Use of selective and non-selective media for the isolation of Helicobacter pylori.

Antral biopsy specimens from patients having gastroduodenal disorders were cultured in parallel on sheep blood agar (SBA) and Skirrow's selective medium (SSM) for Helicobacter pylori. It was found that the overall isolation rate of the organism was much lower in SSM (54.5%) than on SBA (87.9%), a difference which is statistically significant (P less than 0.01). This may be due to the incorporation of polymyxin B in SSM. In absence of a suitable selective medium, blood agar may be used. Although consideration must be given to contamination, we found that contamination of SBA culture plates was not significant enough to hamper the isolation of the organism in the vast majority of the cases (98.5%).