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.

This study determined the distribution of stx1 and stx2 genes in Escherichia coli isolated from dairy herds with regard to animal age, season, and farm production-scale, and analyzed the phylogenetic distribution of the groups A, B1, B2, and D of 276 isolates of bovine feces Shiga toxin-producing E. coli (STEC). The stx1 profile was the most common, detected in 20.4% (202/990) of the isolates, followed by stx2 (4.54%, 45/990) and stx1+stx2 (2.92%, 29/990). The stx1 gene was detected more frequently in calves than in adult animals. In the dry season (winter), the presence of stx1+stx2 profile in cattle feces was higher than in the rainy season (summer), while no significant changes were observed between seasons for the stx1 and stx2 profiles. The most predominant phylogenetic groups in adult animals were B1, A, and D, while groups A and B1 prevailed in calves. Our data highlight the importance of identifying STEC reservoirs, since 7.5% of the tested isolates were positive for stx2, the main profile responsible for the hemolytic-uremic syndrome (HUS). Moreover, these microorganisms are adapted to survive even in hostile environments and can contaminate the food production chain, posing a significant risk to consumers of animal products.

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.

An outbreak of skin burn and ocular damage by calcium oxide in swines is reported. The outbreak occurred in a rural property located in the municipality of Iuiu, Western Bahia, during the transport of 60 pigs from a recreation farm to a fattening farm. The observed macroscopic lesions were erythematous areas; formation of papules, vesicles, and in some cases, there was the formation of firm, parched, high brown plaques and in other cases detachment and loss of skin. His eyes were dull. Histological analysis of the skin revealed areas of necrosis of focally extensive clotting of the epidermis, and dermis, delimited in the paniculus, by cellular debris and rare neutrophils. Corneal necrosis with perforated ulcer formation, superficial epithelial necrosis, edema, and neutrophil infiltration of the cornea adjacent to the ulcer were revealed in the eye.

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RESUMO: O presente estudo objetivou determinar a prevalência e distribuição de lesões abscedativas, identificação do agente etiológico e avaliação das lesões histológicas em caprinos e ovinos abatidos em um matadouro-frigorífico com Serviço de Inspeção Federal do estado da Bahia. Foram coletadas 153 amostras de vísceras e linfonodos com abscessos de 1.148 animais abatidos. A maior prevalência na espécie ovina foi em macho, com faixa etária de 12 meses, sendo os principais órgãos acometidos fígado (21,2%) e linfonodo pré-escapular (20,3%). Na espécie caprina, a prevalência maior foi em macho, com faixa etária de 30 meses, sendo os linfonodos retro faríngeo (25%) e pré-escapular os mais acometidos (25%). Isolou-se os seguintes micro-organismos das amostras: Corynebacterium pseudotuberculosis em 33,33%, Escherichia coli (19,61%), Proteus mirabilis (9,80%), Pseudomonas aeruginosa (7,19%), Trueperella pyogenes (5,22%), Streptococcusspp. (5,22%) e Staphylococcus aureus (4,57%). As lesões macroscópicas e histológicas dos abscessos coletados não apresentaram diferenças entre micro-organismos isolados.

Background: Malignant edema is one of the terms used to designate severe necrotizing syndromes in soft tissues by Clostridium spp. which are potentially fatal in farm animals. These species are responsible for myonecrosis, belonging to the group of histotoxic clostridia, and may also culminate in toxemia with the worsening of the lesions. These clostridia and their spores require a gateway such as wounds on mucous membranes or skin, which may occur due to shear, tail cut, injuries during delivery, castration or injections by contaminated needles. This report aims to describe the clinical-pathological findings of a case of malignant edema caused by C. perfringens type A in an equine.Case: A female equine, undefined breed, used as traction animal, had a history of abdominal pain. According to the requisitioning veterinary, the tutor reused needles for medication. On palpation, a compact mass was noticed in the pelvic flexure, as well as edema on the region of head and neck with crackling areas. After surgical intervention for compactation correction, the animal did not show anesthetic recovery and was submited to euthanasia. Tissue samples were collected, fixed in 10% buffered formalin solution, routinely processed for histopathology and stained with hematoxylin and eosin and Gram stain. Samples of serous-sanguineous edema fluid and fragments of the abdominal muscles and neck were collected. The samples were kept under refrigeration and sent for microbiological culture. Necropsy showed the subcutaneous region of the pectoral was markedly gelatinous and yellowish (edema) and subcutaneous emphysema characterized by accumulation of serous-sanguineous fluid and gas bubbles. In microscopy, we verified fibrous-haemorrhagic, emphysematous, suppurative and diffuse superficial histiocytic necrotizing cellulitis and myositis. Gram-positive bacillary aggregates were observed in spleen and subcutaneous sections. Colony suggestive of Clostridium perfringens were submitted to PCR for confirmation of identity followed by genotyping. Lastly, C. perfringens type A was isolated from the muscle fragments and serosanguinolent liquid collected.Discussion: In the present study, the diagnosis of malignant edema caused by Clostridium perfringens type A in an equine was confirmed by the clinical-pathological findings added to the isolation and genotyping of the agent from fragments of injured muscle. Although C. perfringens has been reported in cases of clostridial myositis in horses in the United States, in Brazil there are only reports of sporadic cases associated with C. septicum, C. novyi and C. chauvoei in this species. In histotoxic cases by C. perfringens, alpha toxin is known to be the main virulence factor involved, causing destruction of the phospholipid membrane of erythrocytes, endothelial cells, leukocytes and muscle fibers. As consequence, there is an increase in the vascular permeability of capillaries and, with the spread of the infection, there is production of inflammatory edema with serosanguineous exudate and gas. Typically, anatomopathological findings are characterized by increased volume of the affected region associated with edema with bloody fluid and rancid odor, gas bubbles in the subcutaneous tissue, and fasciae associated or not with necrotic myositis. It is assumed that a contaminated needle injection, performed during the treatment of colic symptoms on the property has been the gateway to infection. The clinical course of clostridial infection in horses is considered acute, ranging from 24 to 48 h. In this case, was observed the animal with signs of cervical and pectoral edema still in the property, a day before euthanasia. This is the first study to confirm Clostridium perfringens as a cause of gas gangrene in horses in Brazil.