Growth of Helicobacter pylori in Medium Supplemented with Cyanobacterial Extract

Abstract

Solid and liquid media supplemented only with a cyanobacterial extract (CE) and free of fetal calf serum (FCS), blood, and its derivatives support the growth of Helicobacter pylori. A total of 11 strains of H. pylori isolated from gastric biopsy samples were successfully subcultured in Mueller-Hinton agar supplemented with 0.4% CE. When this medium was used for primary isolation of H. pylori, a low isolation rate (30%) was observed because of the abundant growth of contaminants. The growth kinetics of eight isolates and H. pylori reference strain NCTC 11638 in Mueller-Hinton broth (MHB) supplemented with 0.7% CE were estimated by use of growth parameters, and the results were compared with those obtained with MHB-5% FCS. For four strains the cellular concentrations obtained with CE were statistically higher (P < 0.05) than those obtained with FCS, and in some cases these values were similar to the highest values reported in the literature. Depending on the strain, the specific growth rates obtained with CE were similar to or increased compared with those obtained with FCS. The replacement of FCS by CE in H. pylori cultures would facilitate the retrieval of cultures with high cellular densities as a source of cellular and extracellular proteins free of serum. Also, CE has advantages over conventional supplements, such as easier conservation and compliance with the pressing tendency at present to avoid the use of products derived from animals.

The Human Gastric Microbiome Is Predicated upon Infection with Helicobacter pylori

“…Under the permanent process of swallowing microbiota inhabiting the oral cavity or food derived microbial DNA are characterized as well. In studies on cultivable bacterial microbiota of the human stomach, samples are spread to conventional media (Vega et al, 2003 ) without adapting the culture conditions to those present in the natural gastric habitat (Sanduleanu et al, 2001 ; Delgado et al, 2013 ; Khosravi et al, 2014 ). We suggest that gastric habitat like conditions would be inevitable for serious conclusions on viability and above all proliferation capability of isolated microorganisms.…”

Intracellular Locations of Replication Proteins and the Origin of Replication during Chromosome Duplication in the Slowly Growing Human Pathogen Helicobacter pylori

“…This low frequency might be due to the limitation of the IFA or caused by the unusually long generation time of slowly growing H. pylori cells, as previously reported (37). We also determined the generation time (t g ) of H. pylori cells from the linear segment of the growth curve (log 2 OD 600 values plotted against time [see Fig.…”

Diagnosis of Helicobacter pylori Infection

“…Vega et al. [9] studied media supplemented with cyanobacterial extract and showed that growth rates with this supplement are at least as good and partly even significantly better than with fetal calf serum (FCS). This media supplement is considerably more cost‐efficient than FCS, easier to manufacture and store and also provides for enhanced compliance with the requirement for reducing the use of animal products.…”