Heitor F. Ferrari

Immunohistochemical approach to the pathogenesis of clinical cases of bovine Herpesvirus type 5 infections.

Meningoencephalitis by Herpesvirus type 5 (BoHV-5) in cattle has some features that are similar to those of herpetic encephalitis in humans and other animal species. Human Herpesvirus 3 (commonly known as Varicella-zoster virus 1), herpes simplex viruses (HSV), and equid Herpesvirus 1 (EHV-1) induce an intense inflammatory, vascular and cellular response. In spite of the many reports describing the histological lesions associated with natural and experimental infections, the immunopathological mechanisms for the development of neurological disorder have not been established. A total of twenty calf brains were selected from the Veterinary School, University of São Paulo State, Araçatuba, Brazil, after confirmation of BoHV-5 infection by virus isolation as well as by a molecular approach. The first part of the study characterized the microscopic lesions associated with the brain areas in the central nervous system (CNS) that tested positive in a viral US9 gene hybridization assay. The frontal cortex (Fc), parietal cortex (Pc), thalamus (T) and mesencephalon (M) were studied. Secondly, distinct pathogenesis mechanisms that take place in acute cases were investigated by an immunohistochemistry assay. This study found the frontal cortex to be the main region where intense oxidative stress phenomena (AOP-1) and synaptic protein expression (SNAP-25) were closely related to inflammatory cuffs, satellitosis and gliosis, which represent the most frequently observed neurological lesions. Moreover, MMP-9 expression was shown to be localized in the leptomeninges, in the parenchyma and around mononuclear infiltrates (p < 0.0001). These data open a new perspective in understanding the role of the AOP-1, MMP-9 and SNAP-25 proteins in mediating BoHV-5 pathogenesis and the strategies of host-virus interaction in order to invade de CNS.

Comparison of PCR with stained slides of bone marrow and lymph nodes aspirates with suspect diagnosis for leishmaniasis

Visceral leishmaniasis (VL), also known as kala-azar, is a disseminated protozoan infection caused by Leishmania donovani complex. Traditionally the definite diagnosis is made by amastigote detection in the tissue. The aim this study was to evaluate the PCR technique in stained slides of bone marrow and lymph nodes aspirates with suspect diagnosis for leishmaniasis. Slides were selected totaling 62 suspect cases (33 bone marrow samples and 29 lymph node samples) and 17 positive cases (8 bone marrow and 9 lymph node). From 62 suspect cases, 39 (62.90%) were confirmed to be positive being 17 (n=29) lymph node aspirates and 22 (n=33) bone marrow. This finding is in agreement with the higher sensitivity of the PCR assay compared to direct microscopic observation. In conclusion, the findings of this study supports the use of PCR on archive cytological preparation stained slides for the diagnosis of canine visceral leishmaniasis, emphasizing the higher sensitivity of this technique when compared to direct microscopic examination and mostly the use of the suspect status for the cytology samples that presents the previously mentioned particularities with focus on detecting the oligosymptomatic or assymptomatic dogs in endemic areas functioning as potential reservoirs for this disease.

Epidemiological aspects of astrovirus and coronavirus in poults in the South Eastern Region of Brazil

The presence of canine parvovirus type 2 (CPV-2), 2a and 2b has been described in Brazil, however, the type 2c had not been reported until now. In the current study, seven out of nine samples from dogs with diarrhea were characterized as CPV-2c, indicating that this virus is already circulating in the Brazilian canine population.A survey of Turkey Coronavirus (TCoV) and Astrovirus (TAstV-2) prevalence was carried out from February to December during 2006 year in semiarid region of Brazil, from a turkey producer area, localized in South Eastern of Brazil. To asses the risk factor related to clinical material, climatic condition and type of RT-PCR applied, cloacal swabs (CS), faeces, sera, bursa of Fabricius (BF), thymus (TH) and spleen (SP) and ileum-caeca region were collected from 30-day-old poults suffering of enteritis episode characterized as poult enteritis mortality syndrome (PEMS). The PEMS clinical features were characterized by watery to foamy faeces, light brown-yellow in colour and low mortality rate. Meteorological data (rainfall and relative humidity) observed during along the study presented monthly average temperature ranging from 39.3 and 31.2ºC, precipitation in rainy season from 40 to 270.3 mm/month, and no rain during dry season. Simplex RT-PCR gave odds ratio (OR) values suggesting that ileum-caeca region is at higher chance (OR=1.9; p=0.9741) to have both viral RNA than faeces (OR=1.5; p=0.7319). However, multiplex RT-PCR showed 3.98 (p=0.89982) more chance to give positive results in faeces than CS at dry season. The major risk factors seem to be low rate of humidity and high temperatures at winter, probably responsible for spread, easily, the TCoV and TAstv-2 among the flocks. The positive results of both virus suggested that they can play an important role in enteric disorders, associated to low humidity and high temperatures frequently found in tropical countries.

Hypertension and its correlation with renal lesions in dogs with leishmaniosis

To evaluate the prevalence of hypertension and its correlation with the severity of renal injury and proteinuria in dogs with leishmaniosis, sixty-six dogs were divided into two groups. Group 1 (G1) was composed of 54 dogs included in stage 1 of chronic kidney disease (CKD), and group 2 (G2) of twelve dogs in stages 2 and 3 of CKD. Prevalence of hypertension was 28.8%, comprising 22.2% of the dogs from G1 and 58.3% from G2 (P=0.011). The mean arterial blood pressure (BP) of dogs from G1 (135.7 ± 20.5) was lower than from G2 (170.0 ± 26.3) (P <0.001). Urine protein-creatinine ratio (UP/C) revealed values above 0.5 in 75.7% of the dogs, with 34% presenting hypertension. All dogs with hypertension had histopathological and laboratory evidence of glomerular disease. Although there was no statistically significant correlation between elevated BP and the severity of glomerular lesions (P=0.408), there was a statistically significant correlation between elevated BP and increased UP/C in the studied population (P=0.002). Thus, dogs with leishmaniosis and renal disease must be screened for the presence of hypertension so that treatment may be instituted as early as possible, in countries where treatment is allowed, to prevent the progression of renal damage.

Brain and lung cryptococcoma and concurrent corynebacterium pseudotuberculosis infection in a goat: a case report

A four-year-old male goat with a history of neurological disorder was euthanized. It presented uncommon nodules in the brain and lungs associated with multiple abscesses, predominantly in the spleen and liver. Histological examination of brain and lung sections revealed yeast forms confirmed to be Cryptococcus gattii after a combination of isolation and polymerase chain reaction (PCR) procedures. Moreover, Corynebacterium pseudotuberculosis infection was diagnosed by PCR of samples from the lung, spleen and liver. The present report highlights the rare concurrent infection of C. gatti and C. pseudotuberculosis in an adult goat from Sao Paulo state, Brazil, and indicates the necessity of surveillance in the treatment of goats with atypical pulmonary infections associated with neurological disorders.

Leishmania sp. Amastigotes Identification in Canine Transmissible Venereal Tumor

Leishmaniasis is a vector-borne disease with Leishmania chagasi being the etiological agent of canine visceral leishmaniasis in South America. Canine venereal tumor is a transplantable round cell tumor of histiocytic origin which is mostly observed in sexually active male and female intact dogs. It has been shown that Leishmania amastigotes have higher tropism for the canine male genital tract tissues and venereal leishmaniasis transmission has been documented in dogs but, to date, a canine venereal tumor-dependent transmission route has not been fully demonstrated. In this report, a 10-year-old, mixed breed, intact female dog presented a vaginal venereal transmissible tumor but no other clinical abnormalities otherwise. Unexpectedly, tumor tissue imprint smears examination revealed Leishmania sp. amastigotes within infiltrating macrophages. In addition to the cytological direct identification, the protozoan was confirmed within the neoplastic tissue by means of immunohistochemistry and polymerase chain reaction. This report illustrates an asymptomatic Leishmania sp. infection that may have started on or from the canine venereal tumor tissue, the latter option further supporting previous evidence of such an alternative vector-independent route of transmission for canine visceral leishmaniasis in areas where these diseases coexist.