Enterococcus faecalis Adapts to Antimicrobial Conjugated Oligoelectrolytes by Lipid Rearrangement and Differential Expression of Membrane Stress Response Genes.

Conjugated oligoelectrolytes (COEs) are emerging antimicrobials with broad spectrum activity against Gram positive and Gram negative bacteria as well as fungi. Our previous in vitro evolution studies using Enterococcus faecalis grown in the presence of two related COEs (COE1-3C and COE1-3Py) led to the emergence of mutants (changes in liaF and liaR) with a moderate 4- to16-fold increased resistance to COEs. The contribution of liaF and liaR mutations to COE resistance was confirmed by complementation of the mutants, which restored sensitivity to COEs. To better understand the cellular target of COEs, and the mechanism of resistance to COEs, transcriptional changes associated with resistance in the evolved mutants were investigated in this study. The differentially transcribed genes encoded membrane transporters, in addition to proteins associated with cell envelope synthesis and stress responses. Genes encoding membrane transport proteins from the ATP binding cassette superfamily were the most significantly induced or repressed in COE tolerant mutants compared to the wild type when exposed to COEs. Additionally, differences in the membrane localization of a lipophilic dye in E. faecalis exposed to COEs suggested that resistance was associated with lipid rearrangement in the cell membrane. The membrane adaptation to COEs in EFC3C and EFC3Py resulted in an improved tolerance to bile salt and sodium chloride stress. Overall, this study showed that bacterial cell membranes are the primary target of COEs and that E. faecalis adapts to membrane interacting COE molecules by both lipid rearrangement and changes in membrane transporter activity. The level of resistance to COEs suggests that E. faecalis does not have a specific response pathway to elicit resistance against these molecules and this is supported by the rather broad and diverse suite of genes that are induced upon COE exposure as well as cross-resistance to membrane perturbing stressors

LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation

Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack)

Genome characterization and taxonomy of <em>Actinomyces acetigenes</em> sp. nov., and <em>Actinomyces stomatis</em> sp. nov., previously isolated from the human oral cavity

\ua9 2023, The Author(s).Background: Actinomyces strains are commonly found as part of the normal microflora on human tissue surfaces, including the oropharynx, gastrointestinal tract, and female genital tract. Understanding the diversity and characterization of Actinomyces species is crucial for human health, as they play an important role in dental plaque formation and biofilm-related infections. Two Actinomyces strains ATCC 49340 T and ATCC 51655 T have been utilized in various studies, but their accurate species classification and description remain unresolved. Results: To investigate the genomic properties and taxonomic status of these strains, we employed both 16S rRNA Sanger sequencing and whole-genome sequencing using the Illumina HiSeq X Ten platform with PE151 (paired-end) sequencing. Our analyses revealed that the draft genome of Actinomyces acetigenes ATCC 49340 T was 3.27 Mbp with a 68.0% GC content, and Actinomyces stomatis ATCC 51655 T has a genome size of 3.08 Mbp with a 68.1% GC content. Multi-locus (atpA , rpoB, pgi , metG , gltA , gyrA, and core genome SNPs) sequence analysis supported the phylogenetic placement of strains ATCC 51655 T and ATCC 49340 T as independent lineages. Digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI), and average amino acid identity (AAI) analyses indicated that both strains represented novel Actinomyces species, with values below the threshold for species demarcation (70% dDDH, 95% ANI and AAI). Pangenome analysis identified 5,731 gene clusters with strains ATCC 49340 T and ATCC 51655 T possessing 1,515 and 1,518 unique gene clusters, respectively. Additionally, genomic islands (GIs) prediction uncovered 24 putative GIs in strain ATCC 49340 T and 16 in strain ATCC 51655 T, contributing to their genetic diversity and potential adaptive capabilities. Pathogenicity analysis highlighted the potential human pathogenicity risk associated with both strains, with several virulence-associated factors identified. CRISPR-Cas analysis exposed the presence of CRISPR and Cas genes in both strains, indicating these strains might evolve a robust defense mechanism against them. Conclusion: This study supports the classification of strains ATCC 49340 T and ATCC 51655 T as novel species within the Actinomyces, in which the name Actinomyces acetigenes sp. nov. (type strain ATCC 49340 T = VPI D163E-3 T = CCUG 34286 T = CCUG 35339 T) and Actinomyces stomatis sp. nov. (type strain ATCC 51655 T = PK606T = CCUG 33930 T) are proposed

Prediction of concrete residual compressive strength under elevated temperatures : Response surface methodology (rsm) approach

