ABSTRACT
Postharvest deterioration has been a major problem associated with yam storage for both famers and traders and it is caused mostly by micro-organisms especially fungi. During the storage of yam, many organisms such as Aspergillus flavus, Aspergillus niger, Penicillium citrinum and Rhizopus stolonifer are often reported to cause rotting of the stored yams. The aim of this research is to find out the antifungal effect of some commonly used anti-dermatophytic agents, (Fluconazole, Terbinafine Hcl, Ketoconazole, Sodium propionate and Griseofulvin) on the above named fungi spores. This was carried out using zone of inhibition, MICs, MFCs, FICs and FFCs to measure the antifungal activities of the test antifungal agents against the isolated phytopathogenic fungi spores. These agents were found to have fungitoxic effects on the test organisms in the order of: Terbinafine Hcl > Fluconazole > Ketoconazole > Sodium propionate > Griseofulvin. This work indicated that the test antifungal agents were able to inhibit the fungi spores that are widely reported to be associated with yams rot when stored. The observation in this study showed that a good and efficient fungicide against the test organisms that are known to cause yam rot during storage can be effectively arrested with combination of these fungicides.
ABSTRACT
Aims: To carry out the antistaphylococcal activity of n-butanol and aqueous sub-fractions of Alchornea cordifolia (Schumach. And Thonn.) Müll. Arg. leaf extract against multidrug resistant Staphylococcus aureus. Study Design: Characterization and antibiotic susceptibility determination of the test S. aureus isolates, extraction of A. cordifolia leaf, partitioning of the extract, Zones of inhibition and Minimum Inhibitory and Bactericidal Concentrations determination. Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University, Zaria, Nigeria. February 2010 to October 2011. Methodology: A. cordifolia leaves were collected from Abuja, Nigeria. The activity of the ethanol extract, N-butanol (NSF) and aqueous (ASF) sub-fractions of the plant leaf against five clinical staphylococcal isolates and the standard Methicillin Resistant S. aureus (MRSA) ATCC 33591 were determined using agar-well diffusion and broth dilution methods. The antibiotic susceptibility pattern of the isolates was determined by the Kirby- Bauer-CLSI modified disc agar diffusion technique (DAD). Results: The diameter zones of inhibition showed by ethanol extract against the test staphylococcal isolates ranged between 12 mm - 26 mm, while the diameter zones of inhibition observed from N-butanol sub-fraction and aqueous sub-fraction against the isolates were between 11 mm - 36.5 mm and 11 mm - 35 mm respectively. The diameter zones of inhibition of the sub-fractions against the standard MRSA ATCC 33591 ranged from 11 mm – 27.5 mm. The diameter zones of inhibition of the test antibiotics ranged from 10 mm to 23 mm. The Minimum Inhibitory Concentration (M. I. C.) and Minimum Bactericidal Concentration (M. B. C.) values produced by ethanol extract were higher than those of the sub-fractions. N-butanol sub-fraction produced the lowest M. I. C and M. B. C. values of 0.625 mg/ml – 1.25 mg/ml and 1.25 mg/ml – 2.5 mg/ml respectively. The M. I. C. and M. B. C. values of the N-butanol sub-fraction against the standard strain ATCC 33591 were 1.25 mg/ml and 2.5 mg/ml respectively. Conclusion: The tested N-butanol and aqueous sub-fractions of A. cordifolia leaf were active against the S. aureus strains at low concentrations. The plant can be a possible candidate in the search for alternative antistaphylococcal agents.
ABSTRACT
Aims: To investigate the antimicrobial activity of ethyl acetate and residual aqueous fractions of the methanol extract of Alchornea cordifolia leaf against Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 12600, Escherichia coli ATCC 11775 and Candida albicans ATCC 18804 in comparison to standard antibiotics. Study design: Extraction of Alchornea cordifolia leaf, partitioning of the extract, susceptibility tests (Zones of inhibition) and Minimum Inhibitory and Bactericidal Concentrations determination. Place and Duration of Study: Department of Medicinal Plant Research and Department of Pharmaceutical Microbiology and Biotechnology, National Institute for Pharmaceutical Research and Development, Idu – Abuja, Nigeria and Department of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University, Zaria, Nigeria, July and October. Methodology: The leaves of Alchornea cordifolia (Schum. & Thonn.) Muell. Arg. were collected, dried at room temperature and extracted with methanol using a soxhlet extractor. The methanol extract was partitioned between ethyl acetate and distilled water to obtain an ethyl acetate sub-fraction (EAF) and an aqueous residual fraction (AF). Agar well diffusion and agar dilution methods according to Clinical Laboratory Standards Institute (CLSI) were used to test the antimicrobial activity of the ethyl acetate and aqueous fractions of Alchornea cordifolia against the above mentioned microbial species. Results: Both fractions; ethyl acetate and residual aqueous fractions of the methanol extract showed antimicrobial activity against the standard organisms viz: Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 12600, Escherichia coli ATCC 11775 and Candida albicans ATCC 18804. The highest activity was observed for the ethyl acetate fraction against Staphylococcus aureus ATCC 12600 with zone of inhibition of 27 mm, Minimum Inhibitory Concentration (M.I.C) of 1.25 mg/ml and Minimum Bactericidal Concentration (M. B. C) of 2.5mg/ml. Conclusion: Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 12600, Escherichia coli ATCC 11775 and Candida albicans ATCC 18804 were susceptible to the ethyl acetate sub-fraction and residual aqueous fractions of the methanol extract of Alchornea cordifolia leaf.