Fungi of the genus Fusarium are important pathogens of numerous crops including cereals. Infection of the grain with Fusarium spp. often results in the accumulation of various mycotoxins which poses a significant risk to food safety. The Fusarium graminearum species complex, together with F. culmorum, are the main source of trichothecenes in cereal grains. They are comprised of fungal strains producing one of three specific trichothecenes: either 3ADON (3-acetyldeoxynivalenol), 15ADON (15-acetyldeoxynivalenol) (not present in F. culmorum) or NIV (nivalenol). Recently, qualitative PCR approaches have been developed for rapid determination of 3ADON, 15ADON and NIV genotypes within F. graminearum/F. culmorum. This paper presents the development of three TaqMan genotyping assays for quantitative diagnostics of 3ADON, 15ADON and NIV genotypes within F. graminearum/F. culmorum. Primers and probes were designed on the basis of 95 nucleotide site within the Tri12 gene which allowed for specific determination of trichothecene producers. Additionally, to address the problem of detecting inhibitors, an internal positive control (IPC) was developed employing primers and a probe derived from conserved fungal sequence of 5.8S rDNA. The assays developed were successfully applied for direct determination of trichothecene genotypes from Fusarium-damaged wheat kernels (FDK).
Authors:Á. Hornyák, T. Bakonyi, Mónika Kulik, S. Kecskeméti, and M. Rusvai
The occurrence of two important pathogens, equine herpesvirus 1 (EHV1) and equine arteritis virus (EAV) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (PCR) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in Hungary. We found 26 EHV1- and 4 EAV-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccination, EHV1 is a far more important cause of abortions in the studs than EAV. We compared the virus content of different organs of the fetuses by PCR and isolation to identify the organ most suitable for virus demonstration. Our investigations indicate that the quantity of both viruses is highest in the lungs; therefore, according to our observations, in positive cases the probability of detection is highest from lung samples of aborted or newborn foals. Both the PCR and the virus isolation results revealed that the liver, though widely used, is not the best organ to sample either for EHV1 or for EAV detection. From the analysis of the epidemiological data, we tried to estimate the importance of the two viruses in the Hungarian horse population.