GR13-type plasmids in Acinetobacter potentiate the accumulation and horizontal transfer of diverse accessory genes

Carbapenem resistance and other antibiotic resistance genes (ARGs) can be found in plasmids in Acinetobacter, but many plasmid types in this genus have not been well-characterised. Here we describe the distribution, diversity and evolutionary capacity of rep group 13 (GR13) plasmids that are found in Acinetobacter species from diverse environments. Our investigation was prompted by the discovery of two GR13 plasmids in A. baumannii isolated in an intensive care unit (ICU). The plasmids harbour distinct accessory genes: pDETAB5 contains blaNDM-1 and genes that confer resistance to four further antibiotic classes, while pDETAB13 carries putative alcohol tolerance determinants. Both plasmids contain multiple dif modules, which are flanked by pdif sites recognised by XerC/XerD tyrosine recombinases. The ARG-containing dif modules in pDETAB5 are almost identical to those found in pDETAB2, a GR34 plasmid from an unrelated A. baumannii isolated in the same ICU a month prior. Examination of a further 41 complete, publicly available plasmid sequences revealed that the GR13 pangenome consists of just four core but 1086 accessory genes, 123 in the shell and 1063 in the cloud, reflecting substantial capacity for diversification. The GR13 core genome includes genes for replication and partitioning, and for a putative tyrosine recombinase. Accessory segments encode proteins with diverse putative functions, including for metabolism, antibiotic/heavy metal/alcohol tolerance, restriction-modification, an anti-phage system and multiple toxin-antitoxin systems. The movement of dif modules and actions of insertion sequences play an important role in generating diversity in GR13 plasmids. Discrete GR13 plasmid lineages are internationally disseminated and found in multiple Acinetobacter species, which suggests they are important platforms for the accumulation, horizontal transmission and persistence of accessory genes in this genus.

Neuroecology of Alcohol Preference in Drosophila

In this review, we highlight sources of alcohols in nature, as well as the behavioral and ecological roles that these fermentation cues play in the short lifespan of Drosophila melanogaster. With a focus on neuroethology, we describe the olfactory detection of alcohol as well as ensuing neural signaling within the brain of the fly. We proceed to explain the plethora of behaviors related to alcohol, including attraction, feeding, and oviposition, as well as general effects on aggression and courtship. All of these behaviors are shaped by physiological state and social contexts. In a comparative perspective, we also discuss inter- and intraspecies differences related to alcohol tolerance and metabolism. Lastly, we provide corollaries with other dipteran and coleopteran insect species that also have olfactory systems attuned to ethanol detection and describe ecological and evolutionary directions for further studies of the natural history of alcohol and the fly.

Differential Influence of Pueraria lobata Root Extract and Its Main Isoflavones on Ghrelin Levels in Alcohol-Treated Rats

The study was carried out on alcohol-preferring male Wistar rats. The following drugs were repeatedly (28×) administered: acamprosate (500 mg/kg, p.o.), naltrexone (0.1 mg/kg, i.p), and Pueraria lobata (kudzu) root extract (KU) (500 mg/kg, p.o.) and its isoflavones: daidzin (40 mg/kg, p.o.) and puerarin (150 mg/kg, p.o.). Their effects on a voluntary alcohol intake were assessed. KU and alcohol were also given for 9 days in an experiment on alcohol tolerance development. Finally, total and active ghrelin levels in peripheral blood serum were measured by ELISA method. Acamprosate, naltrexone, daidzin, and puerarin, reducing the alcohol intake, caused an increase in both forms of ghrelin levels. On the contrary, though KU inhibited the alcohol intake and alcohol tolerance development, it reduced ghrelin levels in alcohol-preferring rats. The changes of ghrelin concentration could play a role as an indicator of the currently used drugs. The other effect on the KU-induced shift in ghrelin levels in the presence of alcohol requires further detailed study.

