Тhe use of membrane filters in detection of the ASF virus DNA in the feed compound by RT-PCR

For African swine fever (ASF) virus an alimentary transmission way is known to be characteristic. In particular, the infection occurs because of use of the contaminated domestic and slaughtering wastes or the feed compounds originated from epizootic region which have not been duly controlled, or in case the package used for feed transportation were not treated against African swine virus. Under feed compound analysis by real-time PCR (RT-PCR), the samples must be free from large particles and chemical substances which can inhibit the polymerase reaction and influence the sorbent and membrane properties during nucleic acid isolation. We aimed to improve the feed compound processing technique by using membrane filters to prepare the samples for further RT-PCR indication of ASF virus. In the experiments, the feed was artificially contaminated by blood of a swine previously infected by the ASF virus Stavropol 2009 strain, the titer of 5.0 lg HAD 50/sm 3. Also the dilutions of 2.0, 3.0 and 4.0 HAD 50/sm 3 were tested. During processing, the crud filtration, freezing-defrostation procedure, centrifugation and separation on membrane filters (450 mm) were applied. Then the ASF virus DNA isolation and PCR-RT were conducted using the developed test-system and procedure. It was found out that the ASF virus DNA can be detected by the proposed method in the feed compound when the titer of virus used for artificially contaminated is at least 3.0 lg HAD 50/sm 3. So, the modifying procedure of fodder sample preparation described hereinabove is effective to obtain purified and concentrated material for further ASF virus DNA analysis.