1,721,026 research outputs found
Optimum processing conditions for a trivalent-inactivated bovine viral diarrhea virus (BVDV) vaccine using field strains and immunogenicity of candidate formulations with different adjuvants
No full textBovine viral diarrhea virus (BVDV) is among the common bovine pathogens worldwide. One of the prominent protection measures of BVDV is vaccination. This study aimed to determine the growth characteristics, inactivation kinetics of vaccine candidates using local BVDV strains [TR-26 (BVDV-1f), TR-21 (BVDV-1l), and TR-15 (BVDV-2b)], and the serological response in experimental animals to inactivated BVDV vaccine formulations prepared with different adjuvants. Optimum MOI values for BVDV strains TR-26, TR-21, and TR-15 were determined as 0.1, 1.0, and 0.01, respectively. In addition, growth curves of TR-26, TR-21, and TR-15 strains were created, and it was determined that they reached the highest titers at 12, 48, and 36 h p.i., respectively. The strains TR-26, TR-21, and TR-15 with titers of 106.5, 106.5, and 105.25 TCID50/ml were completely inactivated by 1 mM binary ethyleneimine (BEI) at the 10th, 16th, and 10th hours of treatment, respectively. Guinea pigs were immunized with four vaccine formulations (F1, F2, F3, F4), two with aluminum-based [Al(OH)3, Al(OH)3+Saponin] and two with oil-based (ISA 50 and ISA 206) adjuvants. Neutralization tests were applied to determine the humoral immune response developed after vaccination. Both homologous and heterologous BVDV strains were used for evaluations. Oil adjuvanted vaccines were more efficient to induce antibody titers compared to Al(OH)3-based vaccines. In addition, between the oil adjuvanted vaccines, the titers of neutralizing antibodies obtained by Montanide® ISA 206 formulation were significantly higher than in Montanide® ISA 50 (p < 0.05). Post-vaccinal neutralizing antibodies were detected in the first sampling at 21st day and lasted longer than a 111 days period. The highest antibody response in Guinea pigs was for the strain TR-15. The availability of using BVDV-lf, 1l, and 2b local strains in vaccines and their effectiveness against homologous and heterologous strains have been demonstrated.Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 119 O 57
Characterization of bovine rotavirus isolates from diarrheic calves in Turkiye
No full textBackgroundNeonatal calf diarrhea, which is the most common cause in calf deaths, leads to significant economic losses in dairy farming around the world. Diarrhea develops due to infectious and non-infectious reasons. Group A Rotaviruses (RVA) are the leading and predisposing factor for acute neonatal gastroenteritis.Methods and resultsIn this study, 20 diarrheic fecal samples were collected from one farm in Balikesir province of Turkey. During virus isolation, a total of 2 stool samples were detected to produce cytopathogenic effects in MA-104 cell line. The two samples (RV-36, RV-38) were tested positive with antigen ELISA kits detecting RVA antigens. In order to detect the presence of rotavirus viral nucleic acid in cell supernatants, VP6 gene region-specific RT-PCR test was performed and the samples RV-36 and RV-38 were positive for RVA viral nucleic acid. By RT-PCR using genotype specific primers, both the isolates RV-36 and RV-38 formed amplicons compatible with G10 and P[11] genotypes of RVA. RVA nucleic acids segments were also visualized by poliacrilamide gel electrophoresis (PAGE) method. The phylogenetic tree constructed according to the VP6 gene region showed that these isolates were in the Rotavirus A group and in the I2 cluster same as other bovine and some human RVA isolates.ConclusionSuccesful isolation of RVA G10P[11] was echieved in the cattle farm. As rotaviruses play the most important role in the etiology of diarrhea in newborn calves respected genotype G10P[11] should be considered in selection of the vaccines applied to the dams. Those isolates can be further evaluated as vaccine candidate
A novel killed oil adjuvanted bovine viral diarrhea virus vaccine protects from viremia and clinical manifestations: An immune response and challenge study in cattle
