Influence of activated charcoal, porcine gastric mucin and β-cyclodextrin on the morphology and growth of intestinal and gastric Helicobacter spp.

Abstract

Bile-tolerant Helicobacter spp. are emerging human and animal pathogens. However, due to their fastidious nature, which requires nutrient-rich complex media to grow, infection with these bacteria may be underestimated. The accumulation of toxic metabolites in cultures may be one of the main obstacles for successful culture of these organisms. The present study examined various potential growth-enhancing substances for Helicobacter spp. and, furthermore, how they may affect spiral to coccoid conversion. Five Helicobacter spp. were cultured on agar and in broth media supplemented with activated charcoal, β-cyclodextrin, or porcine gastric mucin. Growth was determined by estimating the numbers of colony-forming units and colony diameter, as well as bacterial cell mass. Coccoid transformation was estimated every 24 h by both Gram and acridine-orange staining. Activated charcoal was superior in supporting growth and increased cell mass on agar and in broth media. β-Cyclodextrin delayed spiral to coccoid conversion by Helicobacter pylori and Helicobacter canis, whereas activated charcoal delayed the conversion to coccoid forms of Helicobacter hepaticus and Helicobacter bilis. The progression to coccoid forms by Helicobacter pullorum on agar media was not influenced by any growth supplement. The spiral to coccoid conversion was more rapid in broth media than on agar media. The growth enhancement observed is probably related to the capacity of activated charcoal to remove toxic compounds in culture media.

Helicobacter pullorum induces nitric oxide release in murine macrophages that promotes phagocytosis and killing

“…Therefore, coccoid forms of H. pullorum seem to occur at latter stages, a result which agrees with previous data showing that after 2 days growth in BHI liquid broth, only 20 % of the H. pullorum cells exhibited a coccoid form, and that conversion of all cells to the coccoid form occurred after 4 days (Taneera et al, 2002). …”

Comparative Chemical and Biological Characterization of the Lipopolysaccharides of Gastric and Enterohepatic Helicobacters

“…In the present study, 3-hydroxyhexadecanoic and 3-hydroxytetradecanoic fatty acids were detected in LPSs of H. mustelae, 3-hydroxyhexadecanoic and 3-hydroxyoctadecanoic acids in H. pylori, and 3-hydroxytetradecanoic and 3-hydroxyhexadecanoic acids in H. pullorum (Table 2), findings which are consistent with the previous observations on 3-hydroxy fatty acid profiles [12,14,19,33], thereby demonstrating the validity of our approach. Because of their fastidious nature and the acknowledged difficulties normally encountered in their culture [20], multiple strains of nonpylori Helicobacter spp. were available only for H. pullorum and H. hepaticus (Fig.…”

“…were routinely grown under microaerobic conditions (10% O 2 , 5% CO 2 and 85% N 2 ) generated using an Anoxomat® instrument (MART Microbiology BV, Licthenvoorde, the Netherlands) or a GasPak system (Oxoid, Basingstoke, UK) on blood agar at 37°C [19]. Supplementation of basal medium with 0.1% charcoal was used to improve yields of the majority of enterohepatic species as reported previously [20].…”

Pathogenesis ofHelicobacter pyloriInfection

“…These supplements may act as additional sources of nutrients and possibly also protect against the toxic effects of long-chain fatty acids. The latter function may also be performed by more defined medium supplements, such as ␤-cyclodextrins or IsoVitaleX, or by using activated charcoal (616). Commonly used solid media for routine isolation and culture of H. pylori consist of Columbia or brucella agar supplemented with either (lysed) horse or sheep blood or, alternatively, newborn or fetal calf serum.…”