Nine Cases of Methanogenic Archaea in Refractory Sinusitis, an Emerging Clinical Entity

The authors report the cases of 9 patients eventually diagnosed with methanogenic archaea refractory or recalcitrant chronic rhinosinusitis, a condition known to involve various anaerobic bacteria but in which the role of methanogenic archaea is unknown. The authors retrospectively searched these microorganisms by PCR in surgically-collected sinusal pus specimens from patients diagnosed with refractory sinusitis, defined by the persistance of sinus inflammation and related-symptoms for more than 12 weeks despite appropriate treatment. Of the 116 tested sinus surgical specimens, 12 (10.3%) from 9 patients (six females, three males; aged 20–71 years) were PCR-positive. These specimens were further investigated by fluorescence in-situ hybridization, PCR amplicon-sequencing and culture. Methanobrevibacter smithii was documented in four patients and Methanobrevibacter oralis in another four, one of whom was also culture-positive. They were associated with a mixed flora including Gram-positive and Gram-negative bacteria. In the latter patient, “Methanobrevibacter massiliense” was the sole microorganism detected. These results highlight methanogenic archaea as being part of a mixed anaerobic flora involved in refractory sinusitis, and suggest that the treatment of this condition should include an antibiotic active against methanogens, notably a nitroimidazole derivative

Natural history of tuberculosis : role of microbiota

La tuberculose est une infection contagieuse mortelle causée par les mycobactéries appartenant au complexe Mycobacterium tuberculosis (MTC). Notre revue de la littérature fait une synthèse des sources et des modes de transmission des MTC, montrant l’absence de barrière d’espèce entre les MTC et leurs hôtes mammifères ; et la survie des MTC dans l’environnement. Par ailleurs, ces travaux apportent denouvelles connaissances sur les interactions entre les cellules humaines et les MTC, clarifiant mieux l’utilité des cultures cellulaires pour l’isolement des MTC à partir des prélèvements cliniques. Également, notre étude des interactions entre les MTC et les bactéries du microbiote digestif, démontrent d’une part la diminution de la diversité bactérienne du microbiote digestif à la suite de l’infection par M. tuberculosis, et d’autre part l’interaction directe entre M. tuberculosis et E. mundtii qui inhibe la croissance du pathogène, ouvrant ainsi des perspectives de recherche en médecine.Tuberculosis is a fatal contagious infection caused by the mycobacteria from the Mycobacterium tuberculosis complex (MTBC). Our literature review provides a synthesis of the sources and transmission modes of MTBC, showing the absence of species barrier between MTBC and their mammalian hosts; and the survival of MTBC in the environment. Moreover, this PhD work allowed us to bring new knowledge on the interactions between human cells and MTBC, clarifying the usefulness of cell cultures for the isolation of MTBC from clinical samples. Also, our study of the interactions between MTC and the other bacteria of the gut microbiota demonstrates on the one hand the decrease in the bacterial diversity of the digestive microbiota following infection by M. tuberculosis, and on the other hand the direct interaction between M. tuberculosis and E. mundtii which inhibits the growth of the pathogen, thus opening up prospects for research in human medicine

Genome Sequence of Enorma sp. Strain Marseille-P9525 T , a Member of a Human Gut Microbiome

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Robust continuous third-order finite time sliding mode controllers for exoskeleton robot

In this work, continuous third-order sliding mode controllers are presented to control a five degrees-of-freedom (5-DOF) exoskeleton robot. This latter is used in physiotherapy rehabilitation of upper extremities. The aspiration is to assist the movements of patients with severe motor limitations. The control objective is then to design adept controllers to follow desired trajectories smoothly and precisely. Accordingly, it is proposed, in this work, a class of homogeneous algorithms of sliding modes having finite-time convergence properties of the states. They provide continuous control signals and are robust regardless of non-modeled dynamics, uncertainties and external disturbances. A comparative study with a robust finite-time sliding mode controller proposed in literature is performed. Simulations are accomplished to investigate the efficacy of these algorithms and the obtained results are analyzed

The Enterococcus secretome inhibits the growth of Mycobacterium tuberculosis complex mycobacteria

