Phylogenetic and protein prediction analysis reveals the taxonomically diverse distribution of virulence factors in the Bacillus cereus group

Bacillus cereus is a food contaminant with widely varying enterotoxic potential of its virulence proteins. In this article, phylogenetic analysis of the whole-genome amino acid sequences of 41 strains, evolutionary distance calculation of the amino acid sequences of the virulence genes, and functional and structural prediction of the virulence proteins were performed to reveal the taxonomically diverse distribution of virulence factors. The genome evolution of the strains showed a clustering trend based on the coding virulence genes. The strains of B. cereus have evolved into non-toxic risk and toxic risk clusters with medium-high- and medium-low-risk clusters. The distances of evolutionary transfer relative to housekeeping genes of incomplete virulence genes were greater than those of complete virulence genes, and the distance values of HblACD were higher than those of nheABC and CytK among the complete virulence genes. Cytoplasmic localization was impossible for all the virulence proteins, and NheB, NheC, Hbl-B, and Hbl-L 1 were extracellular according to predictive analysis. Nhe and Hbl proteins except CytK had similar spatial structures. The predicted structures of Nhe and Hbl mainly showed ‘head’ and ‘tail’ domains. The ‘head’ of NheA and Hbl-B, including two α-helices separated by β-tongue strands, might play a special role in Nhe trimers and Hbl trimers, respectively. The ‘cap’ of CytK, which includes two ‘latches’ with many β-sheets, formed a β-barrel structure with pores, and a ‘rim’ balanced the structure. The evolution of B. cereus strains showed a clustering tendency based on the coding virulence genes, and the complete virulence-gene operon combination had higher relative genetic stability. The beta-tongue or latch associated with β-sheet folding might play an important role in the binding of virulence structures and pore-forming toxins in B. cereus .

ASSESSMENT OF THE LEVELS OF GENERAL TOXIC RISK TO THE HEALTH OF THE POPULATION OF UDMURTIA FROM THE CONSUMPTION OF DRINKING WATER FROM UNDERGROUND SOURCES WITH A HIGH CONTENT OF IRON, BORON AND FLUORINE

ASSESSMENT OF THE LEVELS OF GENERAL TOXIC RISK TO THE HEALTH OF THE POPULATION OF UDMURTIA FROM THE CONSUMPTION OF DRINKING WATER FROM UNDERGROUND SOURCES WITH A HIGH CONTENT OF IRON, BORON AND FLUORINE

A Review on Non-target Toxicity of Deltamethrin and Piperonyl Butoxide: Synergist

Deltamethrin and piperonyl butoxide two synthetic pyrethroids, when used in a combination it produces synergistic effect. This two insecticide has found to be widely used in the management of mosquito, housefly and other insects to control the various vector born diseases. In this review we assessed the toxic effect of deltamethrin and piperonyl butoxide on beneficial organisms commonly available in the ecosystem. It was found to be toxic to fish, honey bees the prime pollinators of crop plant; earthworm is also susceptible at a lethal concentration for a particular exposure. As far the birds are concerned, they have a less toxic risk in lower concentration of exposure. The alterations obtained in the hematological, biochemical and histopathological studies, further conclude that it can cause environment hazards and toxic to the non-targeted organisms. This investigation gives an insight into the combined toxicological profile of deltamethrin and PBO for better risk assessment and safe use of pyrethroids and their synergist in non-targeted organisms.

Looming Uncertainties of Neoliberal Techno-optimism

This chapter engages the looming politics of uncertainty and optimism surrounding Ghana’s e-waste management and infrastructural future. Beyond a discardscape of toxic risk, Agbogbloshie can also be understood as an intervention environment in the urban margins where uncertainty and neoliberal techno-optimism thrive. The ethnographic findings explored expose how efforts to address e-waste “crisis” in Agbogbloshie are conditioned by sociotechnical renderings of pollution control, risk mitigation, and e-waste economization efforts that tend to perpetuate green developmentalist agendas, projects, and discourses of hope centered on cleaning up Agbogbloshie. As explored in this chapter, other, more radical, perspectives, ways of knowing, and methods of intervention might be needed to address Ghana’s e-waste challenges, especially environmental health interventions and e-waste policies directly informed by emerging “just transition” and decolonization debates.

Seasonal and Spatial Variations of Ecological Risk from Potential Toxic Elements in the Southern Littoral Zone of İzmir Inner Gulf, Turkey

This study aimed to investigate the ecological risk level of İzmir Inner Gulf. Based on the findings, port, industry, settlement and transportation activities generated Mo, Pb, Cu, Cd, Zn enrichment. Modified hazard quotient (MHQ) point to a high level of pollution and toxic effects for Ni and Cr; significant pollution and toxic effects for As and Hg, and moderate pollution and toxic effects for Pb, Zn, Cu. According to the ecological contamination index (ECI), the inner gulf is significantly-highly polluted. Toxic risk index (TRI) and potantial ecological risk index (PERI) are also consistent with these data. According to the ECI, the inner gulf is significantly/highly polluted. TRI and the PERI are also consistent with these data. Cd has created a significant ecological risk in all seasons due to its high toxicity. Cu and Pb have caused moderate ecological risk in local areas near the port. A moderate potential ecological risk has been identified in all seasons throughout the inner gulf.

Combining single and complex indices of pollution with grain size trend analysis of surficial sediments in Edremit Gulf, western Turkey.

