Enterotoxigenic Escherichia coli (ETEC) is the major cause of diarrhea in newborn and weaned pigs. Bacteria adhesion to the host cell is considered a specific phenomenon among fimbrial and non-fimbrial adhesins with their respective RESUMO Escherichia coli (E. coli) enterotoxigênica (ETEC) é considerada importante causa de diarreia em suínos neonatos e desmamados. A adesão da bactéria à célula do hospedeiro é considerada um fenômeno específico entre as adesinas fimbriais e não fimbriais com seus respectivos receptores nos enterócitos. Os distúrbios entéricos estão relacionados com as fímbrias F4 (K88), F5 (K99), F6 (987P),

Congenital tremor in pigs involves several etiologies, including pestivirus, which may cause neurological injuries in different animal species. To evaluate whether bovine viral diarrhea virus (BVDV), an important pestivirus, is one of the etiological agents of congenital tremor in swine, gilts and the fetuses were challenged at 45 days of gestation with BVDV-2. Four pregnant gilts were inoculated oronasally, four gilts underwent fetal intrauterine inoculation, and two gilts constituted the control group. Antibody titers were determined by virus neutralization (VN), and viral RNA was detected by RT-PCR. Blood samples were collected from all gilts and piglets born to obtain whole blood and serum for analysis. One third of the neonates were euthanized at three days old, and samples of the encephalon, brain stem and spinal cord were collected for anatomopathological evaluation and viral RNA detection. The piglets that remained alive were clinically evaluated every day, and blood sampling was performed regularly for 35 days. The piglets from gilts in both inoculation treatment groups showed no clinical neurological signs and were born with no viral RNA in their blood and organs. Piglets born from oronasally inoculated gilts did not present antibodies against BVDV-2 at birth, although they were acquired by passive maternal transfer. In contrast, intrauterine-inoculated piglets were born with high antibody titers (80 to 640) against the agent, which remained high until the end of the experimental period. Microscopically, no noticeable changes were observed. Macroscopically, 29.5% of the total piglets euthanized, from both inoculation groups, were born with a low cerebellar:brain ratio. Nevertheless, some piglets had a high cerebellar:brain ratio, indicating the need for standardizing this value. Thus, it was concluded that BVDV is not an etiological agent for congenital swine tremor.

Swine can be infected by bovine viral diarrhea virus (BVDV). However, transmission routes among pigs are still unknown. The objective of the present study was to induce experimental infection of BVDV-1 in weaned piglets and to assess the potential transmission through pen back pond water, used to facilitate heat exchange of the pigs housed in barns. Two repetitions (BP1 and BP 2) were performed using 12 piglets proven to be free BVDV (n=6 per repetition) allocated into three groups: control, sentinels and infected with two piglets each. The piglets were placed in stainless steel isolators. The infected group received an inoculum containing BVDV-1, Singer strain. The piglets remained in the cabinets for 25 days, during which samples of nasal swab were collected daily and blood sampled weekly. At the end, the piglets were euthanized, necropsied and organ fragments were collected for histopathology, immunohistochemistry and RT-PCR. In the first experiment (BP1) the infected animals shed the virus between days 6 and 21 post-infection. Regarding the sentinel group, shedding occurred in only one piglet, on the 20th day after infection, and seroconversion was observed on the 25th day post-infection. In BP2, infected piglets I3 and I4 shed the virus on days 4 and 21 post-infection, respectively. Only one sentinel piglet (S3) she the virus on day 13 post-infection. Therefore, it was concluded that pigs can become infected with BVDV-1 and shed potentially infectious viral particles consequently, being able to transmit the virus to other pigs through back pond water.

Swine can be infected by the bovine viral diarrhea virus (BVDV) under natural conditions. For this reason, further information and divulgation are needed regarding the pathogenicity of this virus in swine. This infection is practically unknown in the realm of pig farming, and, as it shares some similarities with the classical swine fever virus (CSFV), its diagnosis becomes a challenge for official sanitary programs. Studies have shown the absence of clinical signs in piglets and reproductive problems in sows due to BVDV infections. There is little research on the prevalence, risk factors, preventive measures and control of BVDV in pigs around the world. And in Brazil, the data is practically non-existent. At the time of diagnosis, comparing the most efficient laboratory tests such as virus neutralization, ELISA, RT-PCR, and immunofluorescence so as to minimize the risk of cross serological reactions when dealing with a persistent or transient infection, can be an important tool. Moreover, the practical implications for CSFV eradication programs are a main reason for the development of further research against this infection. Therefore, this paper aims to review various aspects of BVDV infection in pigs, and how this information can be important for Brazilian herds.

ABSTRACT.-Ricardo P., Oliveira L.G., Baraldi T.G., Mechler M.L., Almeida H.M.S., Silva G.C.P., Gatto I. The aim of this study was to determine the occurrence of antibodies anti-Brucella in 1,940 swine blood samples. Out of the 1,940 sera samples, 1,594 were from 30 intensive pig farming from seven different states, collected during the slaughtering of animals, and 346 samples from 56 non-technified (subsistence) pig herds from Jaboticabal region, São Paulo State, Brazil. All samples were tested by Buffered Plate Acidified Antigen (BPAA) and considered positive in case of agglutination. If positive, the samples were tested by Complement Fixation Reaction (CFR) as a confirmatory test. Out of the 1,594, two were positive for BPAA but negative for CFR, so the occurrence was 0%. Among the 346 samples, two were positive for BPAA but only one was positive in the confirmatory test, whith a titer of 1:8. Thus, the occurrence was 0.29%, an important result to demonstrate the improvement of the sanitary status of Brazilian non-technified pig herds, despite the low conditions of production.