scholarly journals Long-Term Infection of Mongolian Gerbils with Helicobacter pylori: Microbiological, Histopathological, and Serological Analyses

2005 ◽  
Vol 12 (2) ◽  
pp. 347-353 ◽  
Author(s):  
Shigehito Nakagawa ◽  
Takako Osaki ◽  
Yasunori Fujioka ◽  
Hiroyuki Yamaguchi ◽  
Shigeru Kamiya

ABSTRACT The effects of long-term infection with Helicobacter pylori on the gastric mucosa of Mongolian gerbils were examined. Colonization by H. pylori was evaluated by both microaerobic cultivation and real-time reverse transcriptase PCR (RT-PCR). Persistent infection with H. pylori in gastric mucosa was detected by real-time RT-PCR during 6 months after infection, but no H. pylori was isolated 4 months after infection by cultivation. Infiltration with neutrophils and mononuclear cells was observed from 2 months after infection. Both intestinal metaplasia and gastric atrophy were also detected from 2 months after infection. The results by enzyme-linked immunosorbent assay indicated that antibody titers against whole H. pylori antigens, H. pylori heat shock protein 60 (HSP60), and Escherichia coli GroEL were significantly higher in the infected gerbils than in noninfected gerbils. After long-term infection with H. pylori for 18 months, marked atrophy of gastric mucosa and multiple cysts in the submucosa were observed in the glandular stomach of the infected gerbils. In addition, squamous cell papilloma with hyperkeratosis was observed in cardia of all the infected gerbils. These results indicate that evaluation of bacterial colonization during long-term infection can be done by real-time RT-PCR and that mucosal damage might be induced by host immune response against whole H. pylori antigen.

2009 ◽  
Vol 58 (5) ◽  
pp. 656-662 ◽  
Author(s):  
Ichiro Oshio ◽  
Takako Osaki ◽  
Tomoko Hanawa ◽  
Hideo Yonezawa ◽  
Cynthia Zaman ◽  
...  

To identify the time frame and route of mother-to-child Helicobacter pylori infection, a Mongolian gerbil model was used. Four-week-old female Mongolian gerbils were infected with H. pylori, and then mated with uninfected males 2 months after infection. The offspring were sacrificed weekly after birth, and then serum, mother's milk from the stomach and gastric tissues were obtained from pups. Anti-H. pylori antibody titres were measured in sera and maternal milk using an ELISA. The stomach was cut in two in the sagittal plane, and then H. pylori colonization in mucosa was confirmed by culture and real-time RT-PCR in one specimen and by immunochemical staining in the other. Faeces and oral swabs were obtained from infected mothers, and H. pylori 16S rRNA was measured using real-time RT-PCR. H. pylori was not identified in cultures from the gastric mucosa of pups delivered by infected mothers, but H. pylori 16S rRNA was detected from 4 weeks after birth, suggesting that Mongolian gerbil pups become infected via maternal H. pylori transmission from 4 weeks of age. The anti-H. pylori antibody titre in sera of pups from infected mothers was maximum at 3 weeks of age and then rapidly decreased from 4 weeks of age. High antibody titres in mother's milk were detected during the suckling period, and GlcNAcα was detectable at 2–4 weeks of age, but disappeared as the offspring aged. Thus H. pylori seems to infect Mongolian gerbil pups from 4 weeks of age, in parallel with decreasing GlcNAcα expression in the gastric mucosa. These results suggested that H. pylori infection of Mongolian gerbil pups occurs via faecal–oral transmission from an infected mother.


2001 ◽  
Vol 69 (8) ◽  
pp. 4759-4766 ◽  
Author(s):  
Bachra Rokbi ◽  
Delphine Seguin ◽  
Bruno Guy ◽  
Véronique Mazarin ◽  
Emmanuel Vidor ◽  
...  

ABSTRACT Despite increasing knowledge on the biology of Helicobacter pylori, little is known about the expression pattern of its genome during infection. While mouse models of infection have been widely used for the screening of protective antigens, the reliability of the mouse model for gene expression analysis has not been assessed. In an attempt to address this question, we have developed a quantitative reverse transcriptase PCR (RT-PCR) that allowed the detection of minute amounts of mRNA within the gastric mucosa. The expression of four genes, 16S rRNA, ureA (encoding urease A subunit), katA (catalase), and alpA (an adhesin), was monitored during the course of a 6-month infection of mice and in biopsy samples from of 15 infected humans. We found that the selected genes were all expressed within both mouse and human infected mucosae. Moreover, the relative abundance of transcripts was the same (16S rRNA > ureA >katA > alpA), in the two models. Finally, results obtained with the mouse model suggest a negative effect of bacterial burden on the number of transcripts of each gene expressed per CFU (P < 0.05 for 16S rRNA, alpA, andkatA). Overall, this study demonstrates that real-time RT-PCR is a powerful tool for the detection and quantification ofH. pylori gene expression within the gastric mucosa and strongly indicates that mice experimentally infected with H. pylori provide a valuable model for the analysis of bacterial gene expression during infection.


