Aspergillus fumigatus in Poultry

Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood

Multiple-locus variable-number tandem repeat analysis for molecular typing of Aspergillus fumigatus

<p>Abstract</p> <p>Background</p> <p>Multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) is a prominent subtyping method to resolve closely related microbial isolates to provide information for establishing genetic patterns among isolates and to investigate disease outbreaks. The usefulness of MLVA was recently demonstrated for the avian major pathogen <it>Chlamydophila psittaci</it>. In the present study, we developed a similar method for another pathogen of birds: the filamentous fungus <it>Aspergillus fumigatus</it>.</p> <p>Results</p> <p>We selected 10 VNTR markers located on 4 different chromosomes (1, 5, 6 and 8) of <it>A. fumigatus</it>. These markers were tested with 57 unrelated isolates from different hosts or their environment (53 isolates from avian species in France, China or Morocco, 3 isolates from humans collected at CHU Henri Mondor hospital in France and the reference strain CBS 144.89). The Simpson index for individual markers ranged from 0.5771 to 0.8530. A combined loci index calculated with all the markers yielded an index of 0.9994. In a second step, the panel of 10 markers was used in different epidemiological situations and tested on 277 isolates, including 62 isolates from birds in Guangxi province in China, 95 isolates collected in two duck farms in France and 120 environmental isolates from a turkey hatchery in France. A database was created with the results of the present study <url>http://minisatellites.u-psud.fr/MLVAnet/</url>. Three major clusters of isolates were defined by using the graphing algorithm termed Minimum Spanning Tree (MST). The first cluster comprised most of the avian isolates collected in the two duck farms in France, the second cluster comprised most of the avian isolates collected in poultry farms in China and the third one comprised most of the isolates collected in the turkey hatchery in France.</p> <p>Conclusions</p> <p>MLVA displayed excellent discriminatory power. The method showed a good reproducibility. MST analysis revealed an interesting clustering with a clear separation between isolates according to their geographic origin rather than their respective hosts.</p

Nodular Worm Infection in Wild Chimpanzees in Western Uganda: A Risk for Human Health?

This study focused on Oeosophagostomum sp., and more especially on O. bifurcum, as a parasite that can be lethal to humans and is widespread among humans and monkeys in endemic regions, but has not yet been documented in apes. Its epidemiology and the role played by non-human primates in its transmission are still poorly understood. O. stephanostomum was the only species diagnosed so far in chimpanzees. Until recently, O. bifurcum was assumed to have a high zoonotic potential, but recent findings tend to demonstrate that O. bifurcum of non-human primates and humans might be genetically distinct. As the closest relative to human beings, and a species living in spatial proximity to humans in the field site studied, Pan troglodytes is thus an interesting host to investigate. Recently, a role for chimpanzees in the emergence of HIV and malaria in humans has been documented. In the framework of our long-term health monitoring of wild chimpanzees from Kibale National Park in Western Uganda, we analysed 311 samples of faeces. Coproscopy revealed that high-ranking males are more infected than other individuals. These chimpanzees are also the more frequent crop-raiders. Results from PCR assays conducted on larvae and dried faeces also revealed that O. stephanostomum as well as O. bifurcum are infecting chimpanzees, both species co-existing in the same individuals. Because contacts between humans and great apes are increasing with ecotourism and forest fragmentation in areas of high population density, this paper emphasizes that the presence of potential zoonotic parasites should be viewed as a major concern for public health. Investigations of the parasite status of people living around the park or working inside as well as sympatric non-human primates should be planned, and further research might reveal this as a promising aspect of efforts to reinforce measures against crop-raiding

Évaluation de l'aérocontamination fongique dans les environnements intérieurs

Le contrôle de l aérocontamination fongique est devenu un objectif majeur pour préserver la santé humaine et animale. L évaluation de l aérocontamination fongique fait classiquement appel aux techniques de mise en culture ou de dosage de composants fongiques présents dans l air. Ces techniques présentent des inconvénients. C est la raison pour laquelle, nous nous sommes fixés comme objectif de mettre au point des méthodes d analyse alternatives utilisant des outils de biologie moléculaire. Dans un premier temps, nous avons comparé plusieurs techniques de prélèvements d air dans des environnements intérieurs présentant une contamination plus ou moins élevée. Nous avons, par la suite, optimisé les conditions d extraction de l ADN fongique à partir de prélèvements d air. L ADN extrait a été amplifié par PCR semi-nichée avec des amorces universelles permettant d amplifier une partie de l ARNr 18S de champignons. Par la suite, nous avons utilisé la TTGE (Temporal Temperature Gradient Electrophoresis) et la D-HPLC (Denaturing High Performance Liquid Chromatography) pour séparer les amplificats. Chaque produit de PCR a été identifié par séquençage direct après purification. La comparaison des espèces identifiées par ces techniques avec celles qui sont obtenues par la méthode classique (culture) apporte de meilleurs renseignements sur la qualité fongique d un même prélèvement d air. L application de ces techniques dans des environnements à différents niveaux de contamination a permis de déduire que l étude de l évaluation de l aérocontamination fongique se fait par l association de la culture et des méthodes moléculairesFungal spores represent a significant part of the biological contaminants that could be detected in air. Exposure to fungi has been associated with several types of human or animal health problems (mycosis, allergy, mycotoxicosis). To evaluate the relationship between airborne fungi potential and adverse health effect, the fungal types and their relative frequencies in air need to be investigated. Traditional methods for fungal identification (culture and microscopy analysis) are laborious, time-consuming and require expertise. To replace cultivation, several techniques have been proposed. This study showed that molecular techniques (PCR-TTGE or Temporal Temperature Gradient Electrophoresis and PCR-DHPLC or Denaturing High Performance Liquid Chromatography) allowed the separation of amplificons corresponding to distinct fungal species that may be encountered in air. Both methods were proved to be appropriate for analysis of complex fungal communities. The detection and the molecular identification techniques were adapted for the evaluation of indoor airborne fungal contamination. The cultivation method and culture-independent techniques were further compared for the analysis of fungal aerosols from different sitesPARIS-EST-Université (770839901) / SudocSudocFranceF

