[Genetic diversity of Siberian bovine coronavirus isolates (Coronaviridae: Coronavirinae: Betacoronavirus-1: Bovine-Like coronaviruses)].

INTRODUCTION: Bovine coronaviruses (BCoVs) are causative agents of diarrhea, respiratory diseases in calves and winter cow dysentery. The study of genetic diversity of these viruses is topical issue. The purpose of the research is studying the genetic diversity of BCoV isolates circulating among dairy cattle in Siberia. MATERIALS AND METHODS: Specimens used in this study were collected from animals that died or was forcedly slaughtered before the start of the study. The target for amplification were nucleotide sequences of S and N gene regions. RESULTS: Based on the results of RT-PCR testing, virus genome was present in 16.3% of samples from calves with diarrheal syndrome and in 9.9% with respiratory syndrome. The nucleotide sequences of S gene region were determined for 18 isolates, and N gene sequences - for 12 isolates. Based on S gene, isolates were divided into two clades each containing two subclades. First subclade of first clade (European line) included 11 isolates. Second one included classic strains Quebec and Mebus, strains from Europe, USA and Korea, but none of sequences from this study belonged to this subclade. 6 isolates belonged to first subclade of second clade (American-Asian line). Second subclade (mixed line) included one isolate. N gene sequences formed two clades, one of them included two subclades. First subclade included 3 isolates (American-Asian line), and second subclade (mixed) included one isolate. Second clade (mixed) included 8 sequences. No differences in phylogenetic grouping between intestinal and respiratory isolates, as well as according to their geographic origin were identified. CONCLUSION: The studied population of BCoV isolates is heterogeneous. Nucleotide sequence analysis is a useful tool for studying molecular epidemiology of BCoV. It can be beneficial for choice of vaccines to be used in a particular geographic region.

Frequency of detection of bovine herpesvirus 4 in cattle during outbreaks of infectious diseases on big dairy farms

The results of the detection of the BoHV-4 in cattle during outbreaks of infectious diseases in big dairy farms of Siberia using the polymerase chain reaction (PCR) in real time are presented. The glycoprotein L gene sequences were used as amplification targets. According to PCR results, the virus genome was found in 27,7 % of samples from animals with respiratory, gastrointestinal and gynecological diseases. Most often, the virus was present in nasal swabs of calves aged 2 - 3 months (80,0 %), lungs (46,2 %) and bronchial lymphnodes (38,5 %) with pneumonia. In cows, the virus was detected in 20 % of samples with diarrhea and in 10 % of samples with gynecological pathology. Most often, BoHV-4 was present as a mono agent. In respiratory diseases of calves, it was found as a mono agent in 58,1 % of the samples, and in association with BoHV-1 in 21,6 %, with cattle coronavirus (BoCV) in 20,3 % of samples of the biomaterial. In gastrointestinal diseases in calves, the virus was present as a mono agent. In gynecological pathology in cows, BoHV-4 was detected as a mono agent in 10 % of samples, and in association with the BVDV1 in 6 % of cases. The presence of some viruses simultaneously in an animal can enhance the severity of the pathological process during respiratory and gynecological pathologies of animals due to their synergistic interaction with each other. Представлены результаты выявления вируса герпеса 4-го типа (BoHV-4) у крупного рогатого скота при вспышках инфекционных болезней на молочных комплексах Сибири при помощи полимеразной цепной реакции (ПЦР) в режиме реального времени. В качестве мишени амплификации использовали последовательности гена гликопротеина L. По результатам ПЦР геном вируса обнаружен в 27,7 % исследованных проб биоматериала от животных с респираторными, желудочно-кишечными и гинекологическими болезнями. Вирус чаще всего изолировали из носовых смывов телят 2 - 3-месячного возраста (80,0 %), легких (46,2 %) и бронхиальных лимфатических узлов (38,5 %) при пневмониях. У коров вирус выявили в 20 % проб при диарее и в 10 % при гинекологической патологии. BoHV-4 чаще присутствовал в моноварианте. При респираторных болезнях телят его обнаружили в моноварианте в 58,1% проб, а в ассоциации с вирусом герпеса первого типа (BHV-1) в 21,6 %, с коронавирусом крупного рогатого скота (BoCV) в 20,3 % исследованных проб биоматериала. При желудочно-кишечных болезнях у телят вирус присутствовал в моноварианте. При гинекологической патологии у коров BоHV-4 выявили в моноварианте в 10 % проб, а в ассоциации с вирусом вирусной диареи крупного рогатого скота 1 вида (BVDV-1) в 6 % случаев. Присутствие у животного одновременно нескольких вирусов может способствовать усилению тяжести течения патологического процесса при респираторной и гинекологической патологии животных за счет их синергетического взаимодействия между собой.