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Outer membrane vesicles of Helicobacter pylori TK1402 are involved in biofilm formation.

Yonezawa H, Osaki T, Kurata S, Fukuda M, Kawakami H, Ochiai K, Hanawa T, Kamiya S - BMC Microbiol. (2009)

Bottom Line: The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms.In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms.However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Infectious Disease, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan. yonezawa@ks.kyorin-u.ac.jp

ABSTRACT

Background: Helicobacter pylori forms biofilms on glass surfaces at the air-liquid interface in in vitro batch cultures; however, biofilms of H. pylori have not been well characterized. In the present study, we analyzed the ability of H. pylori strains to form biofilms and characterized the underlying mechanisms of H. pylori biofilm formation.

Results: Strain TK1402 showed strong biofilm forming ability relative to the other strains in Brucella broth supplemented with 7% FCS. The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms. In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms. Biofilm formation was strongly correlated with the production of OMV in this strain. We further observed that strain TK1402 did not form thick biofilms in Brucella broth supplemented with 0.2% beta-cyclodextrin. However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation.

Conclusion: The results suggested that OMV produced from TK1402 play an important role in biofilm formation in strain TK1402.

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Related in: MedlinePlus

(A) Biofilm formation by eight H. pylori strains. The graph shows quantification of biofilms formed after 3-days (white bars) and 5-days (black bars) following culture in Brucella broth containing 7% FCS. (B) Eight H. pylori strains were grown in Brucella broth containing 7% FCS-, and OD600 absorbance was measured at 3-days (white bars) and 5-days (black bars). (C, and D) Time course experiments for the H. pylori strains TK1402 (C) and SS1 (D) biofilm formation and their growth. The biofilm mass of these strains are shown as black bars and the lines depict the OD600 absorbances of these strains. All of the results were expressed as the means ± standard deviations from at least three independent experiments. *significantly different (p < 0.05) relative level of biofilm formation (strain TK1402 versus other strains).
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Figure 1: (A) Biofilm formation by eight H. pylori strains. The graph shows quantification of biofilms formed after 3-days (white bars) and 5-days (black bars) following culture in Brucella broth containing 7% FCS. (B) Eight H. pylori strains were grown in Brucella broth containing 7% FCS-, and OD600 absorbance was measured at 3-days (white bars) and 5-days (black bars). (C, and D) Time course experiments for the H. pylori strains TK1402 (C) and SS1 (D) biofilm formation and their growth. The biofilm mass of these strains are shown as black bars and the lines depict the OD600 absorbances of these strains. All of the results were expressed as the means ± standard deviations from at least three independent experiments. *significantly different (p < 0.05) relative level of biofilm formation (strain TK1402 versus other strains).

Mentions: We attempted to grow biofilms of the 8 strains of H. pylori on glass coverslip surfaces in Brucella broth supplemented with 7% FCS with shaking for 3 days or 5 days and found that all strains formed biofilms at the liquid-gas interface of the cultures. Under these conditions, all of the strains except strain TK1402 formed relatively little biofilm biomass (Fig. 1A). In contrast, the clinically isolated strain TK1402 showed significantly higher levels of biofilm formation (Fig. 1A). The growth yields of these strains for 3- or 5-days of culturing were comparable for all of the strains (Fig. 1B). To determine the kinetics of H. pylori biofilm formation, strains TK1402 and SS1 were assessed for biofilm forming ability and growth rates from day 1 to day 6 (Fig. 1C and 1D). Both strains showed similar growth kinetics with both strains fully grown within 2 days although the maximum titers of strain SS1 were slightly lower compared to that of strain TK1402. After 3 days of incubation, the growth yields were slightly decreased and plateaued at day 6. On the other hand, biofilm formation by strain TK1402 increased until day 3 (Fig. 1C). After 3 days of incubation, biofilm formation reached a plateau up to day 6. Biofilm formation by strain SS1 was not significantly different from day 1 to day 3 (Fig. 1D), and biofilm formation was significantly lower than that of TK1402 upon cultivation for up to 6 days.


