Four years of African swine fever in Poland. New insights into epidemiology and prognosis of future disease spread.

Four and a half years of African Swine Fever (ASF) in population of free-ranging wild boars and domestic pigs revealed a number of novel insights into the disease epidemiology. Until No- vember 20th, 2018, in total 3048 cases in wild boars and 213 outbreaks in domestic pigs have been confirmed. In spite of low contagiosity as well as low rate of ASF spread in wild boars the disease has an enormous socio-economical impact on the production of pigs in Poland. One of the most important aspects which directly influences the dynamics of ASF spread is the unpredictable hu- man activity. Another important factor responsible for continuous ASF spread is fast recovery of wild boar population in spite of efforts taken by hunters. Assuming our scientific opinion ASF seems to be present in wildlife for the incoming few or several years. Therefore, extraordinary measures should be prepared and undertaken to limit the risk of the occurrence of future out- breaks in domestic pigs. One of the most crucial issues is implementation of strict biosecurity measures in all domestic pigs holdings.

Molecular analysis of a fragment of gene E1B 19K of canine adenovirus 2 (CAV-2) isolated from dogs with symptoms of cough.

The aim of this study was to perform molecular analysis of canine adenovirus 2 (CAV-2) E1B 19K gene fragment isolated from 20 dogs of various breeds (12 males and 8 females aged 1-9 years), with clinical symptoms of upper respiratory tract infections, from the Lubelszczyzna region. Nasal swabs were taken from dogs. DNA of CAV-2 was detected using the PCR method in 16 swabs. All PCR products were sequenced, and the obtained sequences were compared with each other and with the sequence of the E1B 19K gene of the CAV-2 strain from an online database of NCBI GenBank: AC 000003. Based on analysis of the obtained sequences, three polymorphic variants of CAV-2 (No. 1-3) with homology of 78 - 100% were distinguished. The nucleotide and amino acid sequences of the most frequently represented polymorphic variant, No. 1, differed from the sequences of polymorphic variant No. 2 with one substitution. The nucleotide and amino acid sequence of the E1B 19K gene of CAV-2 AC 000003 differed from the analogous sequences of representatives of variant No. 1 with 44 nucleotide and 19 amino acid substitutions. The small number of nucleotide differences in the E1B 19K CAV-2 gene among the examined own isolates, compared with AC 000003, suggest that the infections in dogs were caused by a relatively genetically stable virus which occurs in eastern

The suitability of selected methods of nucleic acid extraction for detecting Rhodococcus equi DNA in tracheobronchial wash fluid using PCR.

The aim of the present study was to compare the effectiveness of selected DNA extraction methods for the detection of Rhodococcus equi from tracheobronchial wash fluid by PCR. Three methods of nucleic acid extraction were evaluated, based mainly on the activity of proteolytic enzymes. A commercial kit for isolation and purification of bacterial DNA was also used in the study. In one procedure, an additional component, the cationic detergent CTAB, was used. It has been found that the traditional enzyme digestion methods used with the tracheobronchial wash fluid are more suitable to prepare DNA matrix for PCR comparing with commercial DNA isolation kit. Minimum numbers of bacteria detected with the use of traditional enzyme digestion methods and commercial kit were 100 and 500 cells, respectively. Based on the results of the study we can recommend the enzymatic digestion method along with CTAB as an additional component.

Molecular analysis of the nucleoprotein gene of canine distemper virus isolated from clinical cases of the disease in foxes, minks and dogs.

In this study, we used RT-PCR to detect and characterize canine distemper virus isolated from 9 naturally infected foxes, 3 minks and 3 dogs in Poland by amplifying and sequencing a portion of the NP gene. A 293-bp fragment of the CDV NP gene was amplified by RT-PCR. Sequencing of the PCR products from the isolates led to the identification of 3 sequence variants. The mostly representative polymorphic variant No. 1 showed high homology with Chinese isolate of CDV with a accession number EF 375619. The sequences of all isolates from this polymorphic variants compared with the sequences of other polymorphic variants obtained in the study and with European and American isolates sequences from GenBank showed the conservative nucleotides changes in positions 57, 132, 143, 159 and 237. These mutations can indicate that in this part of Europe there are new variants of CDV.