Analysis of virulence diversity of 73 Helicobacter�pylori strains isolated in Guizhou province, China

Abstract

The present study aimed to investigate the virulence diversity of Helicobacter pylori (H. pylori) in major ethnic groups residing in Guizhou province, China, and its association with clinical outcomes. Gastric mucosal biopsies were collected from the pylorus of patients with gastrointestinal disorders. H. pylori was identified by colonial morphology, Gram staining, a urease test and H. pylori‑specific 16S rRNA gene fragment PCR amplification. DNA was extracted from pure culture and used for virulence gene analysis. The cytotoxin associated gene A (cagA), vacuolating cytotoxin A (vacA) and induced by contact with epithelium gene A (iceA) genes were analyzed by polymerase chain reaction analysis. The cagA gene was further analyzed through sequencing of the C‑terminal region containing EPIYA motifs, and phylogenetic analysis of the cagA C‑terminal variable region was performed using MEGA 6.0 software. In the present study, 73 H. pylori strains were isolated from clinical samples. cagA genotypes were detected in all strains, namely cagA‑AB, ‑ABC, ‑ABD and ‑BD genotypes were found in five (6.85%), three (4.11%), 63 (86.30%) and two (2.74%) isolates, respectively. Phylogenetic analysis showed that there was a clustering association between the cagA‑AB and cagA‑ABC genotypes, and between the cagA‑ABD and cagA‑BD genotypes. In terms of the frequency of the four EPIYA or EPIYA‑like motifs, the most predominant was EPIYA (92.92%), followed by EPIYT (3.77%), ESIYA (2.83%) and ESIYT (0.47%). The predominant vacA genotype was s1c/m2 (65.75%), and the predominant iceA genotype was iceA1 (79.45%). There were no associations between the H. pylori cagA, vacA or iceA genotypes and clinical outcomes. No significant difference was found in the distribution of these genotypes according to the age, ethnicity or location of residence of patients. In conclusion, H. pylori isolated from patients in Guizhou region, China, showed a unique genotype, which was mainly East Asia‑type cagA (ABD), vacA s1c/m2 genotype or iceA1‑postiive. These results provide important information on the distribution of H. pylori virulence genotypes in Guizhou province, China.

Sperm parameters and anti-Müllerian hormone remain stable with Helicobacter pylori infection: a cross-sectional study

“…In Western countries, CagA+ strains comprise 50-60% of the HP+ population, and in the Chinese population, CagA+ strains occupy nearly 100% of the HP+ population [32,33]. Studies investigating the CagA status of Chinese HP strains with polymerase chain reaction (PCR) detected CagA genotypes in nearly all strains [34,35]. Considering the high CagA positivity in the Chinese HP+ population, the sperm concentration and motility should be weakened in HP+ patients, but the present study showed stable parameters.…”

Helicobacter pylori Virulence Factors and Clarithromycin Resistance-Associated Mutations in Mexican Patients

“…Similarly, when the combination of the s and m alleles of vacA is analyzed, the prevalence also differs. The vacA m1 allele is common in North Asian countries, including Japan and South Korea, whereas the m2 allele is predominant in Southeast Asia, including Taiwan, China, and Vietnam [ 36 ]. Interestingly, in this study, the vacA s1m1/s2m2/cagA+ genotype in both the antrum and corpus was detected in one patient, and the vacA s1m1/s1m2/cagA− genotype was detected in the corpus in two patients.…”

Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms

“…Other methods of treatments have also received recognition across the globe. The limitation, however, is that different strains exhibiting different drug resistance and susceptibility patterns have been isolated from a single patient from several locations [ 82 – 86 ].…”

“…For more information, a review paper by Roszczenko-Jasinska et al [ 87 ] is recommended. In addition, the co-infection with multiple H. pylori strains, which may have different genotypes and phenotypes, has been observed within the same patient [ 86 ]. Such genetic variability proves drug susceptibility therapy difficult and poses the danger of the evolution of more virulent and adapted strains.…”