Conservation of the cytotoxin-associated (cagA) gene of Helicobacter pylori and investigation of association with vacuolating-cytotoxin activity and gastroduodenal disease.
FEMS Immunol Med Microbiol
; 9(4): 307-15, 1994 Oct.
Article
em En
| MEDLINE
| ID: mdl-7866352
ABSTRACT
Polymerase chain reaction (PCR) amplification and DNA hybridization analyses were used to test for the presence of the cytotoxin-associated (cagA) gene in 108 strains of Helicobacter pylori. Fifty-two geographically diverse strains of known vacuolating cytotoxin activity, and 56 recent UK clinical isolates from patients with duodenal ulceration (n = 28) and from healthy individuals who were endoscopically normal (n = 28) were studied. Overall, cagA was detected by PCR in 74 (69%) strains and DNA hybridization provided evidence of gene homologues in a further eight strains. For 96% of the cytotoxin-producing strains and 46% of the non-cytotoxin producing strains, there was a close association either with presence or absence of cagA. At the genomic level, Southern blot DNA hybridization showed that cagA was probably present in a single copy in most of the H. pylori tested, and that HaeIII restriction site variation within and around the gene provided additional markers of diversity for the species. As 40% of the cagA containing strains did not produce an active cytotoxin, and no significant association between cagA presence and DU-disease was observed, we concluded that the presence of the cagA gene in H. pylori could not be used as a single reliable predictor of higher risk patients.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Helicobacter pylori
/
Citotoxinas
/
Úlcera Duodenal
/
Genes Bacterianos
/
Antígenos de Bactérias
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article