Lack of salidroside impact on selected cytochromes encoding genes transcription in the liver of ethanol induced rats

Summary Introduction: The molecular basis of in vivo metabolism of selected representatives of phenylethanoids in the presence of ethanol has not been fully elucidated. Objective: The aim was to estimate a salidroside (Sal) metabolism in the liver tissue in rats with induced alcohol tolerance by assessing changes in the transcription of genes encoding cytochromes: CYP1A2, 2D2, 3A1, 2C23. Methods: cDNA was synthesized from total RNA isolated from rat liver samples. mRNA level changes were evaluated using real-time PCR (qRT-PCR) technique. Results: Ethanol caused a significant induction of the CYP1A2 and CYP2C23 genes transcription, and a decrease in the CYP3A1 mRNA level, predominantly without statistical significance. A statistically significant increase of the CYP1A2 mRNA level was observed in the group receiving only Sal (4.5 mg/kg b.w.; p.o.) (p<0.01). Conclusions: There was no unequivocal effect of salidroside on the transcription of investigated cytochrome genes in the liver of rats with induced alcohol tolerance.

Computational Screening of Phytochemicals against Munc13-1, a Promising target to treat Alcoholism

In silico analysis and characterization has revolutionized target and drug discovery significantly. Alcohol abuse is a big threat to society, economy and wellbeing of people. It has increased the overall disease and injury burden, globally. Recently, a study revealed a brain protein, Munc13-1 C1 domain to play a significant role in development of alcohol tolerance, by binding to alcohol molecules, eventually leading to Alcohol Use Disorder. The aim of this study was to discover a phytochemical that would attach to our target protein, Munc13-1 C1 domain so that it cannot bind with the alcohol molecules. Munc13-1 3D structure obtained from PDB was docked against a library of compounds by MOE software. Ten phytochemicals based on their binding affinity with the target protein were shortlisted i.e. Tannic Acid, Anemone blue anthocyanin 1, Oolonghomobisflavan B, Diosmin, Oolonghomobisflavan A, Neodiosmin, Blepharocalyxin B, 8-Hydroxyhesperetin, Eupatorin and Monotesone A. However, only 8-Hydroxyhesperetin, Eupatorin and Monotesone A followed Lipinski rules. They were non-toxic and non-carcinogenic according to SwissADME. Moreover, have a good drug-like model score as analysed by Molsoft. Further, in-vivo and invitro examinations are required to inspect their role in reducing alcohol tolerance.

Occurrence and Distribution of Strains of Saccharomyces cerevisiae in China Seas

The yeast Saccharomyces cerevisiae has been widely applied in fermentation industries, chemical industries and biological research and it is widespread in different environments, especially in sugar-rich environments. However, little is known about the occurrence, distribution and roles of S. cerevisiae in marine environments. In this study, only 10 strains among all the yeasts isolated from different marine environments belonged to S. cerevisiae. It was found that most of the strains of S. cerevisiae in marine environments occurred in guts, the surface of marine fish and mangrove trees. In contrast, they were not found in seawater and sediments. All the strains of S. cerevisiae isolated from the marine environments had a lower ability to produce ethanol than the highly alcohol-producing yeast Saccharomyces sp. W0 isolated from fermented rice, but the strains 2E00400, 2E00558, 2E00498, 2E00723, 2E00724 could produce higher concentrations of ethanol than any other marine-derived strains of S. cerevisiae obtained in this study. However, some of them had higher ethanol tolerance and higher trehalose content than Saccharomyces sp. W0. In particular, ethanol tolerance of the yeast strain 2E00498 was higher than that of Saccharomyces sp. W0. This may be related to the harsh marine environments from which they were isolated. Such yeast strains with higher alcohol tolerance could be used to further improve the alcohol tolerance of Saccharomyces sp. W0.