Outer membrane vesicles of Helicobacter pylori TK1402 are involved in biofilm formation.

Yonezawa H, Osaki T, Kurata S, Fukuda M, Kawakami H, Ochiai K, Hanawa T, Kamiya S - BMC Microbiol. (2009)

(A) Biofilm formation by eight H. pylori strains. The graph shows quantification of biofilms formed after 3-days (white bars) and 5-days (black bars) following culture in Brucella broth containing 7% FCS. (B) Eight H. pylori strains were grown in Brucella broth containing 7% FCS-, and OD600 absorbance was measured at 3-days (white bars) and 5-days (black bars). (C, and D) Time course experiments for the H. pylori strains TK1402 (C) and SS1 (D) biofilm formation and their growth. The biofilm mass of these strains are shown as black bars and the lines depict the OD600 absorbances of these strains. All of the results were expressed as the means ± standard deviations from at least three independent experiments. *significantly different (p < 0.05) relative level of biofilm formation (strain TK1402 versus other strains).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2749055&req=5

Figure 1: (A) Biofilm formation by eight H. pylori strains. The graph shows quantification of biofilms formed after 3-days (white bars) and 5-days (black bars) following culture in Brucella broth containing 7% FCS. (B) Eight H. pylori strains were grown in Brucella broth containing 7% FCS-, and OD600 absorbance was measured at 3-days (white bars) and 5-days (black bars). (C, and D) Time course experiments for the H. pylori strains TK1402 (C) and SS1 (D) biofilm formation and their growth. The biofilm mass of these strains are shown as black bars and the lines depict the OD600 absorbances of these strains. All of the results were expressed as the means ± standard deviations from at least three independent experiments. *significantly different (p < 0.05) relative level of biofilm formation (strain TK1402 versus other strains).
Mentions: We attempted to grow biofilms of the 8 strains of H. pylori on glass coverslip surfaces in Brucella broth supplemented with 7% FCS with shaking for 3 days or 5 days and found that all strains formed biofilms at the liquid-gas interface of the cultures. Under these conditions, all of the strains except strain TK1402 formed relatively little biofilm biomass (Fig. 1A). In contrast, the clinically isolated strain TK1402 showed significantly higher levels of biofilm formation (Fig. 1A). The growth yields of these strains for 3- or 5-days of culturing were comparable for all of the strains (Fig. 1B). To determine the kinetics of H. pylori biofilm formation, strains TK1402 and SS1 were assessed for biofilm forming ability and growth rates from day 1 to day 6 (Fig. 1C and 1D). Both strains showed similar growth kinetics with both strains fully grown within 2 days although the maximum titers of strain SS1 were slightly lower compared to that of strain TK1402. After 3 days of incubation, the growth yields were slightly decreased and plateaued at day 6. On the other hand, biofilm formation by strain TK1402 increased until day 3 (Fig. 1C). After 3 days of incubation, biofilm formation reached a plateau up to day 6. Biofilm formation by strain SS1 was not significantly different from day 1 to day 3 (Fig. 1D), and biofilm formation was significantly lower than that of TK1402 upon cultivation for up to 6 days.

Bottom Line: The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms.In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms.However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Infectious Disease, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, 181-8611, Japan. yonezawa@ks.kyorin-u.ac.jp

ABSTRACT

Background: Helicobacter pylori forms biofilms on glass surfaces at the air-liquid interface in in vitro batch cultures; however, biofilms of H. pylori have not been well characterized. In the present study, we analyzed the ability of H. pylori strains to form biofilms and characterized the underlying mechanisms of H. pylori biofilm formation.

Results: Strain TK1402 showed strong biofilm forming ability relative to the other strains in Brucella broth supplemented with 7% FCS. The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms. In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms. Biofilm formation was strongly correlated with the production of OMV in this strain. We further observed that strain TK1402 did not form thick biofilms in Brucella broth supplemented with 0.2% beta-cyclodextrin. However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation.

Conclusion: The results suggested that OMV produced from TK1402 play an important role in biofilm formation in strain TK1402.

Show MeSH
Related in: MedlinePlus