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International audience; The performance of an in-house protocol for virus detection on commercialized electrostatic wipes (EWs) was assessed experimentally by impregnating them with suspensions of cytomegalovirus, adenovirus, and influenza virus, and by determining the recovery efficiency, repeatability, and detection limit of the protocol. The protocol was sensitive enough to detect 4 log10 gene copies of virus. At room temperature, influenza RNA was stable on EWs for at least four days. When EWs were placed high in 32 influenza-infected patients' rooms, influenza RNA was detectable in 75% (N = 24) of EWs, suggesting that EWs are simple and reliable methods for influenza virus airborne detection.

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International audience; BACKGROUND: Environmental surveillance is important in high-risk areas of hospitals to prevent fungal infections in immunosuppressed patients. Conventional culture methods for enumerating environmental fungi are time-consuming. AIM: In this field study, a solid-phase cytometry technique (SPC) and a more conventional culture-based method to quantify fungal contamination of hospital air and surface samples were compared. METHODS: For the air sampling, a liquid cyclone air sampler was used with a flow rate of 300 L/min for 10 min in each of four hospital locations. Surface swabbing was done in two locations, with two different swab types. Samples from all areas were processed by SPC and by culture on malt extract agar. FINDINGS: The mean airborne concentrations of viable fungi determined by SPC were about 1.5-fold higher than the mean concentrations obtained with the culture-based method. These differences for air samples were significant in three hospital environments. No significant difference was observed for surface samples between the two swab types and between the two analytical methods. One of the prominent advantages of SPC was its rapidity in comparison with the culture-based method (5 h versus 5 days). CONCLUSION: In this study, we showed that SPC allows for rapid monitoring of viable fungi in hospital environments. SPC can thus be used to provide an early warning and a rapid implementation of corrective measures. Viable fungi detection may be an important tool to assess infectious risk in wards with immunosuppressed patients.

International audience; The daily number of outdoor spores was counted and the cases of community-acquired invasive aspergillosis (IA) were observed over a period of 31 months. The outdoor fungal load preceding IA occurrences was significantly higher than that measured during IA-free periods, underlining the importance of preventive measures to protect high-risk patients, even at home.

It was previously demonstrated that microbial communities of pig manure were composed of both bacteria and archaea. Recent studies have shown that bacteria are aerosolized from pig manure, but none have ever focused on the airborne archaeal burden. We sought here to develop and apply molecular ecology approaches to thoroughly characterize airborne archaea from swine confinement buildings (SCBs). Eight swine operations were visited, twice in winter and once during summer. Institute of Occupational Medicine cassettes loaded with 25-mm gelatin filters were used to capture the inhalable microbial biomass. The total genomic DNA was extracted and used as a template for PCR amplification of the archaeal 16S rRNA gene. High concentrations of archaea were found in SCB bioaerosols, being as high as 10 8 16S rRNA gene copies per cubic meter of air. Construction and sequencing of 16S rRNA gene libraries revealed that all sequences were closely related to methanogenic archaea, such as Methanosphaera stadtmanae (94.7% of the archaeal biodiversity). Archaeal community profiles were compared by 16S rRNA gene denaturing gradient gel electrophoresis. This analysis showed similar fingerprints in each SCB and confirmed the predominance of methanogenic archaea in the bioaerosols. This study sheds new light on the nature of bioaerosols in SCBs and suggests that archaea are also aerosolized from pig manure.

We have known for 40 years that soils can consume the trace amounts of molecular hydrogen (H 2 ) found in the Earth's atmosphere. This process is predicted to be the most significant term in the global hydrogen cycle. However, the organisms and enzymes responsible for this process were only recently identified. Pure culture experiments demonstrated that several species of Actinobacteria , including streptomycetes and mycobacteria, can couple the oxidation of atmospheric H 2 to the reduction of ambient O 2 . A combination of genetic, biochemical, and phenotypic studies suggest that these organisms primarily use this fuel source to sustain electron input into the respiratory chain during energy starvation. This process is mediated by a specialized enzyme, the group 5 [NiFe]-hydrogenase, which is unusual for its high affinity, oxygen insensitivity, and thermostability. Atmospheric hydrogen scavenging is a particularly dependable mode of energy generation, given both the ubiquity of the substrate and the stress tolerance of its catalyst. This minireview summarizes the recent progress in understanding how and why certain organisms scavenge atmospheric H 2 . In addition, it provides insight into the wider significance of hydrogen scavenging in global H 2 cycling and soil microbial ecology.

