ABSTRACT
In Argentina, cases of malignant catarrhal fever (MCF) are suspected to have occurred according to macro and microscopic lesions. However, none has been corroborated by molecular tests. We describe here the first laboratory confirmed case of MCF in Argentina occurring in American bison confined in the Buenos Aires Zoo.(AU)
Subject(s)
Animals , Cattle/microbiology , Malignant Catarrh/diagnosis , Argentina , Pathology, Molecular , Animals, ZooABSTRACT
In Argentina, cases of malignant catarrhal fever (MCF) are suspected to have occurred according to macro and microscopic lesions. However, none has been corroborated by molecular tests. We describe here the first laboratory confirmed case of MCF in Argentina occurring in American bison confined in the Buenos Aires Zoo.
ABSTRACT
The Circoviridae family includes small viruses containing circular single strand DNA. There are two circoviruses described in pigs. Porcine Circovirus 2 (PCV2) has been linked to a disease termed Postweaning Multisystemic Wasting Syndrome (PMWS) whereas a close relative of this virus, termed PCV type 1 (PCV1) has been considered a non-pathogenic contaminant of the PK15 cell line. Rolling circle replication of small DNA viruses like circoviruses is mediated by a replicase (Rep) gene that is transcribed into different mRNAs by an alternative splicing mechanism. In PCV1, two transcripts Rep and Rep' implicated in DNA replication, have been identified from infected cells. These transcripts are the product of a single gene with Rep' having a different carboxyl end than Rep. Sequence comparison shows that there is a high degree of homology for the Rep gene in both viruses. In this article, we have identified three different transcripts by RT-PCR in PCV2 infected PK15 cells. Two of them have homology with their PCV1 counterparts and the third transcript, termed Rep", corresponds to another spliced version of the Rep gene. This transcript, unique to PCV2, encodes for a protein of 80 aminoacids in frame with the Rep sequence.
Subject(s)
Circovirus/genetics , DNA-Directed DNA Polymerase/genetics , Kidney/virology , Swine/virology , Amino Acid Sequence , Animals , Circovirus/enzymology , DNA-Directed DNA Polymerase/biosynthesis , Molecular Sequence Data , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sequence AlignmentABSTRACT
The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.
Subject(s)
Antigens, Viral/analysis , Herpesvirus 1, Bovine/immunology , Infectious Bovine Rhinotracheitis/prevention & control , Viral Vaccines , Animals , Cattle , Male , Neutralization Tests , Vaccines, InactivatedABSTRACT
La seroneutralización (SN) en cultivos celulares, hemoaglutinación pasiva (HA), la inmunofluorescencia indirecta (IFI) y las pruebas inmunoenzimáticas (ELISA) son de utilizadas para la detección de anticuerpos específicos contra Herpesvirus-bovino 1 (BHV-1). La prueba de SN es la determinación de referencia, sin embargo las dificuldades de implementación por la necessidad de contar con cultivos celulares, así como la celeridad en la obtención de resultados, determinan la optimización de otra prueba de alternativa y equivalente especificidad y sensibilidad. Trabajos previous describen una alta correlación entre las técnicas de SN vs IFI y de SN vs ELISA, destacando una mayor sensibilidad para el ELISA. El presente trabajo compara la sensibilidad y especificidad de IFI, ELISA y SN en la detección de anticuerpos a BHV-1 utilizando 105 sueros bovinos. La especificidad de las técnicas comparadas se demostró por la seroconversión obtenida en sueros de animales experimentalmente infectados (Cuadro 1). Se observó una alta asociación entre sueros reactivos y no reactivos entre SN e IFI, SN y ELISA y entre Ifi y ELISA destacándose una mayor sensibilidad para el ELISA (Figuras 2 y 3). El estudio estadístico de los resultados obtenidos con las tres técnicas diagnósticas determinó un alto coeficiente de correlación entre las mismas (Cuadro 2). Debido a la simplicidad y facilidad de ejecución se recomienda la técnica de ELISA para estudios epizootiológicos de larga escala
Subject(s)
Animals , Cattle , Herpesvirus 1, Bovine/isolation & purification , Infectious Bovine Rhinotracheitis/diagnosis , Enzyme-Linked Immunosorbent Assay , Species Specificity , Fluorescent Antibody Technique , Herpesvirus 1, Bovine/immunology , Neutralization TestsABSTRACT
La seroneutralización (SN) en cultivos celulares, hemoaglutinación pasiva (HA), la inmunofluorescencia indirecta (IFI) y las pruebas inmunoenzimáticas (ELISA) son de utilizadas para la detección de anticuerpos específicos contra Herpesvirus-bovino 1 (BHV-1). La prueba de SN es la determinación de referencia, sin embargo las dificuldades de implementación por la necessidad de contar con cultivos celulares, así como la celeridad en la obtención de resultados, determinan la optimización de otra prueba de alternativa y equivalente especificidad y sensibilidad. Trabajos previous describen una alta correlación entre las técnicas de SN vs IFI y de SN vs ELISA, destacando una mayor sensibilidad para el ELISA. El presente trabajo compara la sensibilidad y especificidad de IFI, ELISA y SN en la detección de anticuerpos a BHV-1 utilizando 105 sueros bovinos. La especificidad de las técnicas comparadas se demostró por la seroconversión obtenida en sueros de animales experimentalmente infectados (Cuadro 1). Se observó una alta asociación entre sueros reactivos y no reactivos entre SN e IFI, SN y ELISA y entre Ifi y ELISA destacándose una mayor sensibilidad para el ELISA (Figuras 2 y 3). El estudio estadístico de los resultados obtenidos con las tres técnicas diagnósticas determinó un alto coeficiente de correlación entre las mismas (Cuadro 2). Debido a la simplicidad y facilidad de ejecución se recomienda la técnica de ELISA para estudios epizootiológicos de larga escala (AU)
Subject(s)
Comparative Study , Animals , Cattle , Infectious Bovine Rhinotracheitis/diagnosis , Herpesvirus 1, Bovine/isolation & purification , Herpesvirus 1, Bovine/immunology , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique , Species Specificity , Neutralization TestsABSTRACT
Serum neutralization (SN), indirect immunofluorescence (IFI) and enzyme-linked immunosorbent assay (ELISA) were compared for their sensitivity and specificity to detect bovine serum antibodies to Bovine Herpesvirus type 1 on 105 bovine serum samples. High correlation coefficients among all three techniques were observed, showing a higher sensitivity for the ELISA test. Due to its simplicity and its feasibility to be adopted in less equipped laboratories, the ELISA test is recommended for large scale epizotiological studies, serological diagnosis and detection of reactive animals.
Subject(s)
Herpesvirus 1, Bovine/isolation & purification , Infectious Bovine Rhinotracheitis/diagnosis , Animals , Cattle , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique , Herpesvirus 1, Bovine/immunology , Neutralization Tests , Sensitivity and SpecificityABSTRACT
Serum neutralization (SN), indirect immunofluorescence (IFI) and enzyme-linked immunosorbent assay (ELISA) were compared for their sensitivity and specificity to detect bovine serum antibodies to Bovine Herpesvirus type 1 on 105 bovine serum samples. High correlation coefficients among all three techniques were observed, showing a higher sensitivity for the ELISA test. Due to its simplicity and its feasibility to be adopted in less equipped laboratories, the ELISA test is recommended for large scale epizotiological studies, serological diagnosis and detection of reactive animals.