Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.
A novel lymphocystivirus causing typical signs of lymphocystis virus disease in whitemouth croaker (Micropogonias furnieri) on the coast of Uruguay was detected and described recently. Based on genetic analysis of some partially sequenced core genes, the virus seemed to differ from previously described members of the genus Lymphocystivirus. In this study, using next-generation sequencing, the whole genome of this virus was sequenced and analysed. The complete genome was found to be 211,086 bp in size, containing 148 predicted protein-coding regions, including the 26 core genes that seem to have a homologue in every iridovirus genome sequenced to date. Considering the current species demarcation criteria for the family Iridoviridae (genome organization, G+C content, amino acid sequence similarity, and phylogenetic relatedness of the core genes), the establishment of a novel species (“Lymphocystis disease virus 4”) in the genus Lymphocystivirus is suggested.
Bovine Leukemia Virus (BLV) produces disorders on the immune system in naturally infected animals, which may counteract the development of immunity after vaccination. The aim of this study was to investigate whether healthy and BLV infected cattle elicited similar humoral responses after foot and mouth disease (FMD) immunization. In a field study, 35 Holstein heifers were selected based on their BLV serological status and immunized with a single dose of a commercial bivalent oil-based FMD vaccine. Serum samples were collected at 0, 15, 60, 165 and 300 days post vaccination (dpv). Total anti-A24/Cruzeiro antibodies, IgM, IgG1, IgG2 titers and avidity index of specific antibodies were determined by ELISA. Although only marginally significant differences were found between groups in terms of total antibodies, anti-FMD IgM and IgG1 titers were significantly lower in heifers infected with BLV at the 15 dpv (p < 0.01). Animals that became infected during the study did not show differences to the BLV negative group. Cattle infected with BLV at the time of immunization may elicit a low-magnitude serological response to a commercial Foot-and-mouth disease vaccine.
Bovine alphaherpesvirus 1 is ubiquitous in cattle populations and is associated with several clinical syndromes, including respiratory disease, genital disease, infertility and abortions. Control of the virus in many parts of the world is achieved primarily through vaccination with either inactivated or live modified viral vaccines. The objective of this study was to evaluate the performance of four commercially available BoHV-1 vaccines commonly used in Central and South America. Animals were divided into eight groups and vaccinated on days 0 and 30. Groups 1 to 4 received two doses of four different BoHV-1 commercial vaccines (named A to D). Groups 5 and 6 received vaccine D plus a vaccine for either Clostridial or Food-and-Mouth-Disease (FMD), respectively. Group 7 received one dose of two different brands of reproductive vaccines. Serum samples were collected from all animals on days 0, 30 and 60 to evaluate neutralizing and isotype-specific (IgG1 and IgG2) antibodies. Of the four commercial vaccines evaluated, only vaccine A induced neutralizing antibodies to titers ≥ 1:8 in 13/15 (86%) of the animals 60 days post-vaccination. Levels of IgG2 antibody increased in all groups, except for group 2 after the first dose of vaccine B. These results show that only vaccine A induced significant and detectable levels of BoHV-1-neutralizing antibodies. The combination of vaccine D with Clostridial or FMD vaccines did not affect neutralizing antibody responses to BoHV-1. The antibody responses of three of the four commercial vaccines analyzed here were lower than admissible by vaccine A. These results may be from vaccination failure, but means to identify the immune signatures predictive of clinical protection against BoHV-1 in cattle should also be considered.