The annual incidence of Q fever in French Guiana was found to have increased in 1996 and was 37/100,000 population over the last 4 years. Subsequent investigations in Cayenne and its suburbs indicated that a wild reservoir of the bacteria was responsible for the epidemiologic pattern. A case-control study showed that residence near a forest and occupations and activities that result in exposure to aerosols of dusts from the soil are risk factors for Q fever. By means of time-series analysis, a strong positive correlation between rainfall and the incidence of Q fever with a time lag of 1-3 months was found. The spatial distribution of the cases showed that transmission occurs widely throughout greater Cayenne, which is incompatible with a pinpoint source of contamination. Transmission from livestock and dissemination of the bacteria by the wind appeared to be unlikely, which strengthens the hypothesis that a wild reservoir is responsible for transmission.

International audience; The aim of this study was to ascertain incidence of symptoms compatible with Pontiac fever (PF) and to assess their association with exposure to legionella bacteria among retirement home nurses who help residents take their shower. Within a non-epidemic framework, 104 nurses of 19 retirement homes were followed up during an average period of four months. Data on symptoms, number and location of showers they attended were recorded daily by each participant. Water and aerosol bacterial quality was characterised at the end of follow-up using the culturable and the in-situ hybridisation techniques. Among 11 Pontiac-like episodes, eight cases complied with the study definition of PF. Water concentrations >10(3) cfu legionella per litre were associated with an increased risk of PF, with dose-response patterns. No association was established between the aerosol legionella concentrations and PF events. A threshold value of 103 cfu legionella per litre of water might be used with a view to protection from legionella-associated occupational conditions.

International audience; BACKGROUND: Nosocomial invasive filamentous fungi infections could result from inhalation of filamentous fungi conidia present in hospital environment. METHODS: The environmental fungal flora in 3 different hospital wards with similar air conditioning was prospectively studied during 30 months and compared to internal (presence of agranulocytosis patient, behavioral practices, activity, cleaning work) and outdoor factors (meteorologic data, outdoor fungi). The general preventive measures differed from one unit to another. RESULTS: The hematology wards with filamentous fungi preventive measures were significantly less contaminated than a conventional ward without specific measures. Internal and outdoor factors influenced the level of fungal flora. However, the influence of internal factors was greater in the conventional ward than in hematology wards. The variation of flora in the hospital environment was seasonal, and the level of this contamination in each ward was influenced by the meteorology. However, outdoor factors more readily explain the variations of fungal load in hematology than in the conventional ward. CONCLUSION: This study highlights that specific preventive measures participate significantly in the control of the filamentous fungal flora intensity due to internal factors but not those due to outdoor factors, stressing the importance of high-efficiency particulate air filtration in high-risk units.

International audience; The air we breathe is filled with thousands of fungal spores (conidia) per cubic metre, which in certain composting environments can easily exceed 10(9) per cubic metre. They originate from more than a hundred fungal species belonging mainly to the genera Cladosporium, Penicillium, Alternaria and Aspergillus. Although these conidia contain many antigens and allergens, it is not known why airborne fungal microflora do not activate the host innate immune cells continuously and do not induce detrimental inflammatory responses following their inhalation. Here we show that the surface layer on the dormant conidia masks their recognition by the immune system and hence prevents immune response. To explore this, we used several fungal members of the airborne microflora, including the human opportunistic fungal pathogen Aspergillus fumigatus, in in vitro assays with dendritic cells and alveolar macrophages and in in vivo murine experiments. In A. fumigatus, this surface 'rodlet layer' is composed of hydrophobic RodA protein covalently bound to the conidial cell wall through glycosylphosphatidylinositol-remnants. RodA extracted from conidia of A. fumigatus was immunologically inert and did not induce dendritic cell or alveolar macrophage maturation and activation, and failed to activate helper T-cell immune responses in vivo. The removal of this surface 'rodlet/hydrophobin layer' either chemically (using hydrofluoric acid), genetically (DeltarodA mutant) or biologically (germination) resulted in conidial morphotypes inducing immune activation. All these observations show that the hydrophobic rodlet layer on the conidial cell surface immunologically silences airborne moulds.

