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Efficacy and safety of phage therapy against Salmonella enterica serovars Typhimurium and Enteritidis estimated by using a battery of in vitro tests and the Galleria mellonella animal model
Get PDFIn light of spreading antibiotic resistance among pathogenic bacteria, the development of novel approaches to combat such microorganisms is crucial. Salmonella enterica is pathogenic to humans, however, it can also infect poultry, being a potential foodborne pathogen when poultry-derived food is contaminated by this bacterium. Phage therapy is one of the alternative ways to treat Salmonella-infected animals while the establishment of this method and its introduction to a general practice requires detailed studies on safety and efficacy. Here, we present the results of such studies with two previously isolated and characterized bacteriophages, vB_SenM2 and vB_Sen-TO17, and four strains of S. enterica belonging to two serovars, Typhimurium and Enteritidis. We demonstrated effective reduction of bacterial cell number and cell culture density when using each phage alone, and in combination (as a cocktail). These phages were also effective in reducing bacterial biofilm. The efficacy of this in vitro phage therapy was compared to the action of known antibiotics, as was the efficiency of appearance of bacteria resistant to both these types of antibacterial agents. Safety of the use of bacteriophages was demonstrated using the LAL chromogenic test and the chicken fibroblast viability assay. Finally, the efficacy of phage therapy was assessed with the in vivo model of S. enterica-infected Galleria mellonella larvae, showing a significant improvement in the survival of the animals. In conclusion, we demonstrated high efficacy and acceptable safety profiles of phage therapy against S. enterica strains using vB_SenM-2 and vB_Sen-TO17 phages (both alone and in a cocktail). These results open a possibility for a trial with the use of poultry and these phages which might potentially allow to introduce of this method for practical use in poultry farming
L-Carnitine Combined with Leucine Supplementation Does Not Improve the Effectiveness of Progressive Resistance Training in Healthy Aged Women
Get PDFInsights from analyses of low complexity regions with canonical methods for protein sequence comparison
No full textLow complexity regions are fragments of protein sequences composed of only a few types of amino acids. These regions frequently occur in proteins and can play an important role in their functions. However, scientists are mainly focused on regions characterized by high diversity of amino acid composition. Similarity between regions of protein sequences frequently reflect functional similarity between them. In this article, we discuss strengths and weaknesses of the similarity analysis of low complexity regions using BLAST, HHblits and CD-HIT. These methods are considered to be the gold standard in protein similarity analysis and were designed for comparison of high complexity regions. However, we lack specialized methods that could be used to compare the similarity of low complexity regions. Therefore, we investigated the existing methods in order to understand how they can be applied to compare such regions. Our results are supported by exploratory study, discussion of amino acid composition and biological roles of selected examples. We show that existing methods need improvements to efficiently search for similar low complexity regions. We suggest features that have to be re-designed specifically for comparing low complexity regions: scoring matrix, multiple sequence alignment, e-value, local alignment and clustering based on a set of representative sequences. Results of this analysis can either be used to improve existing methods or to create new methods for the similarity analysis of low complexity regions
Assembly-dependent translation of subunits 6 (Atp6) and 9 (Atp9) of ATP synthase in yeast mitochondria
Get PDFThe yeast mitochondrial ATP synthase is an assembly of 28 subunits of 17 types of which 3 (subunits 6, 8, and 9) are encoded by mitochondrial
genes, while the 14 others have a nuclear genetic origin. Within the membrane domain (FO) of this enzyme, the subunit 6 and a ring
of 10 identical subunits 9 transport protons across the mitochondrial inner membrane coupled to ATP synthesis in the extra-membrane
structure (F1) of ATP synthase. As a result of their dual genetic origin, the ATP synthase subunits are synthesized in the cytosol and inside
the mitochondrion. How they are produced in the proper stoichiometry from two different cellular compartments is still poorly understood.
