-
International Journal of Infectious... Sep 2016Morganella morganii belongs to the tribe Proteeae of the Enterobacteriaceae family. This species is considered as an unusual opportunistic pathogen that mainly causes... (Review)
Review
Morganella morganii belongs to the tribe Proteeae of the Enterobacteriaceae family. This species is considered as an unusual opportunistic pathogen that mainly causes post-operative wound and urinary tract infections. However, certain clinical M. morganii isolates present resistance to multiple antibiotics by carrying various resistant genes (such as blaNDM-1, and qnrD1), thereby posing a serious challenge for clinical infection control. Moreover, virulence evolution makes M. morganii an important pathogen. Accumulated data have demonstrated that M. morganii can cause various infections, such as sepsis, abscess, purple urine bag syndrome, chorioamnionitis, and cellulitis. This bacterium often results in a high mortality rate in patients with some infections. M. morganii is considered as a non-negligent opportunistic pathogen because of the increased levels of resistance and virulence. In this review, we summarized the epidemiology of M. morganii, particularly on its resistance profile and resistant genes, as well as the disease spectrum and risk factors for its infection.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Enterobacteriaceae Infections; Humans; Morganella morganii; Urinary Tract Infections
PubMed: 27421818
DOI: 10.1016/j.ijid.2016.07.006 -
Nature Feb 2020Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale....
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation; analyses timings and patterns of tumour evolution; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity; and evaluates a range of more-specialized features of cancer genomes.
Topics: Cell Proliferation; Cellular Senescence; Chromothripsis; Cloud Computing; DNA Mutational Analysis; Evolution, Molecular; Female; Genome, Human; Genomics; Germ-Line Mutation; High-Throughput Nucleotide Sequencing; Humans; Information Dissemination; Male; Mutagenesis; Mutation; Neoplasms; Oncogenes; Promoter Regions, Genetic; RNA Splicing; Reproducibility of Results; Telomerase; Telomere
PubMed: 32025007
DOI: 10.1038/s41586-020-1969-6 -
Nature Genetics Feb 2022Human genetic variation affects the gut microbiota through a complex combination of environmental and host factors. Here we characterize genetic variations associated...
Human genetic variation affects the gut microbiota through a complex combination of environmental and host factors. Here we characterize genetic variations associated with microbial abundances in a single large-scale population-based cohort of 5,959 genotyped individuals with matched gut microbial metagenomes, and dietary and health records (prevalent and follow-up). We identified 567 independent SNP-taxon associations. Variants at the LCT locus associated with Bifidobacterium and other taxa, but they differed according to dairy intake. Furthermore, levels of Faecalicatena lactaris associated with ABO, and suggested preferential utilization of secreted blood antigens as energy source in the gut. Enterococcus faecalis levels associated with variants in the MED13L locus, which has been linked to colorectal cancer. Mendelian randomization analysis indicated a potential causal effect of Morganella on major depressive disorder, consistent with observational incident disease analysis. Overall, we identify and characterize the intricate nature of host-microbiota interactions and their association with disease.
Topics: ABO Blood-Group System; Bifidobacterium; Clostridiales; Cohort Studies; Colorectal Neoplasms; Depressive Disorder, Major; Diet; Dietary Fiber; Enterococcus faecalis; Gastrointestinal Microbiome; Gastrointestinal Tract; Genetic Variation; Genome-Wide Association Study; Host Microbial Interactions; Humans; Lactase; Mediator Complex; Mendelian Randomization Analysis; Metagenome; Morganella; Polymorphism, Single Nucleotide
PubMed: 35115689
DOI: 10.1038/s41588-021-00991-z -
Science (New York, N.Y.) Oct 2022Microbiota-derived metabolites that elicit DNA damage can contribute to colorectal cancer (CRC). However, the full spectrum of genotoxic chemicals produced by indigenous...
Microbiota-derived metabolites that elicit DNA damage can contribute to colorectal cancer (CRC). However, the full spectrum of genotoxic chemicals produced by indigenous gut microbes remains to be defined. We established a pipeline to systematically evaluate the genotoxicity of an extensive collection of gut commensals from inflammatory bowel disease patients. We identified isolates from divergent phylogenies whose metabolites caused DNA damage and discovered a distinctive family of genotoxins-termed the indolimines-produced by the CRC-associated species A non-indolimine-producing mutant lacked genotoxicity and failed to exacerbate colon tumorigenesis in mice. These studies reveal the existence of a previously unexplored universe of genotoxic small molecules from the microbiome that may affect host biology in homeostasis and disease.
