Zoénabo Douamba - Academia.edu (original) (raw)

Uploads

Papers by Zoénabo Douamba

Research paper thumbnail of Storage stability of dried tomato slices during storage as affected by salt and lemon pretreatments

International Journal of Food Properties, 2022

Research paper thumbnail of Prevalence and Diversity of the Thermotolerant Bacterium Bacillus cytotoxicus among Dried Food Products

Journal of Food Protection, 2019

Bacillus cytotoxicus, a member of the Bacillus cereus group, is a thermotolerant species original... more Bacillus cytotoxicus, a member of the Bacillus cereus group, is a thermotolerant species originally reported from a lethal foodborne infection in France in 1998. The strain NVH391-98, isolated from this outbreak, produces cytotoxin K1, a potential cytotoxic enterotoxin. However, the habitat and diversity of B. cytotoxicus isolates so far have been poorly explored. The objective of this study was to assess the prevalence of this bacterium in different food products (mainly dried) and to estimate its diversity. Among the 210 samples analyzed, all potato flakes contained the bacterium at low concentrations (≤102 CFU/g). However, prepared and kept at room temperature for 2 days, the puree contained ca. 105 CFU/g B. cytotoxicus. Besides potato flakes, some samples of millet flour, salted potato chips, and soups also contained B. cytotoxicus. From these samples, 55 thermotolerant B. cytotoxicus isolates were obtained. When classified into six distinct random amplified polymorphism DNA pat...

Research paper thumbnail of Fatal intoxications by acenocoumarol, phenprocoumon and warfarin: Method validation in blood using the total error approach

Journal of Chromatography B, 2009

A simple high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection has... more A simple high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection has been developed and validated for simultaneous identification and quantification of three antivitamin K drugs (acenocoumarol, warfarin and phenprocoumon) in whole blood. The aim of this development was to propose an analytical technique adapted to the situations of forensic toxicology, i.e. intoxication with massive anticoagulant doses, when the usual coagulation tests could not be used. The blood sample, after spiked with prazepam as an internal standard (IS), was submitted to a liquid-liquid extraction (LLE) prior to HPLC analysis. A chromatographic separation was achieved on a C8 Symmetry column with a mobile phase consisting of an acetonitrile and phosphate buffer (pH 3.8) mixture in a gradient mode. Detection was carried out at a wavelength between 200 and 400 nm. This method has been validated with the concept of total error as decision criterion. Trueness ranged from 99.1% to 105.0% and precision was good with RSD between 1.3% and 6.7%. Consequently, this rapid and simple chromatographic technique is well adapted to focus intoxications with most important coumarinic drugs available on pharmaceutical market and is now routinely used in our laboratory for forensic "general unknown" screening.

Research paper thumbnail of Prévalence des souches de salmonelles dans les graines de sésame et leurs produits dérivés au Burkina Faso

International Journal of Biological and Chemical Sciences, Aug 27, 2022

Le sésame constitue le deuxième produit d'exportation agricole au Burkina Faso mais sa qualité n'... more Le sésame constitue le deuxième produit d'exportation agricole au Burkina Faso mais sa qualité n'est pas toujours satisfaisante à cause de la présence d'impuretés et parfois de microorganismes pathogènes notamment les salmonelles. La présente étude a pour objectif d'évaluer la prévalence des salmonelles dans le sésame et ses produits dérivés. Au total, 107 échantillons dont 73 échantillons de graines de sésame et 34 échantillons de produits dérivés de sésame (biscuits, croquettes, pâtes, pains) ont été soumis à la recherche de salmonelles selon la norme internationale ISO 6579-1, 2017. La recherche de gènes de virulences (invA, pipD, orfL, misL, spvR) de Salmonella spp. a été réalisée par la méthode de la Polymerase Chain Reaction (PCR). Les résultats ont montré une contamination aux salmonelles du sésame et de ses produits dérivés de 10,28%. Le taux de contamination est de 10,96% (8/73) dans les graines de sésame et 8,82% (3/34) dans les produits dérivés. Le taux de contamination globale est passé à 13,08% par l'analyse moléculaire. Les facteurs de virulence invA, pipD, orfL, misL et spvR ont été retrouvés respectivement à 92,86% ; 92,86% ; 85,71% ; 64,28% et 0%. Ces contaminations aux salmonelles du sésame pourraient être dues à une défaillance dans le respect des bonnes pratiques culturales et/ou des contaminations post-récoltes.

