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XLSX file - 66K, List of the differentially expressed probes for the analysis Epithelioid MPM vs. Sarcomatoid MPM.

XLSX file - 196K, List of the enriched functional terms for the analysis Epithelioid MPM vs. Sarcomatoid MPM.

XLSX file - 240K, List of the differentially expressed probes for the analysis MPM vs. other tumor types.

Supplementary Table S1 from Validation of Genomics-Based Prognostic Tests in Malignant Pleural Mesothelioma

XLSX file - 31K, PCR primers and genes. Sequences of the primers for the differential diagnosis of MPM. Selected genes for each diagnostic test.

XLSX file - 191K, Results of the binary diagnostic tests using microarray data and RT-PCR data in the original set of samples.

XLSX file - 34K, List of the enriched functional terms for for the analysis MPM vs. other tumor types.

XLSX file - 42K, Results of the binary diagnostic tests in a test set analyzed by RT-PCR.

Purpose: Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm with limited pretreatment prognostication strategies. In this report, we examine the accuracy of a previously proposed prognostic test in an independent cohort of MPM patients. This test uses simple ratios of gene expression levels to provide a novel prognostication scheme.Experimental Design: Gene expression data using high-density oligonucleotide microarrays (∼22,000 genes) were obtained for a new cohort of human MPM tumors from patients undergoing similar treatments (n = 39). The relative expression levels for specific genes were also determined using real-time quantitative reverse transcription-PCR. We also used a subset of these tumors associated with widely divergent patient survival (n = 23) as a training set to identify new treatment-specific candidate prognostic molecular markers and gene ratio–based prognostic tests. The predictive nature of these newly discovered markers and gene ratio–based prognostic tests were then examined in an independent group of tumors (n = 52) using microarray data and quantitative reverse transcription-PCR.Results: Previously described MPM prognostic genes and gene ratio–based prognostic tests predicted clinical outcome in 39 independent MPM tumor specimens in a statistically significant manner. Newly discovered treatment-specific prognostic genes and gene ratio–based prognostic tests were highly accurate and statistically significant when examined in an independent group of 52 tumors from patients undergoing similar treatment.Conclusions: The data support the use of gene ratios in translating gene expression data into easily reproducible, statistically validated clinical tests for the prediction of outcome in MPM.

PDF file - 53K, Identification of Diagnostic Molecular Markers and Data Analysis, Real-Time Quantitative PCR Results, Hierarchical clustering analysis.

PDF file - 188K, Heat-map of the 26-gene signature used in the sequential combination of gene expression ratio tests in the 112 thoracic samples. Probes are annotated with gene symbol on the right. Relative gene expression levels are given by the scale at the top. The red asterisk indicates the mesothelioma samples.

Purpose: To develop a standardized approach for molecular diagnostics, we used the gene expression ratio bioinformatic technique to design a molecular signature to diagnose malignant pleural mesothelioma (MPM) from among other potentially confounding diagnoses and differentiate the epithelioid from the sarcomatoid histologic subtype of MPM. In addition, we searched for pathways relevant in MPM in comparison with other related cancers to identify unique molecular features in MPM.Experimental Design: We conducted microarray analysis on 113 specimens including MPMs and a spectrum of tumors and benign tissues comprising the differential diagnosis of MPM. We generated a sequential combination of binary gene expression ratio tests able to discriminate MPM from other thoracic malignancies. We compared this method with other bioinformatic tools and validated this signature in an independent set of 170 samples. Functional enrichment analysis was conducted to identify differentially expressed probes.Results: A sequential combination of gene expression ratio tests was the best molecular approach to distinguish MPM from all the other samples. Bioinformatic and molecular validations showed that the sequential gene ratio tests were able to identify the MPM samples with high sensitivity and specificity. In addition, the gene ratio technique was able to differentiate the epithelioid from the sarcomatoid type of MPM. Novel genes and pathways specifically activated in MPM were identified.Conclusions: New clinically relevant molecular tests have been generated using a small number of genes to accurately distinguish MPMs from other thoracic samples, supporting our hypothesis that the gene expression ratio approach could be a useful tool in the differential diagnosis of cancers. Clin Cancer Res; 19(9); 2493–502. ©2013 AACR.

