Marine sponge microbe provides insights into evolution and virulence of the tubercle bacillus.

Reconstructing the evolutionary origins of Mycobacterium tuberculosis, the causative agent of human tuberculosis, has helped identify bacterial factors that have led to the tubercle bacillus becoming such a formidable human pathogen. Here we report the discovery and detailed characterization of an exceedingly slow growing mycobacterium that is closely related to M. tuberculosis for which we have proposed the species name Mycobacterium spongiae sp.

Global analysis of biosynthetic gene clusters reveals conserved and unique natural products in entomopathogenic nematode-symbiotic bacteria.

Microorganisms contribute to the biology and physiology of eukaryotic hosts and affect other organisms through natural products. Xenorhabdus and Photorhabdus (XP) living in mutualistic symbiosis with entomopathogenic nematodes generate natural products to mediate bacteria-nematode-insect interactions. However, a lack of systematic analysis of the XP biosynthetic gene clusters (BGCs) has limited the understanding of how natural products affect interactions between the organisms.

Exposure to Trypanosoma parasites induces changes in the microbiome of the Chagas disease vector Rhodnius prolixus.

Background: The causative agent of Chagas disease, Trypanosoma cruzi, and its nonpathogenic relative, Trypanosoma rangeli, are transmitted by haematophagous triatomines and undergo a crucial ontogenetic phase in the insect's intestine. In the process, the parasites interfere with the host immune system as well as the microbiome present in the digestive tract potentially establishing an environment advantageous for development. However, the coherent interactions between host, pathogen and microbiota have not yet been elucidated in detail.

Multi-Omic Analysis of Symbiotic Bacteria Associated With Breeding Sites.

Mosquito breeding sites are complex aquatic environments with wide microbial diversity and physicochemical parameters that can change over time during the development of immature insect stages. Changes in biotic and abiotic conditions in water can alter life-history traits of adult mosquitos but this area remains understudied. Here, using microbial genomic and metabolomics analyses, we explored the metabolites associated with breeding sites as well as the potential contribution of sp.

Metabolites as predictive biomarkers for exposure in triatomine bugs.

the causative agent of Chagas disease (American trypanosomiasis), colonizes the intestinal tract of triatomines. Triatomine bugs act as vectors in the life cycle of the parasite and transmit infective parasite stages to animals and humans. Contact of the vector with alters its intestinal microbial composition, which may also affect the associated metabolic patterns of the insect.

A community resource for paired genomic and metabolomic data mining.

Genomics and metabolomics are widely used to explore specialized metabolite diversity. The Paired Omics Data Platform is a community initiative to systematically document links between metabolome and (meta)genome data, aiding identification of natural product biosynthetic origins and metabolite structures.

Enzymatic biosynthesis of B-complex vitamins is supplied by diverse microbiota in the anterior midgut following infection.

the causative agent of Chagas disease, colonizes the gut of triatomine insects, including . It is believed that this colonization upsets the microbiota that are normally present, presumably switching the environment to one more favorable for parasite survival. It was previously thought that one particular bacterium, , was essential for insect survival due to its ability to produce vital B-complex vitamins.

Symbiosis, virulence and natural-product biosynthesis in entomopathogenic bacteria are regulated by a small RNA.

Photorhabdus and Xenorhabdus species have mutualistic associations with nematodes and an entomopathogenic stage in their life cycles. In both stages, numerous specialized metabolites are produced that have roles in symbiosis and virulence. Although regulators have been implicated in the regulation of these specialized metabolites, how small regulatory RNAs (sRNAs) are involved in this process is not clear.

High antibody titres induced by protein subunit vaccines using antigens Hsp18 and MUL_3720 with a TLR-2 agonist fail to protect against Buruli ulcer in mice.

Background: is the causative agent of a debilitating skin and soft tissue infection known as Buruli ulcer (BU). There is no vaccine against BU. The purpose of this study was to investigate the vaccine potential of two previously described immunogenic proteins, MUL_3720 and Hsp18, using a mouse tail infection model of BU.

Vaccine-Specific Immune Responses against Mycobacterium ulcerans Infection in a Low-Dose Murine Challenge Model.

The neglected tropical disease Buruli ulcer (BU) is an infection of subcutaneous tissue with There is no effective vaccine. Here, we assessed an experimental prime-boost vaccine in a low-dose murine tail infection model. We used the enoyl reductase (ER) domain of the mycolactone polyketide synthases electrostatically coupled with a previously described Toll-like receptor 2 (TLR-2) agonist-based lipopeptide adjuvant, RPamCys.

New Vocabulary for Bacterial Communication.

Quorum sensing (QS) is widely accepted as a procedure that bacteria use to converse. However, prevailing thinking places acyl homoserine lactones (AHLs) at the forefront of this communication pathway in Gram-negative bacteria. With the advent of high-throughput genomics and the subsequent influx of bacterial genomes, bioinformatics analysis has determined that the genes encoding AHL biosynthesis, originally discovered to be indispensable for QS (LuxI-like proteins and homologues), are often absent in QS-capable bacteria.

Cyclo(tetrahydroxybutyrate) production is sufficient to distinguish between Xenorhabdus and Photorhabdus isolates in Thailand.

Bacteria of the genera Photorhabdus and Xenorhabdus produce a plethora of natural products to support their similar symbiotic life cycles. For many of these compounds, the specific bioactivities are unknown. One common challenge in natural product research when trying to prioritize research efforts is the rediscovery of identical (or highly similar) compounds from different strains.

