Frequency of virulence genes in mixed infections with Helicobacter pylori strains from a Mexican population
| Autor: | I. Morales-Méndez, F. Armendáriz-Toledano, S.A. Ochoa-Pérez, J. Fonseca-Nájera, R. González-Vázquez, S. Giono-Cerezo, María Guadalupe Córdova-Espinoza, A. Escamilla-Gutiérrez |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Genotyping Virulence Genotipificación Microbiology 03 medical and health sciences Multiplex polymerase chain reaction Genotype CagA Mixed infection Infección mixta lcsh:RC799-869 Gene biology Helicobacter pylori Virulence factors General Medicine biology.organism_classification Virology ADN polimórfico amplificado al azar Exact test 030104 developmental biology Factores de virulencia Random Amplified Polymorphic DNA lcsh:Diseases of the digestive system. Gastroenterology |
| Zdroj: | Revista de Gastroenterología de México (English Edition), Vol 81, Iss 1, Pp 11-20 (2016) |
| Popis: | Background Helicobacter pylori (H. pylori) is associated with gastroduodenal diseases. Virulence of clinical isolates is related to clinical outcome. Moreover, with microdiversity studies in clinical isolates from a single patient, but from a different origin (antrum or corpus), it is possible to demonstrate that there are simultaneous mixed infections. Aims To genotype H. pylori strains with multiplex PCR, according to their clinical virulence, and in this manner know the frequency of each genotype and relate it to clinical outcome in order to prevent the development of severe diseases. Methods A total of 210 patients with gastric alterations were studied. Virulence classification of H. pylori strains was carried out with multiplex PCR and 127 strains were identified as H. pylori by PCR (glmM and cagE). Genotype and clinical outcome were evaluated with the Fisher's exact test. In addition, RAPD-PCR was performed as a fingerprinting method to analyze mixed infections. Results The cagA, vacAs1, and vacAm1 genes were detected in all the clinical isolates. Strains were classified as: type i , 40.15% (51/127); type ii , 22.04% (28/127); and type iii , 28.4% (36/127), but two new different genotypes were also detected: (1) babA2+, cagA+, vacAs1+, 6.29% (8/127) and (2) babA2+, cagA-, vacAs2/m2+, 3.14% (4/127). The cagE gene was detected in type i strains. Conclusions The Fisher's exact test did not support a significant association between clinical outcome and genotype. The main circulating genotypes in the Mexican population studied were: cagA+, vacAs1, and vacAm1. Multiplex PCR can be used as a screening test for H. pylori strains. Furthermore, the cagE gene is a good marker for identifying cag-PAI positive strains. |
| Databáze: | OpenAIRE |
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