Near-Infrared Light Exposure Triggers ROS to Downregulate Inflammatory Cytokines Induced by SARS-CoV-2 Spike Protein in Human Cell Culture

The leading cause of mortality from SARS-CoV-2 is an exaggerated host immune response, triggering cytokine storms, multiple organ failure and death. Current drug- and vaccine-based therapies are of limited efficacy against novel viral variants. Infrared therapy is a non-invasive and safe method that has proven effective against inflammatory conditions for over 100 years. However, its mechanism of action is poorly understood and has not received widespread acceptance. We herein investigate whether near-infrared (NIR) light exposure in human primary alveolar and macrophage cells could downregulate inflammatory cytokines triggered by the SARS-CoV-2 spike (S) protein or lipopolysaccharide (LPS), and via what underlying mechanism. Our results showed a dramatic reduction in pro-inflammatory cytokines within days of NIR light treatment, while anti-inflammatory cytokines were upregulated. Mechanistically, NIR light stimulated mitochondrial metabolism, induced transient bursts in reactive oxygen species (ROS) and activated antioxidant gene transcription. These, in turn, downregulated ROS and inflammatory cytokines. A causal relationship was shown between the induction of cellular ROS by NIR light exposure and the downregulation of inflammatory cytokines triggered by SARS-CoV-2 S. If confirmed by clinical trials, this method would provide an immediate defense against novel SARS-CoV-2 variants and other inflammatory infectious diseases

Hematological changes among Beninese motor-bike taxi drivers exposed to benzene by urban air pollution

Exposure to high-concentration of benzene in polluted air has been associated with bone marrow deficiency, aplastic anemia and leukemia. However, epidemiological studies have reported conflicting data following human exposure to benzene levels below 1 ppm (that is, 3.2 mg/m3). Therefore we investigated the influence of outdoor air benzene on peripheral blood cells among exposed motor-biketaxi drivers (MBTD) in which specific IgG antibodies against reactive benzene metabolites, such as hydroquinone (HQ) and para-benzoquinone (p-BQ) are identified and quantified for further use as biomarker of exposure. We compared 144 MBTD with 30 unexposed age and sex-matched controls. The mean age ± SD (95% CI) were: MBTD 39.5 ± 7.82 (38.2 - 40.7) and village residents 40.3 ± 10.56 (39.1-43.0). Personal benzene exposure was assessed using GABIE diffusive samplers. The levels of specific IgG antibodies to HQ and p-BQ were determined by ELISA. The peripheral blood cells were counted by an automated analyzer. Benzene, Toluene and Xylene levels were much higher in MBTD in comparison to the control group. Benzene exposure levels ranged from 0.012 to 0.550 ppm in MBTD. Their average exposure level per one week was 0.126±0.206 ppm. Accordingly, MBTD had significantly higher levels of specific IgG antibodies to HQ and p-BQ compared to the controls (p< 0.001). WBC, lymphocytes, eosinophils and platelets were significantly decreased in MBTD, whereas RBC and other blood cell numbers remained unchanged. Total WBC, lymphocytes and eosinophils counts were decreased among exposed MBTD compared to unexposed controls. We suggest the use of these blood parameters together with specific IgG antibodies to HQ and p-BQ as biomarkers in biological monitoring of low level benzene exposure. Larger studies are however required to validate this new approach of health survey in workers exposed to benzene.Key words: Benzene, motor-bike-taxi drivers, specific immune responses, peripheral blood cell count

Occurrence of antibiotic residues in raw fish Clarias gariepinus and Oreochromis niloticus from intensive rearing system in Benin

International audienceAn observational cross-sectional study was carriedy out to investigate antibiotic residues in Clarias gariepinus and Oreochromis niloticus from the intensive rearing system in Southern Benin. The targeted antibiotic families were tetracyclins, amphenicols, beta-lactams and macrolides. One hundred and forty-four (144) samples were used per antibiotic family for residue detection in the fish muscle, making 576 treated samples. The Charm II method based on radioimmunoassay was used. The results showed an overall residue prevalence of 11.1%, which is attributable to tetracyclines alone. There was no residue of the other antibiotic families in the treated fish muscles. The adult fish were the only contaminated age group with 22.2% residue prevalence compared to the fingerlings (p < 0.05). Likewise, the antibiotic residues were significantly (p< 0.05) more prevalent in Clarias gariepinus (16.7%) than in Oreochromis niloticus (5.6%). The adult fishes are generally fattier than the young ones, and that can lower the fish body antibiotic elimination capability. This first detection of tetracyclines residues in fish produced in Benin shows the need to rule and control antibiotic use in the developing fish industry to preserve consumers' health

Banana and plantain production systems in Benin: ethnobotanical investigation, varietal diversity, pests, and implications for better production

