The Effects of a systemic insecticide on stretching and production of wax in domestic bees Apis mellifera intermissa in Northen Africa (Algeria)

Imidacloprid is a well-known systemic insecticide which has a deleterious impact on honeybees. Beekeepers in the Tizi-Ouzou wilaya (Algeria) where the imidacloprid insecticide is used, report unusual losses and deaths of bee colonies. Even at sublethal doses, insecticid can impact the most crucial tasks of a bee colony such as comb building. This study was conducted in order to investigate the effect of an imidacloprid based insecticide (Confidor®Supra) on the production of wax by the honeybee Apis mellifera intermissa. After the imidacloprid LD50 was determined in controlled conditions, three sublethal doses were tested. The mortality, the syrup consumption and the weight of the wax generated were recorded. The imidacloprid insecticide LD50 at 48 hours was evaluated at 3.5 ng.per bee on 4 days old spring worker bees. We found that the three sublethal doses (0.175 mg.L-1, 0.087 mg.L-1 and 0.035 mg.L-1) had an impact on the syrup consumption and the wax production by adult bees. Bees exposed to sublethal doses of insecticide consumed less syrup and produced less wax that the control bees. A dose response was observed regarding the production of wax. The reduction of wax production by bees caused by an exposure to an imidacloprid based insecticide ads up to the many other effects of imidacloprid described in the literature.  This kind of impact could have harmful consequences for bee colonies as wax production is the basis of nest building. The physiological causes of the reduction of wax production remain to be investigated

Efficacy of formulated carvacrol on Campylobacter jejuni in challenge test in vivo and impact on the whole caecal microbiota

Efficacy of formulated carvacrol on Campylobacter jejuni in challenge test in vivo and impact on the whole caecal microbiota. Colloque Adebiotech MBIO 2018 Les microbiotes et la santé humaine, animale et environnementale : Prévention et traitements du futu

Prospecting peptides isolated from black soldier fly (Diptera : Stratiomyidae) with antimicrobial activity against Helicobacter pylori (Campylobacterales : Helicobacteraceae)

Helicobacter pylori (Marshall & Goodwin) is a widespread human pathogen that is acquiring resistance to the antibiotics used to treat it.This increasing resistance necessitates a continued search for new antibiotics. An antibiotic source that shows promise is animals whose immune systems must adapt to living in bacteria-laden conditions by producing antibacterial peptides or small molecules. Among these animals is the black soldier fly (BSF; Hermetia illucens Linnaeus), a Diptera that colonizes decomposing organic matter. In order to find anti-H. pylori peptides in BSF, larvae were challenged with Escherichia coli (Enterobacteriales: Enterobacteriaceae). Small peptides were extracted from hemolymph and purified using solid-phase extraction, molecular weight cutoff filtration and two rounds of preparative high performance liquid chromatography (HPLC). The anti-H. pylori fraction was followed through the purification process using the inhibition zone assay in brain-heart infusion agar, while peptides from uninoculated larvae had no activity. The inhibition halo of the active sample was comparable to the action of metronidazole in the inhibition zone assay. The purified sample contained four peptides with average masses of approximately 4.2 kDa that eluted together when analyzed by HPLC-mass spectrometry. The peptides likely have similar sequences, activity, and properties. Therefore, BSF produces inducible antibacterial peptides that have in vitro activity against H. pylori, which highlights BSF's position as an important target for further bioprospecting

Comparative study of the effects of ziram and disulfiram on human monocyte-derived macrophage functions and polarization : involvement of zinc

Ziram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10 mu mol.L(-1)for 4-24 h. To characterize zinc involvement in these changes, we also determined the effects of disulfiram alone (dithiocarbamate without zinc) or in co-incubation with ZnSO4. We have shown that ziram and disulfiram at 0.01 mu mol.L(-1)increased zymosan phagocytosis. In contrast, ziram at 10 mu mol.L(-1)completely inhibited this phagocytic process, the oxidative burst triggered by zymosan and the production of TNF-alpha, IL-1 beta, IL-6, and CCL2 triggered by LPS. Disulfiram had the same effects on these macrophages functions only when combined with zinc (10 mu mol.L-1). In contrast, at 10 mu mol.L(-1)ziram and zinc associated-disulfiram induced expression of several antioxidants genes HMOX1, SOD2, and catalase, which could suggest the induction of oxidative stress. This oxidative stress could be involved in the increase in late apoptosis induced by ziram (10 mu mol.L-1) and zinc associated-disulfiram. Concerning gene expression profiles of membrane markers of macrophage polarization, ziram at 10 mu mol.L(-1)had two opposite effects. It inhibited the gene expression of M2 markers (CD36, CD163) in the same way as the disulfiram-zinc co-treatment. Conversely, ziram induced gene expression of other M2 markers CD209, CD11b, and CD16 in the same way as treatment with zinc alone. Disulfiram-zinc association had no significant effects on these markers. These results taken together show that ziram via zinc modulates macrophages to M2-like anti-inflammatory phenotype which is often associated with various diseases

Polychlorinated biphenyl uptake by carrots after sludge composts application: waste case and operational practice in greenhouse conditions

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