-
[show abstract]
[hide abstract]
ABSTRACT: Quantitative (qt) real time PCR using 16SrDNA primers is useful for determination of the bacterial composition of the gastric microbiota in Mongolian gerbils. The aim of this study was to determine the change in the gastric microbiota after long-term infection with Helicobacter pylori. One year after inoculation with H. pylori, five gerbils were determined as H. pylori-positive and 6 gerbils H. pylori-negative by culture and real time qt PCR methods. The gastric microbiota of each group of gerbils was also compared with that of 6 gerbils uninfected with H. pylori. DNA from the Atopobium cluster, Bifidobacterium spp., Clostridium coccoides group, Clostridium leptum subgroup, Enterococcus spp. and Lactobacillus spp. were detected in the gastric mucus of both infected and uninfected gerbils. In contrast, Eubacterium cylindroides group and Prevotella spp. were detected only in H. pylori-negative gerbils. The numbers of C. leptum subgroup, C. coccoides group and Bifidobacterium spp. in gastric mucus of H. pylori-negative Mongolian gerbils were significantly lower than those in non-infected gerbils. The results obtained suggest that the composition of gastric indigenous microbiota in Mongolian gerbils may be disturbed by long-term infection with H. pylori, and that these changes may in fact inhibit H. pylori infection.
Microbial Pathogenesis 07/2012; 53(1):12-8. · 1.94 Impact Factor
-
Hideo Yonezawa,
Takako Osaki,
Tomoko Hanawa,
Satoshi Kurata, Cynthia Zaman,
Timothy Derk Hoong Woo,
Motomichi Takahashi,
Sachie Matsubara,
Hayato Kawakami,
Kuniyasu Ochiai,
Shigeru Kamiya
[show abstract]
[hide abstract]
ABSTRACT: Helicobacter pylori can be found in the oral cavity and is mostly detected by the use of PCR techniques. Growth of H. pylori is influenced by various factors in the mouth, such as the oral microflora, saliva and other antimicrobial substances, all of which make colonization of the oral cavity by H. pylori difficult. In the present study, we analysed the effect of the cell supernatant of a representative periodontal bacterium Porphyromonas gingivalis on H. pylori and found that the cell supernatant destroyed the H. pylori cell envelope. As P. gingivalis produces butyric acid, we focused our research on the effects of butyrate and found that it significantly inhibited the growth of H. pylori. H. pylori cytoplasmic proteins and DNA were detected in the extracellular environment after treatment with butyrate, suggesting that the integrity of the cell envelope was compromised and indicating that butyrate has a bactericidal effect on H. pylori. In addition, levels of extracellular H. pylori DNA increased following treatment with the cell supernatant of butyric acid-producing bacteria, indicating that the cell supernatant also has a bactericidal effect and that this may be due to its butyric acid content. In conclusion, butyric acid-producing bacteria may play a role in affecting H. pylori colonization of the oral cavity.
Journal of Medical Microbiology 12/2011; 61(Pt 4):582-9. · 2.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Helicobacter pylori is one of the most common causes of bacterial infection in humans. Infection with H. pylori is closely associated with gastritis and peptic ulcers and is a risk factor for gastric cancer and mucosa-associated lymphoid tissue lymphoma. H. pylori forms biofilms on glass surfaces at the air-liquid interface in in-vitro batch cultures. We previously reported that strain TK1402 showed a strong biofilm-forming ability in vitro. We also suggested the outer membrane vesicles (OMV) produced by strain TK1402 might be related to its biofilm forming ability. In the present study, we analyzed the protein profile of the OMV produced by strain TK1402 and found a unique 22-kDa protein in TK1402 OMV cultured for 2-3 days. In addition, this protein could not be detected in the OMVs produced by other H. pylori strains. These results suggest that the 22-kDa protein is involved in effective biofilm formation by strain TK1402.
