%0 Journal Article
%T Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcers
%A Fernando Antonio-Rinc¨®n
%A Yolanda L¨®pez-Vidal
%A Gonzalo Castillo-Rojas
%A Eduardo C Lazcano-Ponce
%A Sergio Ponce-de-Le¨®n
%A Mar¨ªa L Tabche-Barrera
%A Germ¨¢n R Aguilar-Guti¨¦rrez
%J Annals of Clinical Microbiology and Antimicrobials
%D 2011
%I BioMed Central
%R 10.1186/1476-0711-10-18
%X The cag PAI integrity was performed by detection of eleven targeted genes along this locus using dot blot hybridization and PCR assays. The vacA allelic, cag PAI genotype 1 and IS605 status were determined by PCR analysis.Groups of 16-17 isolates (n = 50) from two patients with NPU, NBPU, and BPU, respectively, were studied. 90% (45/50) of the isolates harbored a complete cag PAI. Three BPU isolates lacked the cag PAI, and two of the NBPU had an incomplete cag PAI: the first isolate was negative for three of its genes, including deletion of the cagA gene, whereas the second did not have the cagM gene. Most of the strains (76%) had the vacA s1b/m1 genotype; meanwhile the IS605 was not present within the cag PAI of any strain but was detected elsewhere in the genome of 8% (4/50).The patients had highly virulent strains since the most of them possessed a complete cag PAI and had a vacA s1b/m1 genotype. All the isolates presented the cag PAI without any IS605 insertion (genotype 1). Combined vacA genotypes showed that 1 NPU, 2 NBPU, and 1 BPU patients (66.6%) had a mixed infection; coexistence of H. pylori strains with different cag PAI status was observed in 1 NBPU and 2 BPU (50%) of the patients, but only two of these patients (NBPU and BPU) had different vacA genotypes.H. pylori is a well-recognized pathogen that chronically infects the stomach of up to 50% of the world's human population. The prevalence of H. pylori is high in developing countries; in Mexico its seroprevalence is 66% of the general population and is common in asymptomatic population [1-5].There are two genotypic characteristics of virulent H. pylori strains: the vacA gene, and the cag PAI region. Virtually all H. pylori strains have a copy of vacA, but the structure among alleles varies in three regions: the signal (s) region that is present as type s1 (subtype a, b and c) or type s2, the intermediate (i) region that exists in subtype 1 and 2, and the middle (m) region that exists in three different
%K Helicobacter pylori
%K cag PAI
%K vacA
%K peptic ulcers
%K Mexico
%U http://www.ann-clinmicrob.com/content/10/1/18