Author(s):
Vitoriano, Inês 
; Saraiva-Pava, Kathy ; Rocha-Gonçalves, Alexandra ; Santos, Andrea ; Lopes, Ana Isabel ; Oleastro, Mónica ; Roxo-Rosa, Mónica
Date: 2011
Persistent ID: http://hdl.handle.net/10400.18/373
Origin: Repositório Científico do Instituto Nacional de Saúde
Subject(s): Infecções Gastrointestinais
Description
Infection with Helicobacter pylori is the major cause for the development of
peptic ulcer disease (PUD). In children, with no other etiology for the disease,
this rare event occurs shortly after infection. In these young patients, habits
of smoking, diet, consumption of alcohol and non-steroid anti-inflammatory drugs
and stress, in addition to the genetic susceptibility of the patient, represent a
minor influence. Accordingly, the virulence of the implicated H. pylori strain
should play a crucial role in the development of PUD. Corroborating this, our in
vitro infection assays comparing a pool of five H. pylori strains isolated from
children with PUD to a pool of five other pediatric clinical isolates associated
with non-ulcer dyspepsia (NUD) showed the greater ability of PUD strains to
induce a marked decrease in the viability of gastric cells and to cause severe
damage in the cells cytoskeleton as well as an impairment in the
production/secretion of mucins. To uncover virulence features, we compared the
proteome of these two groups of H. pylori strains. Two-dimensional gel
electrophoresis followed by mass-spectrometry allowed us to detect 27
differentially expressed proteins between them. In addition to the presence of
genes encoding well established virulence factors, namely cagA, vacAs1, oipA "on"
status, homB and jhp562 genes, the pediatric ulcerogenic strains shared a
proteome profile characterized by changes in the abundance of:
motility-associated proteins, accounting for higher motility; antioxidant
proteins, which may confer increased resistance to inflammation; and enzymes
involved in key steps in the metabolism of glucose, amino acids and urea, which
may be advantageous to face fluctuations of nutrients. In conclusion, the
enhanced virulence of the pediatric ulcerogenic H. pylori strains may result from
a synergy between their natural ability to better adapt to the hostile human
stomach and the expression of the established virulence factors.