Exposure of concrete to elevated temperatures causes irreversible damage to the concrete structure and poses a serious threat to the service life of the concrete. Owing to the importance of concrete fire performance, many researchers have extensively studied the behavior of concrete under elevated temperatures with different conditions. The properties of concrete have been significantly affected by the distinct heating and cooling conditions, which include heating temperatures, heating durations, and cooling methods. The residual compressive strength of concrete is considered the most important characteristic after being exposed to elevated temperatures. In this paper, the present works targets to develop the mathematical models for analyzing and predicting the residual compressive strength of concrete at high temperature. Three independent factors were identified in this study, which are heating temperatures, heating duration, and cooling method. Two groups of datasets on the residual compressive strength of concrete under elevated temperatures were reviewed and collected from previous studies and were set as the benchmark dataset and validate dataset, respectively. Response Surface Methodology (RSM) was used to analyze the dataset. The results of various statistical parameters, such as coefficient of determination, sum of square, F-value, and P-value, indicate the significant of predicted model for predicting concrete residual compressive strength under elevated temperatures. From the RSM analysis, the factor of heating temperatures has the most significant effect on the residual compressive strength of concrete. In short, RSM model correlate well with those validate dataset with a coefficient of determination (R2) of 0.854

Appetite for destruction: the inhibition of glycolysis as a therapy for tuberous sclerosis complex-related tumors

The elevated metabolic requirements of cancer cells reflect their rapid growth and proliferation and are met through mutations in oncogenes and tumor suppressor genes that reprogram cellular processes. For example, in tuberous sclerosis complex (TSC)-related tumors, the loss of TSC1/2 function causes constitutive mTORC1 activity, which stimulates glycolysis, resulting in glucose addiction in vitro. In research published in Cell and Bioscience, Jiang and colleagues show that pharmacological restriction of glucose metabolism decreases tumor progression in a TSC xenograft model

Ultimate strength

Concern for the ductile behaviour of ships and offshore structures and their structural components under ultimate conditions. Attention shall be given to the influence of fabrication imperfections and in-service damage and degradation on reserve strength

Culture-independent detection of nontuberculous mycobacteria in clinical respiratory samples

Culture-based detection of nontuberculous Mycobacteria (NTM) in respiratory samples is time consuming and can be subject to overgrowth by nonmycobacterial bacteria. We describe a single-reaction TaqMan quantitative PCR assay for the direct detection of NTM species in clinical samples that is specific, sensitive, and robust

Microbial fuel cells: a green and alternative source for bioenergy production

Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

Divergent Relationships between Fecal Microbiota and Metabolome following Distinct Antibiotic-Induced Disruptions

This is an openaccess article distributed under the terms of the Creative Commons attribution 4.0 International license.The intestinal microbiome plays an essential role in regulating many aspects of host physiology, and its disruption through antibiotic exposure has been implicated in the development of a range of serious pathologies. The complex metabolic relationships that exist between members of the intestinal microbiota and the potential redundancy in functional pathways mean that an integrative analysis of changes in both structure and function are needed to understand the impact of antibiotic exposure. We used a combination of next-generation sequencing and nuclear magnetic resonance (NMR) metabolomics to characterize the effects of two clinically important antibiotic treatments, ciprofloxacin and vancomycin-imipenem, on the intestinal microbiomes of female C57BL/6 mice. This assessment was performed longitudinally and encompassed both antibiotic challenge and subsequent microbiome reestablishment. Both antibiotic treatments significantly altered the microbiota and metabolite compositions of fecal pellets during challenge and recovery. Spearman’s correlation analysis of microbiota and NMR data revealed that, while some metabolites could be correlated with individual operational taxonomic units (OTUs), frequently multiple OTUs were associated with a significant change in a given metabolite. Furthermore, one metabolite, arginine, can be associated with increases/decreases in different sets of OTUs under differing conditions. Taken together, these findings indicate that reliance on shifts in one data set alone will generate an incomplete picture of the functional effect of antibiotic intervention. A full mechanistic understanding will require knowledge of the baseline microbiota composition, combined with both a comparison and an integration of microbiota, metabolomics, and phenotypic data

Association Between Self-Esteem and Happiness Among Adolescents in Malaysia: The Mediating Role of Motivation

Adolescence is the developmental process of becoming an adult. This journey of physical and psychological maturation is filled with challenges and hormonal chaos, and teenagers experience unhappiness at times. From a psychological perspective, this study aimed to examine the association between motivation, self-esteem and happiness; and to explore the mediating role of motivation in the association between self-esteem and happiness among adolescents in Malaysia. 480 secondary school students were recruited using a multistage cluster sampling method and answered the Malay versions of the Subjective Happiness, Brief Motivation and Rosenberg Self-esteem scales. Both self-esteem and motivation were found positively correlated to happiness. The hypothetical mediating role of motivation on the association between self-esteem and happiness was also supported, indicating that individuals with higher self-esteem have higher motivation which may result in greater happiness. Since the direct association between self-esteem and happiness remained significant, a partial mediation of adolescents’ motivation between self-esteem and happiness is indicated. The results showed that perceived self-esteem plays a role in predicting happiness and the presence of motivation enhances happiness, providing an insight to nurture happier adolescents for parents and educators in Malaysia