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Neutralization of African swine fever virus by sera from African swine fever-resistant pigs.
1986
Ruiz Gonzalvo F. | Caballero C. | Martinez J. | Carnero M.E.
In vitro and in vivo activity of Lactobacillus sakei L14 strain against Campylobacter jejuni DC3 strain
2022
Catacutan, John Roybert P. | Subejano, Ma. Socorro Edden P. | Penuliar, Gil M.
Domestic poultry is a natural reservoir of Campylobacter, the host–pathogen interaction being predominantly asymptomatic. This study investigated whether chickens remain asymptomatic partly because of lactic acid bacteria (LAB). Campylobacter spp. and LAB were isolated from the gut of poultry chickens using enrichment and screening assays and were identified via rDNA sequencing. The C. jejuni DC3 isolate was grown in different cell-free supernatants (CFS) generated from a priority LAB isolate. An in vivo challenge involving the C. jejuni and LAB isolates using a chicken model was performed to confirm the in vitro findings. Twelve presumptive LAB isolates had anti-C. jejuni activity based on cross-streak and agar plug assays, with Lactobacillus sakei L14 isolate exhibiting the highest activity. Inhibition by L. sakei L14 CFS of the growth of C. jejuni occurred in a dose-dependent manner. Campylobacter jejuni DC3 inhibition was most evident in CFS harvested at 72 h and produced by co-culture with the pathogen. Neutralisation of the CFS abrogated the observed inhibition. Co-infection with C. jejuni DC3 and L. sakei L14 in vivo, however, failed to inhibit C. jejuni colonisation in chickens. The results suggest that the anti-C. jejuni effect of L. sakei L14 in chickens may be due to mechanisms other than direct inhibition of growth.
Afficher plus [+] Moins [-]ASF -survivors’ sera do not inhibit African swine fever virus replication in vitro
2022
Walczak, Marek | Juszkiewicz, Małgorzata | Szymankiewicz, Krzesimir | Szczotka-Bochniarz, Anna | Woźniakowski, Grzegorz
African swine fever virus (ASFV) causes one of the most dangerous diseases of pigs and wild boar – African swine fever (ASF). Since its second introduction into Europe (in 2007), the disease has been spreading consistently, and now ASF-free European countries are at risk. Complex interactions between the host’s immune system and the virus have long prevented the development of a safe vaccine against ASF. This study analysed the possibility of neutralisation of the ASFV in vitro by sera collected from ASF-survivor animals. Two pig and three wild boar serum samples were collected from previously selected potential ASF survivors. All sera presented high antibody titres (>5 log₁₀/mL). Primary alveolar macrophages were cultured in growth medium containing 10% and 20% concentrations of selected sera and infected with a haemadsorbing ASFV strain (Pol18_28298_O111, genotype II). The progress of infection was investigated under a light microscope by observing the cytopathic effect (CPE) and the haemadsorption phenomenon. Growth kinetics were investigated using a real-time PCR assay. Haemadsorption inhibition was detected in the presence of almost all selected sera; however, the inhibition of virus replication in vitro was excluded. In all samples, a CPE and decreasing quantification cycle values of the viral DNA were found. Anti-ASFV antibodies alone are not able to inhibit virus replication. Interactions between the humoral and cellular immune response which effectively combat the disease are implicated in an ASF-survivor’s organism.
Afficher plus [+] Moins [-]Evaluation of metallothionein and Ki-67 expression in chronic cholangiohepatitis in cats
2021
Jose, Divya | Allen, Andrew L. | Blakley, Barry | Al-Dissi, Ahmad
Chronic cholangiohepatitis (CCH) is a common pathological condition in cats with a guarded prognosis and unknown etiology. Recently, in human medicine, there has been increased interest in enhancing liver defense mechanisms as an effective treatment strategy to control liver diseases that have a poor prognosis. Metallothionein (MT) is a ubiquitous protein, which has been widely researched for its role in liver defense through heavy metal detoxification, neutralization of reactive oxygen species, and liver regeneration. In this study, immunohistochemistry was used to evaluate the role of MT in CCH and hepatocellular regeneration in 34 cats histologically diagnosed with this condition by assessing the correlation between hepatocellular MT and Ki-67 (marker for cellular proliferation) expression with histological parameters of CCH, such as inflammation, fibrosis, and bile duct proliferation. Statistical analysis was performed using the Spearman-rank correlation test. A significant positive correlation was observed between inflammation and the number of MT-positive hepatocytes (r = 0.36, P = 0.03) and MT labelling intensity (r = 0.37, P = 0.03). In 16 of 34 cases (47%) MT labelling intensity was noted to be pronounced towards the centrilobular zone and very weak or absent towards the portal zone. The results suggest that MT is induced in the liver during chronic inflammatory conditions, which could be speculated as a host defensive mechanism to protect the liver from inflammation-mediated liver injury. Therapeutic interventions utilizing MT, therefore, may have a positive effect on cats with chronic cholangiohepatitis.
