Aflatoxigenic strains of Aspergillus section Flavi isolated from marketed peanuts (Arachis hypogaea) in Algiers (Algeria)

The present study reports on the natural mycobiota occurring in Chinese peanuts marketed in Algiers, paying special attention to the incidence of Aspergillus section Flavi species that are potential producers of aflatoxins. The mean value counts of fungi ranged from 155 to 577 CFU/g dry matter (DM) and the predominant fungi were different species of the genus Penicillium (83.81–93.85 %) and Aspergillus belonging to section Flavi (2.73–73.96 %). Results indicated that 82 isolates (100 %) were aflatoxigenic. The Aspergillus section Flavi strains revealed that 65 isolates (79.27 %) were highly aflatoxigenic, producing four kinds of aflatoxins [AFB1 (0.846–3.330 μg/g), AFB2 (0.005–0.007 μg/g), AFG1 (0.008–1.595 μg/g), and AFG2 (0.005–0.010 μg/g)], whereas 17 isolates (20.73 %) synthetized low levels of one or two aflatoxins (AFB1 and AFG2). Aflatoxin production was also screened on Coconut Agar Medium (CAM), and the results were consistent with the HPLC analysis. Based on the combination of mycotoxins produced, five Aspergillus section Flavi chemotypes were established. Sclerotia production expressed a correlation to aflatoxigenicity. The total aflatoxins were detected in four analyzed samples at levels ranging from 0.71 to 25.50 μg/kg. Furthermore, the amplicons corresponding to the ITS1-5.8 S-ITS2 rDNA of six representative strains showed that four strains belonged to Aspergillus flavus, one to A. minisclerotigenes, and one to A. caelatus. The results obtained indicate that there is a possible risk factor posed by aflatoxins contamination of peanuts marketed in Algiers.     

Identification of GBF1 as a cellular factor required for hepatitis E virus RNA replication

The hepatitis E virus (HEV) genome is a single‐stranded, positive‐sense RNA that encodes three proteins including the ORF1 replicase. Mechanisms of HEV replication in host cells are unclear, and only a few cellular factors involved in this step have been identified so far. Here, we used brefeldin A (BFA) that blocks the activity of the cellular Arf guanine nucleotide exchange factors GBF1, BIG1, and BIG2, which play a major role in reshuffling of cellular membranes. We showed that BFA inhibits HEV replication in a dose‐dependent manner. The use of siRNA and Golgicide A identified GBF1 as a host factor critically involved in HEV replication. Experiments using cells expressing a mutation in the catalytic domain of GBF1 and overexpression of wild type GBF1 or a BFA‐resistant GBF1 mutant rescuing HEV replication in BFA‐treated cells, confirmed that GBF1 is the only BFA‐sensitive factor required for HEV replication. We demonstrated that GBF1 is likely required for the activity of HEV replication complexes. However, GBF1 does not colocalise with the ORF1 protein, and its subcellular distribution is unmodified upon infection or overexpression of viral proteins, indicating that GBF1 is likely not recruited to replication sites. Together, our results suggest that HEV replication involves GBF1‐regulated mechanisms.     

A genomic map of climate adaptation in Mediterranean cattle breeds

Domestic species such as cattle (Bos taurus taurus and B. t. indicus) represent attractive biological models to characterize the genetic basis of short‐term evolutionary response to climate pressure induced by their post‐domestication history. Here, using newly generated dense SNP genotyping data, we assessed the structuring of genetic diversity of 21 autochtonous cattle breeds from the whole Mediterranean basin and performed genome‐wide association analyses with covariables discriminating the different Mediterranean climate subtypes. This provided insights into both the demographic and adaptive histories of Mediterranean cattle. In particular, a detailed functional annotation of genes surrounding variants associated with climate variations highlighted several biological functions involved in Mediterranean climate adaptation such as thermotolerance, UV protection, pathogen resistance or metabolism with strong candidate genes identified (e.g., NDUFB3, FBN1, METTL3, LEF1, ANTXR2 and TCF7). Accordingly, our results suggest that main selective pressures affecting cattle in Mediterranean area may have been related to variation in heat and UV exposure, in food resources availability and in exposure to pathogens, such as anthrax bacteria (Bacillus anthracis). Furthermore, the observed contribution of the three main bovine ancestries (indicine, European and African taurine) in these different populations suggested that adaptation to local climate conditions may have either relied on standing genomic variation of taurine origin, or adaptive introgression from indicine origin, depending on the local breed origins. Taken together, our results highlight the genetic uniqueness of local Mediterranean cattle breeds and strongly support conservation of these populations.     

Anti-Alzheimer's Activity of Polyphenolic Stilbene-Rich Acetone Fraction of the Oil-Removed Seeds of Passiflora edulis: in Vivo and in Silico Studies

The stilbene-rich acetone fraction in high yield (6.6 %, PEAS) of Passiflora edulis Sims was prepared and evaluated for neuroprotective activity in murine Alzheimer's disease model induced by aluminum chloride and D-galactose. The phytochemical and HPLC-DAD-MS analysis of the polyphenolic stilbene-rich acetone fraction showed that it contained different stilbenes including trans-piceatannol, scirpusins A−B and cassigarol E. The total phenolic content (TPC) of PEAS was 413.87±1.71 mg GAE eqv/g. The neuroprotective activity of PEAS is typically presented in the Morris water maze-reference Spatial Memory test, where the Alzheimer's mice treated at 100 mg/kg (Alz-ED1) and 200 mg/kg (Alz-ED2) spent less than 47 % and 66 % of the time, respectively, than the Alzheimer's model mice (Alz). Two simple stilbenes, trans-piceatannol and trans-resveratrol, showed selectively inhibitory activity in silico against acetylcholinesterase (AChE). Two stilbene dimers, cassigarol E and scirpusin A, exhibited low nanomolar inhibitory potential against AChE and butyrylcholinesterase (BChE), significantly lower than those of the positive control, donepezil and tacrine. These findings suggest that the stilbenes from P. edulis seeds, particularly the stilbene dimers, warrant further investigation as potential neuroprotective candidates in the prevention of cognitive deficits associated with Alzheimer's disease.