Experimental Yellow Fever in Squirrel Monkey: Characterization of Liver In Situ Immune Response.

Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1-30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.

Antitoxin therapy of natural avian botulism outbreaks occurred in Brazil.

Botulism commonly affects water birds and it has recently been observed to be emerging in poultry production. In the present work, outbreaks of botulism in wild native species, such as the black-fronted Piping-guan (Aburria jacutinga), wild duck (Cairina moschata) and its crosses with mallard (Anas platyrhynchos), and domestic chickens (Gallus gallus domesticus) are described. Following treatments with a commercial botulism antitoxin CD, 28 (96.5%) out of 29 animals fully recovered after 24-72 h. The antitoxin therapy was shown to be a useful option for the treatment of affected birds, including those that were severely affected.

Avaliação lectino-histoquímica de fígado e linfonodo mesentérico de búfalos mantidos em pastagens de Brachiaria spp / Lectin histochemistry evaluation of liver and mesenteric lymph node of buffaloes kept on Brachiaria spp. pastures

Animais que se alimentam em pastos de Brachiaria spp. comumente apresentam macrófagos espumosos isolados ou agrupados no fígado, além de cristais no interior de ductos biliares. A patogênese da formação e a natureza do material armazenado nestas células, contudo, ainda não são completamente conhecidas. Através da avaliação lectino-histoquímica, saponinas esteroidais (metabólitos glicosilados secundários) têm sido identificadas nos cristais e no citoplasma das células espumosas, e provavelmente são responsáveis por danificar o fígado e levar ao acúmulo de filoeritrina. Por meio deste trabalho, objetivou-se padronizar e caracterizar a utilização da lectino-histoquímica na detecção de metabólitos glicosilados nos tecidos de búfalos mantidos em diferentes pastos de Brachiaria spp. no Brasil. Fragmentos de fígado e linfonodo mesentérico de 40 animais foram analisados: 10 búfalos mantidos em pastagem predominante de B. decumbens por aproximadamente 12 meses; 10 búfalos mantidos em pastagem predominante de B. brizantha por aproximadamente 18 meses; 10 búfalos mantidos em pastagem de B. brizantha por aproximadamente quatro anos; e, como controle negativo, 10 búfalos mantidos em pastagem livre de Brachiaria spp. desde o nascimento. Quatorze lectinas foram testadas (Con-A, SBA, WGA, DBA, UEA, RCA, PNA, GSL-I, PSA, LCA, PHA-E, PHA-L, SJA e SWGA), em um total de 1120 fragmentos avaliados. Estudos anteriores demonstraram que a lectina PNA possui marcada reatividade para macrófagos espumosos de bovinos e ovinos. No presente estudo, a lectina SWGA apresentou acentuada reatividade e alta especificidade para macrófagos espumosos; WGA, GSL, PHA-E e PHA-L mostraram moderada a acentuada reatividade, mas baixa especificidade aos macrófagos espumosos; as outras lectinas não apresentaram reatividade ou especificidade relevantes. Além disso, não houve diferença relevante de marcação entre os fragmentos coletados de animais que se alimentaram de B. decumbens por 12 meses e B. brizantha por 18 meses. Porém, a diminuição da presença e marcação lectino-histoquímica dos macrófagos espumosos nos tecidos dos búfalos que ingeriram Brachiaria brizantha durante mais tempo indica que os animais podem passar por um processo de adaptação de acordo com o tempo de ingestão da planta. A avaliação lectino-histoquímica pode ser utilizada para caracterizar o material armazenado em macrófagos espumosos presentes no fígado e linfonodo mesentérico de búfalos que se alimentam em pastagens de Brachiaria spp. e ajuda na compreensão da patogênese de formação destas células.(AU)

