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In this study, we assessed the presence of vector-borne microorganisms in different species of fleas collected from different hosts in diverse areas of South-Western Europe by molecular methods. A total of 319 fleas belonging to eight different species was tested for the presence of eight microorganisms. Wolbachia spp. endosymbionts were detected in Ctenocephalides felis, Pulex irritans, Archaeopsylla erinacei and Ctenophthalmus baeticus boisseauorum specimens. Rickettsia felis, an emerging pathogen, was detected in C. felis, A. erinacei and Ct. b. boisseauorum. Rickettsia typhi, the agent of murine typhus was detected for the first time in A. erinacei and Mycobacterium spp. were detected for the first time in fleas (C. felis, P. irritans and A. erinacei). Lastly, five different species of Bartonella were detected in fleas' DNA in this study, including a possible new bacterium belonging to this genus. With this study, we updated the knowledge of the flea-borne bacteria present in the South-West of Europe reinforcing the idea about the necessity to expand and increase the current knowledge on flea-borne pathogens.

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Truffles are edible mushrooms with similar morphological characteristics, that make it difficult to distinguish between highly prized truffles (such as the Périgord black T. melanosporum) and inexpensive truffles (such as the Asian Black T. indicum). These biological and economic features have led to several misidentifications and/or fraudulent profit in the truffle markets. In this paper, we investigate Matrix-assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) biotyping to identify 34 commercial fresh truffles from Europe and Asia. The MALDI-TOF MS clustering rapidly distinguished seven Tuber species identified by ITS phylogenetic analysis. The tasty T. melanosporum was clearly differentiated from the Chinese and less expensive truffles. These cheaper mushrooms were marketed as T. indicum but corresponded to a mix of three species. In total, the method confirmed misidentifications in 26% of commercial specimens. Several unknown blind-coded truffles were rapidly identified, with scores >= 2, using the Bruker Biotyper algorithm against MS databases. This study demonstrates that MALDI-TOF MS is a reliable, rapid and cheaper new tool compared with molecular methods for the identification of truffle species and could be used to control frauds in the truffle markets. It could also be useful for the certification of truffle-inoculated seedlings and/or diversity in forest ecosystems.

International audience; Rickettsiales are obligate intracellular bacteria originally found in metazoans, but more recently recognized as widespread endosymbionts of various protists. One genus was detected also in several green algae, but reports on rickettsialean endosymbionts in other algal groups are lacking. Here we show that several distantly related eustigmatophytes (coccoid algae belonging to Ochrophyta, Stramenopiles) are infected by Candidatus Phycorickettsia gen. nov., a new member of the family Rickettsiaceae. The genome sequence of Ca. Phycorickettsia trachydisci sp. nov., an endosymbiont of Trachydiscus minutus CCALA 838, revealed genomic features (size, GC content, number of genes) typical for other Rickettsiales, but some unusual aspects of the gene content were noted. Specifically, Phycorickettsia lacks genes for several components of the respiration chain, haem biosynthesis pathway, or c-di-GMP-based signalling. On the other hand, it uniquely harbours a six-gene operon of enigmatic function that we recently reported from plastid genomes of two distantly related eustigmatophytes and from various non-rickettsialean bacteria. Strikingly, the eustigmatophyte operon is closely related to the one from Phycorickettsia, suggesting a gene transfer event between the endosymbiont and host lineages in early eustigmatophyte evolution. We hypothesize an important role of the operon in the physiology of Phycorickettsia infection and a long-term eustigmatophyte-Phycorickettsia coexistence.

International audience; A rickettsial organism harboured by Amblyomma triguttatum ticks on Barrow Island, Western Australia, was discovered after reports of possible rickettsiosis among local workers. Subsequent isolation of this rickettsia (strain BWI-1) in cell culture and analysis of its phylogenetic, genotypic and phenotypic relationships with type strains of Rickettsia species with standing in nomenclature suggested that it was sufficiently divergent to warrant its classification as a new species. Multiple gene comparison of strain BWI-1 revealed degrees of sequence similarity with Rickettsia raoultii, its closest relative, of 99.58, 98.89, 97.03, 96.93 and 95.73% for the 16S rRNA, citrate synthase, ompA, ompB and sca4 genes, respectively. Serotyping in mice also demonstrated that strain BWI-1(T) was distinct from Rickettsia raoultii. Thus, we propose the naming of a new species, Rickettsia gravesii sp. nov., based on its novel genotypic and phenotypic characteristics. Strain BWI-1(T) was deposited in the ATCC, CSUR and ARRL collections under reference numbers VR-1664, CSUR R172 and RGBWI-1, respectively.

