Anti- Helicobacter pylori activity of crude acetonic extracts of Streptomyces sp. H7372

Abstract

IntroductionHelicobacter pylori is a gram negative bacterium and a gastric pathogen that infects approximately 50% of the world's populations. Prolonged H. pylori infection causes chronic inflammation and significantly increases the risk of developing gastric cancer, making it a serious global health issue. Recent studies have showed that the success of current treatment, the standard triple therapy, using a wide range of antibiotics (amoxicillin, metronidazole, tetracycline etc.), has declined to unacceptable rates of 80% or less due to antibiotic resistance. New perspectives at current anti- Helicobacter pylori therapy and strategies as well as novel drug alternatives are essentially needed to eradicate H. pylori infection. ObjectiveWe reported a new strain Streptomyces sp. H7372, a gram-positive aerobic bacterium isolated from mangrove soil in Sabah, Malaysia that has shown anti-Helicobacter pylori activities. MethodsStreptomyces sp. H7372 was extracted once with acetone and dried at 40°C. The dried extract was dissolved in distilled water and was examined in vitro. Broth microdilution method was used to determine minimum inhibitory concentration of Streptomyces sp. H7372 against H. pylori ATCC 700824 strain. For disc assay, both ATCC and some clinical strains of H. pylori were grown on TSA blood agar with varying extract concentrations to study zone of inhibition. ResultsThe acetonic extract was found to be fairly inhibitory to Helicobacter pylori ATCC 700824 strain (MIC: 0.0625 ug/ul) as compared to Amoxicillin (MIC: 1×10−5 ug/ul). Disc assay showed concentration dependent inhibitory effect. ConclusionThe present study shows that the acetone extracts from Streptomyces sp. H7372 displayed a strong potential alternative against H. pylori. In the future, extract will be successively fractioned into different chemical portions and will be examined in vitro. Anti-inflammation and anti-adhesion assays will be performed in human gastric mucosal cell line infected with H. pylori to understand the mechanisms of anti-H.pylori activity of H7372.