Animals grazing Brachiaria spp. commonly present foamy macrophages isolated or grouped in the liver, and crystals within biliary ducts. The pathogenesis of formation and the nature of the material stored in these cells however are not completely known. Through lectin histochemistry evaluation, steroidal saponins (secondary glycosylated metabolites) have been identified in the crystals and within the cytoplasm of the foam cells, which are probably liable for damaging the liver, leading to accumulation of phylloerythrin. This study aims to standardize and characterize the use of lectin histochemistry to detect glycosylated metabolites in tissues of buffaloes kept on different Brachiaria spp. pastures in Brazil. Fragments of liver and mesenteric lymph node from 40 buffaloes were analyzed: 10 buffaloes that were kept in predominant pasture of B. decumbens for 12 months; 10 buffaloes that were kept in pasture with a predominance of B. brizantha for 18 months; 10 buffaloes that were kept on pasture of B. brizantha for about four years; and as a negative control, 10 buffaloes that were maintained on native pasture without Brachiaria spp. since birth. Fourteen lectins were tested (Con-A, SBA, WGA, DBA, UEA, RCA, PNA, GSL-I, PSA, LCA, PHA-E, PHA-L, SJA and SWGA), in a total of 1120 evaluated samples. Previous studies demonstrated that PNA showed great binding reactivity for foamy macrophages in cattle and sheep. In the present study, SWGA showed high specificity and marked binding reactivity for foamy macrophages; WGA, GSL, PHA-E and PHA-L showed moderate to marked reactivity, but low specificity for foamy macrophages. The other lectins had not relevant reactivity or specificity. Moreover there was no relevant reactivity difference between the collected samplesd from buffaloes that grazed B. decumbens for 12 months and Brachiaria brizantha for 18 months. However the decreased presence of foamy macrophages and its lectin histochemical binding in animals that fed on B. brizantha for a longer time, indicates that the buffaloes can pass through an adaptation process according to the plant intake time. Lectin histochemistry analysis can be used to characterize the material stored in foamy macrophages present in liver and mesenteric lymph node of buffaloes that graze on Brachiaria spp. pastures and helps to clarify the pathogenesis of these cells.(AU)

ISOLATION AND GENOTYPING OF CLOSTRIDIUM PERFRINGENS FROM FREE-LIVING SOUTH AMERICAN COATI (NASUA NASUA).

The importance of Clostridium perfringens for most wild animal species remains unclear. This study aimed to isolate and genotype C. perfringens in stool samples from free-living South American coati (Nasua nasua) in Brazil. Forty-six free-living N. nasua were trapped and stool samples were collected. Two different protocols for C. perfringens isolation were tested: direct plating onto selective agar and pre-enrichment in broth followed by plating in selective agar. Clostridium perfringens type A was isolated from 15 (32.6%) animals by direct plating and 36 (78.3%) animals by broth PE, and the rate of isolation was significantly different between these two methods (P < 0.01). Twelve of the 36 (33.3%) isolated strains by the PE protocol were positive for the ß-2 toxin-encoding gene (cpb2) whereas the enterotoxin-encoding gene (cpe) and necrotic enteritis like-B toxin gene (netb) were not found. These results suggest that C. perfringens is commonly part of the microbiota of free-living coatis. Additionally, the use of a PE protocol appears to be essential for studies on C. perfringens in this species.

Complete genome sequence of Peptoclostridium difficile strain Z31.

BACKGROUND: Peptoclostridium (Clostridium) difficile is a spore-forming bacterium responsible for nosocomial infections in humans. It is recognized as an important agent of diarrhea and colitis in several animal species and a possible zoonotic agent. Despite the known importance of P. difficile infection in humans and animals, no vaccine or other effective measure to control the disease is commercially available. A possible alternative treatment for P. difficile infection is the use of a nontoxigenic strain of P. difficile as a competitive exclusion agent. However, a thorough knowledge of this strain is necessary for this purpose. We selected P. difficile Z31, a nontoxigenic strain (PCR ribotype 009), for investigation because it prevents P. difficile infection in a hamster model. RESULTS: The genome sequence of P. difficile Z31 is a circular chromosome of 4298,263 bp, with a 29.21 % GC content, encoding 4128 proteins, and containing 78 pseudogenes. This strain belongs to ST 3, clade 1, and has five phage regions in its genome. Genes responsible for resistance to tetracycline and erythromycin were detected and more importantly, Z31 also contains genes that promote spore production and stability, cell attachment, intestinal adherence, and biofilm formation. CONCLUSION: In this study, we present the first complete genome sequence of nontoxigenic P. difficile strain Z31. When the Z31 genome was compared with those of other isolates available in GenBank, including a draft genome of a nontoxigenic strain, several unique regions were evident. Z31 contains no toxin genes, but encodes several non-toxin virulence factors, which may favor host colonization.