sp. nov., isolated from a human colon tumor adheres to colonic epithelial cells and induces IL-8 secretion.

Cancerous tissue is a largely unexplored microbial niche that provides a unique environment for the colonization and growth of specific bacterial communities, and with it, the opportunity to identify novel bacterial species. Here, we report distinct features of a novel species, sp. nov.

A distinct Fusobacterium nucleatum clade dominates the colorectal cancer niche.

Fusobacterium nucleatum (Fn), a bacterium present in the human oral cavity and rarely found in the lower gastrointestinal tract of healthy individuals, is enriched in human colorectal cancer (CRC) tumours. High intratumoural Fn loads are associated with recurrence, metastases and poorer patient prognosis. Here, to delineate Fn genetic factors facilitating tumour colonization, we generated closed genomes for 135 Fn strains; 80 oral strains from individuals without cancer and 55 unique cancer strains cultured from tumours from 51 patients with CRC.

INVADEseq to identify cell-adherent or invasive bacteria and the associated host transcriptome at single-cell-level resolution.

Single-cell RNA sequencing (scRNAseq) technologies have been beneficial in revealing and describing cellular heterogeneity within mammalian tissues, including solid tumors. However, many of these techniques apply poly(A) selection of RNA, and thus have primarily focused on determining the gene signatures of eukaryotic cellular components of the tumor microenvironment. Microbiome analysis has revealed the presence of microbial ecosystems, including bacteria and fungi, within human tumor tissues from major cancer types.

, isolated from a human colon tumor, adheres to colonic epithelial cells and induces IL-8 secretion.

Cancerous tissue is a largely unexplored microbial niche that provides a unique environment for the colonization and growth of specific bacterial communities, and with it, the opportunity to identify novel bacterial species. Here, we report distinct features of a novel species, ( ), isolated from primary colon adenocarcinoma tissue. We acquire the complete closed genome and associated methylome of this organism and phylogenetically confirm its classification into the genus, with as its closest neighbor.

Effect of the intratumoral microbiota on spatial and cellular heterogeneity in cancer.

The tumour-associated microbiota is an intrinsic component of the tumour microenvironment across human cancer types. Intratumoral host-microbiota studies have so far largely relied on bulk tissue analysis, which obscures the spatial distribution and localized effect of the microbiota within tumours. Here, by applying in situ spatial-profiling technologies and single-cell RNA sequencing to oral squamous cell carcinoma and colorectal cancer, we reveal spatial, cellular and molecular host-microbe interactions.

The cancer chemotherapeutic 5-fluorouracil is a potent Fusobacterium nucleatum inhibitor and its activity is modified by intratumoral microbiota.

Fusobacterium nucleatum (Fn) is a dominant bacterial species in colorectal cancer (CRC) tissue that is associated with cancer progression and poorer patient prognosis. Following a small-molecule inhibitor screen of 1,846 bioactive compounds against a Fn CRC isolate, we find that 15% of inhibitors are antineoplastic agents including fluoropyrimidines. Validation of these findings reveals that 5-fluorouracil (5-FU), a first-line CRC chemotherapeutic, is a potent inhibitor of Fn CRC isolates.

Complete Genome Sequence of Morganella morganii CTX51T, Isolated from a Human Cecal Adenocarcinoma.

We report the complete genome sequence of Morganella morganii CTX51T, a strain isolated from the resected tumor of a patient with cecal colorectal adenocarcinoma of the cecum. The genome comprises a circular chromosome of 4.19 Mbp, with an overall GC content of 50.

Complete Genome Sequence of Clostridium cadaveris IFB3C5, Isolated from a Human Colonic Adenocarcinoma.

We report the complete genome sequence of Clostridium cadaveris IFB3C5, a strain isolated from the resected tumor of a treatment naive colorectal cancer patient. This genome is comprised of a singular chromosome of approximately 3.63 Mbp in length, contains two plasmids, and has an overall mean GC content of 31.

Discovery of coordinately regulated pathways that provide innate protection against interbacterial antagonism.

Bacterial survival is fraught with antagonism, including that deriving from viruses and competing bacterial cells. It is now appreciated that bacteria mount complex antiviral responses; however, whether a coordinated defense against bacterial threats is undertaken is not well understood. Previously, we showed that possess a danger-sensing pathway that is a critical fitness determinant during competition against other bacteria.

The relationship between gastrointestinal cancers and the microbiota.

The contribution of the microbiota to disease progression and treatment efficacy is often neglected when determining who is at the highest risk of developing gastrointestinal cancers or designing treatment strategies for patients. We reviewed the current literature on the effect of the human microbiota on cancer risk, prognosis, and treatment efficacy. We highlight emerging research that seeks to identify microbial signatures as biomarkers for various gastrointestinal cancers, and discuss how we could harness knowledge of the microbiome to detect, prevent, and treat these cancers.

Structure of the type VI secretion system TssK-TssF-TssG baseplate subcomplex revealed by cryo-electron microscopy.

Type VI secretion systems (T6SSs) translocate effectors into target cells and are made of a contractile sheath and a tube docked onto a multi-protein transmembrane complex via a baseplate. Although some information is available about the mechanisms of tail contraction leading to effector delivery, the detailed architecture and function of the baseplate remain unknown. Here, we report the 3.

Conditional toxicity and synergy drive diversity among antibacterial effectors.

Bacteria in polymicrobial habitats contend with a persistent barrage of competitors, often under rapidly changing environmental conditions . The direct antagonism of competitor cells is thus an important bacterial survival strategy . Towards this end, many bacterial species employ an arsenal of antimicrobial effectors with multiple activities; however, the benefits conferred by the simultaneous deployment of diverse toxins are unknown.

Inactivation of the Major Hemolysin Gene Influences Expression of the Nonribosomal Peptide Synthetase Gene in the Insect Pathogen Serratia sp. Strain SCBI.

Hemolysins are important virulence factors for many bacterial pathogens, including The role of the major hemolysin gene in the insect pathogen sp. strain SCBI was investigated using both forward and reverse-genetics approaches. Introduction of the major hemolysin gene into resulted in a gain of both virulence and hemolytic activity.