The experiments herein reported show that the rate of translation of the subunits 9 and 6 is enhanced in strains with mutations leading to
specific defects in the assembly of these proteins. These translation modifications involve assembly intermediates interacting with subunits
6 and 9 within the final enzyme and cis-regulatory sequences that control gene expression in the organelle. In addition to enabling a balanced
output of the ATP synthase subunits, these assembly-dependent feedback loops are presumably important to limit the accumulation
of harmful assembly intermediates that have the potential to dissipate the mitochondrial membrane electrical potential and the main
source of chemical energy of the cell
Sources and composition of chemical pollution in Maritime Antarctica (King George Island), part 1: Sediment and water analysis for PAH sources evaluation in the vicinity of Arctowski station
Get PDFThe paper presents a study regarding the identification of polycyclic aromatic hydrocarbons (PAHs) in fresh waters and surface sediments on the western shore of Admiralty Bay over four sampling seasons from 2017 to 2018. The results were compared to literature data from 2016 to provide a more comprehensive image of the environmental fate of PAHs over the years. The highest value of Σ PAHs was 82.9 ng/L and 445 ng/g dw in water and sediment samples, respectively. The analysis of PAH indicator ratio values showed that pyrogenic or mixed sources contribute to the PAH pollution in Antarctic sediments and water more than does petroleum. The main source is the combustion of biomass (e.g. as a result of fires) and coal, and PAHs are mostly associated with the activity of stations or are transported to a lesser extent by long-range atmospheric transport (LRAT) from South America. The values of the ΣLMW/ΣHMW ratio in sediments indicate that petrogenic sources contribute to PAH contamination, but among the six PAH ratios tested, petrogenic sources were identified as dominant in approximately 17–19% of cases. Lack of coherence in the obtained results confirms the mixed origin of PAHs in the studied samples. Although the differentiation of PAHs sources is still ambiguous, caution is recommended in light of the Antarctic system's evident and rapid response to global and local PAH emissions, and the dependency of accumulation and release cycle processes on weather conditions. A reduction in petrol usage in favour of renewable energy sources, and restriction of tourism are strongly recommended for better preservation of the pristine Antarctic environment
Marginal lands and fungi – linking the type of soil contamination with fungal community composition
Get PDFFungi can be found in almost all ecosystems. Some of them can even survive in harsh, anthropogenically transformed environments, such as post-industrial soils. In order to verify how the soil fungal diversity may be changed by pollution, two soil samples from each of the 28 post-industrial sites were collected. Each soil sample was characterized in terms of concentration of heavy metals and petroleum derivatives. To identify soil fungal communities, fungal internal transcribed spacer 2 (ITS2) amplicon was sequenced for each sample using Illumina MiSeq platform. There were significant differences in the community structure and taxonomic diversity among the analysed samples. The highest taxon richness and evenness were observed in the non-polluted sites, and lower numbers of taxa were identified in multi-polluted soils. The presence of monocyclic aromatic hydrocarbons, gasoline and mineral oil was determined as the factors driving the differences in the mycobiome. Furthermore, in the culture-based selection experiment, two main groups of fungi growing on polluted media were identified - generalists able to live in the presence of pollution, and specialists adapted to the usage of BTEX as a sole source of energy. Our selection experiment proved that it is long-term soil contamination that shapes the community, rather than temporary addition of pollutant
Mutation spectrum data for Saccharomyces cerevisiae psf1-1 pol2-M644G mutants
Get PDFDNA replication in Saccharomyces cerevisiae and other eukaryotes is performed mainly by polymerase epsilon (Pol ε)
on the leading strand and polymerase delta (Pol δ) on the
lagging strand. Using a mutant form of a DNA polymerase
enables tracking its signature in the replicated DNA. Here,
we used the pol2-M644G allele encoding the catalytic sub-
unit of Pol ε to analyse its contribution to DNA replication