International audienceEnterococcus mundtii , a commensal intestinal bacterium, was demonstrated to inhibit the growth of some Mycobacterium tuberculosis complex (MTC) species that cause tuberculosis in humans and mammals. To further explore this preliminary observation, we cross-investigated five E. mundtii strains and seven MTC strains representative of four MTC species using a standardized quantitative agar well diffusion assay. All five E. mundtii strains, calibrated at 10 MacFarland, inhibited the growth of all M. tuberculosis strains with various susceptibility profiles, but no inhibition was observed with lower inoculums. Further, eight E. mundtii freeze-dried cell-free culture supernatants (CFCS) inhibited the growth of M. tuberculosis , Mycobacterium africanum, Mycobacterium bovis and Mycobacterium canettii , the most susceptible MTC species (inhibition diameter 25±1 mm), proportionally to CFCS protein concentrations. The data reported here indicate that the E. mundtii secretome inhibited growth of all MTC species of medical interest, which broadens previously reported data. In the gut, the E. mundtii secretome may modulate the expression of tuberculosis, exhibiting an anti-tuberculosis effect, with some protective roles in human and animal health

Mycobacterium malmoense pulmonary infection in France: a case report

Abstract Background Mycobacterium malmoense infections have frequently been reported in northern Europe since the late 1970s. Factors accounting for this geographically localized epidemiology remain poorly understood. Case presentation We report the case of a 54-year old man concomitantly diagnosed with non-small cell lung carcinoma and M. malmoense pulmonary infection. We present detailed clinical, microbiological and radiological elements strongly arguing for M. malmoense true pathogenicity. Since M. malmoense infection has rarely been reported in France, we also provide elements of the epidemiological investigation and a literature review of potential acquisition and transmission pathways of M. malmoense. We detail therapeutic interventions and subsequent favorable evolution. Conclusion Mycobacterium malmoense is a recognized respiratory pathogen for which routes of infection need to be better investigated

Translocating Mycobacterium ulcerans: An experimental model

Mycobacterium ulcerans is a non-tuberculous environmental mycobacterium responsible for extensive cutaneous and subcutaneous ulcers in mammals, known as Buruli ulcer in humans. M. ulcerans has seldom been detected in the faeces of mammals and has not been detected in human faeces. Nevertheless, the detection and isolation of M. ulcerans in animal faeces does not fit with the current epidemiological schemes for the disease. Here, using an experimental model in which rats were fed with 10(9) colony-forming units of M. ulcerans, we detected M. ulcerans DNA in the faeces of challenged rats for two weeks and along their digestive tract for 10 days. M. ulcerans DNA was further detected in the lymphatic system including in the cervical and axillary lymph nodes and the spleen, but not in any other tissue including healthy and broken skin, 10 days post-challenge. These observations indicate that in some herbivorous mammals, M. ulcerans contamination by the digestive route may precede translocation and limited contamination of the lymphatic tissues without systemic infection. These herbivorous mammals may be sources of M. ulcerans for exposed populations but are unlikely to be reservoirs for the pathogen

SHELL-VIAL ASSAY IN DIAGNOSIS OF DISSEMINATED BCG INFECTION IN AN IMMUNODEFICIENT CHILD

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Homogeneous Finite Time Higher Order Sliding Mode Control Applied to an Upper Limb Exoskeleton Robot

International audienceA homogeneous continuous sliding mode control scheme based on finite time stability is developed in this paper for an upper limb exoskeleton robot dedicated for rehabilitation. Indeed this type of robot interacts directly with human limbs whose dynamics are unknown and different for users. Therefore, the main idea is to provide a robust motion control of the exoskeleton robot using a continuous higher order sliding mode controller despite parameters variations, uncertainties and external disturbances. The proposed controller combines the homogeneity concept and the super-twisting algorithm. Finite time stabilization is achieved using the first part of the controller while disturbance rejection is granted by the second part of the controller. Performance of the controller and its robustness are illustrated through simulations of trajectory tracking tests corresponding to passive rehabilitation exercises

Translocation of Mycobacterium tuberculosis after experimental ingestion

International audienceHuman tuberculosis is a life-threatening infection following the inhalation of Mycobacterium tuberculosis, while the closely related bacteria Mycobacterium bovis and Mycobacterium canettii are thought to be transmitted by ingestion. To explore whether M. tuberculosis could also infect individuals by ingestion, male BALBc mice were fed 2 x 10 6 CFUs of M. tuberculosis Beijing or phosphate-buffered saline as a negative control, over a 28-day experiment. While eight negative control mice remained disease-free, M. tuberculosis was identified in the lymph nodes and lungs of 8/14 mice and in the spleens of 4/14 mice by microscopy, PCR-based detection and culture. Whole-genome sequencing confirmed the identity of the inoculum and the tissue isolates. In these genetically identical mice, the dissemination of M. tuberculosis correlated with the results of the culture detection of four intestinal bacteria. These observations indicate that ingested M. tuberculosis mycobacteria can translocate, notably provoking lymphatic tuberculosis