Research paper thumbnail of Storage stability of dried tomato slices during storage as affected by salt and lemon pretreatments

International Journal of Food Properties, 2022

Research paper thumbnail of Prevalence and Diversity of the Thermotolerant Bacterium Bacillus cytotoxicus among Dried Food Products

Journal of Food Protection, 2019

Bacillus cytotoxicus, a member of the Bacillus cereus group, is a thermotolerant species original... more Bacillus cytotoxicus, a member of the Bacillus cereus group, is a thermotolerant species originally reported from a lethal foodborne infection in France in 1998. The strain NVH391-98, isolated from this outbreak, produces cytotoxin K1, a potential cytotoxic enterotoxin. However, the habitat and diversity of B. cytotoxicus isolates so far have been poorly explored. The objective of this study was to assess the prevalence of this bacterium in different food products (mainly dried) and to estimate its diversity. Among the 210 samples analyzed, all potato flakes contained the bacterium at low concentrations (≤102 CFU/g). However, prepared and kept at room temperature for 2 days, the puree contained ca. 105 CFU/g B. cytotoxicus. Besides potato flakes, some samples of millet flour, salted potato chips, and soups also contained B. cytotoxicus. From these samples, 55 thermotolerant B. cytotoxicus isolates were obtained. When classified into six distinct random amplified polymorphism DNA pat...

Research paper thumbnail of Fatal intoxications by acenocoumarol, phenprocoumon and warfarin: Method validation in blood using the total error approach

Journal of Chromatography B, 2009

A simple high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection has... more A simple high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection has been developed and validated for simultaneous identification and quantification of three antivitamin K drugs (acenocoumarol, warfarin and phenprocoumon) in whole blood. The aim of this development was to propose an analytical technique adapted to the situations of forensic toxicology, i.e. intoxication with massive anticoagulant doses, when the usual coagulation tests could not be used. The blood sample, after spiked with prazepam as an internal standard (IS), was submitted to a liquid-liquid extraction (LLE) prior to HPLC analysis. A chromatographic separation was achieved on a C8 Symmetry column with a mobile phase consisting of an acetonitrile and phosphate buffer (pH 3.8) mixture in a gradient mode. Detection was carried out at a wavelength between 200 and 400 nm. This method has been validated with the concept of total error as decision criterion. Trueness ranged from 99.1% to 105.0% and precision was good with RSD between 1.3% and 6.7%. Consequently, this rapid and simple chromatographic technique is well adapted to focus intoxications with most important coumarinic drugs available on pharmaceutical market and is now routinely used in our laboratory for forensic "general unknown" screening.

Research paper thumbnail of Prévalence des souches de salmonelles dans les graines de sésame et leurs produits dérivés au Burkina Faso

International Journal of Biological and Chemical Sciences, Aug 27, 2022

Le sésame constitue le deuxième produit d'exportation agricole au Burkina Faso mais sa qualité n'... more Le sésame constitue le deuxième produit d'exportation agricole au Burkina Faso mais sa qualité n'est pas toujours satisfaisante à cause de la présence d'impuretés et parfois de microorganismes pathogènes notamment les salmonelles. La présente étude a pour objectif d'évaluer la prévalence des salmonelles dans le sésame et ses produits dérivés. Au total, 107 échantillons dont 73 échantillons de graines de sésame et 34 échantillons de produits dérivés de sésame (biscuits, croquettes, pâtes, pains) ont été soumis à la recherche de salmonelles selon la norme internationale ISO 6579-1, 2017. La recherche de gènes de virulences (invA, pipD, orfL, misL, spvR) de Salmonella spp. a été réalisée par la méthode de la Polymerase Chain Reaction (PCR). Les résultats ont montré une contamination aux salmonelles du sésame et de ses produits dérivés de 10,28%. Le taux de contamination est de 10,96% (8/73) dans les graines de sésame et 8,82% (3/34) dans les produits dérivés. Le taux de contamination globale est passé à 13,08% par l'analyse moléculaire. Les facteurs de virulence invA, pipD, orfL, misL et spvR ont été retrouvés respectivement à 92,86% ; 92,86% ; 85,71% ; 64,28% et 0%. Ces contaminations aux salmonelles du sésame pourraient être dues à une défaillance dans le respect des bonnes pratiques culturales et/ou des contaminations post-récoltes.