[Antimicrobial activity of Morinda morindoides on in vitro growth of vibrio cholerae in Côte d'Ivoire]. / Activité de Morinda morindoides sur la croissance in vitro du vibrion du choléra: expérimentation en Côte d'Ivoire.

Cholera is a major public health problem in developing countries. As a contribution to management of this disease, the study described herein was carried out in Côte d'Ivoire. The purpose was to evaluate the antibacterial activity of products obtained by various techniques from the leaves of Morinda morindoides on a pathogenic strain of Vibrio cholerae O:1. Morinda morindoides is a medicinal plant in the Ivorian pharmacopoeia. The products were obtained as aqueous extracts, 70% ethanolic extracts, residual extracts and a chromatographic fraction (BGG F5). All three extracts and the chromatographic fraction showed considerable in vitro antimicrobial efficacy against Vibrio cholerae O:1. The most active against in vitro growth of Vibrio cholorae O:1 was the 70% ethanolic extract with a minimal bactericidal concentration of 5 mg/ml. The antibacterial properties of this medicinal plant can be of great benefit for management of cholera.

[Implementation of in vitro culture of Mycobacterium ulcerans from clinical samples versus detection of acid-fast bachilli and bacterial genome in Abidjan, Côte d'Ivoire]. / Mise en place de la culture in vitro de Mycobacterium ulcerans à partir d'éhantillons cliniques versus recherche de BAARet détection du génome bactérien à Abidjan, Côte d'Ivoire

Mycobacterium ulcerans infections are a public health problem in Céte d'Ivoire. The etiological diagnosis of this disease made by culture remains a big concern due to the slowness and difficulties encountered. This detection by culture of M. ulcerans represents a big interest as it allows obtaining the circulating strains for research. The purpose of this study was to determine on a routine basis in a poorly equipped laboratory, in vitro culture of M. ulcerans from exudates of skin ulcerations and from biopsy of patients with suspected Buruli ulcer. A particular attention was paid to the conditioning of the sample forwarded to the laboratory and inoculation in Lowenstein-Jensen medium supplemented with glycerol. The results of the three methods for the analysis showed 26.7, 57.4 and 17.8% positive rate respectively in the microscopy examination by nested PCR and by culture. In all the analysis, the positive rate from biopsy is higher than that obtained from exudates. The overall contamination rate by invasion of the three tubes of culture by fungi is 15.8 with 14.3 and 19.4% respectively,from exudates and biopsies. All positive samples in Ziehl-Neelsen staining and in culture were also positive by nested PCR. The nested PCR confirmed the positive strains found in culture, which were responsible for skin ulcerations. After culture, only one strain was nPCR negative. This strain was identified as Mycobacterium Gordonae. Our culture conditions showed that M. ulcerans was not the only strain identified and that other strains were present in the culture. We can conclude that the culture of M. ulcerans, in spite of the growth difficulties of the bacterium can be performed in laboratory in developing countries despite the lack of reagent and consumables. The implementation of this culture is the only way to determine sensitivity tests in vitro and in vivo in order to treat patients with Buruli ulcer.

[Effect of serum on the outcome of in vitro testing of the chemosensitivity of Plasmodium falciparum]. / Influence de la nature du sérum sur la réalisation de test de chimiosensibilité in vitro de Plasmodium falciparum.

Plasmodium falciparum, the parasite responsible for potentially fatal malaria, is a major cause of morbidity and of mortality in tropical countries. In vitro culture of Plasmodium remains indispensable for identification of phenotype and surveillance of the efficacy of antimalarial drugs. Culture of Plasmodium falciparum requires the use of RPMI 1640 medium, the efficacy of which depends on addition of human serum. Culture with medium containing either reference human serum of (RS) or serum containing Plasmodium antibodies (SND) provides a plasmodial maturation rate exceeding 20% (lower threshold of validity according to WHO). Comparison of these two culture supplements for in vitro testing of the chemosensitivity of Plasmodium strains to pyrimethamine showed no difference in IC50: < 2000 nM for sensitive strains (FCB1 and PFB) and > 2000 nM for resistant strains (K1).

