Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1995-9-5
pubmed:databankReference
pubmed:abstractText
Approximately 50% of Helicobacter pylori strains produce a cytotoxin, encoded by vacA, that induces vacuolation of eukaryotic cells. Analysis of a clinically isolated tox- strain (Tx30a) indicated secretion of a 93-kDa product from a 3933-base pair vacA open reading frame. Characterization of 59 different H. pylori isolates indicated the existence of three different families of vacA signal sequences (s1a, s1b, and s2) and two different families of middle-region alleles (m1 and m2). All possible combinations of these vacA regions were identified, with the exception of s2/m1 (p < 0.001); this mosaic organization implies that recombination has occurred in vivo between vacA alleles. Type s1/m1 strains produced a higher level of cytotoxin activity in vitro than type s1/m2 strains; none of 19 type s2/m2 strains produced detectable cytotoxin activity. The presence of cagA (cytotoxin-associated gene A) was closely associated with the presence of vacA signal sequence type s1 (p < 0.001). Among patients with past or present peptic ulceration, 21 (91%) of 23 harbored type s1 strains compared with 16 (48%) of 33 patients without peptic ulcers; only 2 (10%) of 19 subjects harboring type s2 strains had past or present peptic ulcers (p < 0.005). Thus, specific vacA genotypes of H. pylori strains are associated with the level of in vitro cytotoxin activity as well as clinical consequences.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17771-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7629077-Adult, pubmed-meshheading:7629077-Aged, pubmed-meshheading:7629077-Aged, 80 and over, pubmed-meshheading:7629077-Alleles, pubmed-meshheading:7629077-Amino Acid Sequence, pubmed-meshheading:7629077-Antigens, Bacterial, pubmed-meshheading:7629077-Bacterial Proteins, pubmed-meshheading:7629077-Bacterial Toxins, pubmed-meshheading:7629077-Base Sequence, pubmed-meshheading:7629077-Cloning, Molecular, pubmed-meshheading:7629077-Cytotoxins, pubmed-meshheading:7629077-DNA Primers, pubmed-meshheading:7629077-Genotype, pubmed-meshheading:7629077-Helicobacter pylori, pubmed-meshheading:7629077-Humans, pubmed-meshheading:7629077-Middle Aged, pubmed-meshheading:7629077-Molecular Sequence Data, pubmed-meshheading:7629077-Mosaicism, pubmed-meshheading:7629077-Peptic Ulcer, pubmed-meshheading:7629077-Protein Sorting Signals, pubmed-meshheading:7629077-Sequence Homology, Amino Acid
pubmed:year
1995
pubmed:articleTitle
Mosaicism in vacuolating cytotoxin alleles of Helicobacter pylori. Association of specific vacA types with cytotoxin production and peptic ulceration.
pubmed:affiliation
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2605, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't