Topics: Animals; Mice; Colorectal Neoplasms; DNA Damage; Gastrointestinal Microbiome; Inflammatory Bowel Diseases; Morganella morganii; Indoles; Carcinogenesis; Humans; Mutagens; HeLa Cells
PubMed: 36302024
DOI: 10.1126/science.abm3233 -
Nature Feb 2020Somatic mutations in cancer genomes are caused by multiple mutational processes, each of which generates a characteristic mutational signature. Here, as part of the...
Somatic mutations in cancer genomes are caused by multiple mutational processes, each of which generates a characteristic mutational signature. Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), we characterized mutational signatures using 84,729,690 somatic mutations from 4,645 whole-genome and 19,184 exome sequences that encompass most types of cancer. We identified 49 single-base-substitution, 11 doublet-base-substitution, 4 clustered-base-substitution and 17 small insertion-and-deletion signatures. The substantial size of our dataset, compared with previous analyses, enabled the discovery of new signatures, the separation of overlapping signatures and the decomposition of signatures into components that may represent associated-but distinct-DNA damage, repair and/or replication mechanisms. By estimating the contribution of each signature to the mutational catalogues of individual cancer genomes, we revealed associations of signatures to exogenous or endogenous exposures, as well as to defective DNA-maintenance processes. However, many signatures are of unknown cause. This analysis provides a systematic perspective on the repertoire of mutational processes that contribute to the development of human cancer.
Topics: Age Factors; Base Sequence; Exome; Genome, Human; Humans; Mutation; Neoplasms; Sequence Analysis, DNA
PubMed: 32025018
DOI: 10.1038/s41586-020-1943-3 -
Open Forum Infectious Diseases Aug 2021Carbapenems are recommended treatment for serious infections caused by AmpC-producing gram-negative bacteria but can select for carbapenem resistance....
Meropenem Versus Piperacillin-Tazobactam for Definitive Treatment of Bloodstream Infections Caused by AmpC β-Lactamase-Producing spp, , , spp, or : A Pilot Multicenter Randomized Controlled Trial (MERINO-2).
BACKGROUND
Carbapenems are recommended treatment for serious infections caused by AmpC-producing gram-negative bacteria but can select for carbapenem resistance. Piperacillin-tazobactam may be a suitable alternative.
METHODS
We enrolled adult patients with bloodstream infection due to chromosomal AmpC producers in a multicenter randomized controlled trial. Patients were assigned 1:1 to receive piperacillin-tazobactam 4.5 g every 6 hours or meropenem 1 g every 8 hours. The primary efficacy outcome was a composite of death, clinical failure, microbiological failure, and microbiological relapse at 30 days.
RESULTS
Seventy-two patients underwent randomization and were included in the primary analysis population. Eleven of 38 patients (29%) randomized to piperacillin-tazobactam met the primary outcome compared with 7 of 34 patients (21%) in the meropenem group (risk difference, 8% [95% confidence interval {CI}, -12% to 28%]). Effects were consistent in an analysis of the per-protocol population. Within the subcomponents of the primary outcome, 5 of 38 (13%) experienced microbiological failure in the piperacillin-tazobactam group compared to 0 of 34 patients (0%) in the meropenem group (risk difference, 13% [95% CI, 2% to 24%]). In contrast, 0% vs 9% of microbiological relapses were seen in the piperacillin-tazobactam and meropenem arms, respectively. Susceptibility to piperacillin-tazobactam and meropenem using broth microdilution was found in 96.5% and 100% of isolates, respectively. The most common AmpC β-lactamase genes identified were , , , and . No ESBL, OXA, or other carbapenemase genes were identified.
CONCLUSIONS
Among patients with bloodstream infection due to AmpC producers, piperacillin-tazobactam may lead to more microbiological failures, although fewer microbiological relapses were seen.
CLINICAL TRIALS REGISTRATION
NCT02437045.
PubMed: 34395716
DOI: 10.1093/ofid/ofab387 -
Nature Jun 2016We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes...
We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.
Topics: Breast Neoplasms; Cohort Studies; DNA Mutational Analysis; DNA Replication; DNA, Neoplasm; Female; Genes, BRCA1; Genes, BRCA2; Genome, Human; Genomics; Humans; Male; Mutagenesis; Mutation; Mutation Rate; Oncogenes; Recombinational DNA Repair
PubMed: 27135926
DOI: 10.1038/nature17676 -
Nature Feb 2020Cancer develops through a process of somatic evolution. Sequencing data from a single biopsy represent a snapshot of this process that can reveal the timing of specific...