2005 ◽  
Vol 39 (2) ◽  
pp. 221-229 ◽  
Author(s):  
A Bleich ◽  
I Köhn ◽  
S Glage ◽  
W Beil ◽  
S Wagner ◽  
...  

The Mongolian gerbil is an excellent animal model for Helicobacter pylori-induced gastritis in humans. In this study, initially low colonization rates of the H. pylori strains ATCC 43504, SS1, or HP87 inoculated into gerbils caused difficulties in establishing this model. In order to increase the colonization ability and pathogenicity, the clinical HP87 isolate was selected for adaptation to the gerbil stomach by multiple in vivo passages through gerbils. Development of gastritis was examined histologically at 4–52 weeks after infection. The proportion of gerbils which tested positive for H. pylori by culture at four weeks after inoculation gradually increased from 11.1% of gerbils inoculated with HP87 without prior in vivo passage (P0) to 100% of gerbils inoculated with HP87 with seven in vivo passages (P7). In addition, adaptation of HP87 resulted in more severe histopathological changes. Gerbils infected with adapted HP87 (P7) exhibited severe infiltration by monomorphonuclear and polymorphonuclear leukocytes in the mucosa, submucosa, and subserosa of the gastric antrum, as well as epithelial changes consisting of hyperplasia, erosion, and ulceration. Histopathological changes increased in severity from four to 52 weeks after infection. Adaptation of HP87 during its passages through gerbils could be due to genetic changes in bacterial colonization factors. Identification of these changes might be useful to understand the underlying mechanism of gastric adaptation and pathogenesis of H. pylori.


2001 ◽  
Vol 69 (8) ◽  
pp. 4774-4781 ◽  
Author(s):  
Michael A. Heneghan ◽  
Ciaran F. McCarthy ◽  
Daiva Janulaityte ◽  
Anthony P. Moran

ABSTRACT Lewis (Le) antigens have been implicated in the pathogenesis of atrophic gastritis and gastric cancer in the setting ofHelicobacter pylori infection, and H. pylori-induced anti-Le antibodies have been described that cross-react with the gastric mucosa of both mice and humans. The aim of this study was to examine the presence of anti-Le antibodies in patients with H. pylori infection and gastric cancer and to examine the relationships between anti-Le antibody production, bacterial Le expression, gastric histopathology, and host Le erythrocyte phenotype. Anti-Le antibody production and H. pylori Le expression were determined by enzyme-linked immunosorbent assay, erythrocyte Le phenotype was examined by agglutination assays, and histology was scored blindly. Significant levels of anti-Lex antibody (P < 0.0001, T = 76.4, DF = 5) and anti-Ley antibody (P < 0.0001, T = 73.05, DF = 5) were found in the sera of patients with gastric cancer and other H. pylori-associated pathology compared with H. pylori-negative controls. Following incubation of patient sera with synthetic Le glycoconjugates, anti-Lex and -Ley autoantibody binding was abolished. The degree of the anti-Lex and -Leyantibody response was unrelated to the host Le phenotype but was significantly associated with the bacterial expression of Lex (r = 0.863,r 2 = 0.745, P < 0.0001) and Ley (r = 0.796,r 2 = 0.634, P < 0.0001), respectively. Collectively, these data suggest that anti-Le antibodies are present in most patients with H. pyloriinfection, including those with gastric cancer, that variability exists in the strength of the anti-Le response, and that this response is independent of the host Le phenotype but related to the bacterial Le phenotype.