Afficher plus [+] Moins [-]Molecular characterization of a Korean porcine epidemic diarrhea virus strain NB1
2019
Chung, H. C. | Nguyen, V. G. | Le Huynh, T. M. | Moon, H. J. | Kang, B. K. | Kim, S. J. | Kim, H. K. | Park, S. J. | Park, K. T. | Park, Y. H. | Park, B. K.
In Korea, for the past 30 years (1987-present), porcine epidemic diarrhea (PED) has been established as an endemic situation in which multiple genogroups of classical G1 and G2b, and the recently introduced pandemic G2a, coexisted. Because of the dynamic nature of the virus, continuous field monitoring for PEDV strains is required. This study is the first to reveal prevalence of PEDV in 9 sampling provinces, with an overall detection rate of 6.70%. Porcine endemic diarrhea virus (PEDV) was present in pigs of all ages, especially in the non-PED vaccinated groups. The highest detection rate was in the finisher group (2.34%), followed by that in the newborn group (1.56%). Secondly, using Sanger sequencing, this study recovered a complete genome (28 005 nucleotides long) of NB1 strain from a farm severely affected by PED. Analyses of nucleotide and deduced amino acid sequences showed that NB1 differed from 18 other Korean PEDV mostly in 4 protein coding genes: ORF1a, ORF1b, S, and N. Two amino acid substitutions (V635E and Y681Q) in the COE and S1D neutralizing epitopes of NB1 resulted in antigenic index alteration of the adjacent sites, one of which contributed to a mutation that escaped neutralizing antibodies.
Afficher plus [+] Moins [-]Genetic and antigenic changes in porcine rubulavirus
2012
Sanchez-Betancourt, Jose I. | Trujillo, Maria E. | Mendoza, Susana E. | Reyes-Leyva, Julio | Alonso, Rogelio A.
Blue eye disease, caused by a porcine rubulavirus (PoRV), is an emergent viral swine disease that has been endemic in Mexico since 1980. Atypical outbreaks were detected in 1990 and 2003. Growing and adult pigs presented neurological signs, mild neurological signs were observed in piglets, and severe reproductive problems were observed in adults. Amino acid sequence comparisons and phylogenetic analysis of the hemagglutinin-neuraminidase (HN) protein revealed genetically different lineages. We used cross-neutralization assays, with homologous and heterologous antisera, to determine the antigenic relatedness values for the PoRV isolates. We found antigenic changes among several strains and identified a highly divergent one, making up a new serogroup. It seems that genetically and antigenically different PoRV strains are circulating simultaneously in the swine population in the geographical region studied. The cross neutralization studies suggest that the HN is not the only antigenic determinant participating in the antigenic changes among the different PoRV strains.
Afficher plus [+] Moins [-]Serodiagnosis of porcine reproductive and respiratory syndrome virus infection with the use of glycoprotein 5 antigens
2010
Glycoprotein 5 (GP5) of porcine reproductive and respiratory syndrome virus (PRRSV) has been studied extensively as a target for vaccine development. This study evaluated the serodiagnostic application of PRRSV GP5 by enzyme-linked immunosorbent assay (ELISA). Two immunodominant peptides (VR #1 and VR #2) and two neutralizing ectodomain-containing peptides (Ecto #1 and Ecto #2), as well as recombinant GP5 (rGP5) as a control, were prepared. Serum from unvaccinated pigs was screened for the antibodies that bind to these peptide and protein antigens. The results were compared with those from a commercially available diagnostic ELISA kit (HerdChek), which uses the nucleocapsid (N) protein as an antigen. Only VR #1+#2 showed a result statistically similar to that of N protein. Ecto #1 and Ecto #2 had a lower sensitivity than VR #1+#2 and rGP5. The peptides and rGP5 showed significant associations with the N protein (P < 0.05 or 0.01), which suggests that GP5 may also be a candidate serodiagnostic antigen. Since antibodies against GP5 persist much longer than those against the N protein, GP5 itself and some of its fragments are thought to be good targets for serodiagnosis. In addition, the presence of antibodies against the PRRSV structural antigens showed significant antigen-dependent differences.