in yeast with the psf1-1 allele of an essential gene encoding a subunit of the GINS complex. GINS is involved in the recruitment of Pol ε, the major leading strand replicase. Thus, its defective functioning can affect the involvement of Pol ε in DNA replication. Together with Cdc45 and Mcm2-7, GINS forms the CMG helicase complex. Our DNA sequencing data enable the observation of changes in the mutational spectra in the URA3 reporter gene cloned in two orientations regarding the nearest ARS. The data presented in this article support the study "Increased contribution of DNA polymerase delta to the leading strand replication in yeast with an impaired CMG helicase complex
Products of Bisphenol A Degradation Induce Cytotoxicity in Human Erythrocytes (In Vitro)
Get PDFThe aim of this work has been to study the possible degradation path of BPA under the Fenton reaction, namely to determine the energetically favorable intermediate products and to compare the cytotoxicity of BPA and its intermediate products of degradation. The DFT calculations of the Gibbs free energy at M06-2X/6-311G(d,p) level of theory showed that the formation of hydroquinone was the most energetically favorable path in a water environment. To explore the cytotoxicity the erythrocytes were incubated with BPA and three intermediate products of its degradation, i.e., phenol, hydroquinone and 4-isopropylphenol, in the concentrations 5–200 μg/mL, for 1, 4 and 24 h. BPA induced the strongest hemolytic changes in erythrocytes, followed by hydroquinone, phenol and 4-isopropylphenol. In the presence of hydroquinone, the highest level of RONS was observed, whereas BPA had the weakest effect on RONS generation. In addition, hydroquinone decreased the level of GSH the most. Generally, our results suggest that a preferable BPA degradation path under a Fenton reaction should be controlled in order to avoid the formation of hydroquinone. This is applicable to the degradation of BPA during waste water treatment and during chemical degradation in sea water
Validation of the Pathogenic Effect of IGHMBP2 Gene Mutations Based on Yeast S. cerevisiae Model
Get PDFSpinal muscular atrophy with respiratory distress type 1 (SMARD1) is a heritable neu-
rodegenerative disease characterized by rapid respiratory failure within the first months of life and
progressive muscle weakness and wasting. Although the causative gene, IGHMBP2, is well defined,
information on IGHMBP2 mutations is not always sufficient to diagnose particular patients, as the
gene is highly polymorphic and the pathogenicity of many gene variants is unknown. In this study,
we generated a simple yeast model to establish the significance of IGHMBP2 variants for disease
development, especially those that are missense mutations. We have shown that cDNA of the human
gene encodes protein which is functional in yeast cells and different pathogenic mutations affect this
functionality. Furthermore, there is a correlation between the phenotype estimated in in vitro studies
and our results, indicating that our model may be used to quickly and simply distinguish between
pathogenic and non-pathogenic mutations identified in IGHMBP2 in patient
STN7 Kinase Is Essential for Arabidopsis thaliana Fitness under Prolonged Darkness but Not under Dark-Chilling Conditions
Get PDFReversible phosphorylation of photosystem II light harvesting complexes (LHCII) is a well-established protective mechanism enabling efficient response to changing light conditions. However, changes in LHCII phosphorylation were also observed in response to abiotic stress regardless of photoperiod. This study aimed to investigate the impact of dark-chilling on LHCII phosphorylation pattern in chilling-tolerant Arabidopsis thaliana and to check whether the disturbed LHCII phosphorylation process will impact the response of Arabidopsis to the dark-chilling conditions. We analyzed the pattern of LHCII phosphorylation, the organization of chlorophyll–protein complexes, and the level of chilling tolerance by combining biochemical and spectroscopy techniques under dark-chilling and dark conditions in Arabidopsis mutants with disrupted LHCII phosphorylation. Our results show that during dark-chilling, LHCII phosphorylation decreased in all examined plant lines and that no significant differences in dark-chilling response were registered in tested lines. Interestingly, after 24 h of darkness, a high increase in LHCII phosphorylation was observed, co-occurring with a significant FV/FM parameter decrease. The highest drop of FV/FM was detected in the stn7-1 line–mutant, where the LHCII is not phosphorylated, due to the lack of STN7 kinase. Our results imply that STN7 kinase activity is important for mitigating the adverse effects of prolonged darkness