Full text linkBovine viral diarrhea virus continues to threaten animal health with serious economic losses worldwide. Various killed, live-modified, or recombinant vaccine strategies are being developed for protection and control against this virus. The most important thing discovered is the choice of local and widespread strains in the vaccine content. In this study, the effectiveness of a Montanide (R) ISA 206 adjuvanted killed trivalent vaccine containing endemic local strains (TR-21 [BVDV-1l], TR-26 [BVDV-1f], and TR-15 [BVDV-2b]) isolated from T & uuml;rkiye, was evaluated with a cattle challenge study. Experimental groups were designed as single dose vaccination (Group-I, n:11), two dose vaccination (Group-II, n:11), and unvaccinated (Group-III, n:6) with male calves aged about 6 months. Following the immunization, challenge virus (TR-72 [BVDV-1l], TCID50 106.5) was given intranasally to each group (5 animals in Group-I and II and 4 animals in Group-III), and clinical findings, hematological changes, virus shedding, side effects, and viremia were monitored for 14 days after inoculation. Serological monitoring of the remaining animals against homologous and heterologous strains was carried out at one-month intervals between the 21st and 201st days after the first vaccination. The obtained results showed that the viremia, hematological changes, and clinical findings shown in unvaccinated animals (Group-III) were significantly suppressed (p = 8 log2 for vaccinal and also for all reference BVDV-1 strains, which is more than three-fold protective antibody response, lasting more than 7 months after the first vaccination, whether in single or two dose application. The rise of nAbs was also detected for heterogous BVDV strains. The detected nAb titers were significantly higher (p < 0.05) in the two dose vaccination group. Based on the results, it was concluded that this trivalent- inactivated vaccine candidate can protect cattle against acute BVDV infections
In vitro antiviral activity of thymbra spicata L. extract on bovine respiratory viruses (BCoV, BPIV-3, BRSV, BVDH and BoHV-1)
No full textAims Viral pathogens are the primary agents in bovine respiratory disease cases, and there is no direct effective antiviral drug application. Thymbra is a genus of oregano commonly found in Turkey. The primary component (34.9%) of the extract obtained from Thymbra spicata L. is the carvacrol which is used in traditional medicine. This study evaluates the potential antiviral activity and inactivation efficiency of T. spicata L. extract against bovine respiratory viruses, including BCoV, BPIV-3, BRSV, BVDV and BoHV-1. Methods and Results To evaluate its effect on viral replication, viral titres were taken from infected cells treated with non-cytotoxic T. spicata L. extract concentrations (0.75% and 1.5%, 1.32 and 2.64 mu g/ml of carvacrol as active ingredient, respectively) and compared to non-treated infected cells. The viruses were treated directly with 1.5% T. spicata L. extract, and the viral titres were evaluated at certain time points to determine the efficiency of direct inactivation. The number of infectious virions for BCoV, BPIV-3, BRSV, BVDV and BoHV-1 treated with 1.5% T. spicata L. extract were decreased by 99.44%, 100.0%, 94.38%, 99.97% and 99.87%, respectively.T. spicata L. extract strongly inhibits the replication of mentioned viruses in a dose-dependent manner in vitro. In addition, T. spicata L. extract shared direct inactivation efficiency on the mentioned viruses in a time-dependent manner. Conclusion This study shows the antiviral efficiency of T. spicata L. on BRD-related viral agents for the first time. The oregano species T. spicata and its main component, carvacrol, may have a potential for antiviral activity in the alternative treatment of respiratory viral diseases in cattle. Significance and Impact of the Study Given the similarity of replication strategies, obtained data suggest the possible efficiency of T. spicata L. on human respiratory viruses
Molecular characterization and comparison of diagnostic methods for bovine respiratory viruses (BPIV-3, BRSV, BVBV, and BoHV-1) in field samples in northwestern Turkey
