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Ulcerogenic Helicobacter pylori strains isolated from children: a contribution to get insight into the virulence of the bacteria.

Vitoriano I, Saraiva-Pava KD, Rocha-Gonçalves A, Santos A, Lopes AI, Oleastro M, Roxo-Rosa M - PLoS ONE (2011)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Engenharia, Universidade Católica Portuguesa, Rio de Mouro, Portugal.

ABSTRACT
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.

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Related in: MedlinePlus

Motility of the two isogenic groups of pediatric H. pylori strains in study.The five strains of each class, recovered from 24 h grown plates, were pooled together, inoculated on semi-solid BHI broth −5% FBS medium plates and incubated for 11 days at 37°C under microaerophilic conditions. A) The growth halo observed at day 5 for the pool of PUD and of NUD strains. B) Variation of the diameter of the growth halo along the time (▪ in full line refers to PUD strains and • in dashed line refers to NUD strains). Symbols are means of the values at each point for 2 observations.
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pone-0026265-g004: Motility of the two isogenic groups of pediatric H. pylori strains in study.The five strains of each class, recovered from 24 h grown plates, were pooled together, inoculated on semi-solid BHI broth −5% FBS medium plates and incubated for 11 days at 37°C under microaerophilic conditions. A) The growth halo observed at day 5 for the pool of PUD and of NUD strains. B) Variation of the diameter of the growth halo along the time (▪ in full line refers to PUD strains and • in dashed line refers to NUD strains). Symbols are means of the values at each point for 2 observations.

Mentions: As there were proteins related somehow to bacteria motility included in the group of proteins which were expressed differentially between NUD and PUD strains, we further evaluated whether this was translated into differences in motility. Accordingly, the pools of five NUD strains and of five PUD strains under study were inoculated in an agar motility medium and, at 5, 7 and 11 days the diameter of the growth halo was measured (Figure 4). In agreement with the higher abundance of FlgE (spot 2), FlaA (spot 3) in PUD strains (both in DU and GU strains), the H. pylori strains associated with PUD in children showed bigger growth halos (Figure 4), indicating that they have higher motility than the strains associated with NUD. These experiments were carried out twice, leading to consistent results.


Ulcerogenic Helicobacter pylori strains isolated from children: a contribution to get insight into the virulence of the bacteria.

Vitoriano I, Saraiva-Pava KD, Rocha-Gonçalves A, Santos A, Lopes AI, Oleastro M, Roxo-Rosa M - PLoS ONE (2011)

Motility of the two isogenic groups of pediatric H. pylori strains in study.The five strains of each class, recovered from 24 h grown plates, were pooled together, inoculated on semi-solid BHI broth −5% FBS medium plates and incubated for 11 days at 37°C under microaerophilic conditions. A) The growth halo observed at day 5 for the pool of PUD and of NUD strains. B) Variation of the diameter of the growth halo along the time (▪ in full line refers to PUD strains and • in dashed line refers to NUD strains). Symbols are means of the values at each point for 2 observations.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198394&req=5

pone-0026265-g004: Motility of the two isogenic groups of pediatric H. pylori strains in study.The five strains of each class, recovered from 24 h grown plates, were pooled together, inoculated on semi-solid BHI broth −5% FBS medium plates and incubated for 11 days at 37°C under microaerophilic conditions. A) The growth halo observed at day 5 for the pool of PUD and of NUD strains. B) Variation of the diameter of the growth halo along the time (▪ in full line refers to PUD strains and • in dashed line refers to NUD strains). Symbols are means of the values at each point for 2 observations.
Mentions: As there were proteins related somehow to bacteria motility included in the group of proteins which were expressed differentially between NUD and PUD strains, we further evaluated whether this was translated into differences in motility. Accordingly, the pools of five NUD strains and of five PUD strains under study were inoculated in an agar motility medium and, at 5, 7 and 11 days the diameter of the growth halo was measured (Figure 4). In agreement with the higher abundance of FlgE (spot 2), FlaA (spot 3) in PUD strains (both in DU and GU strains), the H. pylori strains associated with PUD in children showed bigger growth halos (Figure 4), indicating that they have higher motility than the strains associated with NUD. These experiments were carried out twice, leading to consistent results.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Engenharia, Universidade Católica Portuguesa, Rio de Mouro, Portugal.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus