Comparative study on alginate/chitosan microcapsules and Montanide ISA 61 as vaccine adjuvants in mice.

Selection of adjuvant to be combined with the antigen is an extremely important point for formulating effective vaccines. The aim of this study was to evaluate reactogenicity, levels of IgM, IgG and subclasses (IgG1, IgG2b and IgG3), and protection elicited by vaccine formulations with association of chitosan coated alginate or Montanide ISA 61 with γ-irradiated Brucella ovis. The alginate/chitosan biopolymers as well as the Montanide ISA 61 emulsion elicited intense and long-lasting local response, especially when associated with the antigen. However, Montanide ISA 61 induced less intense reactogenicity when compared to alginate/chitosan. Furthermore, γ-irradiated B. ovis with Montanide ISA 61 induced higher levels of IgG2b an important marker of cellular immune response. In conclusion, Montanide ISA 61 resulted in milder reactogenicity when compared to the alginate/chitosan, while it induced a high IgG2b/IgG1 ratio compatible with a Th1 profile response.

Pericytes modulate endothelial inflammatory response during bacterial infection.

Pericytes are located around blood vessels, in close contact with endothelial cells. We discovered that pericytes dampen pro-inflammatory endothelial cell responses. Endothelial cells co-cultured with pericytes had markedly reduced expression of adhesion molecules (PECAM-1 and ICAM-1) and proinflammatory cytokines (CCL-2 and IL-6) in response to bacterial stimuli (Brucella ovis, Listeria monocytogenes, or Escherichia coli lipopolysaccharide). Pericyte-depleted mice intraperitoneally inoculated with either B. ovis, a stealthy pathogen that does not trigger detectable inflammation, or Listeria monocytogenes, developed peritonitis. Further, during Citrobacter rodentium infection, pericyte-depleted mice developed severe intestinal inflammation, which was not evident in control mice. The anti-inflammatory effect of pericytes required connexin 43, as either chemical inhibition or silencing of connexin 43 abrogated pericyte-mediated suppression of endothelial inflammatory responses. Our results define a mechanism by which pericytes modulate inflammation during infection, which shifts our understanding of pericyte biology: from a structural cell to a pro-active player in modulating inflammation. IMPORTANCE: A previously unknown mechanism by which pericytes modulate inflammation was discovered. The absence of pericytes or blocking interaction between pericytes and endothelium through connexin 43 results in stronger inflammation, which shifts our understanding of pericyte biology, from a structural cell to a player in controlling inflammation.

Brucella ovis mutant in ABC transporter protects against Brucella canis infection in mice and it is safe for dogs.

BACKGROUND/OBJECTIVES: Vaccination is the most important tool for controlling brucellosis, but currently there is no vaccine available for canine brucellosis, which is a zoonotic disease of worldwide distribution caused by Brucella canis. This study aimed to evaluate protection and immune response induced by Brucella ovis ΔabcBA (BoΔabcBA) encapsulated with alginate against the challenge with Brucella canis in mice and to assess the safety of this strain for dogs. METHODS: Intracellular growth of the vaccine strain BoΔabcBA was assessed in canine and ovine macrophages. Protection induced by BoΔabcBA against virulent Brucella canis was evaluated in the mouse model. Safety of the vaccine strain BoΔabcBA was assessed in experimentally inoculated dogs. RESULTS: Wild type B. ovis and B. canis had similar internalization and intracellular multiplication profiles in both canine and ovine macrophages. The BoΔabcBA strain had an attenuated phenotype in both canine and ovine macrophages. Immunization of BALB/c mice with alginate-encapsulated BoΔabcBA (108 CFU) induced lymphocyte proliferation, production of IL-10 and IFN-γ, and protected against experimental challenge with B. canis. Dogs immunized with alginate-encapsulated BoΔabcBA (109 CFU) seroconverted, and had no hematologic, biochemical or clinical changes. Furthermore, BoΔabcBA was not detected by isolation or PCR performed using blood, semen, urine samples or vaginal swabs at any time point over the course of this study. BoΔabcBA was isolated from lymph nodes near to the site of inoculation in two dogs at 22 weeks post immunization. CONCLUSION: Encapsulated BoΔabcBA protected mice against experimental B. canis infection, and it is safe for dogs. Therefore, B. ovis ΔabcBA has potential as a vaccine candidate for canine brucellosis prevention.

Sarcoptic mange (Sarcoptes scabiei) in wild canids (Cerdocyon thous) / Sarna sarcóptica (Sarcoptes scabiei) em cachorro-do-mato (Cerdocyon thous)

Crab-eating foxes (Cerdocyon thous) are wild canids found in practically all Brazilian states. They usually live and hunt in pairs, but can be found in small groups, which favors the transmission of diseases such as sarcoptic mange. This study aims to describe the epidemiological, parasitological and pathological findings of two fatal cases of sarcoptic mange in C. thous. Two wild canids were necropsied and cytological examination of skin and crust samples and histologic evaluation of various tissue samples were performed. Gross findings included poor body condition and extensive alopecia with thick skin crusts interspersed by intensely reddened alopecic areas. The cytological examination revealed numerous mites with short gnathosoma and rounded idiosoma that were transversally striated and presented triangular spines on the dorsal surface, terminal anus, and short and thick legs, characteristic of Sarcoptes scabiei. Histologic examination of the skin revealed numerous tunnels into and under the stratum corneum of the epidermis containing high amounts of S. scabiei. The mites were associated with marked acanthosis and hyperkeratosis, and mild superficial dermatitis. The findings reveal that sarcoptic mange is an important disease in wild canids.(AU)

Cachorros-do-mato (Cerdocyon thous) são canídeos selvagens encontrados em praticamente todos os estados brasileiros. Geralmente vivem e caçam em pares, mas podem ser encontrados em pequenos grupos, o que favorece a transmissão de doenças, como a sarna sarcóptica. O presente trabalho tem como objetivo descrever os achados epidemiológicos, parasitológicos e patológicos de dois casos fatais de sarna sarcóptica em cachorros-do-mato. Foram realizados necropsia de dois cachorros do mato, exame citológico de amostras de pele e crostas e exame histológico de amostras dos órgãos e tecidos. Na necropsia foram observados mau estado corporal, extensas áreas de alopecia, crostas cutâneas espessas que se desprendiam e eram intercaladas por áreas alopécicas intensamente eritematosas. No exame citológico foi observada grande quantidade de ácaros com gnatossoma curto e largo, idiossoma globoso, transversalmente estriado e com espinhos triangulares na superfície dorsal, ânus terminal e pernas curtas e grossas, característicos de Sarcoptes scabiei. Ao exame histológico da pele havia muitos túneis no estrato córneo da epiderme e abaixo dele, contendo grande quantidade de S. scabiei. Essas estruturas parasitárias estavam associadas a acantose e hiperqueratose acentuadas e dermatite superficial discreta. Os achados revelam a sarna sarcóptica como uma doença importante em cachorros do mato.(AU)

Aspectos anatomopatológicos em cães naturalmente infectados por Hepatozoon canis / Anatomopathological findings in dogs naturally infected by Hepatozoon canis

A hepatozoonose canina é causada principalmente pelos protozoários Hepatozoon canis e H. americanum, transmitida por ingestão de carrapatos parasitados. Os sinais clínicos podem ser inespecíficos ou de difícil reconhecimento, pois geralmente ocorre associada a outras doenças. No Brasil, o parasito, e a doença, já foram identificados em vários Estados, no entanto pouco se sabe sobre as alterações clínicas e anátomo-patológicas decorrentes da infecção. O presente trabalho relata cinco casos de infecções naturais por Hepatozoon canis em cães do Estado de Minas Gerais e descreve pela primeira vez no Brasil os achados de necropsias e histopatológicos relacionados à infecção. Merontes de Hepatozoon sp., submetidos a avaliação morfométrica, foram observados em cortes histológicos de fígado, baço, medula óssea e rim.(AU)

Canine hepatozoonosis is mainly caused by protozoa Hepatozoon canis and H. americanum that are transmitted by ingestion of infected ticks. Clinical signs may be unspecific or difficult to identify, because usually hepatozoonosis occurs associated with other disease. In Brazil, the parasite and the disease, have been identified in several states, however little is known about the clinical and anatomopathological lesions resulting from the infection. This paper reports five cases of natural infection by Hepatozoon canis in dogs from Minas Gerais State and describes for the first time in Brazil the necropsy and histopathological findings related to infection. Meronts of Hepatozoon sp., submitted to morphometric evaluation, were observed in histological sections of liver, spleen, bone marrow and kidney.(AU)

Transitional cell carcinoma of urinary bladder with metastasis in lumbar vertebrae and spinal cord compression in an ocelot(Leopardus pardalis) / Carcinoma de células de transição de bexiga urinária com metástase em vértebras lombares e compressão de medula espinhal em uma jaguatirica (Leopardus pardalis)

This paper reports a case of nonpapillary and infiltrative transitional cell carcinoma (TCC) of the urinary bladder with metastasis of lumbar vertebrae and spinal cord compression in an adult female ocelot (Leopardus pardalis), from the Mato Grosso state, Brazil. The ocelot had pelvic limb paralysis and skin ulcers in the posterior region of the body and was submitted to euthanasia procedure. At necropsy was observed a multilobulated and irregular shaped, yellowish to white nodule in the urinary bladder. The nodule had a soft consistency and arised from the mucosa of the urinary bladder extending throughout the muscular layers and the serosa. Nodules of similar appearance infiltrating the vertebral column the at L6 and L7 vertebrae with corresponding spinal canal invasion were also observed. The histological evaluation showed epithelial neoplastic proliferation in the urinary bladder with characteristics of nonpapillary and infiltrative TCC, with positive immunohistochemical staining for pancytokeratin, and strong immunostaining for cytokeratin of low molecular weight, and weak or absent labeling for high molecular weight cytokeratin. This is the first report of TCC of urinary bladder in ocelot in Brazil...

O presente trabalho relata um caso de carcinoma de células de transição (TCC) da bexiga urinária com metástase em vértebras lombares e compressão da medula espinhal em uma jaguatirica fêmea adulta (Leopardus pardalis), no estado do Mato Grosso. A jaguatirica manifestava paralisia de membros pélvicos e úlceras de decúbito na região posterior do corpo e foi submetida a eutanásia. Na necropsia observou-se um nódulo multilobulado e irregular, brancoamarelado na bexiga urinária, de consistência macia com origem na mucosa vesical e que se estendia às camadas musculares e à serosa. Nódulos de aspecto semelhante infiltrando as vértebras L6 e L7 e invasão do canal vertebral correspondente. No exame histológico foi observada proliferação neoplásica na bexiga urinária com com características de TCC não papilar e infiltrativo, com marcação imuno-histoquímica positiva para pancitoqueratina, forte marcação para citoqueratina de baixo peso molecular e fraca ou inexistente para citoqueratina de alto peso molecular. Este é o primeiro relato de TCC em bexiga urinária de jaguatirica no Brasil...