Biomedical subjects
Publications and source records attributed to N Nolard.
Twenty-six patients were implicated in a nosocomial pseudo-outbreak of Fusarium verticillioides. Examination of clinical records and handling procedures revealed a fungal contamination of supposedly sterile containers used for biological materials. An accurate system of monitoring permitted us to determine the origin of the infection and the means of its spread.
Fusarium spp. have emerged as major opportunistic fungal agents. Since new antifungal agents exhibit variable activity against Fusarium isolates depending on the species, rapid identification at the species level is required. Conventional culture methods are difficult, fastidious, and sometimes inconclusive. In this work, we sequenced a 440-bp fragment encoding the 28S rRNA from 33 Fusarium isolates belonging to six Fusarium species associated with human infections. The data were then analyzed by the neighbor-joining method. By using distance matrix analysis and constructing the phylogram, we could easily distinguish the different species for all but one isolate. The method also allowed differentiation between the closely related genera Acremonium and Cylindrocarpon. In contrast to the case with conventional methods, the results could be obtained within 48 h from a 3-day culture and are independent of mycologist experience, making this method rapid and reliable for identification of Fusarium species isolated from patients.
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A PCR typing method has been developed and tested to investigate the polymorphism of clinical strains of Aspergillus fumigatus. Firstly, the DNA fragments from random amplified polymorphic DNA (RAPD) patterns of nine epidemiologically and geographically non-related monosporal strains of A. fumigatus were cloned and sequenced. The pairs of five sequence-specific DNA primers (SSDP), characteristic of the 5' and 3' extremities of the RAPD products, were then used in high stringency PCR to type 43 clinical strains of A. fumigatus from 13 patients, according to the presence or absence of a single amplified band. This original approach, which uses the advantages of PCR, has made it possible to overcome the difficulties resulting from the low stringency amplification. The SSDP analysis of 51 A. fumigatus strains (9 unrelated monosporal strains and 43 clinical strains from 13 patients) can be classed into 22 different types with a high reproducibility and a high level of discrimination (D = 0.96). The results suggest that seven lung transplant patients with necrotizing aspergillosis, bronchitis aspergillosis and bronchial colonization were infected by multiple strain genotypes, whereas three patients with invasive aspergillosis seem to have been infected by a single strain.
The genotypes of 63 isolates of Aspergillus fumigatus obtained from three hospitals in different geographical areas and of eight culture collection strains were determined by multilocus enzyme electrophoresis. Twelve of the 17 enzymatic loci studied were polymorphic, giving rise to 48 different electrophoretic types. The existence of fixed multilocus genotypes, significant heterozygote deficits and excesses at the different loci, and linkage disequilibria within subpopulations strongly suggests a clonal reproduction mode for A. fumigatus. Numerical analysis of the comparison and disposition of the different electrophoretic types demonstrates a significant genetic differentiation between the three sampling sites. However, no correlation could be found between geographical distances and genetic differentiation. On account of the multiple discriminatory markers, multilocus enzyme electrophoresis typing seems to be a very powerful tool for epidemiological and reproductive mode studies of A. fumigatus.
The growing incidence of nosocomial invasive aspergillosis is related with the development of new therapies and the presence of Aspergillus spores in the patients'vicinity. Earth moving, demolition or renovation works adjacent to or inside the hospital are undoubtfully implied in this process. Potted plants and individual sachets of ground pepper distributed to patients are another significant source of Aspergillus spores. The extrinsic and multiple causes of hospital contamination may explain the numerous problems in our studies of strain typing, whatever the methods used (phenotype and genotype).
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Invasive aspergillosis is often nosocomially acquired and carries a high mortality. Molecular typing methods to discriminate isolates have now been developed. Using simple restriction endonuclease (Sal1 and Xho1) digestion of total genomic DNA, we have typed 25 epidemiologically-related isolates of A. fumigatus from six hospital episodes of invasive aspergillosis. Eight DNA types were found and in each case the DNA type matched precisely the epidemiological data. Thus DNA typing of A. fumigatus can provide the means to match isolates from linked sources and distinguish isolates from diverse origins.