The cultivated banana and plantain (Musa spp.) are valuable for nutritional and socio-economic security for millions of people worldwide. In Benin, banana and plantain are among the most produced, consumed, and traded commodities. Its production is mainly for local consumption and remains insufficient to the demand. However, the varietal diversity of banana and plantain cultivated in Benin is not documented. This study aims at characterizing the banana and plantain cropping systems, genetic diversity, and production constraints as a baseline to the full utilization of this resource in crop improvement and to identify the potential production and agronomic qualities. A baseline investigation of ethnobotanical attributes of banana cultivars was done in 51 randomly chosen villages in southern Benin. Interviews with randomly selected representative farmers were carried out. Key informant interviews and focus group discussions were used for global confirmatory investigation of survey data. Socio-demographic data and indigenous knowledge on the farmer uses of banana and plantain diversity, such as cultural practices, origin, and availability of banana and plantain planting materials, and the constraints and criteria of varietal preference cited by farmers were ranked. Eighty-seven locally recognized cultivars were found: 73 of banana and 14 of plantain groups. The most popular cultivars were Sotoumon (banana) (52.94%), Aloga (plantain) (41.17%), Planta (banana) (33.33%), and Adjangan (plantain) (27.45%). Of the eleven production constraints identified, the main biotic challenges were banana weevil Cosmopolites sordidus Germar and banana bunchy top virus (BBTV), while abiotic problems were drought and the wind. Some local varieties like Amandan, Assonwonnou, Coleti, and Ninkouin are extremely rare owing to agronomic and economic preference perceptions. This study provides a baseline for banana diversity in Benin and the West African region and entry points for biological characterization and production improvement. This would enable the exploitation of this resource for plant breeding towards biotic and abiotic challenges facing banana production

Variabilidade genética para caracteres de frutos em acessos de fruteiras tropicais (Spondias spp.)

Recursos Genético

Poorly conserved p15 proteins of cileviruses retain elements of common ancestry and putative functionality: a theoretical assessment on the evolution of cilevirus genomes.

The genus Cilevirus groups enveloped single-stranded (+) RNA virus members of the family Kitaviridae, order Martellivirales. Proteins P15, scarcely conserved polypeptides encoded by cileviruses, have no apparent homologs in public databases. Accordingly, the open reading frames (ORFs) p15, located at the 5?-end of the viral RNA2 molecules, are considered orphan genes (ORFans). In this study, we have delved into ORFs p15 and the relatively poorly understood biochemical properties of the proteins P15 to posit their importance for viruses across the genus and theorize on their origin. We detected that the ORFs p15 are under purifying selection and that, in some viral strains, the use of synonymous codons is biased, which might be a sign of adaptation to their plant hosts. Despite the high amino acid sequence divergence, proteins P15 show the conserved motif [FY]-L-x(3)-[FL]-H-x-x-[LIV]-S-C-x-C-x(2)-C-x-G-x-C, which occurs exclusively in members of this protein family. Proteins P15 also show a common predicted 3D structure that resembles the helical scaffold of the protein ORF49 encoded by radinoviruses and the phosphoprotein C-terminal domain of mononegavirids. Based on the 3D structural similarities of P15, we suggest elements of common ancestry, conserved functionality, and relevant amino acid residues. We conclude by postulating a plausible evolutionary trajectory of ORFans p15 and the 5?-end of the RNA2 of cileviruses considering both protein fold superpositions and comparative genomic analyses with the closest kitaviruses, negeviruses, nege/kita-like viruses, and unrelated viruses that share the ecological niches of cileviruses

Variabilidade genética para caracteres de frutos em genótipos de maracujazeiro

Recursos Genético

Insecticide resistance and species diversity in Anopheles gambiae s.l. in Côte d’Ivoire

Background Insecticide resistance in malaria vectors poses a significant threat to effective control of malaria vectors across sub-Saharan Africa. In Côte d’Ivoire, Anopheles gambiae s.l. exhibits considerable variability in species distribution and insecticide resistance levels across distinct ecological areas. This study reports on insecticide resistance profiles within An. gambiae complex as well as species composition dynamics in various ecological settings in Côte d’Ivoire. Methods: From July to October 2020, larval and adult mosquitoes were collected across three ecological settings (savannah, pre-forest and forest) in Côte d’Ivoire. Larvae were reared to adult stage for susceptibility bioassays. Diagnostic concentrations (DCs) applied against An. gambiae s.l. were deltamethrin 0.05%, permethrin 0.75% and pirimiphos methyl 0.25% using WHO susceptibility test kits. When increased survival to diagnostic concentrations (DCs) was observed, intensity bioassays were conducted using 5x and 10x DCs. In addition, synergist assays were performed at the DC level with pre-exposure to 4% piperonyl butoxide (PBO). Together with adults directly collected from the field, female samples from the bioassays outcome were speciated and resistance target site mechanisms (Kdr L1014F and Ace-1R G119S) were determined using PCR. Species distribution and insecticide resistance were analyzed across ecological areas. Results: Significant variations in insecticide resistance phenotypes and mechanisms in An. gambiae s.l. were found across the three ecological areas in Côte d’Ivoire. Mortality rates, following pyrethroid exposure, were significantly higher in An. gambiae s.l. collected in the savannah zone compared to those collected from the forest zone (p &lt; 0.05). An. gambiae was more predominant in the savannah area (98.8%, 95% confidence of interval (CI) [93.5–100.0]), whereas An. coluzzii dominated in the pre-forest (92.9%, 95% CI [88.9–95.8]) and forest zones (61.3%, 95% CI [53.4–68.9]). Such predominance of An. coluzzii was associated with high intensity of pyrethroid resistance in these areas. Overall, the allelic frequencies of the resistance mutations in An. gambiae were higher than those in An. coluzzii regardless of the area. Kdr L1014F frequency in the forest zone was 78.1% (95% CI [68.0–88.2]) in An. gambiae larvae, 51.8% (95% CI [33.3–70.4]) in adults, and 63.1% (95% CI [52.4–73.8]) in An. coluzzii larvae. Conclusion: Variations in species distribution and insecticide resistance in ecological areas in Côte d’Ivoire should be carefully considered when developing and implementing vector control strategies.</p