Polyphénols et activités antioxydantes des fruits de Grewia spp. consommés par les bonobos à Luikotale, R.D. Congo

De nombreuses études ont prouvé le rôle important que jouent les antioxydants en tant que capteurs de radicaux libres dans la protection des organismes contre les affections pathologiques causées par les radicaux libres telles que l’arthrite, l’ischémie, les anémies, l’asthme, les affections neuro-dégénératives, la maladie de Parkinson, le mongolisme, le vieillissement, les affections démentielles, les inflammations, les cancers etc. Les observations sur le régime alimentaire des bonobos (Pan paniscus) dans les forêts de la Cuvette Centrale de la R.D. Congo, au Sud du Parc National de la Salonga sur le site de recherche du Max-Planck Institute for Evolutionary Anthropology (MPI-EVA) à Luikotale, ont montré que les fruits du genre Grewia font parties de la diète de ces primates. Aussi, nous sommes-nous proposés d’évaluer le potentiel antioxydant et les polyphénols présents dans les fruits mûrs de cinq espèces du genre Grewia afin d’estimer de façon comparative les potentiels bénéfices des fruits des différentes espèces pour la santé des bonobos. Les études ont porté sur les fruits de Grewia coriacea Mast. (GC), Grewia malacocarpoides De Wild. (GM), Grewia oligoneura Sprague (GO), Grewia pinnatifida Auct. (GP) et Grewia sp. (GSP). Toutes les mesures de quantifications réalisées sur les extraits totaux éthanoliques de fruits ont été effectuées par spectrophotométrie. La meilleure activité antioxydante contre le radical 1,1-diphényl-2-picrylhydrazyle (DPPH), a été obtenue avec le GO (CI50 = 450,44±20,41µg/ml). Tandis que, les contenus par g d’extraits secs, en anthocyanes, flavonoïdes, et polyphénols ont été plus élevés pour GO avec 17,08±3,71 mg de catéchine/g, 16,17±2,32 mg de quercétrine/g et 16,27±0,64 mg d’acide gallique/g respectivement. Les résultats obtenus semblent confirmer les bénéfices nutritionnels des fruits analysés pour la santé des bonobos ; ils constituent en outre une référence pour les études ultérieures visant à comprendre les conséquences de la consommation de ces fruits sur la santé de ces bonobos

High prevalences and a wide genetic diversity of simian retroviruses in non-human primate bushmeat in rural areas of the Democratic Republic of Congo [+ Erratum]

Like the majority of emerging infectious diseases, HIV and HTLV are of zoonotic origin. Here we assess the risk of cross-species transmissions of their simian counterparts, SIV and STLV, from non-human primates (NHP) to humans in the Democratic Republic of Congo (DRC). A total of 331 samples, derived from NHP bushmeat, were collected as dried blood spots (DBS, n = 283) or as tissue samples (n = 36) at remote forest sites mainly in northern and eastern DRC. SIV antibody prevalences in DBS were estimated with a novel high throughput immunoassay with antigens representing the actual known diversity of HIV/SIV lineages. Antibody-positive samples were confirmed by PCR and sequence analysis. Screening for STLV infection was done with universal primers in tax, and new strains were further characterized in LTR. SIV and STLV infection in tissue samples was done by PCR only. Overall, 5 and 15.4% of NHP bushmeat was infected with SIV and STLV, respectively. A new SIV lineage was identified in Allen's swamp monkeys (Allenopithecus nigroviridis). Three new STLV-1 subtypes were identified in Allen's swamp monkeys (Allenopithecus nigroviridis), blue monkeys (Cercopithecus mitis), red-tailed guenons (Cercopithecus ascanius schmidti) and agile mangabeys (Cercocebus agilis). SIV and STLV prevalences varied according to species and geographic region. Our study illustrates clearly, even on a small sample size from a limited number of geographic areas, that our knowledge on the genetic diversity and geographic distribution of simian retroviruses is still limited and that humans continue to be exposed to relative high proportions on infected NHP bushmeat

Extensive serological survey of multiple African nonhuman primate species reveals low prevalence of immunoglobulin G antibodies to 4 Ebola virus species

Bats are considered a reservoir species for Ebola viruses, but nonhuman primates (NHPs) have represented a source of infection in several outbreaks in humans. Here we report serological screening of blood or fecal samples from monkeys (n = 2322) and apes (n = 2327). Thirty-six NHP species from Cameroon, Democratic Republic of the Congo, and Ivory Coast were tested with a sensitive and specific Luminex-based assay for immunoglobulin G antibodies to 4 Ebola virus species. Using the simultaneous presence of antibodies to nucleoproteins and glycoproteins to define positivity, we showed that specific Ebola virus antibodies are not widespread among NHPs. Only 1 mustached monkey (Cercopithecus cephus) from Cameroon was positive for Sudan ebolavirus. These observations support that NHPs are most likely intermediate hosts for Ebola viruses. With the increasing frequency of Ebola outbreaks, it is crucial to identify the animal reservoir and understand the ecology of Ebola viruses to inform disease control

Survey of Ebola viruses in frugivorous and insectivorous bats in Guinea, Cameroon, and the Democratic Republic of the Congo, 2015-2017

To clarify the role of bats in the ecology of Ebola viruses, we assessed the prevalence of Ebola virus antibodies in a large-scale sample of bats collected during 2015-2017 from countries in Africa that have had previous Ebola out- breaks (Guinea, the Democratic Republic of the Congo) or are at high risk for outbreaks (Cameroon). We analyzed 4,022 blood samples of bats from >= 12 frugivorous and 27 insectivorous species; 2-37 (0.05%-0.92%) bats were seropositive for Zaire and 0-30 (0%-0.75%) bats for Sudan Ebola viruses. We observed Ebola virus antibodies in 1 insectivorous bat genus and 6 frugivorous bat species. Certain bat species widespread across Africa had serologic evidence of Zaire and Sudan Ebola viruses. No viral RNA was detected in the subset of samples tested (n = 665). Ongoing surveillance of bats and other potential animal reservoirs are required to predict and prepare for future outbreaks