Supplementary Tables 1-4, Figures 1-11 from miR-99 Family of MicroRNAs Suppresses the Expression of Prostate-Specific Antigen and Prostate Cancer Cell Proliferation

The lack of samples for generating standardized DNA datasets for setting up a sequencing pipeline or benchmarking the performance of different algorithms limits the implementation and uptake of cancer genomics. Here, we describe reference call sets obtained from paired tumor–normal genomic DNA (gDNA) samples derived from a breast cancer cell line—which is highly heterogeneous, with an aneuploid genome, and enriched in somatic alterations—and a matched lymphoblastoid cell line. We partially validated both somatic mutations and germline variants in these call sets via whole-exome sequencing (WES) with different sequencing platforms and targeted sequencing with >2,000-fold coverage, spanning 82% of genomic regions with high confidence. Although the gDNA reference samples are not representative of primary cancer cells from a clinical sample, when setting up a sequencing pipeline, they not only minimize potential biases from technologies, assays and informatics but also provide a unique resource for benchmarking ‘tumor-only’ or ‘matched tumor–normal’ analyses.

Clinical applications of precision oncology require accurate tests that can distinguish true cancer-specific mutations from errors introduced at each step of next-generation sequencing (NGS). To date, no bulk sequencing study has addressed the effects of cross-site reproducibility, nor the biological, technical and computational factors that influence variant identification. Here we report a systematic interrogation of somatic mutations in paired tumor–normal cell lines to identify factors affecting detection reproducibility and accuracy at six different centers. Using whole-genome sequencing (WGS) and whole-exome sequencing (WES), we evaluated the reproducibility of different sample types with varying input amount and tumor purity, and multiple library construction protocols, followed by processing with nine bioinformatics pipelines. We found that read coverage and callers affected both WGS and WES reproducibility, but WES performance was influenced by insert fragment size, genomic copy content and the global imbalance score (GIV; G > T/C > A). Finally, taking into account library preparation protocol, tumor content, read coverage and bioinformatics processes concomitantly, we recommend actionable practices to improve the reproducibility and accuracy of NGS experiments for cancer mutation detection.

We report the complete genome sequence of a clinical isolate of Providencia stuartii strain CMC-4104, isolated from a splenic abscess. Oxford Nanopore Technologies (ONT) and Illumina sequencing reads were assembled using Geneious to generate a 4,504,925-bp circular chromosome containing multiple copies of the NDM-1 and PER-1 genes in a genomic resistance island.

We reported the complete genome sequence of a member of the pathogenic

Pleural mesothelioma (PM) comprises three major histologic types: epithelioid, sarcomatoid, and a mixture of the two types termed biphasic. We and others have investigated whole transcriptome profiles of bulk PM samples, identifying a molecular gradient with features of epithelial-mesenchymal transition, which is related to, but not redundant with, histology. To date bulk studies of heterogeneity across PM tumors have not explained how biphasic tumors contain sarcomatoid (mesenchymal) and epithelioid (epithelial) components. We hypothesized that sarcomatoid and epithelioid components arose from distinct tumor clones. We performed integrated bulk and single-cell RNA-sequencing and pathologic analyses of 93 samples from 39 patients’ surgical resections including 3 negative-control pleura cases with non-PM pathology. Single-cell sequencing analysis was performed using the Seq-Well S3 platform. Tumor clones were identified using inferCNV in R. Copy number and somatic variants were identified in adjacent bulk samples of each PM case with optical genome mapping and exome sequencing, respectively. We generated libraries from 19 epithelioid, 3 sarcomatoid, and 13 biphasic cases resulting in an average of 6,657 single cells per case (n=266,262 total cells; UMIs ≥ 300 & features ≥ 80). Among the 32,383 high quality malignant cells, we characterized epithelioid and sarcomatoid programs independent of non-malignant cells in the microenvironment. We observed malignant cells expressing both programs at low levels, termed uncommitted. Uncommitted cells were not outliers in terms of UMIs detected, genes expressed, or mitochondrial transcript content, and were detected in 96.4% of PM cases with at least 50 high quality tumor cells. Most (72.7%) uncommitted cells were isolated from biphasic tumors. Additionally, we observed that individual tumor clones from biphasic tumors exhibited all three cell phenotypes. In one biphasic tumor, five of six clones comprised cells from all three types, where these clones were well-represented across multiple sites with epithelioid content ranging from 10% to 40%. In conclusion, our integrated analysis of multi-site pleural mesothelioma samples suggests that a single tumor clone may be capable of generating all molecular subtypes. Further work aims to identify candidate drivers of this plasticity, to relate single-cell transcriptomic phenotype to histology and to further characterize uncommitted cells. We will also assess the prognostic implications of uncommitted cells content in a wider cohort. Citation Format: David T. Severson, Samuel Freyaldenhoven, Benjamin Wadowski, Travis Hughes, Yin P. Hung, Roderick V. Jensen, William G. Richards, Corinne E. Gustafson, Kimberly Vermilya, Simona Innocenti, Julianne S. Barlow, Matthew B. Cougar, Jamie Anderson, Vivian Wang, Mary N. Dao, Alex K. Shalek, Assunta De Rienzo, Raphael Bueno. Uncommitted cells and phenotypic plasticity elucidate the complexity of the epithelial-mesenchymal molecular gradient of pleural mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 95.