2019 ◽  
Vol 9 (2) ◽  
pp. 253-261
Author(s):  
O. K. Pozdeev ◽  
A. O. Pozdeeva ◽  
Yu. V. Valeeva ◽  
P. E. Gulyaev ◽  
A. N. Savinova

Gastric and duodenal recurrent inflammatory diseases have a high prevalence, but the role played by microbes in its development remained unclear. However, the data published in 1983 by Marshall and Warren about isolatingHelicobacter pylorifrom the stomach mucosa of the patient with gastritis and proposing relevant cultivation methods was the turning point in investigating etiology of the upper digestive tract inflammatory disorders. Moreover, it was shown that the majority ofH. pylorispp. are found within the gastric lumen upon colonization, whereas around 20% of them are attached to the epithelial cells in the stomach. In addition, effects of interacting H. pylori with gastric epithelium and activation of some defense mechanisms due to bacterial colonization and spreading were analyzed. It was found that along with triggering pro-inflammatory response induced by proteins VacA as well as phosphorylated/unphosphorylated CagA, wherein the latter is able to induce a set of protective reactionsH. pyloridisrupts intercellular contacts, affects epithelial cell polarity and proliferation, and activates SHP-2 phosphatase resulting in emerging diverse types of cellular responses. The activation mechanisms for the mitogen-activated protein kinase (MAPK) pathway were discussed. The ability ofH. pylorito regulate apoptosis, particularly via its suppression, by expressing ERK kinase and protein MCL1 facilitating bacterial survival in the gastric mucosa as well as beneficial effects related to bacterial circulation on gastric epithelial cell survival elicited by anti-apoptotic factors were also examined. Of note, persistence of H. pylori are mainly determined by activating transcriptional factors including NF-κB, NFAT, SRF, T-cell lymphoid enhancing factor (TCF/LEF), regulating activity of MCL1 protein, in turn, being one of the main anti-apoptotic factors, as well as induced production of the migration inhibitory factor (MIF). The role of VacA cytotoxin in triggering epithelial cell apoptosis via caspase-mediated pathways was also considered. Infection withH. pyloriis accompanied by release of proinflammatory cytokine cocktail detected bothin vitroandin vivo. In particular, bacterial urease activating transcriptional factor NF-κB was shown to play a crucial role in inducing cytokine production. Moreover, such signaling pathways may be activated afterH. pyloriis attached to the cognate receptor in the gastric epithelial surface by interacting with CD74 and MHC class II molecules. Finally, a role for various CD4+T cell subsets, particularly type 17 T helper cells (Th17) in inducing immune response against H. pylori antigens in gastric mucosa was revealed were also discussed. 


2007 ◽  
Vol 75 (4) ◽  
pp. 1738-1744 ◽  
Author(s):  
Antonia Pellicanò ◽  
Ladislava Sebkova ◽  
Giovanni Monteleone ◽  
Giovanni Guarnieri ◽  
Maria Imeneo ◽  
...  

ABSTRACT In this study we examined mechanisms that regulate T-helper lymphocyte 1 (Th1) commitment in Helicobacter pylori-infected human gastric mucosa. The levels of gamma interferon (IFN-γ), interleukin-4 (IL-4), and IL-12 in total extracts of gastric biopsies taken from H. pylori-infected and uninfected patients were determined by an enzyme-linked immunosorbent assay. The levels of signal transducer and activator of transcription 4 (STAT4), STAT6, and T-box expressed in T cells (T-bet) in total proteins extracted from gastric biopsies were determined by Western blotting. Finally, the effect of a neutralizing IL-12 antibody on expression of Th1 transcription factors and the levels of IFN-γ in organ cultures of H. pylori-infected biopsies was examined. Increased levels of IFN-γ and IL-12 were found in gastric biopsy samples of H. pylori-infected patients compared to the levels in uninfected patients. In addition, H. pylori-infected biopsies exhibited high levels of expression of phosphorylated STAT4 and T-bet. Higher levels of IFN-γ and expression of Th1 transcription factors were associated with greater infiltration of mononuclear cells in the gastric mucosa. By contrast, production of IL-4 and expression of phosphorylated STAT6 were not associated with the intensity of mononuclear cell infiltration. In ex vivo organ cultures of H. pylori-infected biopsies, neutralization of endogenous IL-12 down-regulated the expression of phosphorylated STAT4 and T-bet and reduced IFN-γ production. Our data indicated that IL-12 contributes to the Th1 cell commitment in H. pylori-infected human gastric mucosa.


2000 ◽  
Vol 192 (11) ◽  
pp. 1601-1610 ◽  
Author(s):  
Keiji Ogura ◽  
Shin Maeda ◽  
Masafumi Nakao ◽  
Takeshi Watanabe ◽  
Mayumi Tada ◽  
...  

