Summary Recently, a putative new pestivirus species, provisionally named as Atypical Porcine Pestivirus (APPV), was associated with the congenital tremor in piglets in North America and consequently in Europe and Asia. The present research aimed to describe the detection and characterization of APPV employing NS5B gene partial sequencing, gross pathology and histologic examination of piglets displaying congenital tremor from two different farms of Southern Brazil. No gross lesions were observed, and the histological findings revealed moderate vacuolization of the white matter of the cerebellum. RT‐PCR followed by DNA sequencing and a phylogenetic analysis confirmed the presence of APPV in samples from the two farms, which the samples were distinct in nature. Phylogenetic reconstruction reinforced the high genetic variability within the APPVs previously reported. This is the first report of APPV in South America suggesting that this new group of viruses may be widespread in swine herds in other countries as it is in Brazil.

No abstract

The aim of this study was to assess the frequency and association of virulence factors of Escherichia (E.) coli isolated from weaned piglets with diarrhea and to correlate it with fecal consistency. A total of 152 rectal swabs were collected from 25-40 day-old piglets with diarrhea, in farms of Southern Brazil. Phenotypical and molecular techniques were used for bacterial isolation, characterization and classification of enterotoxigenic E. coli (ETEC) pathotypes. Statistical analysis was carried out to determine the frequency of virulence factors and virotypes, of fimbriae F4, F5, F6, F18, F41 and toxins LT, STa, STb and STx2e. Out of 456 E. coli isolates, 287 (62.9%) samples showed significant growth of E. coli. Among them, 194 (67.6%) samples showed at least one virulence factor, indicating that ETEC is an important etiological agent of diarrhea in weaned piglets. Higher frequencies were found of fimbria F4 and F18 and enterotoxins LT, STa and STb. Significant association was found to F4, LT, STa and STb; between F18 and STa and STx2e; between F5 and LT, STa and STb. The most frequent virotypes were F18-STa, F4-LT-STa-STb, F4-STa, F4-LT-STb and F18-STa-STx2e. Beta-hemolysis was observed in 47.4% of samples and there was significant association between hemolytic samples and virulence factors F4, F18, STa and STx2e. Regarding fecal consistency, there was significant association of liquid feces and F4 fimbria, STa toxin and virotypes F4-STa and F4-F5-LT-STa-STb. Since there was significant association of ETEC and liquid feces in nursery piglets, it is important to prioritize the sampling of liquid feces for the diagnosis etiologic cause of diarrhea.

No abstract