Surfactant-free synthesis of carbon-supported silver (Ag/C) nanobars as an efficient electrocatalyst for alcohol tolerance and oxidation of sodium borohydride in alkaline medium

We have synthesized carbon-supported silver (Ag/C) nanobars by a simple surfactant-free hydrothermal method using glucose as the reducing reagent as well as the source of carbon in Ag/C nanobars. Physicochemical characterization of the materials was performed by X-ray Diffraction (XRD), field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The XRD pattern confirmed the presence of a pure metallic silver phase. No carbon phase was detected, which indicates that the carbon exists mainly in the amorphous form. The electrocatalytic activity of Ag/C in different electrolyte solutions such as 0.5 M NaOH, 0.5 M NaOH + 1 M ethanol (EtOH), 0.5 M NaOH + 1 M ethylene glycol (EG), and 0.5 M NaOH + 0.01 M NaBH4 (sodium borohydride) was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) study. Alcohol tolerance of the catalysts was also established in the presence of ethanol and ethylene glycol. The forward-to-backward current ratio from cyclic voltammetry (CV) study of Ag/C-20 (20 h) in 0.5 M NaOH + 1 M ethanol solution at 100 mV s−1 scan rate is 4.13 times higher compared to that of Ag/C-5 (5 h). Hence, Ag/C-20 is a better candidate for the tolerance of ethanol. In the presence of ethylene glycol (1 M) in 0.5 M NaOH solution, it is obtained that the forward-to-backward current ratio at the same scan rate for Ag/C-20 is lower than that in the presence of ethanol. The durability of the catalyst was studied by chronoamperometry measurement. We studied the electrochemical kinetics of Ag/C catalysts for borohydride oxidation in an alkaline medium. The basic electrochemical results for borohydride oxidation show that Ag/C has very well strength and activity for direct borohydride oxidation in an alkaline medium. The reaction of borohydride oxidation with the contemporaneous BH4−. hydrolysis was noticed at the oxidized silver surface. Among all the synthesized Ag/C catalysts, Ag/C-20 exhibited the best electrocatalytic performance for borohydride oxidation in an alkaline medium. The activation energy and the number of exchange electrons at Ag/C-20 electrode surface for borohydride electro-oxidation were estimated as 57.2 kJ mol−1 and 2.27, respectively.

Sleep modulates alcohol toxicity in Drosophila

Study ObjectivesAlcohol abuse is a significant public health problem, particularly in populations in which sleep deprivation is common as such as shift workers and aged individuals. Although research demonstrates the effect of alcohol on sleep, little is known about the role of sleep in alcohol sensitivity and toxicity. We investigated sleep as a factor modulating alcohol toxicity using Drosophila melanogaster, a model system ideal for studies of sleep, alcohol and aging.MethodsFollowing 24 hours of sleep deprivation using mechanical stimulation, Drosophila were exposed to binge-like alcohol exposures. Behavioral sensitivity, tolerance, and mortality were assessed. The effects of chronic sleep deprivation on alcohol toxicity were investigated using a short sleep mutant insomniac. Pharmacological induction of sleep for prior to alcohol exposure was accomplished using a GABAA-receptor agonist, 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP) to determine if increased sleep mitigated the effects of alcohol toxicity on middle-aged flies and flies with environmentally disrupted circadian clocks mimicking groups more vulnerable to the effects of alcohol.ResultsAcute sleep deprivation increased alcohol-induced mortality following alcohol exposure. However, sleep deprivation had no effect on alcohol absorbance or clearance. Sleep deprivation also abolished functional tolerance measured 24 hours after the initial alcohol exposure, although tolerance at 4 h was observed. Pharmacologically increasing sleep prior to alcohol exposure decreased alcohol-induced mortality.ConclusionsSleep quantity prior to alcohol exposure affects alcohol toxicity with decreased sleep increasing alcohol toxicity and dampened 24-hour alcohol tolerance. In contrast, increased sleep mitigated alcohol-induced mortality even in vulnerable groups such as aging flies and those with circadian dysfunction.Statement of significanceWith the growing incidence of sleep deprivation and sleep disorders across adolescents and adults, it is important to understand the role of sleep in alcohol toxicity to develop future therapies for prevention and treatment of alcohol-induced pathologies. Using Drosophila melanogaster, an established model for both sleep and alcohol research, we found that acute and chronic sleep deprivation increased alcohol toxicity and eliminated long-term functional alcohol tolerance. In contrast, increased sleep prior to binge-like alcohol exposure mitigated alcohol-induced mortality even in vulnerable groups with higher susceptibility to alcohol toxicity.