K. Ouattara

Bio: K. Ouattara is an academic researcher from Université Félix Houphouët-Boigny. The author has contributed to research in topics: Minimum inhibitory concentration & Minimum bactericidal concentration. The author has an hindex of 3, co-authored 8 publications receiving 54 citations.

Evaluation of the Antibacterial Activity of 14 Medicinal Plants in Côte d’Ivoire

Abstract: Purpose: To evaluate the antibacterial potentials of fourteen ethnobotanically selected plants traditionally used in different parts of Cote d’Ivoire for the treatment of typhoid fever and gastrointestinal disorders. Method: The antimicrobial activity of the extracts of the plant was tested against a collection strain of Salmonella typhimurium, a clinical strain of Salmonella typhi and Pseudomonas aeruginosa by macrobroth dilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Results: All the plants had bactericidal activity against at least one of the test microorganisms with both MIC and MBC ranging from 2.5 to > 80 mg/ml. Among the plant extracts, Terminalia glaucescens . (Combretaceae) Bersama abyssinica subsp. paullinioides (Melianthaceae ) and Abrus precatorius (Fabaceae) showed the most promising broad spectrum antibacterial properties, inhibiting all of the strains tested, especially S. Typhi and P. aeruginosa , with MBC ranging from 2.5 to 5 mg/ml. Conclusion: The findings provide support for the use of these plants in traditional medicine for treatment of typhoid fever and gastrointestinal disorders, and are thus, potential sources of drugs that would need to be subjected to further studies. Keywords: Antimicrobial activity, Ivorian medicinal plants, MIC, MBC.

Étude botanique et exploration de l’activité antifongique de Morinda morindoides (Baker) Milne-Redh. sur la croissance in vitro de Cryptococcus neoformans

Abstract: Morinda morindoides est une plante qui est citee de facon recurrente dans plusieurs prescriptions therapeutiques. Afin de mieux connaitre cette plante et de pouvoir l’identifier sur le terrain, nous avons, dans cette etude, fait sa description botanique suivie d’une exploration de son activite antifongique. Il ressort de cette etude que Morinda morindoides (Rubiaceae) est une espece guineo-congolaise qui se retrouve dans les lisieres des forets. C’est une liane grimpante avec des feuilles opposees et possedant des fruits bosseles. Cette plante possede une activite antifongique in vitro sur Cryptococcus neoformans. Parmi les extraits testes, la fraction 1 (F1) (CMF = 0,78 mg/ml; CI50 = 0,08 ± 0,02 mg/ml) est la plus active.

Activité antibactérienne des extraits des feuilles de Morinda morindoides (Morinda, Rubiaceae) sur Staphylococcus aureus et Pseudomonas aeruginosa

Abstract: Le but de ce travail est d’evaluer l’activite antibacterienne de quatre extraits des feuilles de Morinda morindoides sur Staphylococcus aureus et Pseudomonas aeruginosa, deux germes responsables d’infections cutanees chez l’Homme. Les methodes de diffusion en milieu solide et de dilution en milieu liquide ont ete utilisees respectivement pour la determination des diametres d’inhibition et des parametres antibacteriens que sont les concentrations minimales inhibitrice et bactericide (CMI et CMB). Avec une CMI de 31,25 mg/ml et des concentrations pour 50 % d’inhibition (CI50) variant de 2,13 a 3,38 mg/ml, l’extrait acetatique (Eace) a presente la plus forte activite. Les resultats obtenus confirment l’utilisation traditionnelle de la plante dans le traitement des infections cutanees dans nombre de pays ouest-africains.

Mise en évidence des propriétés antistaphylococciques des flavonoïdes totaux de Thonningia sanguinea (Vahl), une plante de la pharmacopée ivoirienne

Abstract: Les activites antibacteriennes des flavonoides totaux de Thonningia sanguinea ont ete evaluees in vitro sur trois souches du genre Staphylococcus. Les essais antibacteriens ont ete realises par la methode de diffusion en milieu solide et celle de dilution en milieu liquide couplee a l’etalement sur milieu gelose. Une souche de reference (Staphylococcus aureus ATCC 25923) et deux souches cliniques hospitalieres (Staphylococcus aureus Meti-S et Staphylococcus aureus Meti-R) ont servi a cette etude. Des trois souches testees en presence des flavonoides, Staphylococcus aureus Meti-S a ete la plus sensible avec des valeurs de concentration minimale inhibitrice (CMI) et de concentration minimale bactericide (CMB) de 50 mg/ml. A l’issue de ce travail, il ressort que les flavonoides totaux de Thonningia sanguinea ont des pouvoirs bactericides sur toutes les souches testees. Cette activite antibacterienne observee pourrait justifier l’emploi de la plante dans le traitement des staphylococcoses dans certaines regions de la Cote-d’Ivoire.