Heterogeneity in Bacterial Specialized Metabolism.

Specialized metabolites (SMs) like typical antibiotics, signaling molecules or other bioactive compounds of bacterial origin (sometimes also used in human therapy) are often complex natural products that are costly for the cell to make. Several bacterial taxa are known to produce multiple SM classes in parallel and therefore a division of labor within a clonal population of bacteria might be beneficial. In this review, examples of SM of gram-negative and gram-positive bacterial taxa that are produced by different cell types are presented, and the possibility that such a heterogeneity is more widespread in SM biosynthesis is discussed.

An Uncommon Type II PKS Catalyzes Biosynthesis of Aryl Polyene Pigments.

Aryl polyene (APE) pigments are a widely distributed class of bacterial polyketides. So far, little is known about the biosynthesis of these compounds, which are produced by a novel type II polyketide synthase (PKS). We have identified all enzymes involved in APE biosynthesis and determined their peculiar functions.

Dual phenazine gene clusters enable diversification during biosynthesis.

Biosynthetic gene clusters (BGCs) bridging genotype and phenotype continuously evolve through gene mutations and recombinations to generate chemical diversity. Phenazine BGCs are widespread in bacteria, and the biosynthetic mechanisms of the formation of the phenazine structural core have been illuminated in the last decade. However, little is known about the complex phenazine core-modification machinery.

Refining the Natural Product Repertoire in Entomopathogenic Bacteria.

Members of the genera Xenorhabdus and Photorhabdus are capable of producing a huge repertoire of different natural products to support a complex life cycle involving insect pathogenesis and nematode symbiosis. Many of the natural products have direct functions, specifically targeting different facets of nematode development or the insect immune system. These adaptations have allowed the bacteria to thrive in a unique environment and become highly efficient, versatile insect pathogens.

Natural Product Diversification Mediated by Alternative Transcriptional Starting.

Photorhabdus luminescens dedicates a significant proportion of its genome to the production of natural products. These products and the structural variation in their derivatives may occur by a number of well-described mechanisms, such as module skipping or precursor promiscuity. Cappable-seq was used to identify transcriptional start sites of many of the gene clusters present in P.

Comparative Genomics Shows That Mycobacterium ulcerans Migration and Expansion Preceded the Rise of Buruli Ulcer in Southeastern Australia.

Since 2000, cases of the neglected tropical disease Buruli ulcer, caused by infection with , have increased 100-fold around Melbourne (population 4.4 million), the capital of Victoria, in temperate southeastern Australia. The reasons for this increase are unclear.

Natural product diversity associated with the nematode symbionts Photorhabdus and Xenorhabdus.

Xenorhabdus and Photorhabdus species dedicate a large amount of resources to the production of specialized metabolites derived from non-ribosomal peptide synthetase (NRPS) or polyketide synthase (PKS). Both bacteria undergo symbiosis with nematodes, which is followed by an insect pathogenic phase. So far, the molecular basis of this tripartite relationship and the exact roles that individual metabolites and metabolic pathways play have not been well understood.

Screening of the Antimicrobial Activity against Drug Resistant Bacteria of and Associated with Entomopathogenic Nematodes from Mae Wong National Park, Thailand.

and are symbiotic with entomopathogenic nematodes (EPNs) of the genera and , respectively. These bacteria produce several secondary metabolites including antimicrobial compounds. The objectives of this study were to isolate and identify EPNs and their symbiotic bacteria from Mae Wong National Park, Thailand and to evaluate the antibacterial activities of symbiont extracts against drug resistant bacteria.

Insect Vectors of Disease: Untapped Reservoirs for New Antimicrobials?

With the increase in antibiotic resistance among infectious diseases, the need for new strategies for identifying compounds with inhibitory effects is dire. Traditional methods of genome sequencing and systematic characterization of potential antimicrobial gene clusters, although effective, are unfortunately not yielding results at a speed consistent with the rise in antimicrobial resistance. One approach could be to use a more targeted approach to antimicrobial compound discovery.

Xenorhabdus thuongxuanensis sp. nov. and Xenorhabdus eapokensis sp. nov., isolated from Steinernema species.

Two slightly yellowish-pigmented, oxidase-negative, rod-shaped and Gram-stain-negative bacterial strains (30TX1T and DL20T), isolated from Steinernema sangi and Steinernema eapokense, respectively, during soil sampling in Vietnam were studied using a polyphasic taxonomic approach. Strain 30TX1T showed highest 16S rRNA gene sequence similarity to the type strain of Xenorhabdus ehlersii (98.9 %) and strain DL20T to that of Xenorhabdus ishibashii (98.

Photorhabdusluminescens subsp. namnaonensis subsp. nov., isolated from Heterorhabditisbaujardi nematodes.

A lightly yellowish-pigmented, oxidase-negative bacterial strain (PB45.5T) isolated from the Nam Nao district of Phetchabun in central Thailand was investigated to determine its taxonomic position. Cells of the isolate showed a rod shaped appearance.

Heterogeneous regulation of bacterial natural product biosynthesis via a novel transcription factor.

Biological diversity arises among genetically equal subpopulations in the same environment, a phenomenon called phenotypic heterogeneity. The life cycle of the enteric bacterium involves a symbiotic interaction with nematodes as well as a pathogenic association with insect larvae. exists in two distinct phenotypic forms designated as primary (1°) and secondary (2°).