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Toxin complex (Tc) toxins are virulence factors of pathogenic bacteria. Tcs are composed of three subunits: TcA, TcB and TcC. TcA facilitates receptor-toxin interaction and membrane permeation, TcB and TcC form a toxin-encapsulating cocoon. While the mechanisms of holotoxin assembly and pore formation have been described, little is known about receptor binding of TcAs. Here, we identify heparins/heparan sulfates and Lewis antigens as receptors for different TcAs from insect and human pathogens. Glycan array screening reveals that all tested TcAs bind negatively charged heparins. Cryo-EM structures of Morganella morganii TcdA4 and Xenorhabdus nematophila XptA1 reveal that heparins/heparan sulfates unexpectedly bind to different regions of the shell domain, including receptor-binding domains. In addition, Photorhabdus luminescens TcdA1 binds to Lewis antigens with micromolar affinity. Here, the glycan interacts with the receptor-binding domain D of the toxin. Our results suggest a glycan dependent association mechanism of Tc toxins on the host cell surface.

Knowing what makes a top gastronomy experience unique and retrievable in the long term is of interest for scientific and economic reasons. Recent attempts to isolate predictors of the hedonic evaluation of food have afforded several factors, such as individual and social attributes, or liking/disliking profiles. However, in these studies relevant variables have been examined in isolation without an integrative perspective. Here we investigated 80 guests enjoying a 23-course meal in a top gastronomy restaurant, in groups of four. Our main question concerned the factors driving the overall evaluation of the meal at its conclusion and after three months. To this aim we administered the Big Five Personality Inventory before the meal, dish-by-dish hedonic ratings, and a multi-dimensional Meal Experience Questionnaire (MEQ) at the end of the meal. Hedonic evaluations of the meal were collected immediately after the meal and three months later. Better immediate overall evaluations were predicted by both the number of peaks in dish-by-dish ratings and by positive ratings of the final dish. Both factors and the number of troughs were also critical for the long-term evaluation after three months. The MEQ dimensions overall interest, valence and distraction predicted immediate evaluations, while the long-term evaluations were determined by interest and high scores on the personality traits agreeableness and conscientiousness. High consistency of the hedonic ratings within quartets indicated the relevance of commensality for the meal experience. The present findings highlight the simultaneous relevance of food- and personality-related factors and commensality for a top gastronomy meal experience in the short and long-run. The uncovered relationships are of theoretical interest and for those involved in designing meals for consumers in various settings., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Methicillin-resistant Staphylococcus aureus (MRSA) may cause prolonged outbreaks of infections in neonatal intensive care units (NICUs). While the specific factors favouring MRSA spread on neonatal wards are not well understood, colonized infants, their relatives, or health-care workers may all be sources for MRSA transmission. Whole-genome sequencing may provide a new tool for elucidating transmission pathways of MRSA at a local scale., Methods and Findings: We applied whole-genome sequencing to trace MRSA spread in a NICU and performed a case-control study to identify risk factors for MRSA transmission. MRSA genomes had accumulated sequence variation sufficiently fast to reflect epidemiological linkage among individual patients, between infants and their mothers, and between infants and staff members, such that the relevance of individual nurses' nasal MRSA colonization for prolonged transmission could be evaluated. In addition to confirming previously reported risk factors, we identified an increased risk of transmission from infants with as yet unknown MRSA colonisation, in contrast to known MRSA-positive infants., Conclusions: The integration of epidemiological (temporal, spatial) and genomic data enabled the phylogenetic testing of several hypotheses on specific MRSA transmission routes within a neonatal intensive-care unit. The pronounced risk of transmission emanating from undetected MRSA carriers suggested that increasing the frequency or speed of microbiological diagnostics could help to reduce transmission of MRSA.

Background: Alterations of chromosome region 3p14 are observed in numerous human malignancies. Because the pattern of allelic losses suggests the existence of at least one tumor suppressor gene within this region, we established a library of yeast artificial chromosomes (YACs) containing contiguous human 3p14 sequences to permit a search for tumor suppressor loci within the 3p14 region by use of functional complementation., Methods: YACs specific for human chromosome region 3p14 were transduced by spheroplast fusion into cells of the human nonpapillary renal carcinoma cell line RCC-1, which shows a cytogenetically detectable 3p deletion and is tumorigenic in nude mice., Results: We identified a 3p14.2-specific YAC clone, located in the vicinity of the fragile histidine triad (FHIT) gene (but toward the telomere), that is capable of inducing sustained suppression of tumorigenicity in nude mice and of activating cellular senescence in vitro. Among 23 mice given injections of RCC-1 cells containing this YAC, 16 (70%) remained tumor free for at least 6 months, whereas tumor formation occurred after a median of 6 weeks in control mice given injections of either RCC-1 parental cells or a revertant cell line (in which the YAC had lost all human sequences) or RCC-1 parental cells containing other, unrelated YACs. Similar results were obtained following microcell-mediated transfer of the entire human chromosome 3., Conclusion: These data provide strong evidence for the existence of a novel tumor suppressor locus adjacent to the previously identified candidate tumor suppressor gene, FHIT, in 3p14.2. Positional cloning of the novel suppressor element within the 3p14.2-specific YAC and the sequence's molecular and functional characterization should add to the understanding of the pathogenesis of renal cell carcinoma and other human tumors that exhibit 3p14 aberrations.

