Influence of medium composition on the growth and antigen expression of Helicobacter pylori

Abstract

An evaluation of the ability of various solid and liquid media to support both growth and antigen expression, particularly lipopolysaccharide (LPS) expression, by Helicobacterpylori culture collection strains and clinical isolates was performed. Liquid‐based basal media (brain heart infusion, Brucella broth, Mueller–Hinton broth and tryptone soya broth) supported the growth of strains, whereas solid basal media of the same formulation did not support growth. Optimal growth of all strains was obtained on solid and in liquid media containing blood. Supplemented solid media containing supplements other than blood supported growth but only to a small extent. In liquid media excluding blood, serum supplements enhanced growth and horse serum was found to be superior to fetal calf serum. In general, β‐cyclodextrin did not increase growth. Mueller–Hinton broth or tryptone soya broth containing horse serum and a nitrogen source such as yeast extract or proteose peptone no. 3 were found to give optimal growth of H. pylori in a blood‐free environment. Strains after cultivation in liquid media, irrespective of composition, maintained production of high‐molecular weight (mol. wt) LPS with an O side chain independent of medium composition, whereas subculturing on solid media resulted in production of low‐mol. wt LPS. Expression of proteins differed in liquid and on solid media, particularly proteins of 57 and 60 kDa, but qualitatively no differences were observed upon supplementation of basal media.

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

“…Although blood is the major iron source for some micro-organisms and enhances their growth, bile-tolerant Helicobacter spp., with the exception of H. hepaticus, were capable of growth on blood-free media. This indicates that blood is not essential for their growth, although it did enhance the growth of all these helicobacters, similar to previous observations with H. pylori (Walsh & Moran, 1997). Our data also indicated that hydrogen is an essential growth factor for bile-tolerant helicobacters, but the mechanism by which these organisms utilize hydrogen is poorly understood.…”

“…remain difficult to culture from clinical samples. Various solid and broth culture media have been designed to optimize growth for the production of various antigens (Shahamat et al, 1991 ;Marchini et al, 1995 ;Walsh & Moran, 1997), to facilitate metabolic and enzyme studies, and to prevent accumulation of toxic metabolites that inhibit growth in the stationary phase (Hazell et al, 1989). However, culture media for Helicobacter spp.…”

Intra‐strain variation in expression of lipopolysaccharide by Helicobacter pylori

“…However, individual colonies produced a stable LPS structure over subsequent subcultures. The culture media used here contained 10% (v/v) rather than the 7% (v/v) defibrinated horse blood used by Walsh and Moran (1997) and this small increase in blood content may influence LPS expression in these fastidious organisms.…”

The Effect of the Repeated Subcultures of Helicobacter pylori on Adhesion, Motility, Cytotoxicity, and Gastric Inflammation

“…In vitro cultivation of H. pylori isolates on solid media may result in loss of the antigenic O side-chain (8). Also, specific mutants of the original organisms can be made by adjusting the culture condition (9,10).…”