No full textThe aim of this study was to evaluate the compatibility among virus isolation (VI), ELISA, and PCR for diagnosis of the major viral agents (BPIV-3, BRSV, BVDV, and BoHV-1) responsible for BRD in the field samples. For that purpose, a total of 193 samples (133 nasal swabs and 60 lung tissue samples) from cattle with respiratory signs in northwestern Turkey were examined. For VI, all the samples were inoculated at least 3 blind passages onto MDBK cell culture. In addition, the samples were tested by hemadsorption assay and RT-PCR for BPIV-3; nested RT-PCR for BRSV; immunoperoxidase monolayer assay, antigen-ELISA, and RT-PCR for BVDV; and antigen-ELISA and PCR for BoHV-1. The detected 1 (0.52%) BPIV-3 isolate was found to be in the genotype BPIV-3c. No BRSV isolate could be obtained, while 5 (2.59%) samples were evaluated positive in nested-RT PCR. The presence of BVDV antigen in 10 (5.18%) samples and the BVDV genome in 5 (2.59%) samples were detected, while non-cytopathogenic BVDV isolates were obtained only in 2 (1.04%) samples. The detected BVDV strains fell into the genetic clusters of BVDV-1a, -1f, and -1l. For detection of BoHV-1, although viral isolation and Ag-ELISA results were negative, presence of BoHV-1.1 genome was detected in 2 (1.04%) samples. By the results of VI, ELISA, and PCRs, 10.88% (21/193) of samples were found positive for the evaluated viruses. Depending on the obtained data, combined uses of the diagnostic methods were evaluated to be more reliable for routine diagnosis of bovine respiratory viruses
Recent strains of influenza D virus create a new genetic cluster for European strains
Full text linkBovine respiratory diseases (BRD) are one of the significant health problems for cattle breeding industry. Influenza D virus (IDV) alone or in combination with other respiratory pathogens plays a role in BRD. According to the IDV-HEF gene region, phylogenetic analyzes revealed five lineages: D/OK, D/660, D/Yama2016, D/ Yama2019, and D/CA2019, so far. In this study, despite no success in virus isolation, the presence of IDV was investigated by RT-PCR (partial HEF gene region) in 219 nasal swab samples collected from cattle with BRD between 2012 and 2021. The presence of IDV was demonstrated in two samples, and genome characterization data of the IDV sequences both in the partial and complete HEF gene regions showed that one of the obtained sequences (D/bovine/Turkey-Bursa/ET-138/2021) was in the lineage D/Yama2019 while the other (D/bovine/ Turkey-Bursa/ET-130/2013) created a new lineage tentatively called D/Bursa2013 as including few partial IDV sequences reported in Europe. Two nucleotide substitutions (nt252A-*G, nt299T-*C) were typically character-ized for the tentative lineage D/Bursa2013, one of which also leads to a unique amino acid change at position aa100 (V-*A). When the amino acid differences between the lineages were evaluated, amino acid substitution changes were detected in four regions [aa12 (Alanine-*Aspartic acid), aa19 (Glycine-*Arginine), aa22 (Proli-ne-*Serine), and aa110 (Aspargine-*Arginine)] of the D/Yama2019 lineage, unlike the other lineages. Consid-ering the most common D/OK lineage in Europe, many nucleotide substitutions were shown between D/OK and D/Bursa2013. Accordingly, aminoacid substitutions were observed in aa27 (Threonine-*Asparagine) and aa100 (Valine-*Alanine) in the D/bovine/Turkey-Bursa/ET-138/2021 sequence. Study results describe the circulation of D/Yama2019 and D/Bursa2013 (new lineage) in Turkey. Expansion of new strains seems possible due to the high mutation rate of influenza viruses. It is important to understand the development of IDV with compre-hensive characterization studies
Persistent BVD virus infections in offspring from imported heifers
No full textThe aim of this study was to investigate the possible risk of bovine viral diarrhea virus transport from imported live animals. For this purpose, two different groups of animals were sampled in this study. Group 1 consisted of pregnant heifers; group 2 consisted of male beef cattle imported during 2011-2012 and 2015, respectively. Blood samples were tested for pestivirus antigen using a commercial BVDV antigen ELISA. All the pregnant heifers were negative, but 9 out of 412 offspring and 5 of the 332 male cattle were BVDV antigen positive. Virus isolation and also investigation by RT-PCR were carried out by using 14 ELISA-positive samples. At the end of three blind