Helicobacter pylori infection induces various gastroduodenal diseases. We examined the role of two genes, vacA and cagE, in the gastric pathogenesis induced by H. pylori using a long-term (62 wk) animal model. Reportedly, both genes are associated with the virulence of H. pylori: vacA encodes vacuolating cytotoxin, and cagE, with other genes in the cag pathogenicity islands, encodes a type IV secretion system. Mongolian gerbils were challenged in this study by a wild-type TN2 strain and its isogenic mutants of cagE or vacA. The wild-type and vacA mutants induced severe gastritis, whereas cagE mutants induced far milder changes. Gastric ulcer was induced at the highest rate (22/23) by the wild-type TN2, followed by the vacA mutant (19/28). No ulcer was found in the gerbils infected with the cagE mutant (0/27) or in controls (0/27). Intestinal metaplasia was also found in the gerbils infected with the wild-type (14/23) or vacA mutant (15/28). Gastric cancer developed in one gerbil with wild-type infection and in one with vacA mutant infection. In conclusion, the knocking out of the cagE gene deprived wild-type H. pylori of the pathogenicity for gastritis and gastric ulcer, suggesting that the secretion system encoded by cag pathogenicity island genes plays an essential role.


2001 ◽  
Vol 69 (5) ◽  
pp. 2902-2908 ◽  
Author(s):  
Kathryn A. Eaton ◽  
Dange Kersulyte ◽  
Megan Mefford ◽  
Stephen J. Danon ◽  
Steven Krakowka ◽  
...  

ABSTRACT The Helicobacter pylori chromosomal region known as the cytotoxin-gene associated pathogenicity island (cag PAI) is associated with severe disease and encodes proteins that are believed to induce interleukin (IL-8) secretion by cultured epithelial cells. The objective of this study was to evaluate the relationship between the cag PAI, induction of IL-8, and induction of neutrophilic gastric inflammation. Germ-free neonatal piglets and conventional C57BL/6 mice were given wild-type or cagdeficient mutant derivatives of H. pylori strain 26695 or SS1. Bacterial colonization was determined by plate count, gastritis and neutrophilic inflammation were quantified, and IL-8 induction in AGS cells was determined by enzyme-linked immunosorbent assay. Deletion of the entire cag region or interruption of thevirB10 or virB11 homolog had no effect on bacterial colonization, gastritis, or neutrophilic inflammation. In contrast, these mutations had variable effects on IL-8 induction, depending on the H. pylori strain. In the piglet-adapated strain 26695, which induced IL-8 secretion by AGS cells, deletion of the cag PAI decreased induction. In the mouse-adapted strain SS1, which did not induce IL-8 secretion, deletion of thecagII region or interruption of any of threecag region genes increased IL-8 induction. These results indicate that in mice and piglets (i) neither the cag PAI nor the ability to induce IL-8 in vitro is essential for colonization or neutrophilic inflammation and (ii) there is no direct relationship between the presence of the cag PAI, IL-8 induction, and neutrophilic gastritis.


2014 ◽  
Vol 63 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Cynthia Zaman ◽  
Takako Osaki ◽  
Tomoko Hanawa ◽  
Hideo Yonezawa ◽  
Satoshi Kurata ◽  
...  

Animal models are essential for in vivo analysis of Helicobacter-related diseases. Mongolian gerbils are used frequently to study Helicobacter pylori-induced gastritis and its consequences. The presence of some gastric microbiota with a suppressive effect on H. pylori suggests inhibitory gastric bacteria against H. pylori infection. The aim of the present study was to analyse the microbial ecology between H. pylori and the gastric microbiota of Mongolian gerbils. Gastric mucosa samples of H. pylori-negative and -positive gerbils were orally inoculated to five (Group 1) and six (Group 2) gerbils, respectively, and the gerbils were challenged with H. pylori infection. The colonization rate (40 %) of H. pylori in Group 1 gerbils was lower than the rate (67 %) in Group 2 gerbils. Culture filtrate of the gastric mucosa samples of Group 1 gerbils inhibited the in vitro growth of H. pylori. Three lactobacilli species, Lactobacillus reuteri, Lactobacillus johnsonii and Lactobacillus murinus, were isolated by anaerobic culture from the gerbils in Groups 1 and 2, and identified by genomic sequencing. It was demonstrated that the three different strains of lactobacilli exhibited an inhibitory effect on the in vitro growth of H. pylori. The results suggested that lactobacilli are the dominant gastric microbiota of Mongolian gerbils and the three lactobacilli isolated from the gastric mucosa samples with an inhibitory effect on H. pylori might have an anti-infective effect against H. pylori.


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