We report the complete genome of a clinical strain of Pseudomonas aeruginosa CMC-097, which was isolated from a ventilator-associated pneumonia patient with a chronic infection. Illumina sequence reads were assembled using Geneious to yield a 7,044,064-bp circular chromosome containing a carbapenem resistance integron, In2020. Carilion Clinic; Fralin Life Science Institute Published version This study was supported by the Carilion Clinic (D.C.G. and J.R.)., a graduate student research supply grant to A.A. was approved by Virginia Tech, and the Illumina sequencing was completed with the support of the Fralin Life Science Institute (R.V.J.).

Background Clostridium perfringens is a Gram-positive anaerobic pathogen that causes multiple diseases in humans and animals. C. perfringens lack flagella but have type IV pili (TFP) and can glide on agar surfaces. When C. perfringens bacteria are placed on surfaces, they become elongated, flexible and have TFP on their surface, traits not seen in liquid-grown cells. In addition, the main pilin in C. perfringens TFP, PilA2, undergoes differential post-translational modification when grown in liquid or on plates. To understand the mechanisms underlying these phenotypes, bacteria were grown in three types of liquid media and on agar plates with the same medium to compare gene expression using RNA-Seq. Results Hundreds of genes were differentially expressed, including transcriptional regulatory protein-encoding genes and genes associated with TFP functions, which were higher on plates than in liquid. Transcript levels of TFP genes reflected the proportion of each protein predicted to reside in a TFP assembly complex. To measure differences in rates of translation, the Escherichia coli reporter gene gusA gene (encoding β-glucuronidase) was inserted into the chromosome downstream of TFP promoters and in-frame with the first gene of the operon. β-glucuronidase expression was then measured in cells grown in liquid or on plates. β-glucuronidase activity was proportional to mRNA levels in liquid-grown cells, but not plate-grown cells, suggesting significant levels of post-transcriptional regulation of these TFP-associated genes occurs when cells are grown on surfaces. Conclusions This study reveals insights into how a non-flagellated pathogenic rod-shaped bacterium senses and responds to growth on surfaces, including inducing transcriptional regulators and activating multiple post-transcriptional regulatory mechanisms associated with TFP functions.

Simple Summary Sex differences in tumor incidence and mortality have been documented for many different cancer types. In malignant pleural mesothelioma, a deadly disease, many studies have shown that women not only develop this cancer less frequently than men, but those who do are likely to live longer after surgery. These differences have been postulated to reflect circulating estrogen levels and tumor expression of estrogen receptors that may influence tumor progression. We identified high expression of the RAS like estrogen regulated growth inhibitor gene (RERG), to correlate with longer survival after surgery among women. Survival in men was not associated with RERG expression. Additionally, we found no association between survival and tumor expression of estrogen receptor genes. Additional studies are needed to elucidate any role RERG may play in mesothelioma, and whether estrogen may be involved. Abstract Sex differences in incidence, prognosis, and treatment response have been described for many cancers. In malignant pleural mesothelioma (MPM), a lethal disease associated with asbestos exposure, men outnumber women 4 to 1, but women consistently live longer than men following surgery-based therapy. This study investigated whether tumor expression of genes associated with estrogen signaling could potentially explain observed survival differences. Two microarray datasets of MPM tumors were analyzed to discover estrogen-related genes associated with survival. A validation cohort of MPM tumors was selected to balance the numbers of men and women and control for competing prognostic influences. The RAS like estrogen regulated growth inhibitor (RERG) gene was identified as the most differentially-expressed estrogen-related gene in these tumors and predicted prognosis in discovery datasets. In the sex-matched validation cohort, low RERG expression was significantly associated with increased risk of death among women. No association between RERG expression and survival was found among men, and no relationship between estrogen receptor protein or gene expression and survival was found for either sex. Additional investigations are needed to elucidate the molecular mechanisms underlying this association and its sex specificity.

