The full-length genome of the highly lethal feline infectious peritonitis virus (FIPV) strain DF-2 was sequenced and cloned into a bacterial artificial chromosome (BAC) to study the role of ORF3abc in the FIPV-feline enteric coronavirus (FECV) transition. The reverse genetic system allowed the replacement of the truncated ORF3abc of the original FIPV DF-2 genome with the intact ORF3abc of the canine coronavirus (CCoV) reference strain Elmo/02. The in vitro replication kinetics of these two viruses was studied in CrFK and FCWF-4 cell lines, as well as in feline peripheral blood monocytes. Both viruses showed similar replication kinetics in established cell lines. However, the strain with a full-length ORF3 showed markedly lower replication of more than 2 log 10 titers in feline peripheral blood monocytes. Our results suggest that the truncated ORF3abc plays an important role in the efficient macrophage/monocyte tropism of type II FIPV.

Brucella spp. were isolated from an abortion case submitted for laboratory examination 8 months after the first clinical symptoms appeared in a kennel consisting of 31 dogs. Pathological investigations revealed the parallel presence of necrotic placentitis and the strong immunostaining of trophoblast cells by immunohistochemistry (IHC) using hyperimmune rabbit anti-Brucella canis primary antibodies. The rapid slide agglutination test was positive in 7 of 31 (23%) cases. The organism B. canis was successfully cultured from the blood, tissues, or vaginal swabs of only 3 of 31 (10%) cases. The isolated strains were identified as B. canis based on their colony morphology and agglutination with R sera. The strains were initially misidentified as B. suis with the "Bruce-ladder" method, and were subsequently correctly identified as B. canis with a single nucleotide polymorphism (SNP) typing test. Three culture-positive cases and 3 culture-negative cases with histories of reproductive disorders were selected and examined for the presence of B. canis infection using histopathology, IHC, and polymerase chain reaction (PCR) assays. Characteristic histologic lesions were found in all of the 6 animals, whereas IHC and PCR yielded positive results only in single cases from both groups. The results imply that all cases of canine abortion should be examined for brucellosis by bacterial culture of aborted fetuses and placentas. Immunohistochemical examination of placentas is also recommended because it is a quick and sensitive technique compared with bacterial culture. Multiple methods (i.e., serology, blood, and genital bacterial cultures) should be applied simultaneously and repeatedly for the reliable screening of B. canis infection in live individuals.

Porcine circovirus 3 (PCV3) infection has been reported in piglets and sows with porcine dermatitis and nephropathy syndrome, reproductive failure, and cardiac and multisystemic inflammation. Few studies linked PCV3 infection to increased incidence of abortion and weak-born piglets. This is the first report of a detection of PCV3 Hungarian strain in several organs of aborted and weak-born piglets, including the thymus, lymph node, placenta, spleen, kidney and the liver. The tissue tropism of PCV3 in affected litters was analysed using real-time quantitative PCR, and the result showed the highest load of viral DNA in the thymus and lymph nodes. The ORF2 of Hungarian PCV3 strains was 524 nucleotides in length, and the sequence identity to GenBank sequences ranged from 98.5 per cent to 99.2 per cent. The results suggest that PCV3 may have a relevant role in reproductive failure in gilts.

No abstract

No abstract