Cancer develops through a process of somatic evolution. Sequencing data from a single biopsy represent a snapshot of this process that can reveal the timing of specific genomic aberrations and the changing influence of mutational processes. Here, by whole-genome sequencing analysis of 2,658 cancers as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), we reconstruct the life history and evolution of mutational processes and driver mutation sequences of 38 types of cancer. Early oncogenesis is characterized by mutations in a constrained set of driver genes, and specific copy number gains, such as trisomy 7 in glioblastoma and isochromosome 17q in medulloblastoma. The mutational spectrum changes significantly throughout tumour evolution in 40% of samples. A nearly fourfold diversification of driver genes and increased genomic instability are features of later stages. Copy number alterations often occur in mitotic crises, and lead to simultaneous gains of chromosomal segments. Timing analyses suggest that driver mutations often precede diagnosis by many years, if not decades. Together, these results determine the evolutionary trajectories of cancer, and highlight opportunities for early cancer detection.
Topics: DNA Repair; Evolution, Molecular; Gene Dosage; Genes, Tumor Suppressor; Genetic Variation; Genome, Human; Humans; Mutagenesis, Insertional; Neoplasms
PubMed: 32025013
DOI: 10.1038/s41586-019-1907-7 -
Cell May 2019Whole-genome-sequencing (WGS) of human tumors has revealed distinct mutation patterns that hint at the causative origins of cancer. We examined mutational signatures in...
Whole-genome-sequencing (WGS) of human tumors has revealed distinct mutation patterns that hint at the causative origins of cancer. We examined mutational signatures in 324 WGS human-induced pluripotent stem cells exposed to 79 known or suspected environmental carcinogens. Forty-one yielded characteristic substitution mutational signatures. Some were similar to signatures found in human tumors. Additionally, six agents produced double-substitution signatures and eight produced indel signatures. Investigating mutation asymmetries across genome topography revealed fully functional mismatch and transcription-coupled repair pathways. DNA damage induced by environmental mutagens can be resolved by disparate repair and/or replicative pathways, resulting in an assortment of signature outcomes even for a single agent. This compendium of experimentally induced mutational signatures permits further exploration of roles of environmental agents in cancer etiology and underscores how human stem cell DNA is directly vulnerable to environmental agents. VIDEO ABSTRACT.
Topics: Carcinogens, Environmental; DNA Damage; DNA Mutational Analysis; DNA Repair; DNA Replication; Genetic Profile; Genome, Human; Humans; INDEL Mutation; Mutagenesis; Mutation; Neoplasms; Pluripotent Stem Cells; Whole Genome Sequencing
PubMed: 30982602
DOI: 10.1016/j.cell.2019.03.001 -
Nature Genetics Mar 2020Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, for which whole-genome and-for a subset-whole-transcriptome sequencing data from 2,658...
Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, for which whole-genome and-for a subset-whole-transcriptome sequencing data from 2,658 cancers across 38 tumor types was aggregated, we systematically investigated potential viral pathogens using a consensus approach that integrated three independent pipelines. Viruses were detected in 382 genome and 68 transcriptome datasets. We found a high prevalence of known tumor-associated viruses such as Epstein-Barr virus (EBV), hepatitis B virus (HBV) and human papilloma virus (HPV; for example, HPV16 or HPV18). The study revealed significant exclusivity of HPV and driver mutations in head-and-neck cancer and the association of HPV with APOBEC mutational signatures, which suggests that impaired antiviral defense is a driving force in cervical, bladder and head-and-neck carcinoma. For HBV, HPV16, HPV18 and adeno-associated virus-2 (AAV2), viral integration was associated with local variations in genomic copy numbers. Integrations at the TERT promoter were associated with high telomerase expression evidently activating this tumor-driving process. High levels of endogenous retrovirus (ERV1) expression were linked to a worse survival outcome in patients with kidney cancer.
Topics: DNA Copy Number Variations; DNA Tumor Viruses; Genome, Human; Hepatitis B virus; Herpesvirus 4, Human; Humans; Mutation; Neoplasms; Papillomavirus Infections; Promoter Regions, Genetic; Telomerase; Transcriptome; Tumor Virus Infections; Virus Integration
PubMed: 32025001
DOI: 10.1038/s41588-019-0558-9