Boukaré Zeba

Polyphenol Content and Antioxidant Activity of Fourteen Wild Edible Fruits from Burkina Faso

A total of fourteen (14) species of wild edible fruits from Burkina Faso were analyzed for their phenolic and flavonoid contents, and their antioxidant activities using the DPPH, FRAP and ABTS methods. The data obtained show that the total phenolic and total flavonoid levels were significantly higher in the acetone than in the methanol extracts. Detarium microcarpum fruit had the highest phenolic and the highest flavonoid content, followed by that of Adansonia digitata, Ziziphus mauritiana, Ximenia americana and Lannea microcarpa. Significant amounts of total phenolics were also detected in the other fruit species in the following order of decreasing levels: Tamarindus indica > Sclerocarya birrea > Dialium guineense > Gardenia erubescens > Diospyros mespiliformis > Parkia biglobosa > Ficus sycomorus > Vitellaria paradoxa. Detarium microcarpum fruit also showed the highest antioxidant activity using the three antioxidant assays. Fruits with high antioxidant activities were also found to possess high phenolic and flavonoid contents. There was a strong correlation between total phenolic and flavonoid levels and antioxidant activities.

Antiacetylcholinesterase and antioxidant activity of essential oils from six medicinal plants from Burkina Faso

In this investigation, we evaluated essential oils from six medicinal plants from Burkina Faso for their antiacetylcholinesterase and antioxidant abilities. The chemotype of most active were also determined. The best antiacetylcholinesterase activities were recorded for the essential oils of Eucalyptus camaldulensis (IC50 18.98 µ g/mL) and Ocimum canum (IC50 36.16 µ g/mL). Their chemotype have been related to the 1,8-cineole one. Both essential oils demonstrated a linear mixed non competitive inhibition. The essential oil of Ocimum basilicum which belong to the linalool-eugenol chemotype exhibited the best radical scavenging activity (IC50 3.82 µ g/mL) and reducing power (531.75 mg AAE/g). In comparison with gallic and ascorbic acids, O. basilicum essential oil evidenced interesting antioxidant activities. The antiacetylcholinesterase and antioxidant activities of essential oils were discussed in regard with their chemical composition.

IND-6, a Highly Divergent IND-Type Metallo-β-Lactamase from Chryseobacterium indologenes Strain 597 Isolated in Burkina Faso

ABSTRACT The genus Chryseobacterium and other genera belonging to the family Flavobacteriaceae include organisms that can behave as human pathogens and are known to cause different kinds of infections. Several species of Flavobacteriaceae, including Chryseobacterium indologenes, are naturally resistant to β-lactam antibiotics (including carbapenems), due to the production of a resident metallo-β-lactamase. Although C. indologenes presently constitutes a limited clinical threat, the incidence of infections caused by this organism is increasing in some settings, where isolates that exhibit multidrug resistance phenotypes (including resistance to aminoglycosides and quinolones) have been detected. Here, we report the identification and characterization of a new IND-type variant from a C. indologenes isolate from Burkina Faso that is resistant to β-lactams and aminoglycosides. The levels of sequence identity of the new variant to other IND-type metallo-β-lactamases range between 72 and 90% (for IND-4 and IND-5, respectively). The purified enzyme exhibited N-terminal heterogeneity and a posttranslational modification consisting of the presence of a pyroglutamate residue at the N terminus. IND-6 shows a broad substrate profile, with overall higher turnover rates than IND-5 and higher activities than IND-2 and IND-5 against ceftazidime and cefepime.

Prevalence of bla SHV genes in clinical isolates of Klebsiella pneumoniae at Saint Camille medical Center in Ouagadougou. Isolation of bla SHV11 -like gene

Five bacterial strains (4 Klebsiella pneumoniae and 1 Escherichia coli ) representative of pathogenic species and resistant to β-lactam antibiotics are investigated to isolate the genes responsible of β--lactamase activity. The use of engineering techniques enables us to show the widespread of bla SHV genes particularly in clinical isolates of K. pneumoniae . Our results highlighted an atypical bla SHV-11 gene. Key words: β--Lactamases, Klebsiella pneuminiae, bla SHV gene, Saint Camille medical centre, Ouagadougou. African Journal of Biotechnology Vol.3(9) 2004: 477-480

Production périplasmique de β-lactamases par des isolats cliniques

Resume Le profil de production des β-lactamases a ete examine chez plusieurs isolats cliniques recoltes au centre medical Saint Camille de Ouagadougou au Burkina Faso. Le but recherche est de mettre en evidence les conditions experimentales qui accroissent le niveau periplasmique de β-lactamase et donc maximisent le rendement extractif de l’enzyme a des fins experimentales. Les facteurs temps de croissance et concentration de l’imipeneme en tant qu’inducteur ont ete explores. Les resultats obtenus suggerent la necessite de la prise en compte des facteurs « temps de croissance et concentration de l’inducteur » pour l’optimisation du rendement dans une perspective preparative. Ces resultats mettent en lumiere pour chaque isolat, l’existence d’une combinaison favorable : temps de croissance/ concentration de l’inducteur qui determine l’activite enzymatique maximale recherchee.