BRCA1-associated protein-1(BAP1) expression is commonly lost in several tumors including malignant pleural mesothelioma (MPM). Presence or absence of immunohistochemical BAP1 nuclear staining in tumor cells is currently used for differential diagnosis of MPM. In this study, a large cohort of 596 MPM tumors with available clinical data was analyzed to examine associations of BAP1 staining pattern with clinical and molecular features that may reflect the impact ofBAP1mutation on MPM biology. Cases were classified according to the BAP1 staining pattern of tumor cells. Exome and RNA-sequencing data were available for subsets of cases. Levels of mRNA encoding claudin 15 (CLDN15) and vimentin (VIM) were determined using RT-qPCR on 483 cases to estimate the relative proportions of epithelial-like and mesenchymal-like components in each tumor. Four BAP1 staining patterns were observed: single-pattern nuclear staining (36%), single-pattern cytoplasmic staining (25%), single-pattern absent staining (12%), and combinations of these staining patterns (27%). This study confirmed prior reports that nuclear BAP1 is more frequently associated with wild-typeBAP1and sarcomatoid histology. However, no associations between BAP1 staining pattern(s) and mutations in specific protein domains and/or mutation type were observed. BAP1 staining patterns were significantly associated (p < 0.001) withBAP1gene expression, MPM histologic subtypes, molecular clusters, and markers of epithelial-to-mesenchymal transition. Frequent observation of combinations of BAP1 staining patterns in MPM tumors indicated intra-tumoral heterogeneity ofBAP1status. Cytoplasmic BAP1 staining was identified as a putative indicator of favorable prognosis in non-epithelioid MPM. In conclusion, novel significant associations among different BAP1 staining patterns and subgroups of MPM tumors were observed, suggesting that the role ofBAP1in tumor progression may be more complex than its presumed tumor suppressor function. Cytoplasmic staining was identified as a putative indicator of favorable prognosis in non-epithelioid MPM, potentially addressing a critical need in clinical decision-making in this disease. (c) 2020 The Authors.The Journal of Pathologypublished by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland. National Cancer InstituteUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Cancer Institute (NCI) [NCI 2 R01 CA120528-11A1]; International Mesothelioma Program at Brigham and Women's Hospital; NCI Cancer Center Support GrantUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Cancer Institute (NCI) [NIH 5 P30 CA06516] This work was supported by grants to RB from the National Cancer Institute (NCI 2 R01 CA120528-11A1) and the International Mesothelioma Program at Brigham and Women's Hospital. The study sponsors played no role in the study design, collection, analysis, interpretation of data, writing of the report, or decision to submit the paper for publication. We thank the Dana-Farber/Harvard Cancer Center in Boston, MA, for the use of the Specialized Histopathology Core, which provided histology and immunohistochemistry service. Dana-Farber/Harvard Cancer Center is supported in part by an NCI Cancer Center Support Grant #NIH 5 P30 CA06516.

We report the complete genome of clinical strain Pseudomonas aeruginosa CMC-115, which was isolated from an acute ventilator-associated pneumonia patient. Illumina sequencing reads were assembled using Geneious to yield a 6,375,262-bp circular chromosome that exhibited an unusual ferrichrome receptor in the pyoverdine synthesis locus and the absence of type 3 secretion system genes.

