Open AccessDevelopment and evaluation of a new growth medium for Helicobacter pylori
Author(s) -
Sasidharan Sreenivasan,
Uyub Abdul M.
Publication year - 2009
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2009.00554.x
Subject(s) - sulfite , agar , cysteine , sodium , biology , sodium sulfite , agar plate , microbiology and biotechnology , food science , bacteria , biochemistry , chemistry , enzyme , genetics , organic chemistry
The present study was aimed at modifying the original formulation of Commercial Eugon agar (CEA) to develop a new H. pylori growth medium. Initial studies were carried out to determine the number of H. pylori colonies recovered on in‐house H. pylori agar (IHPA), IHPA without l ‐cysteine and sodium sulfite (IHPA‐NC), IHPA without l ‐cysteine (IHPA‐C), IHPA without sodium sulfite (IHPA‐N) and CEA as the control. Significant differences ( P <0.001) in the number of colonies recovered were observed between IHPA‐N, IHPA‐NC and IHPA‐C. Incorporation of sodium sulfite decreased the number of colonies recovered, indicating that sodium sulfite was inhibitory to H. pylori growth. Removal of l ‐cysteine reduced the number of colonies recovered, suggesting that l ‐cysteine is necessary for the growth of H. pylori . In the subsequent study, incorporation of K 2 HPO 4 further increased the number of colonies recovered compared with IHPA‐N ( P <0.001), and 0.25% (w/v) of K 2 HPO 4 yielded the highest numbers of colonies ( P ≤0.04). Finally, thirty other H. pylori clinical isolates were evaluated for their growth in the IHPAP‐N, a new medium consisting of 1.5% (w/v) pepticase, 0.5% (w/v) peptone, 0.4% (w/v) sodium chloride, 0.03% (w/v) l ‐cysteine, 0.55% (w/v) dextrose, 0.25% (w/v) K 2 HPO 4 and 1.5% (w/v) agar. The number of colonies recovered in IHPAP‐N was significantly ( P <0.005) higher than that of CEA. IHPAP‐N with 0.25% K 2 HPO 4 and without sodium sulfite were adequate solid media for the growth of H. pylori .