Essais antimicrobiens d’un savon à base d’extrait éthanolique des feuilles de Morinda morindoides (Morinda, Rubiaceae) sur la croissance in vitro de germes impliqués dans les infections cutanées

Abstract: L’objectif de la presente etude est d’elaborer un savon a base de l’extrait ethanolique des feuilles de Morinda morindoides et d’evaluer son activite antimicrobienne sur la croissance in vitro de deux bacteries (Staphylococcus aureus et Pseudomonas aeruginosa) et quatre champignons (Candida albicans, Candida tropicalis, Trichophyton rubrum et Trichophyton mentagrophytes) impliques dans les infections cutanees. L’extrait ethanolique de Morinda morindoides a ete utilise comme agent antimicrobien dans la fabrication d’un savon anti-infectieux codifie « S2 » suivant le procede a froid. Les tests antifongiques du savon a l’extrait ethanolique Morinda morindoides (S2) et du savon temoin (S0) ont ete realises suivant la methode de la double dilution par incorporation du savon a tester dans la gelose Sabouraud. Les parametres antibacteriens des savons S2 et S0 ont ete determines par la methode d’incorporation dans la gelose Mueller-Hinton et le test en milieu liquide. Le savon S2 a exprime une activite antimicrobienne effective comparativement au savon temoin S0 avec une concentration minimale inhibitrice de 31,25 mg/ml vis-a-vis des germes testes. L’incorporation de l’extrait ethanolique de Morinda morindoides a raison de 10 % dans la formulation d’un savon anti-infectieux n’altere pas ses proprietes antimicrobiennes. Au regard de l’efficacite du savon S2 sur des germes impliques dans les infections cutanees, sa production a l’echelle industrielle constituera un reel espoir dans la lutte contre les maladies de la peau qui sont tres repandues en Cote-d’Ivoire.

Antimicrobial activity and mechanisms of Salvia sclarea essential oil

Abstract: Nowadays, essential oils are recognized as safe substances and can be used as antibacterial additives. Salvia sclarea is one of the most important aromatic plants cultivated world-wide as a source of essential oils. In addition to being flavoring foods, Salvia sclarea essential oil can also act as antimicrobials and preservatives against food spoilage. Understanding more about the antibacterial performance and possible mechanism of Salvia sclarea essential oil will be helpful for its application in the future. But so far few related researches have been reported. In our study, Salvia sclarea oil showed obvious antibacterial activity against all tested bacterial strains. Minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) of seven pathogens were 0.05 and 0.1 % respectively. In addition, Salvia sclarea oil also exhibited a significant inhibitory effect on the growth of Escherichia coli (E. coli) in phosphate buffer saline (PBS) and meats. After treated with Salvia sclarea oil, Scanning Electron Microscope (SEM) images can clearly see the damage of cell membrane; the intracellular ATP concentrations of E. coli and S. aureus reduced 98.27 and 69.61 % respectively, compared to the control groups; the nuclear DNA content of E. coli and S. aureus was significantly reduced to 48.32 and 50.77 % respectively. In addition, there was massive leakage of cellular material when E. coli and S. aureus were exposed to Salvia sclarea oil. Salvia sclarea essential oil damaged the cell membrane and changed the cell membrane permeability, leading to the release of some cytoplasm such as macromolecular substances, ATP and DNA. In general, the antimicrobial action of Salvia sclarea essential oil is not only attributable to a unique pathway, but also involves a series of events both on the cell surface and within the cytoplasm. Therefore, more experiments need to be done to fully understand the antimicrobial mechanism of Salvia sclarea essential oil.