Background Despite the recent surge of viral metagenomic studies, recovering complete virus/phage genomes from metagenomic data is still extremely difficult and most viral contigs generated from de novo assembly programs are highly fragmented, posing serious challenges to downstream analysis and inference. Results Here we develop FVE-novel, a computational pipeline for reconstructing complete or near-complete viral draft genomes from metagenomic data. FVE-novel deploys FastViromeExplorer to efficiently map metagenomic reads to viral reference genomes or contigs, performs de novo assembly of the mapped reads to generate scaffolds, and extends the scaffolds via iterative assembly to produce final viral scaffolds. We applied FVE-novel to an ocean metagenomic sample and obtained 268 viral scaffolds that potentially come from novel viruses. Through manual examination and validation of the ten longest scaffolds, we successfully recovered four complete viral genomes, two are novel as they cannot be found in the existing databases and the other two are related to known phages. Conclusions The hybrid reference-based and de novo assembly approach used by FVE-novel represents a powerful new approach for exploring viral diversity in metagenomic data. FVE-novel is freely available at https://github.com/saima-tithi/FVE-novel .

The bacterium Pantoea stewartii ssp. stewartii causes Stewart's wilt disease in corn. Pantoea stewartii is transmitted to plants via corn flea beetles, where it first colonizes the apoplast causing water-soaked lesions, and then migrates to the xylem and forms a biofilm that blocks water transport. Bacterial quorum sensing ensures that the exopolysaccharide production necessary for biofilm formation occurs only at high cell density. A genomic-level transposon sequencing (Tn-Seq) analysis was performed to identify additional bacterial genes essential for survival in planta and to provide insights into the plant-microbe interactions occurring during wilt disease. A mariner transposon library of approximately 40 000 mutants was constructed and used to inoculate corn seedlings through a xylem infection model. Cultures of the library grown in Luria-Bertani (LB) broth served as the in vitro pre-inoculation control. Tn-Seq analysis showed that the number of transposon mutations was reduced by more than 10-fold for 486 genes in planta compared with the library that grew in LB, suggesting that they are important for xylem survival. Interestingly, a small set of genes had a higher abundance of mutants in planta versus in vitro conditions, indicating enhanced strain fitness with loss of these genes inside the host. In planta competition assays retested the trends of the Tn-Seq data for several genes, including two outer membrane proteins, Lon protease and two quorum sensing-associated transcription factors, RcsA and LrhA. Virulence assays were performed to check for correlation between growth/colonization and pathogenicity. This study demonstrates the capacity of a Tn-Seq approach to advance our understanding of P. stewartii-corn interactions.

The differential expression of two closelyassociated cyclooxygenase isozymes, COX-1 and COX-2, exhibited functions beyond eicosanoid metabolism. We hypothesized that COX-1 or COX-2 knockout lung fibroblasts may display altered protein profiles which may allow us to further differentiate the functional roles of these isozymes at the molecular level. Proteomic analysis shows constitutive production of macrophage migration inhibitory factor (MIF) in lung fibroblasts derived from COX-2-/- but not wild-type (WT) or COX-1-/- mice. MIF was spontaneously released in high levels into the extracellular milieu of COX2-/- fibroblasts seemingly from the preformed intracellular stores, with no change in the basal gene expression of MIF. The secretion and regulation of MIF in COX-2-/- was "prostaglandin-independent." GO analysis showed that concurrent with upregulation of MIF, there is a significant surge in expression of genes related to fibroblast growth, FK506 binding proteins, and isomerase activity in COX-2-/- cells. Furthermore, COX-2-/- fibroblasts also exhibit a significant increase in transcriptional activity of various regulators, antagonists, and co-modulators of p53, as well as in the expression of oncogenes and related transcripts. Integrative Oncogenomics Cancer Browser (IntroGen) analysis shows downregulation of COX-2 and amplification of MIF and/or p53 activity during development of glioblastomas, ependymoma, and colon adenomas. These data indicate the functional role of the MIF-COX-p53 axis in inflammation and cancer at the genomic and proteomic levels in COX-2-ablated cells. This systematic analysis not only shows the proinflammatory state but also unveils a molecular signature of a pro-oncogenic state of COX-1 in COX-2 ablated cells.

