Three feminizing strains in a single host species: comparative genomics paves the way for identifying sex reversal factors.

Introduction: Endosymbiotic bacteria in the genus have evolved numerous strategies for manipulating host reproduction in order to promote their own transmission. This includes the feminization of males into functional females, a well-studied phenotype in the isopod . Despite an early description of this phenotype in isopods and the development of an evolutionary model of host sex determination in the presence of , the underlying genetic mechanisms remain elusive.

Reassessment of the genetic basis of natural rifampin resistance in the genus Rickettsia.

Rickettsia, a genus of obligate intracellular bacteria, includes species that cause significant human diseases. This study challenges previous claims that the Leucine-973 residue in the RNA polymerase beta subunit is the primary determinant of rifampin resistance in Rickettsia. We investigated a previously untested Rickettsia species, R.

Seasonality and growth in tropical freshwater ectotherm vertebrates: Results from 1-year experimentation in the African gray bichir, giraffe catfish, and the West African mud turtle.

Growth in ectotherm vertebrates is strongly rhythmed by seasonal variation in environmental parameters. To track the seasonal variation in ancient times in a continental and tropical context, we aim to develop a method based on the use of the growth rate of fossil ectotherm vertebrates (actinopterygians and chelonians) influenced by seasonal environmental fluctuations they experienced in their lifetime. However, the impact of environmental parameters on growth, positive or negative, and its intensity, depends on the taxa considered, and data are scarce for tropical species.

The terrestrial isopod symbiont 'Candidatus Hepatincola porcellionum' is a potential nutrient scavenger related to Holosporales symbionts of protists.

The order Holosporales (Alphaproteobacteria) encompasses obligate intracellular bacterial symbionts of diverse Eukaryotes. These bacteria have highly streamlined genomes and can have negative fitness effects on the host. Herein, we present a comparative analysis of the first genome sequences of 'Ca.

Supergroup F in terrestrial isopods: Horizontal transmission from termites?

Unlabelled: Horizontal transmission between distantly related species has been used to explain how infect multiple species at astonishing rates despite the selection for resistance. Recently, a terrestrial isopod species was found to be infected by an unusual strain of supergroup F . However, only of supergroup B is typically found in isopods.

Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod.

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host's diet. We studied these impacts by manipulating the digestive microbiota of the detritivore and analyzing the consequences on its structure and function.

Isopod holobionts as promising models for lignocellulose degradation.

Background: Isopods have colonized all environments, partly thanks to their ability to decompose the organic matter. Their enzymatic repertoire, as well as the one of their associated microbiota, has contributed to their colonization success. Together, these holobionts have evolved several interesting life history traits to degrade the plant cell walls, mainly composed of lignocellulose.

Lignocellulose degradation in isopods: new insights into the adaptation to terrestrial life.

Background: Isopods constitute a particular group of crustaceans that has successfully colonized all environments including marine, freshwater and terrestrial habitats. Their ability to use various food sources, especially plant biomass, might be one of the reasons of their successful spread. All isopods, which feed on plants and their by-products, must be capable of lignocellulose degradation.

Spatio-temporal survey of opportunistic premise plumbing pathogens in the Paris drinking water distribution system.

Opportunistic premise plumbing pathogens present in drinking water are linked to a significant number of infections for health compromised patients. However, their monitoring is not required in current water potability standards and they have been poorly studied in a full-scale network. In this study, we quantified, by qPCR, three opportunistic pathogens, Mycobacterium spp.

Targeted Metagenomics of Microbial Diversity in Free-Living Amoebae and Water Samples.

The presence of Legionella spp. in natural and man-made water systems is a great public health concern and heavily depends on the presence of free-living amoebae. Taking advantage of the development and affordability of next-generation sequencing technology, we present here a method to characterize the whole bacterial community directly from water samples, as well as from isolated free-living amoebae.

Microbiome of drinking water: A full-scale spatio-temporal study to monitor water quality in the Paris distribution system.

The microbiological water quality of drinking water distribution system (DWDS) is of primary importance for human health. High-throughput sequencing has gained more and more attention in the last decade to describe this microbial diversity in water networks. However, there are few studies describing this approach on large drinking water distribution systems and for extended periods of time.

The Importance of Revisiting Legionellales Diversity.

Bacteria of the order Legionellales, such as Legionella pneumophila, the agent of Legionnaires' disease, and Coxiella burnetii, the agent of Q fever, are widely recognized as human pathogens. While our view of the Legionellales is often limited to clinical isolates, ecological surveys are continually uncovering new members of the Legionellales that do not fall into the recognized pathogenic species. Here we emphasize that most of these Legionellales are nonpathogenic forms that have evolved symbiotic lifestyles with nonvertebrate hosts.

Lignocellulose degradation at the holobiont level: teamwork in a keystone soil invertebrate.

Background: Woodlice are recognized as keystone species in terrestrial ecosystems due to their role in the decomposition of organic matter. Thus, they contribute to lignocellulose degradation and nutrient cycling in the environment together with other macroarthropods. Lignocellulose is the main component of plants and is composed of cellulose, lignin and hemicellulose.

