RESUMEN
Abstract In Argentina there are no reports on Aspergillus fumigatus fumagillin-producingstrains. In this study we describe the isolation and mycotoxin production capacity of ten A.fumigatus strains isolated from farm and clinical samples. Farm strains were isolated frommilk samples taken from dairy cows in Córdoba province, some of which were associated withsubclinical mastitis. A culture medium was defined to optimize fumagillin production and adetection method was developed by HPLC chromatography. It is known that in addition to thehost immune status, strain virulence is a fundamental characteristic that will determine itspathogenicity and, in this sense, fumagillin is considered to be among the virulence factors. Inthe present work, all the strains tested for the production of fumagillin were able to synthesizeit, highlighting that the strain A. fumigatus RC2243, from a milk sample from a cow with clinicalmastitis, was the most productive. The existence of fumagillin-producing strains represents apotential risk of mycotoxins being transferred to raw milk, constituting a public health risk.
Resumen En Argentina no existen reportes sobre cepas de Aspergillus fumigatus productoras de fumagilina. En este trabajo se describe el aislamiento y la producción de dicha micotoxina clínicaspor 10 cepas, provenientes del medioambiente rural y aisladas de muestras clínicas. Las cepasde origen rural fueron aisladas de vacas lecheras en tambos de la provincia de Córdoba, yalgunas de esas cepas se asociaron a casos de mastitis subclínica. Se definió la composición deun medio de cultivo para optimizar la producción de fumagilina y se desarrolló un método decromatografía HPLC para su determinación. Es conocido que, además del estado inmunitario delhuésped, la virulencia de la cepa es una de las características fundamentales que determinansu potencial patogénico y, en este sentido, la fumagilina es considerada un factor de virulencia. En el presente trabajo todas las cepas estudiadas fueron capaces de sintetizarla y la cepa A.fumigatus RC2243, proveniente de leche de una vaca con mastitis subclínica, se destacó comola cepa más productora. La existencia de cepas productoras de fumagillina representa un riesgopotencial por el pasaje de dicha micotoxina a la leche, lo cual constituye un problema para lasalud pública.
RESUMEN
Objective To study dectin-1 mRNA expression in lung of different immune status mice infected with Aspergillusfumigatus, and to explore the influence of immunosuppressive agent on the expression of dectin-1 and its relationship with the progression of disease. Methods Mice were divided into four groups which were normal control, immuncompromised, immuncompromised with A.fumigatus inoculation and immuncompetent with A.fumigatus inoculation groups. We explored the kinetic mRNA expression of dectin-1 in lung of different groups by real-time quantitative PCR. Pulmonary fungal burden assessment was performed to reflect the progressing of disease during the experimental time course. Results On day 3 after inoculation, pulmonary fungal burden of the immuncompromised mice was higher than that of the immuncompetent group. On day 1 and 3, dectin-I mRNA expression in lung of the immuncompromised group was much lower than that of the normal control. On day 3, dectin-1 mRNA expression in lung of the immuncompetent mice infected with A.fumigatus was much higher than that of the immuncompromised with A.fumigatus inoculation and the normal control groups ( P < 0.05 ). Conclusion During the infection, expression of dectin-1 in lung of the immuncompetent group was strikingly increased, which may play an important role on the defence to A.fumigatus invasion. Cyclophosphamide inhibited the expression of dectin-1 in lung of mice which may be one of the mechanisms of the invasive pulmonary aspergillosis development induced by eyclophosphamide.