Shrimp disease results in significant annual economic loss to the global aquaculture industry. Since 2009, the primary causative agent of shrimp disease has been Vibrio parahaemolyticus (VP) strains that cause Early Mortality Syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND). EMS strains have acquired a plasmid via horizontal gene transfer that encodes an insect toxin, which is responsible for the rapid death of infected shrimp. Based on previous experiments, it was hypothesized that an EMS strain of VP has unique growth properties compared to other VP strains, which may give it an interspecific competitive advantage in the environment. Accordingly, three strains of VP underwent testing; EMS 13-028/A3 that causes EMS disease in shrimp, RIMD2210633 that is a human clinical isolate, and LM5312 that is an environmental isolate. The ability of these three different strains of VP to grow on 71 different carbon sources/substrates was measured using Biolog GEN III MicroPlates. The EMS strain was able to utilize a variety of nutrient sources (23 out of 71) more efficiently than the other two strains as ascertained by significantly greater growth. A comparative bioinformatics analysis of the EMS genome identified a unique set of genes associated with fucose metabolism. This study demonstrates that Biolog plates can be used to ascertain distinctive metabolic properties of pathogenic bacterial strains such as VP EMS that may help guide development of new disease mitigation strategies for production of shrimp in aquaculture environments.

Fusion of somatic cells to pluripotent cells such as mouse embryonic stem (ES) cells induces reprogramming of the somatic nucleus, and can be used to study the effect of trans-acting factors from the pluripotent cell on the somatic nucleus. Moreover, fusion of cells from different species permits the identification of the transcriptome of each cell, so the gene expression changes can be monitored. However, fusion only happens in a small proportion of the cells exposed to fusogenic conditions, hence the need for a protocol that produces high fusion rate with minimal cell damage, coupled with a method capable of identifying and selecting fusion events from the bulk of the cells. Polyethylene glycol (PEG) is a polymer of repeated ethylene oxide units known to induce cell fusion within a certain range of molecular weight. Here, we describe a method to induce formation of bi-species heterokaryons from adherent mammalian cells, which can then be specifically labeled and selected using live cell immunostaining and a combination of imaging and traditional flow cytometry. First, we tested several PEG-based fusion conditions to optimize a protocol to consistently produce both mouse NIH/3T3 fibroblast and primary bovine fetal fibroblast (bFF) homokaryons. Initially, we obtained 7.28% of NIH/3T3 homokaryons when using 50% PEG 1500. Addition of 10% of DMSO to the PEG solution increased the percentage of NIH/3T3 homokaryons to 11.71%. In bFFs, treatment with 50% PEG 1500 plus 10% DMSO produced 11.05% of homokaryons. We then produced interspecies heterokaryons by fusing mouse embryonic stem (mES) cells to bFFs. To identify bi-species fusion products, heterokaryons were labeled using indirect immunostaining in live cells and selected using imaging (Amnis ImageStream Mark II) and traditional (BD FACSAria I) flow cytometry. Heterokaryons selected with this method produced ES cell-like colonies when placed back in culture. The method described here can also be combined with downstream applications such as nucleic acid isolation for RT-PCR and RNA-seq, and used as a tool to study cellular processes in which the effect of trans-acting factors is relevant, such as in nuclear reprogramming.

We characterized two reference samples for NGS technologies: a human triple-negative breast cancer cell line and a matched normal cell line. Leveraging several whole-genome sequencing (WGS) platforms, multiple sequencing replicates, and orthogonal mutation detection bioinformatics pipelines, we minimized the potential biases from sequencing technologies, assays, and informatics. Thus, our “truth sets” were defined using evidence from 21 repeats of WGS runs with coverages ranging from 50X to 100X (a total of 140 billion reads). These “truth sets” present many relevant variants/mutations including 193 COSMIC mutations and 9,016 germline variants from the ClinVar database, nonsense mutations inBRCA1/2and missense mutations inTP53andFGFR1.Independent validation in three orthogonal experiments demonstrated a successful stress test of the truth set. We expect these reference materials and “truth sets” to facilitate assay development, qualification, validation, and proficiency testing. In addition, our methods can be extended to establish new fully characterized reference samples for the community.