Immortalization and tumorigenic transformation of many human cell types, including human uroepithelial cells (HUCs), are frequently associated with loss of genetic material from the short arm of chromosome 3 (3p). In addition, losses of 3p have been observed in many human cancers including renal cell carcinoma, lung cancer, breast cancer, and bladder cancer. Genetic studies suggest that there are at least two regions on 3p in which tumor suppressor genes might be located, but the precise location of these genes is not known. We studied chromosome 3 losses that were specifically associated with immortalization of five independent human papilloma virus 16 (HPV16) E6- or E7-transformed HUCs. Cytogenetic analysis showed that the smallest common region of deletion was 3p14.1-->14.2. Fluorescence in situ hybridization using a 3p13-->14-specific yeast artificial chromosome (YAC) contig showed the precise localization of the breakpoints to be in 3p13 and 3p14.2, thus defining the smallest common overlap of 3p deletions in HPV16 E6- or E7-immortalized HUCs. These results suggest the presence in this region of genes involved in the control of senescence in vitro and possibly tumorigenesis in vivo.

Losses of genetic material within human chromosome regions (HCR) 3p12-p14 and 3p21-p22 are observed in various neoplasias, suggesting tumor suppressor gene (TSG) loci within these regions. HCR 3p14 is particularly interesting as it contains the t(3;8) translocation breakpoint of a hereditary renal cell carcinoma, the FRA3B fragile site, and DNA markers deleted in several types of human cancer. We here report on the identification of five novel 'expressed sequence tags' (ESTs) within 3p14.2 which map proximal to exon 9 of the candidate TSG, FHIT. These ESTs may be valuable for elucidation of the supposed TSG content in 3p14.2.

Successful transfer of yeast artificial chromosomes (YACs) into human cells has been described in only a single study. We here report on the evaluation of YAC transfer strategies into a human renal cell carcinoma cell line by yeast spheroplast fusion and cationic lipids. While the latter approach proved inefficient, significant numbers of clones containing both vector arms were obtained by spheroplast fusion. FISH analyses on such clones revealed the presence of YAC integration and the co-localization of both vector arms with insert sequences. These data demonstrate that under certain experimental conditions efficient YAC transfer into human cells by spheroplast fusion is possible and may be useful for the cloning of human disease-related genes.

Chromosomal deletions and translocations of human chromosome region 3p14 are observed in various human malignancies and suggest the existence of a tumor suppressor gene locus within this region. Tumors most frequently affected by these aberrations are small-cell lung cancer and renal-cell carcinoma. In continuation of our previously published YAC contig of chromosome region 3p14.2-p14.3, we report here on the construction of a YAC contig of at least 11 Mb that consisted of 171 YACs and covers the entire subregion 3p14.1. This contig includes the t(3;8) breakpoint of a hereditary renal-cell carcinoma localized in 3p14.2 and extends into human chromosome region 3p12-p13. It defines the order of 34 DNA probes in relation to reference markers D3S6 and D3S30 as well as the human protein tyrosine phosphatase-gamma gene. For 31 DNA probes we identified nonchimeric YACs by fluorescence in situ hybridization. The minimal tilling pathway consists of 16 yeast artificial chromosomes. As a prerequisite for identification of a putative tumor suppressor gene within this region, this contig renders human chromosome region 3p14.1 accessible to gene isolation.

UV-B irradiation is often inevitable for visualization of DNA fragments after ethidium bromide staining. Three different simple-repeat-containing, double-stranded genomic DNA fragments were analyzed for UV-B (312 nm) damage using different gel electrophoretic systems. The effects of UV-B light were obvious after 5 min (31.5 kJ/m2) of irradiation in native polyacrylamide gel electrophoresis (PAGE). Standard single-strand conformation analyses revealed no alterations while a modification did. Sodium dodecyl sulfate (SDS)-PAGE was found to be highly sensitive with regard to the detection of damages and their time/dosage dependency. In addition, SDS-PAGE analysis pointed to different events occurring during UV-B irradiation. Alterations in DNA conformation were detected in every single strand analyzed after 1 min (6.3 kJ/m2) of UV-B exposure. Gel retardation analyses revealed significant changes of protein binding to target DNAs after 2 min of irradiation--possibly stemming from structural modifications and/or originating from binding sites for proteins involved in DNA repair.