Abstract:
:Colonization of the mucosa of the stomach and the duodenum by Helicobacter pylori is the major cause of acute and chronic gastroduodenal pathologies in humans. Duodenal ulcer formation strongly correlates with the expression of an antigen (CagA) that is usually coeexpressed with the vacuolating cytotoxin (VacA), a protein that causes ulceration in the stomach of mice. However, the relationship between these two virulence factors is unknown. To define whether CagA and VacA are coexpressed in all clinical isolates and their relationships, we collected 43 clinical isolates of H. pylori and studied their genetic and phenotypic properties. Based on this analysis, most of the strains could be classified into two major types. Type I bacteria had the gene coding for CagA and expressed the CagA protein and the vacuolating cytotoxin. Type II bacteria did not have the gene coding for CagA and did not express either the CagA protein or the vacuolating cytotoxin. Type I and type II bacteria represented 56 and 16%, respectively, of the 43 clinical isolates, while the remaining 28% had an intermediate phenotype, expressing CagA independently of VacA or vice versa. This finding shows that although it is present in most cytotoxic strains, CagA is not necessary for the expression of the vacuolating cytotoxin.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Xiang Z,Censini S,Bayeli PF,Telford JL,Figura N,Rappuoli R,Covacci Adoi
10.1128/IAI.63.1.94-98.1995subject
Has Abstractpub_date
1995-01-01 00:00:00pages
94-8issue
1eissn
0019-9567issn
1098-5522journal_volume
63pub_type
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更新日期:1999-10-01 00:00:00
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journal_title:Infection and immunity
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更新日期:1993-09-01 00:00:00
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更新日期:1998-01-01 00:00:00
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