Search

Norovirus (NoV) has been classified into 6 genogroups, GI-GVI. In the present study, we identified novel feline NoV (FNoV) M49-1 strain. The C-terminal of RNA-dependent RNA polymerase of the FNoV M49-1 strain was highly homologous with GIV FNoV and GIV lion norovirus, whereas VP1 was highly homologous with GVI canine NoV (CNoV). Based on the results of the Simplot analysis, the FNoV M49-1 strain may have been produced by recombination between GIV.2 FNoV and GVI.1 CNoV. In addition, specific pathogen-free cats inoculated with FNoV gene-positive-fecal samples developed diarrhea symptoms, and the viral gene was detected in their feces and blood. [ABSTRACT FROM AUTHOR]

Abstract: Canine monocytic ehrlichiosis is a highly prevalent disease in Brazil, where the genetic diversity of Ehrlichia canis remains undefined. In this study, we used the TRP36 gene to examine the genetic diversity of E. canis strains from naturally infected dogs residing in five distinct geographic regions in Brazil. E. canis DNA was detected in 82/126 (65%) dogs by dsb-specific PCR and E. canis was isolated in cell culture from 13 dogs. Sequences obtained from dsb genes amplified from the isolates were identical to the US E. canis strain. An extended molecular characterization based on the TRP36 gene identified two major genogroups based on differences among eight isolates. Isolates with tandem repeat amino acid sequence (TEDSVSAPA) identical to the previously reported TRP36 sequence were found in the midwest, northeast and southeast regions of Brazil, and classified into the US genogroup. A novel Brazilian genotype with a different tandem repeat sequence (ASVVPEAE) was also identified in midwest, northern and southern regions. Similarity in the N-terminal sequence of a US genogroup member with the Brazilian genogroup suggested that genomic recombination between the two genogroups may have occurred. Other subtypes within the Brazilian genogroup were also identified using C-terminal amino acid divergence. We identified two distinct major Brazilian genogroups and several subtypes based on analysis of TRP36, and such information will be useful for further genotyping and possible associations with disease severity, understanding of the genetic and antigenic variability of E. canis, and for developing strain-specific vaccines and diagnostic methods based on TRP36. [Copyright &y& Elsevier]

Abstract: Our primary objectives were to determine: the relative virulence of porcine circovirus (PCV) 2a and PCV2b, if heterologous infection induces severe illness, and the relative concentration of PCV2a and PCV2b in tissues of heterologously infected pigs. In experiment 1, 18 germ-free piglets served as controls or were infected with PCV2a or PCV2b. Half were immune stimulated with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund''s adjuvant (2aKLH, 2bKLH). No piglets demonstrated severe illness. Lesion severity did not differ, but PCV2 capsid staining was more intense in 2a- than 2b-infected pigs (P <.05). In experiment 2, 20 germ-free piglets were dual inoculated 7 days apart with PCV2a and PCV2b (2a2b, 2b2a), PCV2b twice (2b2b), or PCV2a (2a2a) twice. Five of 9 heterologous-infected pigs developed severe illness. All heterologously infected pigs demonstrated ascites or edema, and 8/9 developed thymic atrophy. By contrast, 1 of 5 2b2b-infected pigs developed bronchopneumonia and pleural effusion. No 2a2a-infected pig developed illness. Gross lesions were more severe in heterologously infected pigs than in 2b2b pigs (P <.05), and were more severe in 2b2b than 2a2a pigs (P <.05). PCV2 capsid staining intensity did not differ by group. In heterologously infected pigs, higher levels of PCV2 DNA reflective of the first inoculum compared to the second were found in mesenteric lymph node (P =.04), spleen (P =.004) and liver (P =.04). These results indicate that dual heterologous PCV2a/2b inoculation 7 days apart may induce severe clinical illness, but PCV2a and PCV2b when administered singularly or in combination with KLH appear to be of equivalent virulence. [Copyright &y& Elsevier]

Abstract: A retrospective study to detect evidence of swine Torque teno virus (TTV) genogroups 1 and 2 infection in sera of pigs from the Spanish livestock between years 1985 and 2005 was carried out by means of PCR. Also, the molecular evolution of TTV genogroups 1 and 2 during the 20-year period studied using a 250-base sequence of the non-coding region of the viral genome was assessed. Both TTV genogroup genomes were found in pig sera from the first year of study. Taking into account the whole study period, 113 out of 162 animals (69.8%) were infected with one or the other genogroup, while 38 out of 162 pigs (23.5%) were co-infected with both genogroups. Moreover, TTV genogroup 2 (90 out of 162, 55.6%) was significantly more prevalent than genogroup 1 (54 out of 162, 33.3%). The non-coding region of swine TTV genome sequenced showed its adequacy as a molecular marker in swine TTV. This study represents the earliest evidence of TTV infection in pigs to date, 14 years before the initial description of this virus. Moreover, this is also the earliest evidence of TTV infection in any species. [Copyright &y& Elsevier]