An increasing number of nosocomial invasive aspergilloses is related with the development of new therapies and to Aspergillus spores in the vicinity of the patient. The infiltration of thermophilic fungal spores in the patients' environment is linked not only with contaminated air systems but also to different other factors among which earth moving, demolition or renovation works adjacent to or inside the hospital. Potted plants and individual sachets of ground pepper distributed to patients are another source of Aspergillus spores. To limit fungal exposure, patients undergoing bone marrow transplant should be isolated under laminar flow while simple procedures such as taping windows and doors, shutting down air systems and mycological environmental control measures should be encouraged to protect immunocompromised patients.
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The acaricidal and fungicidal activities of a new acaricide Allerbiocid, formulated for the control of house dust mites, were investigated. The components of the Allerbiocid formula are: 3% benzyl benzoate (acaricidal and fungicidal), 1% tannic acid (protein denaturant) and 0.5% Tween (surface active agent) in 70% isopropyl alcohol (antiseptic). At application rates of both 150 and 250 ml/m2, the acaricidal activity appeared to work by both ingestion and contact and remained active upon contact with mites for up to 10 weeks. When Sabouraud agar was treated with Allerbiocid at a concentration of 5 ml/20 ml medium, the preparation was also found to have fungicidal and fungistatic activities on various species of fungi commonly found in house dust. Allerbiocid contains tannic acid which is a protein denaturant. Levels of Der p I in dust were found to be reduced by over 90% after treatment with Allerbiocid. The importance of denaturation of mite faecal allergens and allergens associated with dead fungal spores is discussed.
We report the case of a young man who developed severe asthma a few months after starting work in a factory producing a single type of mushroom: Pleurotus cornucopiae (a basidiomycete). Immunological investigations, performed with material recovered from the filtering devices of the mushroom's bed, led to demonstration of specific IgE and IgG against spore extracts and to isolation of one discriminant antigen (molecular weight: 10.5 kd). Current data concerning the underestimated role of the basidiomycetes in allergic asthma are reviewed.
Somatic extracts from dermatophytes of the Trichophyton mentagrophytes complex and of Trichophyton interdigitale grown on trypticase soy broth were prepared for analytical isoelectric focusing in thin layer polyacrylamide gels over the pH range 4-6.5. A total of 44 strains were studied: 8 Arthroderma benhamiae (4 Americano-European and 4 African races), 4 Arthroderma vanbreuseghemii, 6 Trichophyton mentagrophytes and 26 Trichophyton interdigitale. Laser densitometric analysis revealed two outstanding clusters of profiles. The first one matched with the Arthroderma vanbreuseghemii profile and gathered all the Trichophyton interdigitale strains studied and 4 Trichophyton mentagrophytes. The second one corresponded to the Arthroderma benhamiae profile and gathered 2 Trichophyton mentagrophytes. This isoelectric focusing analysis suggests on one hand that Trichophyton interdigitale might be the anamorph species corresponding to the teleomorph Arthroderma vanbreuseghemii, and on the other hand that Trichophyton mentagrophytes might correspond to two teleomorph species, either Arthroderma vanbreuseghemii or Arthroderma benhamiae.
In this paper we present the results of volumetric sampling of the airborne pollen grains of the Oleaceae family (Fraxinus, Ligustrum and Olea) in some European towns, in the period from 1982 to 1986. The sampling and appraisal of pollen content in the air is of particular interest to clinicians and allergic patients in order to assess exposure to the various pollen types in relation to allergy. In the Oleaceae family, the most allergenic pollen is produced by Olea europaea, the olive tree, which in the Mediterranean area has a pollination period lasting from May to the end of June and sometimes causes severe symptoms of pollinosis. In Northern and Central Europe, where there are no olive trees, there are two other commonly occurring genera of the Oleaceae family, namely Fraxinus and Ligustrum, but these have a low frequency of allergic sensitization.
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Explore the source record for details and available documents.