Genetic characterisation of Helicobacter pylori isolates from an Argentinean adult population based on cag pathogenicity island right-end motifs, lspA-glmM polymorphism and iceA and vacA genotypes

Abstract

Isolates of Helicobacter pylori from 88 patients were characterised by cagA status, cagA pathogenicity island (PAI) right-end motifs, iceA, vacA and lspA-glmM genotypes, primarily by PCR-based analysis, to investigate whether Argentinean isolates differed from those recovered in southern Europe or other Latin American countries. PCR-based analysis of vacA alleles was confirmed by reverse hybridisation in 56 cases, while sequence analysis was performed either when iceA and vacA genotypes could not be determined by PCR, or to investigate PCR and reverse hybridisation vacA genotyping discordance. Typing by lspA-glmM restriction fragment length polymorphism was performed with HhaI and AluI. The pattern of cag PAI right-end motifs and the prevalence of type Ia were similar to those in isolates from southern European countries, with cagA(+)/iceA1/vacA-s1 m1 being the commonest genotype. Reverse hybridisation identified a vacA-s1a/s1b recombinant allele, confirmed by sequencing analysis. Analysis of lspA-glmM genotypes identified at least 73 unrelated strains. Few mixed infections were identified, but in one case, isolates from a single biopsy exhibiting two vacA alleles were shown by lspA-glmM fingerprints to be two unrelated strains. No associated effect on ulcer disease risk was demonstrated by analysis of cagA, vacA and iceA status. Overall, the isolates of H. pylori from Argentina were similar to isolates from southern Europe or Latin American countries, and infections were associated mainly with single H. pylori strains.

Virulence Factors of Helicobacter pylori and Their Relationship with the Development of Early and Advanced Distal Intestinal Type Gastric Adenocarcinoma

“…Although located on a different loci of the H. pylori chromosome, cagA is strongly linked with VacA cytotoxic activity (Hocker & Hohenberger, 2003) and strains expressing the combination of these alleles and cag-PAI show enhanced epithelial cell injury (Ghiara et al, 1995). In our study, for patients with advanced gastric cancer, we found prevalent cagA positive (82.8%) and vacA s1m1 (70.7%) strains, corroborating the results of other studies (Miehlke et al, 2000;Leanza et al, 2004), and demonstrating that this combination can result in more virulent strains. These results are also similar to those obtained in China (Qiao et al, 2003), where H. pylori strains were cagA positive in 95% of samples in the gastric cancer group and the expression of type s1 vacA was more than type s2.…”

Helicobacter pylori iceA, Clinical Outcomes, and Correlation with cagA: A Meta-Analysis

“…An age- and sex-matched case-control study was conducted in only 1 report [47]. Although 46 articles showed a difference in the iceA type between gastritis and PUD, 14 articles did not show the distribution of GU and DU [12], [18]–[20], [24], [28], [32], [36], [39], [43], [48], [52], [53], [55]. Four studies examined the prevalence of iceA types in gastritis and GC, but not in PUD [13], [26], [44], [51].…”

Turkish isolates of Helicobacter pylori belong to the Middle Eastern genotypes

“…We were interested to read the recent accounts in CMI regarding the distribution of Helicobacter pylori genotypes in Mexico and Argentina [1,2]. Epidemiological studies suggest that the prevalence of H. pylori infection varies between developed and developing countries, as well as according to ethnicity, place of birth and socioeconomic factors, even among people living in the same country.…”