Antibacterial activity of Thonningia sanguinea against some multi-drug resistant strains of Salmonella enterica.

BACKGROUND: The emergence of strains of S.enterica with multiple drug resistance (MDR) is of great concern worldwide.The extracts of flowers of Thonningia sanguinea are used in traditional medicine in Ivory Coast to treat diarrhoeal diseases including salmonellosis. Previous studies had shown inhibition of the MDR strain Salmonella Enteritidis lysotype 6. OBJECTIVES: The present study focused to investigate the effect of the extract of the flowers of Thonningia sanguinea on some clinical MDR strains of Salmonella namely S. Tyhpi, S. Typhimurium, S. Hadar and a sensitive strain (S. Enteritidis). METHODS: The antimicrobial parameters were determined by double dilution with agar slant method. This method led us to determine MIC, IC50 and MBC. RESULTS: The MDR strain of S.Typhimurium presented the highest MIC (2.5 mg/ml) whereas the other two MDR strains (S. Hadar, S. Typhi) and the sensitive one (S. Enteritidis) had the same MIC (1.25 mg/ml). The four strains presented the same MBC (2.5 mg/ml). The MDR strain of S. Typhi is the most susceptible strain to the aqueous extract of the flowers of Thonningia sanguinea according to The IC50 values. CONCLUSIONS: The aqueous extract of Thonningia sanguinea can provide an alternative therapy for the treatment of salmonellosis, mainly for typhoid fever caused by MDR strains of S Typhi. The extract also inhibits S.Hadar a MDR emerging strain in Ivory Coast.

[Efficiency of ethanol of Thonningia sanguinea against Cryptococcus neoformans]. / Efficacité de l'extrait éthanolique de Thonningia sanguinea sur Cryptococcus neoformans.

Herbal treatment of infectious diseases is a common practice in traditional society. One of the herbs used by African populations against skin and systemic infectious diseases is Thonningia sanguinea (THOS). In the Ivory Coast, Togo, and Ghana, this herb is used to prepare traditional remedies for diarrhoeas, asthma and mycoses. The latter account for a substantial number of the opportunistic infections associated with HIV/AIDS. Some species of eumycetes, such as Cryptococcus neoformans, infect mainly immunocompromised patients but can sometimes infect immunocompetent hosts and they are often fatal. In this study we evaluated the antimicrobial activity of aqueous extracts of T. sanguinea against C. neoformans (and several other microorganisms). We first assessed the fungal growth in vitro on agar medium. We then incubated the cultures for 48 h with various concentrations of THOS to determine the percentage of survival according to the concentration of THOS and the concentration required for 50% inhibition (IC50). The minimum fungicidal concentration (MFC) of the total aqueous extract was 6.25 mg/mL. (THOS was thus most effective against C. neoformans). Accordingly we sought to improve the extract by preparing it with ethanol. This solution yielded an IC50=0.06 mg/mL and an MFC=0.098 mg/mL against C. neoformans.

Antibacterial Activity of Thonningia sanguinea against some Multi-Drug Resistant Strains of Salmonella enterica

Background : The emergence of strains of S.enterica with multiple drug resistance (MDR) is of great concern worldwide.The extracts of flowers of Thonningia sanguinea are used in traditional medicine in Ivory Coast to treat diarrhoeal diseases including salmonellosis. Previous studies had shown inhibition of the MDR strain Salmonella Enteritidis lysotype 6. Objectives: The present study focused to investigate the effect of the extract of the flowers of Thonningia sanguinea on some clinical MDR strains of Salmonella namely S.Tyhpi; S. Typhimurium; S. Hadar and a sensitive strain (S.Enteritidis). Methods : The antimicrobial parameters were determined by double dilution with agar slant method. This method led us to determine MIC; IC 50 and MBC. Results: The MDR strain of S.Typhimurium presented the highest MIC (2.5 mg/ml) whereas the other two MDR strains (S.Hadar; S.Typhi) and the sensitive one (S.Enteritidis) had the same MIC (1.25 mg/ml). The four strains presented the same MBC (2.5 mg/ml). The MDR strain of S.Typhi is the most susceptible strain to the aqueous extract of the flowers of Thonningia sanguinea according to The IC 50 values. Conclusions: The aqueous extract of Thonningia sanguinea can provide an alternative therapy for the treatment of salmonellosis; mainly for typhoid fever caused by MDR strains of S Typhi. The extract also inhibits S.Hadar a MDR emerging strain in Ivory Coast

Isolation of cholinergic active ingredients in aqueous extracts of Mareya micrantha using the longitudinal muscle of isolated guinea-pig ileum as a pharmacological activity marker.