passages, eight non-cytopathogenic isolates were obtained by indirect immunoperoxidase monolayer assay, which were also RT-PCR positive using panpesti-virus primers. After discriminative RT-PCR, all the isolates that were identified as BVDV-1 and 5UTR-based analysis demonstrated the existence of BVDV-1b (n=4), BVDV-1f (n=2), BVDV-1l (n=1), and BVDV-1r (n=1) subgenotypes. There was no BVDV subgroup that is newly introduced into the country. However, detection of persistent infection in calves born from imported animals demonstrates the risk of BVDV virus introduction by imported animals into the receiving country. Viral strains from persistently infected animals were characterized as BVDV-1b, which is predominant subgroup in the country where animals are imported. These results highlight a possible problem for the areas where a BVDV control program is currently ongoing. Additionally, sequences obtained in this study also showed that there are two distinct branches identified in BVDV-1l
Failure in dry period vaccination strategy for bovine viral diarrhea virus
No full textBovine viral diarrhea is a common disease of cattle and has significant impact on animal welfare worldwide. There are fundamental approaches i.e. elimination of persistently infected animals, vaccination and biosecurity measures for effective control and eradication of BVD virus (BVDV). By this study, the presence of persistent infection with divergent BVDV subgenotype in the calves in a dairy herd having regular vaccination program was investigated. In the herd, vaccinated with a killed whole virion trivalent vaccine (composed of BVDV-1a) during the dry period of the cows, abortion cases were existed in the late autumn 2019. During herd screening by BVDV antigen-ELISA, 2 out of 300 dams were detected positive. Following, by ear notch-based BVDV antigen-ELISA, 30 calves were detected positive. Confirmation of persistent BVDV infection was performed 3 weeks later by testing with antigen-ELISA, where 8 of 9 selected newborn calves were positive for the second time. The entire antigen-ELISA positive samples were subjected to virus isolation on MDBK cell culture and identified as non-cytopathogenic pestiviruses by indirect immunoperoxidase assay. Presence of pestivirus RNA was detected in the 8 isolates by panpestivirus RT-PCR. Analysis of the 5'UTR regions revealed that BVDV-1 r circulate in the herd. Results of this study lead to questioning the efficiency of dry period vaccination strategy against BVDV. But otherwise, vaccination with BVDV-1a can be inefficient for complete protection against BVDV-1 r. Therefore, serological relationship between mentioned subgenotypes or protection by current vaccines against latest field isolates needs to be investigated before development of new BVDV vaccine candidates
Detection of central nervous system tissues as BSE specified risk material in meat products in Turkey
No full textSpinal cord and brain tissues have the highest importance to transfer bovine spongiform encephalopathy (BSE) to human. European Union issued complete removal of spinal cord and brain tissues from meat products (Commission Decision 2000/418/EC). In Turkey, regulation on meat products [Turkish Food Code, Regulation on Meat Products. Official Journal No: 23960, 10 Feb, 2000] is applied by their government veterinarians. But there are some questions on the effective application of the regulation especially in some private slaughterhouses. This study was designed to represent the mixing of these tissues to meat products which sold in Marmara region of Turkey. For this purpose, a total of 179 meat product samples belonged to 17 different trademarks were tested. A semi-quantitative ELISA kit, which detects glial fibrillary acidic protein (GFAP) as marker, was used. In the test, standard controls 0, 0.2%, 1%, and 2% were practiced. Of the 179 sampled, 18 samples (10.05%) gave an optical density over than standard 0.2%. Optical density of three samples was near to standard 1%. It is concluded that central nervous system tissue mixing to the meat products still happen and more effective control measurements needs to be developed and applied in Turkey. (C) 2003 Elsevier Ltd. All rights reserved
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