Inhibitory and Bactericidal Potential of Crude Acetone Extracts of Combretum molle (Combretaceae) on Drug-resistant Strains of Helicobacter pylori.

Infection with Helicobacter pylori is strongly associated with a number of gastroduodenal pathologies. Antimicrobial resistance to commonly-used drugs has generated a considerable interest in the search for novel therapeutic compounds from medicinal plants. As an ongoing effort of this search, the susceptibility of 32 clinical strains of H. pylori and a reference strain—NCTC 11638—was evaluated against five solvent extracts of Combretum molle, a plant widely used for the treatment of gastric ulcers and other stomach-related morbidities in South Africa. The extracts were screened for activity by the agar-well diffusion method, and the most active one of them was tested against the same strains by micro-broth dilution and time kill assays. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. The solvent extracts all demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm. The most potent anti-H. pylori activity was demonstrated by the acetone extract, to which 87.5% of the clinical strains were susceptible. The minimum inhibitory concentration (MIC90) values for this extract ranged from 1.25 to 5.0 mg/mL while those for amoxicillin and metronidazole ranged from 0.001 to 0.94 mg/mL and from 0.004 to 5.0 mg/mL respectively. The acetone extract was highly bactericidal at a concentration of 2.5 and 5.0 mg/mL, with complete elimination of the test organisms in 24 hours. Its inhibitory activity was better than that of metronidazole (p<0.05) as opposed to amoxicillin (p<0.05). The results demonstrate that C. molle may contain therapeutically-useful compounds against H. pylori, which are mostly concentrated in the acetone extract.

Bacterial contamination of Vhuswa--a local weaning food and stored drinking-water in impoverished households in the Venda region of South Africa.

Bacterial contaminants of Vhuswa--a traditional maize-based weaning food, and domestic drinking-water stored in impoverished rural households in Venda of Limpopo province, South Africa, were determined. One hundred and twenty-five samples of Vhuswa fed to children aged less than five years were assessed for Escherichia coli, Campylobacter jejuni, Salmonella, and Shigella. The microbiological quality of 125 drinking-water samples was also evaluated using total coliforms, faecal coliforms, and faecal streptococci as indicators. The frequency of isolation of E. coli, Salmonella, Shigella, and C. jejuni from the Vhuswa samples was 70%, 5%, 5%, and 2% respectively. The geometric mean counts of total coliforms, faecal coliforms, and faecal streptococci in tap-water stored in household containers ranged from 4.9x10(2) to 5.8x10(3) cfu 100 mL(-1), 2.6x10(2) to 3.7x10(3) cfu 100 mL(-1), and 3.1x10(3) to 5.8x10(3) cfu 100 mL(-1) respectively, and for stored spring water it was 5.1x10(3) cfu 100 mL(-1), 3.2x10(3) cfu 100 mL(-1), and 5.1x10(3) cfu 100 mL(-1) respectively. The frequent contamination of water and food samples in this study has important implications for the health of children from impoverished communities.