Journal of Veterinary Research最新文献

Introduction: Small ruminant lentiviruses (SRLV) cause multisystemic, degenerative and chronic disease in sheep and goats. There are five genotypes (A, B, C, D and E), of which A and B are the most widespread. The purpose of this study was to evaluate the serotyping efficiency of the Eradikit SRLV Genotyping ELISA and the molecular typing efficiency of a newly developed nested real-time PCR targeting the long terminal repeat-gag (LTR-gag) region using samples from animals infected with subtypes of SRLV known to circulate in Poland.

Material and methods: A total of 97 sera samples taken from 34 sheep and 63 goats were immunoassayed, and 86 DNA samples from 31 sheep and 55 goats were tested with the PCR. All ruminants were infected with known SRLV strains of the A1, A5, A12, A13, A16, A17, A18, A23, A24, A27, B1 and B2 subtypes.

Results: A total of 69 (80.2%, 95% confidence interval 71.6%-88.8%) out of 86 tested samples gave positive results in the PCR. In 17 out of the 86 (19.8%) samples, no proviral DNA of SRLV was detected. The differentiation between MVV (genotype A) and CAEV (genotype B) by PCR matched the predating phylogenetic analysis invariably. No cross-reactivity was observed. On the other hand, the proportion of samples genotyped the same by the older phylogenetic analysis and the Eradikit SRLV Genotyping ELISA was 42.3%. The test was unable to classify 40.2% of samples, and 17.5% of sera were incorrectly classified.

Conclusion: Our results showed that the Eradikit SRLV genotyping kit is not a reliable method for predicting SRLV genotype, while the nested real-time PCR based on the LTR-gag region did prove to be, at least for genotypes A and B.

Introduction: Lotmaria passim (L. passim) is a single-celled flagellate which colonises the bee gastrointestinal tract and is highly prevalent in honey bees. This parasite is associated with colony losses. Honey bee (Apis mellifera) colonies were sampled from five apiaries in the north-eastern part of Poland for the phylogenetic analysis of L. passim.

Material and methods: Each apiary consisted of approximately 60 bee colonies, of which 20 were randomly selected. Samples of 60 differently aged worker bees were collected from each colony and pooled. A total of 100 bee colonies from five apiaries were examined. Protozoa of the Trypanosomatidae family were identified by PCR. L. passim was detected in 47 (47%) of the samples. The 18S ribosomal (r) RNA amplicons of L. passim were sequenced by a commercial service. Their sequences were analysed with BLASTN and noted to be compatible with the GenBank sequences of this region of the organism's genome. A sequence analysis was performed using the BioEdit Sequence Alignment Editor and Clustal W software.

Results: The amplicon sequences of L. passim were 100% homologous with the sequences deposited in GenBank under accession numbers KM066243.1., KJ684964.1 and KM980181.1.

Conclusion: This is the first study to perform a phylogenetic analysis of L. passim in Polish honey bees. The analysis demonstrated high levels of genetic similarity between isolates of L. passim colonising apiaries in the north-eastern region of Poland.

Introduction: Although the presence of rotaviruses in pigeon samples has been reported since the 1980s, its importance as an aetiological agent of the "classical" young pigeon disease (YPD) was not proven until 2020, when the Henle-Koch postulates were confirmed for pigeon-type rotavirus A (RVA) genotype G18P(17).

Material and methods: From 2011 to 2020, archived liver samples from 117 pigeons submitted by 74 individual lofts were tested for the presence of pigeon-type RVA using a VP6-specific RT-qPCR test. For four positive racing pigeons, a more detailed necropsy and histopathological analysis was performed.

Results: Indicators of an acute RVA infection were found in 24 out of 117 (20.5%) samples tested, the earliest in 2014. Necropsies of the four selected RVA-positive pigeons showed changes mainly in the liver, spleen and kidneys similar to those described by other researchers. The histopathological examination revealed mainly hyperaemia and necrosis in the liver, as well as mononuclear cell infiltrates in these organs.

Conclusion: Pigeon-type RVA is also a cause of YPD in Poland and is a serious challenge for racing pigeon breeders and veterinarians, especially during the training and flights of young pigeons.