International audience; Coxiella-like bacteria have been recently proposed as human pathogens. Using molecular techniques, we detected Coxiella-like bacteria in the blood and serum samples of a patient with a scalp eschar, neck lymphadenopathy, severe urticaria, edema, fever, and arthralgia indicating that this organism can provide systemic complications.

International audience; BACKGROUND INFORMATION: The MIPs (major intrinsic proteins) constitute a large family of membrane proteins that facilitate the passive transport of water and small neutral solutes across cell membranes. Since water is the most abundant molecule in all living organisms, the discovery of selective water-transporting channels called AQPs (aquaporins) has led to new knowledge on both the physiological and molecular mechanisms of membrane permeability. The MIPs are identified in Archaea, Bacteria and Eukaryota, and the rapid accumulation of new sequences in the database provides an opportunity for large-scale analysis, to identify functional and/or structural signatures or to infer evolutionary relationships. To help perform such an analysis, we have developed MIPDB (database for MIP proteins), a relational database dedicated to members of the MIP family. RESULTS: MIPDB is a motif-oriented database that integrates data on 785 MIP proteins from more than 200 organisms and contains 230 distinct sequence motifs. MIPDB proposes the classification of MIP proteins into three functional subgroups: AQPs, glycerol-uptake facilitators and aquaglyceroporins. Plant MIPs are classified into three specific subgroups according to their subcellular distribution in the plasma membrane, tonoplast or the symbiosome membrane. Some motifs of the database are highly selective and can be used to predict the transport function or subcellular localization of unknown MIP proteins. CONCLUSIONS: MIPDB offers a user-friendly and intuitive interface for a rapid and easy access to MIP resources and to sequence analysis tools. MIPDB is a web application, publicly accessible at http://idefix.univ-rennes1.fr:8080/Prot/index.html

Ectomycorrhizal diversity (ED) associated with Pinus halepensis trees was examined 1.5 years after outplanting at a fire-disturbed site of Rieucoulon (Herault, France). ED analysis was examined on non-inoculated and Suillus collinitus-inoculated plants, and on naturally regenerated trees. A total of 461 single ectomycorrhizas was typed using PCR-RFLP analysis and sequencing of the internal transcribed spacer ( ITS) of the nuclear rDNA. Twelve ITS RFLP-taxa were detected. The ectomycorrhizal fungus S. collinitus ( ITS RFLP-taxon 1) was the most abundant (45.8 - 59.7%) species in the three treatments, suggesting that it is a strong ectomycorrhizal competitor in this site. S. mediterraneensis ( ITS RFLP-taxon 2) was restricted to control and naturally regenerated trees and was unequally moderate (11.7 - 31.9%). The remaining below-ground ITS RFLP-taxa were uncommon and rare (0.0 - 9.6%). The current experimental P. halepensis plantation showed a species-poor community dominated by two Suillus species. Ecological strategies of these symbionts are discussed., Diversité ectomycorhizienne dans une plantation à Pinus halepensis. La diversité génétique des ectomycorhizes de plants de P. halepensis a été examinée une année et demie après introduction dans un site incendié de Rieucoulon (Hérault, France). Cette diversité a été caractérisée à l’aide du polymorphisme de fragments de restriction (RFLP) et du séquençage de l’espaceur interne transcrit (ITS) de l’ADN ribosomal nucléaire. Trois traitements ont été examinés : des plants témoins, des plants mycorhizés avec Suillus collinitus et des plants en régénération naturelle. Au total, 461 ectomycorhizes ont été soumises au typage moléculaire. Douze ribotypes d’ITS ont été détectés. S. collinitus (ribotype 1) est l’espèce dominante (45,8–59,7 %) dans les trois traitements suggérant une forte capacité de colonisation dans ce site. La présence de S. mediterraneensis (ribotype 2) est limitée aux plants témoins et aux autres issus de la régénération naturelle et sa fréquence est modérée (11,7–31,9 %). Les autres symbiotes ectomycorhiziens sont rares (0,0–9,6 %) et leur abondance diffère d’un traitement à l’autre. Cette étude révèle une faible diversité des symbiotes ectomycorhiziens dans la plantation à P. halepensis; elle est dominée par deux espèces du genre Suillus. Les stratégies écologiques de ces symbiotes sont discutées.

Summary In the mediterranean region, the strong edaphic, climatic and economic constraints lead to the increase of the transplantation crisis of young trees. The use of controlled mycorrhizal infection is one of the means open to reduce the effects of this crisis by improving the quality of the forest trees grown in nursery, and the reforestation. To achieve this objective, a research/development programme was started and preliminary results are presented: screening of mycorrhizal isolates using physiological criteria; controlled mycorrhizal infection including the study of enzymic polymorphism in mycorrhizae as a tool for characterization of these organs; measurement of the effects of mycorrhizal infection on the nutrition of trees in nursery; ecophysiological study of experimental wood lots.