The aim of performed study was to determine the level of enzootic abortion (EA) in sheep breeding farms in different districts of Lithuania, to determine differences in clinical signs and infection frequency between various age groups, and to evaluate the sensitivity and specificity of complement fixation test for antibodies detection and indirect immunofluorescence for antigen detection in sheep chlamydiosis. The clinical, serological and immunological tests in sheep farms were performed in 2004 and 2005. Comparing different age groups of sheep revealed that the lowest number of infected sheep was registered in animals younger than 18 months (23.1%, antibodies titre 3.191 log2, P<0.05) and highest in animals aged 18 to 24 months (53.8%, antibodies titre 4.224 log2, P<0.001). In sheep aged more than 3 years, titre of antibodies was significantly reduced. The majority of infected sheep which aborted (86.4%) was registered in 18-24 month age group. Furthermore, in sheep which aborted the infection level was 2.5-fold higher as compared to sheep which didn’t abort. Analysis of smears from patological material by indirect FAT revealed that 54.5% of animals were positive to Chlamydophila abortus infection. The highest prevalence of chlamydia (66.7%) was registered in placentas of sheep which aborted.
The aim of the present study was to detect canine parvovirus (CPV) from faecal samples of clinically ill domestic dogs by polymerase chain reaction (PCR) followed by VP2 gene partial sequencing and molecular characterization of circulating strains in Lithuania. Eleven clinically and antigen-tested positive dog faecal samples, collected during the period of 2014-2015, were investigated by using PCR. The phylogenetic investigations indicated that the Lithuanian CPV VP2 partial sequences (3025-3706 cds) were closely related and showed 99.0-99.9% identity. All Lithuanian sequences were associated with one phylogroup, but grouped in different clusters. Ten of investigated Lithuanian CPV VP2 sequences were closely associated with CPV 2a antigenic variant (99.4% nt identity). Five CPV VP2 sequences from Lithuania were related to CPV-2a, but were rather divergent (6.8 nt differences). Only one CPV VP2 sequence from Lithuania was associated (99.3% nt identity) with CPV-2b VP2 sequences from France, Italy, USA and Korea. The four of eleven investigated Lithuanian dogs with CPV infection symptoms were vaccinated with CPV-2 vaccine, but their VP2 sequences were phylogenetically distantly associated with CPV vaccine strains VP2 sequences (11.5-15.8 nt differences). Ten Lithuanian CPV VP2 sequences had monophyletic relations among the close geographically associated samples, but five of them were rather divergent (1.0% less sequence similarity). The one Lithuanian CPV VP2 sequence was closely related with CPV-2b antigenic variant. All the Lithuanian CPV VP2 partial sequences were conservative and phylogenetically low associated with most commonly used CPV vaccine strains.
Forty-five cattle of different ages and gender were selected from three separate farms with a total number of 929 animals. Blood serum samples from each of the animals were tested twice at two-month intervals for bovine viral diarrhoea virus (BVDV) antigen (BVDV Ag) and BVDV antibodies (BVDV Ab) using ELISA. Five animals were found to be BVDV Ag positive and BVDV Ab negative. Therefore, their blood and saliva samples were subjected to further investigation. The samples of blood serum and saliva were additionally screened by a nested reverse transcription PCR (RT-nPCR), real-time PCR, and virus isolation to confirm BVDV persistent infection. Viral RNA was isolated from blood and saliva samples. The cDNA was synthesised and amplification of DNA was performed. The results of RT-nPCR were analysed by gel electrophoresis using ethidium bromide while those of real-time PCR were interpreted according to the amplification curve. Laboratory testing of blood and saliva samples revealed 5 persistently infected (PI) animals from one farm with 579 cattle (0.9% prevalence). The results were confirmed by RT-nPCR and real-time PCR screening samples of blood serum. Using PCR techniques and virus isolation, BVDV RNA was detected; however, the level of viral RNA in saliva was found to be lower than that in blood serum. The results obtained show the possibility to identify PI animals by RT-nPCR and real-time PCR techniques from saliva samples. The collection and testing of saliva is a simple and quick technique, and can be successfully applied in field conditions to identify PI animals, avoiding the risk of intervention while sampling blood or dependence on animal gender and lactation period while sampling milk or semen.
A serological study of BoHV-1 distribution was conducted in Lithuania from 2005 to 2009. Antibody level was measured using a commercial ELISA. For serological examination, 15,368 random blood samples from cattle of different age, gender, and size of herd, which was unvaccinated against IBR, were collected in 37 districts. It was registered that 11.97% of BoHV-1 were seropositive samples. It was also shown that BOHV-1 is most widespread in cattle herds with population >200 individuals (14.79%). Comparison of different sex groups of cattle revealed that the highest number of infected animals was identified in cows (34.64%) and the lowest in bulls (2.01%). In heifers the number of infected animals was 10.01% and in calves - 4.41%. It was shown that seroprevalence of BoHV-1 infection in Lithuania increased with age of animals. The highest prevalence of BoHV-1 (53.98%) was registered in cattle aged more than 7 years.
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