In Vitro Antimicrobial Activity of Extracts from Plants Used Traditionally in South Africa to Treat Tuberculosis and Related Symptoms

Abstract: Respiratory ailments are major human killers, especially in developing countries. Tuberculosis (TB) is an infectious disease causing a threat to human healthcare. Many South African plants are used in the traditional treatment of TB and related symptoms, but there has not been a sufficient focus on evaluating their antimicrobial properties. The aim of this study was to evaluate the antimicrobial properties of plants used traditionally to treat TB and related symptoms against microorganisms (Klebsiella pneumoniae, Staphylococcus aureus, and Mycobacterium aurum A+) associated with respiratory infections using the microdilution assay. Ten plants were selected based on a survey of available literature of medicinal plants used in South Africa for the treatment of TB and related symptoms. The petroleum ether, dichloromethane, 80% ethanol, and water extracts of the selected plants were evaluated for antibacterial activity. Out of 68 extracts tested from different parts of the 10 plant species, 17 showed good antimicrobial activities against at least one or more of the microbial strains tested, with minimum inhibitory concentration ranging from 0.195 to 12.5 mg/mL. The good antimicrobial properties of Abrus precatorius, Terminalia phanerophlebia, Indigofera arrecta, and Pentanisia prunelloides authenticate their traditional use in the treatment of respiratory diseases. Thus, further pharmacological and phytochemical analysis is required.

Antimicrobial activities of saponins from Melanthera elliptica and their synergistic effects with antibiotics against pathogenic phenotypes

Abstract: Resistance of bacteria and fungi to antibiotics is one of the biggest problems that faces public health. The present work was designated to evaluate the antimicrobial activities of saponins from Melanthera elliptica and their synergistic effects with standard antibiotics against pathogenic phenotypes. The plant extract was prepared by maceration in methanol. The methanol extract was partitioned into ethyl acetate and n-butanol extracts. Column chromatography of the n-butanol extract followed by purification of different fractions led to the isolation of four saponins. Their structures were elucidated on the basis of spectra analysis, and by comparison with those from the literature. The antimicrobial activities of the extracts/compounds alone and their combinations with tetracycline and fluconazole were evaluated using the broth microdilution method through the determination of minimum inhibitory concentration (MIC) and minimum microbicidal concentration. Four compounds: 3-O-β-d-glucuronopyranosyl-oleanolic acid (1), 3-O-β-d-glucuronopyranosyloleanolic acid 28-O-β-d-glucopyranosyl ester (2), 3-O-β-d-glucopyranosyl(1 → 2)-β-d-glucuronopyranosyl oleanolic acid (3) and 3-O-β-d-glucopyranosyl(1 → 2)-β-d-glucuronopyranosyl oleanolic acid 28-O-β-d-glucopyranosyl ester (4) were isolated. Compounds 1, 2 and 3 showed the largest antibacterial activities (MIC = 8–128 μg/mL) whereas compound 4 displayed the highest antifungal activities (MIC = 8–16 μg/mL). The antibacterial activities of compounds 1 and 2 (MIC = 16–32 μg/mL) against multi-drug-resistant Escherichia coli S2 (1) and Shigella flexneri SDINT are equal to those of vancomycin (MIC = 16–32 μg/mL) used as reference antibiotic. The present study showed significant antimicrobial activity of compounds 1, 2, 3 and 4 against the tested microorganisms. The saponins act in synergy with the tested standard antibiotics. This synergy could lead to new options for the treatment of infectious diseases and emerging drug resistance.

Insecticidal Activity of Some Traditionally Used Ethiopian Medicinal Plants against Sheep Ked Melophagus ovinus

Abstract: Twelve medicinal plants and a commercially used drug Ivermectin were examined for insecticidal activity against Melophagus ovinus sheep ked at different time intervals using in vitro adult immersion test. The findings show that at 3.13 µL/mL, 6.25 µL/mL and 12.5 µL/mL concentration of Cymbopogon citratus, Foeniculum vulgare and Eucalyptus globulus essential oils respectively, recorded 100% mortalities against M. ovinus within 3 hour of exposure. Significantly higher insecticidal activity of essential oils was recorded (P = 0.00) when compared to 10 μ g/mL Ivermectin after 3-hour exposure of M. ovinus at a concentration of ≥1.57 μ L/mL, ≥3 μ L/mL, and ≥12.7 μ L/mL essential oils of C. citratus, F. vulgare, and E. globulus, respectively. Among essential oils, C. citratus has showed superior potency at a three-hour exposure of the parasite (P = 0.00) at a concentration of ≥0.78 μ L/mL. Strong antiparasitic activity was recorded by aqueous extract of Calpurnia aurea (80% mortality) at a concentration of 200 mg/mL within 24 h among aqueous extracts of 9 medicinal plants. The results indicated all the four medicinal plants, particularly those tested essential oils, can be considered as potential candidates for biocontrol of M. ovinus sheep ked.

Phytochemical Composition and Antibacterial Activity of Moroccan Lavandula angustifolia Mill.

Abstract: Bacterial resistance to antibiotics is a major public health problem. The emergence and spread of multi-resistant bacteria, associated with the limited number of antibiotics in development have led...