Phenomic and genomic approaches to studying the inhibition of multiresistant Salmonella enterica by microcin J25

In livestock production, antibiotics are used to promote animal growth, control infections and thereby increase profitability. This practice has led to the emergence of multiresistant bacteria such as Salmonella, of which some serovars are disseminated in the environment. The objective of this study is to evaluate microcin J25 as an inhibitor of Salmonella enterica serovars of various origins including human, livestock and food. Among the 116 isolates tested, 37 (31.8%) were found resistant to at least one antibiotic, and 28 were multiresistant with 19 expressing the penta-resistant phenotype ACSSuT. Microcin J25 inhibited all isolates, with minimal inhibitory concentration values ranging from 0.06 μg/ml (28.4 nM) to 400 μg/ml (189 μM). Interestingly, no cross-resistance was found between microcin J25 and antibiotics. Multiple sequence alignments of genes encoding for the different proteins involved in the recognition and transport of microcin J25 showed that only ferric-hydroxamate uptake is an essential determinant for susceptibility of S. enterica to microcin J25. Examination of Salmonella strains exposed to microcin J25 by transmission electronic microscopy showed for the first-time involvement of a pore formation mechanism. Microcin J25 was a strong inhibitor of several multiresistant isolates of Salmonella and may have a great potential as an alternative to antibiotics.     

Differentiation of non-pylori Helicobacter species based on PCR–restriction fragment length polymorphism of the 23S rRNA gene

Phenotypic identification of non-pylori Helicobacter species has always been problematic and time-consuming in comparison with many other bacteria. We developed a rapid two-step identification assay based on PCR–restriction fragment length polymorphism (PCR–RFLP) analysis of the 23S rRNA gene for differentiating between non-pylori Helicobacter species. A new genus-specific primer pair based on all available complete and partial 23S rRNA sequences of Helicobacter species was designed. In silico restriction analysis of variable regions of the 23S rRNA gene suggested SmaI and HindIII endonucleases would provide a good level of differentiation. Analysis of the obtained 23S rRNA RFLP patterns divided all Helicobacter study strains into three species groups (groups A–C) and 12 unique restriction patterns. Wolinella succinogenes also gave a unique pattern. Our proposed PCR–RFLP method was found to be as a valuable tool for routine identification of non-pylori Helicobacter species from human or animal samples.     

Serum bile acids as a sensitive biological marker for evaluating hepatic effects of organic solvents

Serum bile acids (SBAs) are suggested as a potentially sensitive and specific indicator of liver function which, accordingly, could provide an early indication of hepatobiliary dysfunction. This offers advantages over more traditional parameters of liver integrity/function. Recent studies have shown that occupational exposure to low levels of halogenated aliphatic or non-halogenated aromatic solvents is associated with significant increases in SBA levels. As this has often been evident in the absence of any effect on conventional parameters of hepatobiliary integrity/function, elevated SBA levels may well be regarded as a sensitive biological marker of exposure/effect of these compounds. In addition, it may be considered that they provide an early indicator of solvent-induced changes in hepatobiliary function. Extensive studies with experimental animals have also provided supporting evidence for these observations in solvent-exposed individuals. Investigations of the mechanisms at cellular and subcellular levels by which these increases occur have suggested that these effects are likely to be the result of selective, dose-related and reversible inhibition of bile acid uptake at the sinusoidal domain of the hepatocyte plasma membrane. Increased concentrations of SBA under low levels of exposure to different solvents have been demonstrated to be a short-lived and reversible effect which is not accompanied by any other evidence of liver damage. Therefore, it could be assumed that it is unlikely that there would be pathological sequelae to these effects, although the longer term ramifications of such effects have not been thoroughly investigated. Nevertheless, the available evidence indicates that investigation of SBA in solvent-exposed workers could provide useful indications of exposure and effect.     

Universality in kinetic models of circadian rhythms in $$Arabidopsis\,\,thaliana$$

Journal of Mathematical Biology - Precision-cut lung-slices (PCLS), in which viable airways embedded within lung parenchyma are stretched or induced to contract, are a widely used ex vivo assay to...     

An updated overview of the application of CAR-T cell therapy in neurological diseases

Genetically modified immune cells, especially CAR-T cells, have captured the attention of scientists over the past 10 years. In the fight against cancer, these cells have a special place. Treatment for hematological cancers, autoimmune disorders, and cancers must include CAR-T cell therapy. Determining the therapeutic targets, side effects, and use of CAR-T cells in neurological disorders, including cancer and neurodegenerative diseases, is the goal of this study. Due to advancements in genetic engineering, CAR-T cells have become crucial in treating some neurological disorders. CAR-T cells have demonstrated a positive role in treating neurological cancers like Glioblastoma and Neuroblastoma due to their ability to cross the blood–brain barrier and use diverse targets. However, CAR-T cell therapy for MS diseases is being researched and could be a potential treatment option. This study aimed to access the most recent studies and scientific articles in the field of CAR-T cells in neurological diseases and/or disorders.     

The Gray Toad-headed Agama,Phrynocephalus scutellatus,on the Iranian Plateau: The degree of niche overlap depends on the phylogenetic distance

The Gray Toad-headed Agama (Phrynocephalus scutellatus) occurs in Iran, Pakistan and Afghanistan and is represented in Iran by four distinctive genetic clades. We built distribution models for three of these clades (one clade was not included due to a low number of distribution records) using Maximum Entropy Algorithm in order to determine the contribution of ecological factors to the distribution pattern. The degree of spatial niche overlap between every pair of clades were measured using Schoener's D niche overlap metric. The results showed that at species-level climate variables (annual precipitation, annual mean temperature) were the most influential parameters determining the boundaries of the distribution in Iran. Temperature seasonality was found to be the most influential factor in the distribution of both Clade I and Clade II. However, this variable was replaced by the annual mean temperature for Clade VI. Based on the results of Schoener's D metric, Clades I and II had the lowest, and Clades II and VI the highest level of ecological niche overlap. Comparing the result of niche overlap with genetic distance between the clades, it was found that the ecologically least similar clades were those with the longer history of genetic segregation.     

Laboratory evaluation of Alsystin, a chitin synthesis inhibitor, against Culex pipiens pipiens L. (Dip., Culicidae): effects on development and cuticle secretion

Alsystin, a benzoylphenylurea derivative, was evaluated on Culex pipiens pipiens L. Treatment was made on newly third- and fourth-instar larvae for 24 h. Mortality occurred at various developmental stages following treatment. However, death as larvae was relatively important compared with the mortality recorded for the other later developmental stages. Treatment resulted in a dose-dependent reduction in adult emergence. Moreover, treatment caused morphological aberrations depending upon the importance of larval–adult transformation and significantly increased the duration of both third and fourth larval instars. A histological study conducted on fourth instar larval integument, revealed that Alsystin delayed the ecdysis and significantly reduced the thickness of both larval and pupal cuticles secreted compared with controls. Moreover, the apolysis that occurred at day 4 in controls was not affected by treatment.