From Satellites to Microsatellites. European Multicolloquium of Parasitology No10, Paris , FRANCE (24/08/2008); International audience; Airborne transmission of Pneumocystis sp. from host to host has been demonstrated in rodent models and several observations suggest that interindividual transmission occurs in humans. Moreover, it is accepted that the Pneumocystis organisms infecting each mammalian species are host specific and that the hypothesis of an animal reservoir for Pneumocystis jirovecii (P. jirovecii), the human-specific Pneumocystis species, can be excluded. An exosaprophytic form of the fungus cannot be strictly ruled out. However, these data point toward the potential for the specific host to serve as its own reservoir and for Pneumocystis infection in humans as an anthroponosis with humans as a reservoir for P. jirovecii. This review highlights the main data on host-to-host transmission of Pneumocystis in rodent models and in humans by the airborne route and provides a rationale for considering the occurrence of nosocomial infections and measures for their prevention.

Background: Invasive aspergillosis is one of the most lethal airborne dangers for immune-suppressed subjects. Providing patient protection from such airborne threats requires costly and high-maintenance facilities. We herein evaluate a new self-contained mobile unit as an alternative for creating a patient protective environment. Methods: Airborne contamination levels were monitored for different simulated scenarios and under actual clinical conditions. Functional tests were used to challenge the unit under adverse conditions, and a preliminary clinical study with patients and staff present was performed at 2 different French hospitals. Results: Functional tests demonstrated that the unit can rapidly decontaminate air in the protected zone created by the unit and in the surrounding room. In addition, the protected zone is not sensitive to large disturbances that occur in the room. The clinical study included 4 patients with 150 accumulated days of testing. The protected zone created by the unit systematically provided an environment with undetectable airborne fungal levels (ie, ,1 CFU/m 3 ) regardless of the levels in the room or corridor (P , .01). Conclusions: These tests show that the unit can be used to create a mobile protective environment for immune-suppressed patients in a standard hospital setting. (Am J Infect Control 2007;35:460-6.) Invasive aspergillosis, notably Aspergillus fumigatus, is one of the most lethal airborne dangers for immunesuppressed subjects. Although the reported attributable mortality from invasive pulmonary aspergillosis differs depending on the patient population studied, the Centers for Disease Control and Prevention (CDC) reports rates as high as 95% in recipients of allogeneic bone marrow transplants and patients who have aplastic anemia, compared with rates of 13%-80% in leukemic patients. 1 The most important nosocomial infection caused by Aspergillus sp is pneumonia, and the primary route of acquiring Aspergillus sp infection is via inhalation of the fungal spores. In severely immunesuppressed patients, primary Aspergillus sp pneumonia results from invasion of local lung tissue

We compared the yields of 4 recently developed sieve impactor air samplers that meet international standard ISO 14698-1, using 2 growth media (tryptic soy agar and malt extract agar) in real conditions of use. Several hospital sites expected to have different densities of airborne microflora were selected in 2 hospitals. The Samplair MK2, Air Ideal, and Mas-100 samplers yielded higher bacterial counts than did the SAS Super-100 device (P

International audience; AIM: To compare the performance of various types of airflow system in operating theatre. METHODS: Besançon Hospital has three types of airflow system in operating theatre: laminar (unidirectional) flow, stabilized flow and turbulent flow. We have compared performances of these airflow systems during operations by evaluating several indicators: number of airborne particles, microbial contamination, kinetics of decontamination, rate of mixing and an index of functionality. RESULTS: At rest, performances of stabilized flow are close to these of laminar flow. On the other hand, during operations, the laminar flow is the single airflow system to reach the class B10. CONCLUSION: Our study suggest that laminar flow should be used for prosthetic orthopaedic surgery. However, clinical studies are needed to confirm the superiority of laminar airflow systems in operating theatre.

International audience; Exposure to microorganisms in farm environments may cause respiratory disorders, e.g. asthma, organic dust toxic syndrome and allergic alveolitis. By reducing microbiological deterioration of organic materials, some agricultural practices have a protective effect. Microbiological analyses were carried out on hay, silage and flour samples (n=107) from farms in Finland and France (n=23) that use different methods of haymaking. High concentrations of Absidia corymbifera were found in approximately 35 % of French hay samples and only 10 % of Finnish hay samples. Concentrations of Eurotium spp. were found in 20 % of hay samples from both regions. High concentrations of Wallemia sebi typified Finnish hay (38 %) more than French hay (8 %). Rhodotorula yeast was frequently and abundantly found in Finland, but never in France. The method used to make hay appeared to be the main factor affecting the microbiology of the hay. A. corymbifera and Eurotium spp. concentrations were smaller in low-density square bales than in others. In conclusion, our results emphasize the importance of good agricultural practice in the microbiological quality of fodder.