In our attempt to isolate the pharmacologically active ingredients in the aqueous extracts of Mareya micrantha, we have selected the contractions of the longitudinal muscle of the isolated guinea-pig ileum preparation as a pharmacological marker to monitor retention of pharmacological activity during the chromatographic separation. The aqueous extracts of Mareya micrantha elicited concentration-dependent contractions of the preparation. The maximum response elicited by the aqueous extracts was 50% of the maximum response elicited by the maximum dose of acetylcholine (ACh), 10(-7) M. Mepenzolate (10(-8)-10(-5) M), a specific muscarinic receptor antagonist, similarly antagonized contractions elicited by the aqueous extracts suggesting that the cholinergic ingredient(s) in the extract are acting at the muscarinic receptors of the preparation. Fraction 2-4, which was separated from the aqueous extracts by Sephadex gel chromatography, dose-dependently elicited contractions of the preparation. The maximum response was 80% of the maximum response elicited by the maximum dose of ACh suggesting that separation has enhanced the cholinergic activity of the content in the extract.

The use of isolated functional heart to pharmacologically characterize active ingredients in the aqueous extracts of Mareya micrantha.

Aqueous extracts of Mareya micrantha are used as folk medicine in West Africa. However, no systemic investigation directed to the identification of the active ingredients in M. micrantha has been done. Therefore, this study investigated the effects of M. micrantha on the cardiac contractility of the isolated frog heart. Also, two sequential fractions from M. micrantha were separated and their effects on cardiac contractility investigated. M. micrantha concentration-dependently suppressed cardiac contractility. Separation of the cardioactive components in series by column chromatography (Sephadex G-50, Column 2.5 x 30 cm and 1 x 20 cm) produced two fractions which facilitated a leftward shift of the dose-response curve of the cardiodepressant effects suggesting that column chromatograph is effective in the isolation of the cardioactive ingredients in M. micrantha. The data suggest that M. micrantha contains cardioactive components and that contractions of the isolated functional frog heart can be used as a pharmacological activity marker during the process of isolation of cardioactive ingredients in M. micrantha.

Mise en evidence de phytosteroides antifongiques contre cryptococcus neoformans

Par des methodes simples d'extraction; de chromatographie sur colonne de SEPHADEX de filtration G50; et par des reactions colorees; les auteurs ont mis en evidence la presence unique de phytosterols dans la fraction ethanolique (F2) d'un extrait foliaire de mitracapus verticillatus; valke; (Rubiacee). L'activite antifongique de ces phytosterols a ete testee sur cryptococcus neoformans; un germe fongique implique dans la redoutable meningite a cryptocoque. La culture du cryptocoque sur agar Sabouraud/chloramphenicol incorpore a F2 en double dilution a donne une concentration minimale fongique (CMF) egale a 12 gammas (12 ug/ml) quand l'extrait total (Et) donne 768 ug/ml et sa fraction 80acqueuse (F1) 2500 ug/ml. Un dosage chimique des ions a revele egalement la presence d'iode (I-) et de baryum (Ba++)qui confirme le pouvoir antiseptique et medical de la fraction (F2)

Cassia alata and the preclinical search for therapeutic agents for the treatment of opportunistic infections in AIDS patients.

In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antibacterial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml, respectively; corresponding data for chloramphenicol were 2 micrograms/ml and 10 micrograms/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 micrograms/ml and 0.98 micrograms/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.

Cassia alata and the preclinical search for therapeutic agents for the treatment of opportunistic infections in AIDS patients.

In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antimicrobial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml respectively; corresponding data for chloramphenicol were 2 ug/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 ug/ml and 0.98 ug/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.