Afficher plus [+] Moins [-]Immunological relationships of FMD vaccine strain and Asia1 field isolate from East Asia
2009
Park, J.H., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Ko, Y.J., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Kim, S.M., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Lee, H.S., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Lee, K.N., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Cho, I.S., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea
Foot-and-mouth disease (FMD) is the most contagious disease of mammals. The use of inactivated vaccine can be chosen to prevent or control FMD. However, vaccination against one serotype of FMDV doses not cross-protect against other serotypes and may not protect fully against some strains of the same serotype. Appropriate selection of vaccine strain is an important element in the control of FMD. The immunity of vaccine antigens should be matched against newly circulating viruses. The phylogenetic analysis of serotype Asia1 reported from China, Mongolia, North Korea and Russia since 2005 shows that they are all classified into genetic group V, but the strain, Asia1/Shamir (ISR/89) which have been used as a vaccine strain in Korea, is clustered into different genetic group. So, in this study the serological relationship between the isolate (Asia1/MOG/05; MOG) and the Shamir stain was determined by ELISA and virus neutralization test. Even though the matching value of the virus (MOG) against the vaccinated sera in target animals was not so high, the vaccinated animals elicited antibodies enough for protection after vaccinated once or twice. Conclusively, we suggest that the vaccine containing Asia1/Shamir antigen could protect the genetic group V strains circulating in East Asia currently if vaccinated twice or the more.
Afficher plus [+] Moins [-]Role of bovine viral diarrhea virus biotype in the establishment of fetal infections
2002
Harding, Martha J. | Cao, Xuemei | Shams, Homayoun | Johnson, Anthony F. | Vassilev, Ventzislav B. | Gil, Laura H. | Wheeler, David W. | Haines, Deborah | Sibert, Gary J. | Nelson, Lynn D. | Campos, Manuel | Donis, Ruben O.
Objective-To examine the role of bovine viral diarrhea virus (BVDV) biotype on the establishment of fetal infection in cattle. Animals-30 mixed-breed pregnant cows. Procedure-Pregnant cows were inoculated oronasally with either i-VVNADL, originating from an infectious BVDV cDNA clone of the National Animal Disease Laboratory (NADL) isolate, or the parental virus stock, termed NADL-A. Results-All cows developed neutralizing antibodies to BVDV, and virus was commonly isolated from peripheral blood mononuclear cells or nasal swab specimens of NADL-A inoculated cows; however, virus was rarely isolated from specimens of i-VVNADL inoculated cows. i-VVNADL did not cause fetal infection, whereas all fetuses harvested from NADL-A inoculated cows at 6 weeks after inoculation had evidence of infection. Immunoblot analysis of fetal virus isolates revealed the absence of NS3, confirming a noncytopathic (NCP) biotype BVDV in the NADL-A stock. The sequence of the NCP contaminant (termed NADL-1102) and the i-VVNADL genome were virtually identical, with the exception of a 270 nucleotide-long insert in the i-VVNADL genome. Phylogenetic analyses revealed that NADL-1102 forms a monophyletic group with 6 other NADL genomes. Conclusions and Clinical Relevance-These data suggest that the contaminating NCP virus in the NADL-A stock was the ancestral NADL virus, which originally infected a bovine fetus and recombined to produce a cytopathic (CP) variant. Following oronasal infection of pregnant cows, viremia and transplacental transmission of CP BVDV to the fetus is rare, compared with the high occurrence of maternal viremia and fetal infection observed with NCP BVDV.
Afficher plus [+] Moins [-]Three-dimensional kinematic evaluation of Tightrope CCL in a canine in vitro cranial cruciate deficient stifle model
2019
Lauqier, M. | Tremblay, J. | Petit, Y. | Griqnon-Lemieux, A. | Levasseur, A. | Lussier, B.
The impact of surgical correction of cranial cruciate ligament-deficient stifles (CCDS) on the 3-dimensional (3D) kinematics of the canine stifle has been sparsely evaluated. Tightrope (TR) cranial cruciate ligament (CCL) has been proposed to restore baseline 3D kinematics in CCDS by using isometric points. We hypothesized that TR would restore baseline 3D kinematics of the stifle in our model. Ten pelvic limbs were used with a previously validated apparatus. Three experimental conditions were evaluated: i) intact stifle, ii) cranial cruciate ligament transection (CCLt), and iii) CCLt stabilized with TR; kinematic data was recorded. Tightrope CCL in CCDS did not limit sagittal flexion. Tightrope CCL neutralized internal rotation without restoring baseline curves, but it did not restore abduction, nor did it neutralize or restore cranial translation, but it did restore latero-medial and proximo-distal translations. In our model, TR without pre-conditioning of the FiberTape strands did not restore baseline stifle 3D kinematics and residual cranial translation could result in frequent meniscal tears.
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