Anaerobe 04/2011; 17(6):388-90. · 2.41 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Amu-ru 7, a Mongolian folk medicine, is used to treat digestive diseases such as gastritis and gastric and duodenal ulcers. We examined the effect of Amu-ru 7 on the growth and viability of Helicobacter pylori in vivo and in vitro. By the agar dilution method, the MIC of Amu-ru 7 for H. pylori strains was shown to be 100-200 μg/mL with a MIC(90) of 200 μg/mL. Two hundred micrograms per milliliter of Amu-ru 7 exhibited potent bactericidal activity against H. pylori in the stationary phase of growth 6 hr after treatment. Amu-ru 7 inhibited the growth of both AMPC-resistant and CAM-resistant strains, and also had a combined effect with AMPC on AMPC-resistant strain 403. The Amu-ru 7 inhibited biofilm formation by H. pylori and induced morphological changes, such as bleb-like formation and shortening of the cell. Although colonization of the stomach of the Mongolian gerbil by H. pylori was not cured by treatment with Amu-ru 7, both the mean number of H. pylori colonized and the colonization rate were decreased in Amu-ru 7 treated gerbils. These results suggest the effectiveness Amu-ru 7 as an adjunct therapy for eradication therapies consisting of a PPI combined with antibiotics.
Microbiology and Immunology 09/2010; 54(9):508-15. · 1.30 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Biofilms are surface-bound communities of bacterial cells that are implicated in their survival. As with various bacteria studied to date, Helicobacter pylori can have an alternate lifestyle as a biofilm. We previously reported that strain TK1402 showed a strong biofilm-forming ability in vitro. However, the mechanisms of its biofilm development remain unclear. We analyzed the basic characteristics of the biofilm-forming ability in strain TK1402.
In order to characterize the biofilm-forming ability of the H. pylori strains, auto-aggregation, motility and hydrophobicity, which are important factors in biofilm formation by other bacteria, were analyzed. Further, we tested whether cell growth participated in biofilm formation in strain TK1402.
There were no significant differences in the auto-aggregation, motility and hydrophobicity of strain TK1402 compared with the other strains. On the other hand, pre-culture of this strain for 24-48 h resulted in decreased biofilm formation.
TK1402 is a strong biofilm-forming strain of H. pylori in Brucella broth supplemented with 7% fetal calf serum. It is possible that biofilm-forming cell growth is a principal factor in biofilm development.
Journal of Gastroenterology and Hepatology 05/2010; 25 Suppl 1:S90-4. · 2.87 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mongolian gerbils are frequently used to study Helicobacter pylori-induced gastritis and its consequences. The presence of some gastric flora with a suppressive effect on H. pylori suggests inhibitory microflora against H. pylori infection. The aim of the present study was to analyze the microflora in the stomach of Mongolian gerbils with H. pylori infection.
H. pylori ureA was detected by polymerase chain reaction (PCR) in the fecal samples of infected Mongolian gerbils. H. pylori was isolated from the gastric mucosa of the gerbils by microaerophilic cultivation. Gastric microflora were isolated by aerobic and anaerobic culture, and the identification of gastric bacterial species was performed by API20E and API20A.
Oral administration of H. pylori TK1402 induced colonization and gastric inflammation of the stomach of the Mongolian gerbils. According to the frequency of detection of H. pylori ureA in fecal samples, the gerbils were divided into three groups (frequently detected, moderately detected and infrequently detected). According to the analysis of the gastric microflora in the frequently and infrequently detected groups, Lactobacillus spp. and Eubacterium limosum were isolated from the former and latter group, respectively.
Some gastric flora, such as Lactobacillus spp., may inhibit colonization by H. pylori.
Journal of Gastroenterology and Hepatology 05/2010; 25 Suppl 1:S11-4. · 2.87 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 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 GlcNAcalpha 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 GlcNAcalpha 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.
Journal of Medical Microbiology 06/2009; 58(Pt 5):656-62. · 2.50 Impact Factor
