Influence of activated charcoal, porcine gastric mucin and beta-cyclodextrin on the morphology and growth of intestinal and gastric Helicobacter spp.
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, beta-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. beta-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.
Taneera
Jalal
J
Department of Medical Microbiology, Dermatology and Infection, Lund University, Lund Sölvegatan 23,SE-22362, Sweden1.
Moran
Anthony P
AP
Department of Microbiology, National University of Ireland, Galway, Ireland2.
Hynes
Sean O
SO
Department of Medical Microbiology, Dermatology and Infection, Lund University, Lund Sölvegatan 23,SE-22362, Sweden1.
Nilsson
Hans-Olof
HO
Department of Medical Microbiology, Dermatology and Infection, Lund University, Lund Sölvegatan 23,SE-22362, Sweden1.
Al-Soud
Waleed Abu
WA
Department of Medical Microbiology, Dermatology and Infection, Lund University, Lund Sölvegatan 23,SE-22362, Sweden1.
Wadström
Torkel
T
Department of Medical Microbiology, Dermatology and Infection, Lund University, Lund Sölvegatan 23,SE-22362, Sweden1.
D000818:Animals; D001431:Bacteriological Techniques; D002606:Charcoal; D015169:Colony Count, Microbial; D003470:Culture Media; D003505:Cyclodextrins; D005752:Gastric Mucins; D016480:Helicobacter pylori / Q000254:growth & development* / Q000302:isolation & purification / Q000648:ultrastructure*; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008854:Microscopy, Electron; D013270:Stomach / Q000382:microbiology*; D013552:Swine
D003470:Culture Media; D003505:Cyclodextrins; D005752:Gastric Mucins; D002606:Charcoal