International audience; The purpose of this study was to assess the prevalence of Staphylococcus aureus nasal carriage of dairy sheep in farms producing cheeses manufactured with raw ewe's milk. The study showed that 29% of ewes carried S. aureus in their nares. The genetic diversity of the 136 isolates recovered from the anterior nares of the ewes, from the ambient air of the milking parlour and from cheeses was investigated using pulsed-field gel electrophoresis (PFGE) of DNA SmaI digests. The genotyping results showed that 75 out of 106 isolates recovered from nasal carriage in dairy sheep belonged to a dominant pattern (previously named OV) and a genetically related pattern (named OV'). The same profile (OV or OV') was found in the ambient air and cheeses, suggesting a continuum between isolates within these different compartments.

In order to study horizontal transmission of Mycoplasma synoviae an avian pathogen, a reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to detect viable Mycoplasma in environment. The test was based on the RT-PCR of the 16S ribosomal RNA (rRNA) of Mycoplasma genus. Results showed that Mycoplasma 16S rRNA was stable up to 23 h after cell death. Therefore, the test allowed detection of viable or very recently (less than 23 h) dead mycoplasmas. M. synoviae survival in artificially contaminated water, food and soil and in the environment of M. synoviae experimentally infected turkeys was estimated by culture and RT-PCR. The RT-PCR method was then applied in a naturally infected laying hen farm showing problems of recurrent mycoplasmosis in the hens. Results confirmed the usefulness of RT-PCR in checking the efficiency of biosecurity measures and in improving cleaning and disinfection protocols.

Studies have shown a link between living on a farm, exposure to microbial components (e.g., endotoxins or β- d -glucans), and a lower risk for allergic diseases and asthma. Due to the lack of validated sampling methods, studies of asthma and atopy have not relied on exposure assessment based on culture techniques. Our objective was therefore to compare several dust sampling methods for the detection of cultivable-microorganism exposure in stables. Sixteen French farms were sampled using four different methods: (i) active air sampling using a pump, (ii) passive dust sampling with a plastic box, (iii) dust sampling with an electrostatic dust fall collector (wipe), and (iv) dust sampling using a spatula to collect dust already settled on a windowsill. The results showed that collection of settled dust samples with either plastic boxes or wipes was reproducible (pairwise correlations, 0.72 and 0.73, respectively) and resulted in highly correlated results (pairwise correlation between the two methods, 0.82). We also found that settled dust samples collected with a plastic box correctly reflected the composition of the samples collected in the air of the stable when there was no farmer activity. A loss of microbial diversity was observed when dust was kept for 3 months at room temperature. We therefore conclude that measurement of viable microorganisms within a reasonable time frame gives an accurate representation of the microbial composition of stable air.

International audience; Agricultural occupations associated with animal breeding and the processing of animal materials in confinement systems could potentially lead to bioaerosol exposures. Moulds and mycotoxins could be constituents of bioaerosols and should be studied because of their possible involvement in respiratory diseases and cancers. In order to characterize the fungal contamination of the indoor air in a dairy barn, bioaerosols were collected during 20 days in a cattle farm located in Normandy (France). Mycobiota, mycotoxins and the mutagenicity of bioaerosols were studied. The toxigenic ability of Aspergillus flavus group and Aspergillus fumigatus isolates was also evaluated in vitro. The prevalent airborne moulds were from the following potentially toxigenic species: Aspergillus flavus group, Aspergillus fumigatus, Penicillium chrysogenum, Stachybotrys chartarum, and the allergenic species Ulocladium chartarum, Cladosporium cladosporioides. In comparison with harvesting, grain handling or broiler breeding, the concentrations of viable moulds were lower in the cattle shed. Seasonal variations in levels of several species were also observed. This study revealed that aflatoxins were detected in bioaerosols and, for the first time, showed that farmers are possibly exposed to Stachybotrys chartarum during routine barn work. Moreover, the finding of mutagenicity from bioaerosols needs further investigations on bioaerosol composition.