Introduction: Porcine reproductive and respiratory syndrome virus (PRRSV) infection results in a serious disease, posing a huge economic threat to the global swine industry. The transient receptor potential mucolipin proteins (TRPMLs) have been shown to be strongly associated with virus infection and other physiological processes in humans, but their tissue distribution and responses to PRRSV in pigs remain unknown.

Material and methods: Quantitative reverse-transcription PCR analysis was undertaken to determine the optimal primer for TRPML expression detection and for quantifying that expression individually in different pig tissue samples. Meat Animal Research Center 145 (MARC-145) monkey kidney cells and the TRPML-specific activator mucolipin synthetic agonist 1 (ML-SA1) were used to reveal the relationship between TRPML and PRRSV-2 infection.

Results: The best primers for each TRPML gene used in a fluorescence-based quantitative method were identified and TRPML1 was found to be highly expressed in the kidneys and liver of pigs, while TRPML2 and TRPML3 were observed to be primarily expressed in the kidney and spleen tissues. The expression of TRPML2 was upregulated with the rise in PRRSV-2 infection titre but not the expression of TRPML1 or TRPML3, and ML-SA1 inhibited PRRSV-2 in a dose-dependent manner.

Conclusion: Our research revealed the gene expression of TRPMLs in pigs and identified that TRPML channels may act as key host factors against PRRSV infection, which could lead to new targets for the prevention and treatment of pig infectious diseases.

Introduction: Bovine viral diarrhoea virus (BVDV) can cause diarrhoea (BVD) in an animal herd, leading to heavy economic losses. There are limited drugs available for treating and controlling BVD. This research aims to investigate the antiviral and immunoregulatory effects of two traditional Chinese herb extracts against BVDV infection. The extracts are matrine and icariin, which have been proved to have immunostimulant and antiviral effects.

Material and methods: A cell counting kit-8 assay was used to analyse the toxicity of matrine and icariin to Madin-Darby bovine kidney (MDBK) cells. The model of MDBK cells infected with BVDV was utilised to uncover the antiviral mechanism of matrine and icariin, which along with their immunoregulatory ability was evaluated by quantitative reverse-transcription PCR and ELISA.

Results: The results showed that matrine and icariin can significantly inhibit the gene expression level of the BVDV 5' untranslated region through various pathways. Both matrine and icariin can statistically upregulate the gene expression level of interferon alpha, interferon beta (IFN-β), toll-like receptor 3, retinoic acid-inducible gene I and interferon regulatory factor 3, and raise the concentration of IFN-β after BVDV infection.

Conclusion: This study proves that both matrine and icariin have inhibitory effects on BVDV replication by activating IFN production and the IFN signalling pathway. The finding is promising and should open up the possibility of larger-scale in vitro research followed by in vivo experiments evaluating matrine and icariin as therapeutic agents in BVD cases.

Introduction: Macrophages are crucial immune cells that play a role in tissue repair and can exhibit pro- or anti-inflammatory behaviour based on environmental stimulation. Their functional phenotype can be affected by platelet-derived products as determined by those products' composition. When the inflammatory response caused by implantation is excessive, it can lead to rejection of the implant. Therefore, a thorough evaluation of implant haemocompatibility is necessary to minimise undesirable consequences.

Material and methods: In an in vitro study, monocyte-derived macrophages (MDMs) were obtained from the whole blood of sheep after a silicon-doped diamond-like carbon-coated implant insertion. These MDMs were then exposed to autologous platelet-derived products for functional marker analysis.

Results: Platelet-poor plasma (PPP) and pure platelet-rich plasma (P-PRP) stimulation increased arginase-1 activity, while leukocyte-rich PRP stimulation produced a mixed response involving higher O₂^- (6.49 ± 2.43 nM vs non-stimulated 3.51 ± 1.23 nM, P-value < 0.05) and NO (3.28 ± 1.38 μM vs non-stimulated 2.55 ± 0.32μM, P-value < 0.05) generation.

Conclusion: Using PPP and P-PRP stimulation in post-implantation procedures may contribute to the polarisation of macrophages towards the M2-like pro-resolving phenotype, thereby accelerating wound healing. This would also prevent implant degradation due to an excessive inflammatory process.