Feminizing Wolbachia influence microbiota composition in the terrestrial isopod Armadillidium vulgare.

Wolbachia are widespread heritable endosymbionts of arthropods notorious for their profound effects on host fitness as well as for providing protection against viruses and eukaryotic parasites, indicating that they can interact with other microorganisms sharing the same host environment. Using the terrestrial isopod crustacean Armadillidium vulgare, its highly diverse microbiota (>200 bacterial genera) and its three feminizing Wolbachia strains (wVulC, wVulM, wVulP) as a model system, the present study demonstrates that Wolbachia can even influence the composition of a diverse bacterial community under both laboratory and natural conditions. While host origin is the major determinant of the taxonomic composition of the microbiota in A.

Phenotypic shift in virulence towards its native host across serial horizontal passages.

Vertical transmission mode is predicted to decrease the virulence of symbionts. However, , a widespread vertically transmitted endosymbiont, exhibits both negative and beneficial effects on arthropod fitness. This 'Jekyll and Hyde' behaviour, as well as its ability to live transiently outside host cells and to establish new infections via horizontal transmission, may reflect the capacity of to exhibit various phenotypes depending on the prevailing environmental constraints.

Mycobacterium llatzerense, a waterborne Mycobacterium, that resists phagocytosis by Acanthamoeba castellanii.

Nontuberculous mycobacteria (NTM) are environmental bacteria increasingly associated to public health problems. In water systems, free-living amoebae (FLA) feed on bacteria by phagocytosis, but several bacteria, including many NTM, are resistant to this predation. Thus, FLA can be seen as a training ground for pathogenic bacteria.

Fate of Eight Different Polymers under Uncontrolled Composting Conditions: Relationships Between Deterioration, Biofilm Formation, and the Material Surface Properties.

With the ever-increasing volume of polymer wastes and their associated detrimental impacts on the environment, the plastic life cycle has drawn increasing attention. Here, eight commercial polymers selected from biodegradable to environmentally persistent materials, all formulated under a credit card format, were incubated in an outdoor compost to evaluate their fate over time and to profile the microbial communities colonizing their surfaces. After 450 days in compost, the samples were all colonized by multispecies biofilms, these latest displaying different amounts of adhered microbial biomass and significantly distinct bacterial and fungal community compositions depending on the substrate.

The Terrestrial Isopod Microbiome: An All-in-One Toolbox for Animal-Microbe Interactions of Ecological Relevance.

Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity, and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete our understanding of host-microbiota interactions. In this review, we present terrestrial isopod crustaceans as an emerging model organism to investigate symbiotic associations with potential relevance to ecosystem functioning.

Armadillidin H, a Glycine-Rich Peptide from the Terrestrial Crustacean , Displays an Unexpected Wide Antimicrobial Spectrum with Membranolytic Activity.

Antimicrobial peptides (AMPs) are key components of innate immunity and are widespread in nature, from bacteria to vertebrate animals. In crustaceans, there are currently 15 distinct AMP families published so far in the literature, mainly isolated from members of the Decapoda order. Up to now, armadillidin is the sole non-decapod AMP isolated from the haemocytes of , a crustacean isopod.

Environmental factors shaping cultured free-living amoebae and their associated bacterial community within drinking water network.

Free-living amoebae (FLA) constitute an important part of eukaryotic populations colonising drinking water networks. However, little is known about the factors influencing their ecology in such environments. Because of their status as reservoir of potentially pathogenic bacteria, understanding environmental factors impacting FLA populations and their associated bacterial community is crucial.

Host origin and tissue microhabitat shaping the microbiota of the terrestrial isopod Armadillidium vulgare.

We present the first in-depth investigation of the host-associated microbiota of the terrestrial isopod crustacean Armadillidium vulgare. This species is an important decomposer of organic matter in terrestrial ecosystems and a major model organism for arthropod-Wolbachia symbioses due to its well-characterized association with feminizing Wolbachia 16S rRNA gene pyrotags were used to characterize its bacterial microbiota at multiple levels: (i) in individuals from laboratory lineages and field populations and (ii) in various host tissues. This integrative approach allowed us to reveal an unexpectedly high bacterial diversity, placing this species in the same league as termites in terms of symbiotic diversity.

The Mutualistic Side of Wolbachia-Isopod Interactions: Wolbachia Mediated Protection Against Pathogenic Intracellular Bacteria.

Wolbachia is a vertically transmitted endosymbiont whose radiative success is mainly related to various host reproductive manipulations that led to consider this symbiont as a conflictual reproductive parasite. However, lately, some Wolbachia have been shown to act as beneficial symbionts by protecting hosts against a broad range of parasites. Still, this protection has been mostly demonstrated in artificial Wolbachia-host associations between partners that did not co-evolved together.

Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free-living amoeba.

The TM6 phylum belongs to the so-called microbial dark matter that gathers uncultivated bacteria detected only via DNA sequencing. Recently, the genome sequence of a TM6 bacterium (TM6SC1) has led to suggest that this bacterium would adopt an endosymbiotic life. In the present paper, free-living amoebae bearing a TM6 strain were isolated from a water network.