A commercial corn ethanol production byproduct (syrup) was used as a bacterial growth medium with the long-term aim to repurpose the resulting microbial biomass as a protein supplement in aquaculture feeds. Anaerobic batch reactors were used to enrich for soil bacteria metabolizing the syrup as the sole nutrient source over an eight-day period with the goal of obtaining pure cultures of facultative organisms from the reactors. Amplification of the V4 variable region of the 16S rRNA gene was performed using barcoded primers to track the succession of microbes enriched for during growth on the syrup. The resulting PCR products were sequenced using Illumina MiSeq protocols, analyzed via the program QIIME, and the alpha-diversity was calculated. Seven bacterial families were the most prevalent in the bioreactor community after eight days of enrichment: Clostridiaceae, Alicyclobacillaceae, Ruminococcaceae, Burkholderiaceae, Bacillaceae, Veillonellaceae, and Enterobacteriaceae. Pure culture isolates obtained from the reactors, and additional laboratory stock strains, capable of facultative growth, were grown aerobically in microtiter plates with the syrup substrate to monitor growth yield. Reactor isolates of interest were identified at a species level using the full 16S rRNA gene and other biomarkers. Bacillus species, commonly used as probiotics in aquaculture, showed the highest biomass yield of the monocultures examined. Binary combinations of monocultures yielded no apparent synergism between organisms, suggesting competition for nutrients instead of cooperative metabolite conversion. © 2019 Packard et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Sex differences in incidence, prognosis, and treatment response have been described for many cancers. In malignant pleural mesothelioma (MPM), a lethal disease associated with asbestos exposure, men outnumber women 4 to 1, but women consistently live longer than men following surgery-based therapy. This study investigated whether tumor expression of genes associated with estrogen signaling could potentially explain observed survival differences. Two microarray datasets of MPM tumors were analyzed to discover estrogen-related genes associated with survival. A validation cohort of MPM tumors was selected to balance the numbers of men and women and control for competing prognostic influences. The RAS like estrogen regulated growth inhibitor (RERG) gene was identified as the most differentially-expressed estrogen-related gene in these tumors and predicted prognosis in discovery datasets. In the sex-matched validation cohort, low RERG expression was significantly associated with increased risk of death among women. No association between RERG expression and survival was found among men, and no relationship between estrogen receptor protein or gene expression and survival was found for either sex. Additional investigations are needed to elucidate the molecular mechanisms underlying this association and its sex specificity. Published version

Summary Testosterone mediates several key aspects of male reproduction, but maintaining high testosterone levels can reduce long-term survival. One of the proposed pathways by which testosterone can influence survival is through increased risk of parasite infection. The hormone has the potential to affect the transmission of sexually transmitted infections by promoting behaviours that increase sexual contact rates and/or by decreasing immune function. We hypothesized that males with high concentrations of testosterone would increase their chances of being infected with sexually transmitted bacteria, which would manifest as increased diversity of cloacal bacteria. To test this hypothesis, we measured circulating testosterone concentrations in breeding male rufous-collared sparrows (Zonotrichia capensis) and collected cloacal swabs to quantify bacterial diversity using 16S rRNA gene amplicon sequencing. There was a positive correlation between testosterone concentrations and the phylogenetic diversity of cloacal bacteria. In addition, individuals with high and medium testosterone concentrations had cloacal bacterial communities that were more similar to each other than to those of low testosterone individuals. Finally, when considering bacterial taxa that are potential avian pathogens, we found that the relative abundance of Chlamydiae, a class of obligate intracellular parasites, was positively correlated with testosterone concentrations. Two non-exclusive explanations for these results are that testosterone affects behaviours that lead to increased sexual contacts and thus the exposure and acquisition of additional phylogenetically diverse bacteria, and/or that testosterone is altering the immune system or the cloacal environment, thus making it easier for bacteria to colonize. Either way, these data suggest that increased exposure to sexually transmitted pathogens in the form of cloacal bacteria could be a cost of maintaining high testosterone levels. A Lay Summary is available for this article.