Fitness Cost of Litomosoides sigmodontis Filarial Infection in Mite Vectors; Implications of Infected Haematophagous Arthropod Excretory Products in Host-Vector Interactions

Filariae are a leading cause of infections which are responsible for serious dermatological, ocular, and vascular lesions. Infective third stage larvae (L3) are transmitted through the bite of a haematophagous vector. Litomosoides sigmodontis is a well-established model of filariasis in the mouse, with the vector being the mite Ornithonyssus bacoti. The aim of the study was to analyse the filarial infection in mites to determine the consequences of filarial infection in the blood-feeding and the reproduction of mites as well as in the regulation of vector-induced inflammation in the mouse skin. Firstly, L3 are unevenly distributed throughout the host population and the majority of the population harbours a moderate infection (1 to 6 L3). Filarial infection does not significantly affect the probing delay for blood feeding. The number of released protonymphs is lower in infected mites but is not correlated with the L3 burden. Finally, induced excreted proteins from infected mites but not from uninfected mites stimulate TNF-α and the neutrophil-chemoattractant KC production by antigen-presenting cells (APCs). Altogether, these results describe the modification of the mite behavior under filarial infection and suggest that the immunomodulatory capacity of the mite may be modified by the presence of the parasite, hindering its defensive ability towards the vertebrate host

Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung

Filarial infections are tropical diseases caused by nematodes of the Onchocercidae family such as Mansonella perstans. The infective larvae (L3) are transmitted into the skin of vertebrate hosts by blood-feeding vectors. Many filarial species settle in the serous cavities including M. perstans in humans and L. sigmodontis, a well-established model of filariasis in mice. L. sigmodontis L3 migrate to the pleural cavity where they moult into L4 around day 9 and into male and female adult worms around day 30. Little is known of the early phase of the parasite life cycle, after the L3 is inoculated in the dermis by the vector and enters the afferent lymphatic vessels and before the moulting processes in the pleural cavity. Here we reveal a pulmonary phase associated with lung damage characterized by haemorrhages and granulomas suggesting L3 reach the lung via pulmonary capillaries and damage the endothelium and parenchyma by crossing them to enter the pleural cavity. This study also provides evidence for a transient inflammation in the lung characterized by a very early recruitment of neutrophils associated with high expression levels of S100A8 and S100A9 proteins

Hemorrhages in the lung of infected mice.

<p>BALB/c mice were inoculated with 40 L3 of <i>L</i>. <i>sigmodontis</i> either subcutaneously (SC) or intravenously (IV). Representative picture of (A) a normal lung, (B) a lung with superficial numerous roundish well-delineated red hemorrhages. (C) Number of superficial pulmonary hemorrhages in lungs at six hours (h6), four days (d4) and eight days (d8) post inoculation. n = 6, bars represent the mean ± SEM; two-way ANOVA followed by Bonferonni, *** = <i>p</i><0.001 (difference between IV- and SC-infected mice), ^## = <i>p</i><0.01(difference between timepoints in IV-infected mice). (D) Correlation test (Pearson) between the number of L3 recovered in the lung and the number of hemorrhages, r² = 0.9148.</p

Transient early increase of S100A9 in bronchoalveolar and pleural fluids and of s100a8 / s100a9 transcripts in lungs.

<p>BALB/c mice were inoculated with 40 L3 <i>L</i>. <i>sigmodontis</i> either subcutaneously (SC) or intravenously (IV). Two hours (h2), six hours (h6), four days (d4) and 8 days (d8) post inoculation, mice were sacrificed. Bronchoalveolar and pleural lavages were performed then lungs were isolated and frozen. (A—D) Bronchoalveolar fluid (BAL) (A & B, respectively SC and IV infected mice; n = 6) and pleural fluid (PL) (C & D, respectively SC and IV infected mice; n = 10–12, pool of 3 independent experiments) were tested for S100A9 by ELISA. The results are expressed as mean ± SEM. One way ANOVA followed by a Bonferonni, ** = <i>p</i><0.01, * = <i>p</i><0.05 (difference between infected and naïve mice). nt: not tested. (E-F) A q-RTPCR was performed for (E) s100a8 and (F) s100a9 transcripts. Normalization was made with β-actin housekeeping gene by 2^-ΔΔCT method, n = 5–6 (pool of 3 independent experiments). The results are expressed as fold-change mean ± SEM; a two-way ANOVA followed by a Bonferonni was performed, *p<0.05 difference between IV-and SC- infected mice, ^##p<0.01, ^###p<0.001 difference between timepoints.</p