Pollution risk assessment of heavy metals (Pb, Cr, Cu, Ni, Zn, As) in sediment samples from 68 locations in the Gulf of Edremit, western Turkey, was performed using single and complex indices of pollution assessment approaches. The pollution indices used in the sediment analyses included pollution load index(PLI), contamination factor(CF), contamination degree(Cdeg) for individual metals, geoaccumulation index (Igeo), enrichment factors(EF), toxic risk index(TRI), modified pollution index (MPI), frequency of adverse biological effects (TEL-PEL), percent incidence of biological effects (ERL-ERM), and total risk quotients (QTEL-QPEL). Results indicated a low degree of contamination for the entire surveyed area except moderate contamination factor for arsenic using single indices. Enrichment factors and geoaccumulation indices indicated moderate to significant enrichment and uncontaminated to moderately contaminated both for arsenic(As) and lead(Pb), respectively. According to the results of ecological risk assessment based on TELs and PELs, the adverse biological effects of heavy metals on aquatic organisms; are for As, Cr, Ni frequently, Cu and Pb occasionally and Zn rare. The TRI values displayed low to considerably toxic risk for the entire Gulf and calculated TRI results showed that arsenic accounted for most of the entire sediment toxicity. Transport patterns of sediment grain size trend analyses were correlated with the results of pollution assessment models. Transport trends are compatible with the sources of lithogenic, anthropogenic, mining activities and wastewater treatment/geothermal originated arsenic.

Neurotoxic Effects of Neonicotinoids on Mammals: What Is There beyond the Activation of Nicotinic Acetylcholine Receptors?—A Systematic Review

Neonicotinoids are a class of insecticides that exert their effect through a specific action on neuronal nicotinic acetylcholine receptors (nAChRs). The success of these insecticides is due to this mechanism of action, since they act as potent agonists of insect nAChRs, presenting low affinity for vertebrate nAChRs, which reduces potential toxic risk and increases safety for non-target species. However, although neonicotinoids are considered safe, their presence in the environment could increase the risk of exposure and toxicity. On the other hand, although neonicotinoids have low affinity for mammalian nAChRs, the large quantity, variety, and ubiquity of these receptors, combined with its diversity of functions, raises the question of what effects these insecticides can produce in non-target species. In the present systematic review, we investigate the available evidence on the biochemical and behavioral effects of neonicotinoids on the mammalian nervous system. In general, exposure to neonicotinoids at an early age alters the correct neuronal development, with decreases in neurogenesis and alterations in migration, and induces neuroinflammation. In adulthood, neonicotinoids induce neurobehavioral toxicity, these effects being associated with their modulating action on nAChRs, with consequent neurochemical alterations. These alterations include decreased expression of nAChRs, modifications in acetylcholinesterase activity, and significant changes in the function of the nigrostriatal dopaminergic system. All these effects can lead to the activation of a series of intracellular signaling pathways that generate oxidative stress, neuroinflammation and, finally, neuronal death. Neonicotinoid-induced changes in nAChR function could be responsible for most of the effects observed in the different studies.

A new charophyte habitat with a stabilized good ecological potential of mine water

Each newly-created pond which is supplied with mine water gives the opportunity to study a unique ecosystem in context of possible conditions for biotic live. Therefore, this research aimed to assess a phytoplankton-based ecological potential against the trophic conditions and the risk of contamination with trace elements, and demonstrate the possibility to stabilize at least good water quality of a clarification pond. The gradual decrease in turbidity-related variables (including suspended solids and iron) and nutrients, on the one hand, and an increase in phytoplankton-related indicators, on the other hand, were the most evident. Besides, relative stability in trace elements (the best water quality class), trophic level (slightly eutrophic level) and ecological potential (maximum potential), and relative instability in sulfates and calcium were also recorded. The final stabilization of water habitat resulted in abundant growth of charophyte Nitella mucronata. This all suggested a new ecological opportunity for settlement of a rare species and important for biodiversity enhancement. Furthermore, the study revealed that a clarification pond did not pose any toxic risk from the elevated content of trace elements or the growth of toxic or potentially toxic cyanobacteria which is essential for proper functioning and management of water ecosystems.

Investigation of qualitative indicators of non-tobacco nicotine-containing shisha mixtures: consumer characteristics and nicotine content

Shisha tobacco and non-tobacco nicotine-containing shisha mixtures are an alternative way of consuming nicotine with a potential reduction in toxicological risk apart from smoking cigarettes. The Federal Law of July 31, 2020 N 303-FZ «On Amendments to Certain Legislative Acts of the Russian Federation on the Protection of Citizens’ Health from the Consequences of Consuming Nicotine-Containing Products» [1] equated the consumption of nicotine-containing products with the traditional use of tobacco. The absence of state regulation predetermines the relevance of conducting large-scale studies of both shisha tobacco and non-tobacco nicotine-containing shisha mixtures. The specificity of the product consumption in this segment is the production of a highly dispersed aerosol that occurs without the combustion / smoldering process. The variety of the ingredient composition of nicotine-containing shisha mixtures determines the consumer properties and the toxic load of the aerosol produced. Assessment of the toxic effects of an aerosol should take into account the concentration of the ingredients in the mixture, the nicotine content and their transfer to the aerosol. The methods for determining the composition of nicotine-containing products have been updated in the laboratory of technology for the production of tobacco products of the FSBSI RSRITTP [2] over the past years. The article presents the results of studies to determine the content of glycerin and propyl- ene glycol, which determine the consumer properties of the product and nicotine as the main factor that determines the potential level of toxic risk of the product in shisha tobacco and non-tobacco nicotine-containing shisha mixture. The result of the research: the dependence of the tasting assessment on the content of VG glycerin in the ingredient composition of the mixture has been revealed. Insufficient glycerin content is the reason for the weak ability to form a saturated dense aerosol. The content of nicotine in the studied samples of shisha mixture has been determined and transition of nicotine into aerosol has been established.