Anti-Salmonella activity of metabolites from African soldier termites, Macrotermes bellicosus

Background: The global emergence and rapid dissemination of multidrug resistant Salmonella strains necessitate research to find new antimicrobials that will effectively be used against these pathogens. In the present study, anti-Salmonella activity of metabolites from African Soldier Termites, Macrotermes bellicosus was demonstrated and subsequently compared with a potent antibiotic, ciprofloxacin.Materials and Methods: N-hexane, ethylacetate, methanol and aqueous extracts of metabolites from the M. bellicosus were assayed for anti-Salmonella activity using the agar dilution method in the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The inhibitory activities of the extracts were compared to ciprofloxacin (256μg/ml). Also, the bioactive components of the extracts were determined using standard techniques.Results: At 4000 μg/ml, N-hexane extract inhibited the growth of Salmonella Typhi, S. Paratyphi A, B and C while ethylacetate extract was able to inhibit S. Paratyphi A and C. Methanolic and aqueous extracts at the same concentration were unable to inhibit these strains of Salmonella. Furthermore, our findings revealed that the MIC of ethylacetate extract was 2000μg/ml for S. Paratyphi A and B, 250μg/ml for S. Typhi, and 125μg/ml for S. Paratyphi C. Also, the MIC of hexane extract was 4000μg/ml for S. Paratyphi B, 2000 μg/ml for S. Paratyphi C, 500μg/ml for S. Typhi and 250μg/ml for S. Paratyphi A respectively. The screening of bioactive components revealed the presence of cardiac glycosides and alkaloids.Conclusion: Our results provide evidence of anti-Salmonella action of metabolites from African Soldier Termites, M. bellicosus. N-hexane and ethylacetate extracts of M. bellicosus may be explored as novel antimicrobials for the treatment of typhoid and paratyphoid fevers thereby reducing the pressure exerted on available antibiotics.Keywords: Salmonella, antimicrobials, insects, extract

The antimicrobial activities of methanolic extracts of Eucalyptus camaldulensis and Terminalia catappa against some pathogenic microorganisms

Methanolic extracts of leaves of Eucalyptus camaldulensis and Terminalia catappa were studied for in vitro microbial activities by agar dilution method. The phytochemical analysis of the crude extracts of the medicinal plants revealed the presence of saponin, saponin glycosides, steroid, cardiac glycoside, tannins, volatile oils, phenols and balsam (gum). The methanolic extracts of the two plants inhibited the growth of Bacillus subtilis and Staphylococcus aureus (ATCC 103207 and Clinical strain respectively) but had no inhibitory effects on Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli. Candida albicans was inhibited by the crude extracts of E. camaldulensis only. Accelerated gradient chromatography (AGC) gave fractions of the extract of T. catappa that were more active on Candida albicans and Escherichia coli than the crude extract. The minimum inhibitory concentration (MIC) of the extracts ranged from 1.25:g/ml to 5:g/ml. The results obtained suggest that T. catappa and E. camaldulensis can be used in treating diseases caused by the test organisms. Key Words: Antimicrobial; medicinal plants; pathogenic microorganisms; inhibitory activity Biokemistri Vol.16(2) 2004: 106-11

Effect of Cold Storage on the Nutritive and Microbiological Quality of Fermented Soy Drink from Tamarind and Nono

The effect of cold storage on fermented soy drink from tamarind and nono was assessed. Soymilk was produced by milk extraction from whole soybean seeds and pasteurized at 76oC for 30 minutes. The soymilk was divided into two portions. One portion inoculated with tamarind pulp containing 5.3×103 cfu/mL and the other with nono containing 11.6×103 cfu/mL. They were incubated at 42oC for 12 hours, fermentation was harvested by stirring, packaged, refrigerated at 5oC and subjected to microbial analysis using standard method. Preservation of drink by refrigeration method increased the microbial load of sample A from day 0 (8.7×103 cfu/mL) to day 9 (15.0×103 cfu/mL) but decreased on day 12 (11×103 cfu/mL). Similar results were recorded for samples B and C. However, sample A had neither coliform nor fungal growth. Sample A and B had no significant (p>0.05) difference in energy value (41.91±0.89 and 42.50±1.14) but sample C had the highest energy (96.69±2.03- 77.80±1.17), ash (4.10±0.13- 96.69±2.03), crude protein (0.51±0.01- 0.55±0.03), oil extract (3.44±0.17- 3.65±0.15) and NFE (7.61±0.14- 11.16±0.17) but lowest in moisture (79.84±1.07- 80.27±1.30) contents on day 6– 12. However, sample B had high moisture content ranged (84.43±1.17- 87.15±2.3) but lower in other parameters. Statistical analysis for the vitamin C, potassium and calcium of sample’s A, B and C were carried to determine their significant differences. Refrigeration slows down the bacterial activity hence reducing spoilage thus making fermented soy drink a good source of desired protein in Nigeria

The antimicrobial activities of methanolic extracts of Eucalyptus camaldulensis and Terminalia catappa against some pathogenic microorganisms

Methanolic extracts of leaves of Eucalyptus camaldulensis and Terminalia catappa were studied for in vitro microbial activities by agar dilution method. The phytochemical analysis of the crude extracts of the medicinal plants revealed the presence of saponin, saponin glycosides, steroid, cardiac glycoside, tannins, volatile oils, phenols and balsam (gum). The methanolic extracts of the two plants inhibited the growth of Bacillus subtilis and Staphylococcus aureus (ATCC 103207 and Clinical strain respectively) but had no inhibitory effects on Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli. Candida albicans was inhibited by the crude extracts of E. camaldulensis only. Accelerated gradient chromatography (AGC) gave fractions of the extract of T. catappa that were more active on Candida albicans and Escherichia coli than the crude extract. The minimum inhibitory concentration (MIC) of the extracts ranged from 1.25mg/ml to 5mg/ml. The results obtained suggest that T. catappa and E. camaldulensis can be used in treating diseases caused by the test organisms