Pantoea stewartiisubsp.stewartii, a Gram-negative proteobacterium, causes Stewart’s wilt disease in corn. Bacterial transmission to plants occurs primarily via the corn flea beetle insect vector, which is native to North America.P. stewartiiDC283 is the wild-type reference strain most used to study pathogenesis. Previously the complete genome ofP. stewartiiwas released. Here, the method whereby the genome was assembled is described in greater detail. Data from a matepair library preparation with 3.5 kilobase insert size and high-throughput sequencing from the MiSeq Illumina platform, together with the available incomplete genome sequence of AHIE00000000.1 (containing 65 contigs) was used. This work resulted in the complete assembly of one circular chromosome, ten circular plasmids and one linear phage fromP. stewartiiDC283. A high number of sequences encoding repetitive transposases (> 400) were found in the complete genome. The separation of plasmids from genomic DNA revealed that two Type III secretion systems inP. stewartiiDC283 are located on two separate mega-plasmids. Interestingly, the assembly identified a previously unknown 66-kb region in a location interior to a contig in the previous reference genome. Overall, a novel approach was successfully utilized to fully assemble a prokaryotic genome that contains large numbers of repetitive sequences and multiple plasmids, which resulted in some interesting biological findings.

Skin symbiotic bacteria on amphibians can play a role in protecting their host against pathogens. Chytridiomycosis, the disease caused by Batrachochytrium dendrobatidis, Bd, has caused dramatic population declines and extinctions of amphibians worldwide. Anti-Bd bacteria from amphibian skin have been cultured, and skin bacterial communities have been described through 16S rRNA gene amplicon sequencing. Here, we present a shotgun metagenomic analysis of skin bacterial communities from a Neotropical frog, Craugastor fitzingeri. We sequenced the metagenome of six frogs from two different sites in Panamá: three frogs from Soberanía (Sob), a Bd-endemic site, and three frogs from Serranía del Sapo (Sapo), a Bd-naïve site. We described the taxonomic composition of skin microbiomes and found that Pseudomonas was a major component of these communities. We also identified that Sob communities were enriched in Actinobacteria while Sapo communities were enriched in Gammaproteobacteria. We described gene abundances within the main functional classes and found genes enriched either in Sapo or Sob. We then focused our study on five functional classes of genes: biosynthesis of secondary metabolites, metabolism of terpenoids and polyketides, membrane transport, cellular communication and antimicrobial drug resistance. These gene classes are potentially involved in bacterial communication, bacterial-host and bacterial-pathogen interactions among other functions. We found that C. fitzingeri metagenomes have a wide array of genes that code for secondary metabolites, including antibiotics and bacterial toxins, which may be involved in bacterial communication, but could also have a defensive role against pathogens. Several genes involved in bacterial communication and bacterial-host interactions, such as biofilm formation and bacterial secretion systems were found. We identified specific genes and pathways enriched at the different sites and determined that gene co-occurrence networks differed between sites. Our results suggest that skin microbiomes are composed of distinct bacterial taxa with a wide range of metabolic capabilities involved in bacterial defense and communication. Differences in taxonomic composition and pathway enrichments suggest that skin microbiomes from different sites have unique functional properties. This study strongly supports the need for shotgun metagenomic analyses to describe the functional capacities of skin microbiomes and to tease apart their role in host defense against pathogens.

The role of chemotaxis and motility in Salmonella enterica serovar Typhimurium tumor colonization remains unclear. We determined through swim plate assays that the well-established anticancer agent S. Typhimurium VNP20009 is deficient in chemotaxis, and that this phenotype is suppressible. Through genome sequencing, we revealed that VNP20009 and four selected suppressor mutants had a single nucleotide polymorphism (SNP) in cheY causing a mutation in the conserved proline residue at position 110. CheY is the response regulator that interacts with the flagellar motor-switch complex and modulates rotational bias. The four suppressor mutants additionally carried non-synonymous SNPs in fliM encoding a flagellar switch protein. The CheY-P110S mutation in VNP20009 likely rendered the protein unable to interact with FliM, a phenotype that could be suppressed by mutations in FliM. We replaced the mutated cheY in VNP20009 with the wild-type copy and chemotaxis was partially restored. The swim ring of the rescued strain, VNP20009 cheY(+), was 46% the size of the parental strain 14028 swim ring. When tested in capillary assays, VNP20009 cheY(+) was 69% efficient in chemotaxis towards the attractant aspartate as compared to 14028. Potential reasons for the lack of complete restoration and implications for bacterial tumor colonization will be discussed.