
