Introduction: Colibacillosis – the most common disease of poultry, is caused mainly by avian pathogenic Escherichia coli (APEC). However, thus far, no pattern to the molecular basis of the pathogenicity of these bacteria has been established beyond dispute. In this study, genomes of APEC were investigated to ascribe importance and explore the distribution of 16 genes recognised as their virulence factors. Material and Methods: A total of 14 pathogenic for poultry E. coli strains were isolated, and their DNA was sequenced, assembled de novo, and annotated. Amino acid sequences from these bacteria and an additional 16 freely available APEC amino acid sequences were analysed with the DIFFIND tool to define their virulence factors. Results: The DIFFIND tool enabled quick, reliable, and convenient assessment of the differences between compared amino acid sequences from bacterial genomes. The presence of 16 protein sequences indicated as pathogenicity factors in poultry resulted in the generation of a heatmap which categorises genomes in terms of the existence and similarity of the analysed protein sequences. Conclusion: The proposed method of detection of virulence factors using the capabilities of the DIFFIND tool may be useful in the analysis of similarities of E. coli and other sequences deriving from bacteria. Phylogenetic analysis resulted in reliable segregation of 30 APEC strains into five main clusters containing various virulence associated genes (VAGs).

Brucellosis in goats is mainly caused by the bacterium Brucellamelitensis, which is one of the most important pathogenic species in the world. In Malaysia, the annual prevalence data of brucellosis was recorded in goats and the control strategy of the disease basedon test and cull of infected animals. This strategy has caused huge economic losses to farmers and government alike. Therefore, whole genome sequencing of B. melitensis local strain is essential forimproving the current vaccine. B. melitensis strain VRI 6530/11 wasobtained from veterinary research institute biobank, Ipoh. The strain was submitted for classical identification procedures and the total genomic DNA was extracted by using DNeasy blood and tissue kit(QIAGEN). The concentration and purity of DNA were determined by using agarose gel electrophoresis and spectrophotometer (DNA/RNA) assay respectively. The genome was sequenced by using IlluminaHiSeq platform with insert size ~200 bp. A total of 1.0 Gb data was generated from the sample. More than 95% of sequencing data was retained in the sample after quality filtering, this indicatethe sequencing reads are of high quality. Final assembly had 33 scaffolds with total size ~3.28 Mb, 44 contigs, GC content is 57.25%, N50 is 293,291. A total of 3,238 protein coding genes, 48 tRNAs and 3rRNAs were predicted and over 87% of the genes were functionally annotated. Genome sequencing of a local B. melitensis strain is the first of its kind in Malaysia and work from this study can contribute towards the development of a new effective vaccine for the control ofthe disease in the country.

The molecular genetic characterization of Aujeszky's disease virus (ADV) Yangsan strain (ADV-YS), a Korean isolate, was investigated by analyzing the electrophoresis patterns and the physical maps of the viral DNA digested with various endonucleases. To establish DNA library for ADV-YS, twelve major BamHI restricted segments were cloned. Each location of the segments in the ADV genome was determined by sequence comparison with the sequences reported in Genbank and those sequences of the both termini of the segments. Physical maps were constructed based on the electrophoresis patterns of the digested viral DNA by restriction endonuclease and the results of Southern blot analyses with various DIG labeled probes originated from those of enzyme restricted segments of virulent (Shope) and avirulent (Bartha) strain. Comparing ADV-YS with a standard strainof Kaplan in the maps of restriction enzymes, following major respects were identified: (ⅰ) disappearance of BamHI restriction site between the first and second BamHI segments, (ⅱ) creation of the BamHI restriction site in the fifth segment, and (ⅲ) generation of the BglⅡ site in the unique short (Us) regions. The genome of ADV-YS also contains a type 2 herpesvirus DNA molecule (in which the Us region only inverts itself relative to the unique longregion) like all other ADV strains except Norden strain(type3), analyzed up to date. The size of the ADV genome estimated from the sizes of the restriction enzyme fragments, was approximately 145.3kb (BamHI) or 145.3kb (BglⅡ) 145.4kb (BglⅡ). BamHI enzyme cleavage pattern were compared among the five Korean ADV isolates: Yangsan, Yongin, Dangjin, Jincheon and Iksan strains. Difference either in the number or in the size of the DNA fragments, suspected regions of termini of IR and TR, could be detected among all five strains.

For detecting Borna disease virus (BDV) genomic stranded RNA, single-tube reverse transcription-polymerase chain reaction (St RT-PCR) was developed to equal the sensitivity of RT-nested PCR but with reduced risk of contamination. BDV-genomic stranded RNA was synthesized in vitro using plasmid cDNA of BDV p24 region as a template and RNA was also extracted from BDV-persistently infected MDCK (MDCK/BDV) cells. Both RNAs were amplified by St RT-PCR in which a single round of RT and a single round of PCR were performed in the same tube. Ten copies of synthesized RNA could be amplified by St RT-PCR, indicating that St RT-PCR method is as sensitive as the ordinary RT-nested PCR method. Furthermore, this method was applied to quantify the exact copy number of genomic RNA in MDCK/BDV cells. Signals were obtained from the samples containing more than 1 pg total cellular RNA. From the results, approximately 100 copies of BDV genomic RNA exist in one MDCK/BDV cell. BDV genomic RNA from the in vivo RNA samples using St RT-PCR, indicating this method is applicable for the epidemiological study of BDV without contamination

Analysis of influence of boar genotype by MUC4 gene on viability of progeny was realized in the conditions in the Republic of Belarus, as well as the evaluation of possibilities of association of polymorphic variants of gene with fattening and meaty qualities of obtained from the boars progeny were conducted. In course of studies there was analyzed the polymorphism of MUC4 gene at producer boars of studied breeds. There was revealed high occurring frequency of desirable allele MUC4**c and MUC4**cc genotype in all studied populations. Boars of Belarusian Meaty breed with genotypes MUC4**cc by MUC4 gene authentically (P less than 0,01) exceeded boars with genotype MUC4**cg according to piglet viability indexes at weaning period on 5,6%. For the further evaluation of the potential role of MUC4gene in marker selection there was realized determination of relations between genotypes of studied marker and other economic traits of swine (fattening and meaty traits of boar progeny). There was stated the authentic increasing of fattening and meaty traits of stores obtained from boars with homozygous genotype MUC4**cc in comparison with progeny fathers of which in their genotype had mutant allel MUC4**g. For the forecasting and modeling of genotypes resistant to colibacillosis there was presented a scheme of selection boars and sows of different genotypes by MUC4 gene for the increasing of progeny viability. According to the scheme the preferred selection was MUC4**cc x MUC4**cc. This selection was recommended for the self-replacement and creation of nuclear stock