Patrick Mickala

Effects of storage type and time on DNA amplification success in tropical ungulate faeces

The present study compares the effect of three storage media (silica, RNAlater®, ethanol) and time to extraction (1 week, 1 month and 3 months) on mitochondrial and nuclear marker amplification success in faecal DNA extracts from a sympatric community of small to medium‐sized Central African forest ungulates (genera Cephalophus, Tragelaphus, Hyemoschus). The effect of storage type and time on nuclear DNA concentrations, genotyping errors and percentage recovery of consensus genotypes was also examined. Regardless of storage method, mitochondrial and nuclear amplification success was high in DNA extracted within the first week after collection. Over longer storage periods, RNAlater yielded better amplification success rates in the mitochondrial assay. However, samples stored on silica showed (i) highest nuclear DNA concentrations, (ii) best microsatellite genotyping success, (iii) lowest genotyping errors, and (iv) greatest percentage recovery of the consensus genotype. The quantity of nuclear DNA was generally a good predictor of microsatellite performance with 83% amplification success or greater achieved with sample DNA concentrations of ≥ 50 pg/µL. If faecal DNA samples are to be used for nuclear microsatellite analyses, we recommend silica as the best storage method. However, for maximum mitochondrial amplification success, RNAlater appears to be the best storage medium. In contrast, ethanol appeared inferior to the other two methods examined here and should not be used to store tropical ungulate faeces. Regardless of storage method, samples should be extracted as soon as possible after collection to ensure optimal recovery of DNA.

Biodiversity and conservation genetics research in Central Africa: new approaches and avenues for international collaboration

A five-day international workshop was recently convened at the Université des Sciences et Techniques de Masuku in Gabon to enhance international collaboration among Central African, US and European scientists, conservation professionals and policy makers. The overall aims of the workshop were to: (1) discuss emerging priorities in biodiversity and conservation genetics research across Central Africa, and (2) create new networking opportunities among workshop participants. Here we provide a brief overview of the meeting, outline the major recommendations that emerged from it, and provide information on new networking opportunities through the meeting web site.

Bio-efficacy of medicinal plants used for the management of diabetes mellitus in Gabon. An ethnopharmacological approach -

Background/Aim: People suffering of diabetes increased significantly worldwide. Population, in Sub-Saharan Africa and mainly in Gabon, rely on medicinal plants to manage diabetes, as well in rural as in urban areas. This study aimed to survey a wide range of Gabonese plants for their antidiabetic activity. Materials and Methods: This study focused on the identification of medicinal plants used in the local treatment of diabetes mellitus. Ethnobotanical investigations were carried out in rural and urban areas of three provinces of Gabon using a semi-structured interview. Results: About 50 plant species belonging to 31 families and 50 genera were recorded, a majority of which have been documented previously to have medicinal properties. Most have documented antidiabetic properties with characterized therapeutic chemical compounds. Of the plant parts used for treatment, stem barks were employed most frequently (50%), followed by leaves (26%); the remaining 24% comprised roots, fibers, fruit, bulbs, flowers, rhizom, skin, and stem. Regarding the mode of preparation, decoction was the most widely used (58%), followed by maceration (18%) and infusion (14%). Almost all the plant products were administered orally (98%). Conclusions: Taken in concert, this study highlights the possibility of exploiting traditional knowledge of specific medicinal plants for the inexpensive treatment and management of diabetes.

Patterns and risk factors of birth defects in rural areas of south‐eastern Gabon

Within the context of high neonatal mortality in sub‐Saharan Africa, a retrospective study was conducted on the prevalence of congenital malformations and the association between maternal risk factors and birth defects in rural populations of south‐eastern Gabon. Two populations were studied: a group of 3500 births recorded in rural area (Koula‐Moutou) and a second group of 4212 births in a semi‐rural area (Franceville) in Gabon. Our data showed an increasing prevalence in congenital anomalies from rural to urban areas (P < 0.001). Maternal risk factors such as age > 35 years, multiparity and employment status were significantly associated with the levels of stillbirth. Together with abortions and stillbirths, congenital malformations require strong monitoring in rural and urban areas of sub‐Saharan Africa.

Facteurs influençant la perte de vue et la mortalité chez les personnes vivant avec le VIH suivies au Centre de Traitement Ambulatoire de Koula-Moutou (Gabon) de 2005 à 2015

INTRODUCTION: cette etude avait pour but principal d’evaluer les facteurs biologiques et cliniques associes aux pertes de vue et a la mortalite des patients suivis au Centre de Traitement Ambulatoire VIH/SIDA (CTA) de Koula-Moutou. METHODES: de 2005 a 2015, 1268 patients ont ete suivis au CTA. Le diagnostic serologique du VIH et le comptage des cellules T CD4 ont ete realises respectivement par les kits commerciaux Determine, SD Bioline, Immunocombs et par les reactifs FACS Count. RESULTATS: la majorite des patients suivis etait de sexe feminin (66,8%) et recevait un traitement antiretroviral (TAR) de 1 ere ligne (63,3%). Les pertes de vue et la mortalite a concerne respectivement 33,5% et 24,6% des patients. La perte de vue etait significativement associee a l’absence de prise du TAR (p 500 cellules/mm 3 a l’inclusion (p ere ligne du TAR (p=0,003) et ceux ayant un taux de CD4>500 cellules/mm 3 a l’inclusion (p<0,001). La mortalite des patients tres elevee a l’ouverture du CTA en 2005, a connu une reduction significative entre 2013 et 2015, passant de 4,8% a 1,6% (p<0,001). CONCLUSION: cette etude decrit l’epidemiologie du VIH dans une zone rurale du Gabon. Elle donne les causes des pertes de vue et de la mortalite des patients suivis dans un des dix (10) CTA du pays.

Genotyping of CCR5 gene, CCR2b and SDF1 variants related to HIV-1 infection in Gabonese subjects.

Objective: Given the magnitude of the HIV epidemic infection, many viral and human factors were analyzed, and the most decisive was the variant CCR5-Δ32. The presence of a low HIV prevalence (1.8%) in Gabon in the 1990s, compared to neighboring countries, represents a paradox that led us to search for viral and human genetic variants in this country. In this study, only variants of coreceptors and chemokines were investigated. Methods: Variants of the coding region of the CCR5 gene were analyzed by denaturing gradient gel electrophoresis, and then variants of SDF1 and CCR2b were determined by polymerase chain reaction-restriction fragment length polymorphism. Results: Four rare variants of the CCR5 coreceptor were found, while CCR5-Δ32 and CCR5m303 variants were not found. No association with CCR2b-V64I (17%) and SDF1-3′A (2%) variants was determined in relation to HIV-1 infection in Gabonese patients. Conclusion: The paradox of HIV seroprevalence in Gabon, which ended in the 2000s, was not caused by human genetic variants but rather by environmental factors.