Claw bed inverted squamous papilloma associated with canine papillomavirus type 2 in a dog.

A claw bed inverted squamous papilloma (ISP) presented clinically as a swollen digit in a dog. Canine papillomavirus (CPV) type 2 was amplified by PCR and localised to the papilloma's epidermis using in situ hybridisation. This is the first report demonstrating a claw bed ISP caused by CPV.

Un papillome squameux inversé de la matrice unguéale est décrit cliniquement comme un gonflement du doigt chez un chien. Le papillomavirus canin (CPV) de type 2 a été amplifié par PCR et localisé dans l'épiderme du papillome par hybridation in situ. Il s'agit du premier rapport faisant état d'un papillome squameux inversé de la matrice unguéale par le CPV.

Um caso de papiloma escamoso invertido no leito ungueal em um cão apresentando aumento de volume em um dígito. O vírus do papiloma canino (CVP) Tipo 2 foi amplificado por PCR e localizado na epiderme do papiloma utilizando hibridização in situ. Este foi o primeiro relato demonstrando um papiloma escamoso invertido causado por CPV.

Un papiloma escamoso invertido del lecho ungueal se presentó clínicamente como un dedo hinchado en un perro. Se amplificó mediante PCR genoma del virus papiloma canino tipo 2 (CPV) y se localizó en la epidermis el papiloma mediante hibridación in situ. Este es el primer reporte de caso que demuestra la existencia de un papiloma escamoso invertido del lecho ungueal causado por CPV.

Apoptosis in postweaning multisystemic wasting syndrome (PMWS) hepatitis in pigs naturally infected with porcine circovirus type 2 (PCV2).

The degree of apoptosis in the livers of pigs with hepatitis due to naturally-occurring postweaning multisystemic wasting syndrome (PMWS) was evaluated semi-quantitatively by immunohistochemical detection of the apoptotic marker cleaved caspase-3 (CCasp3). The amount and distribution of porcine circovirus type 2 (PCV2) virus in the liver was evaluated using in situ hybridisation. Livers with mild, stage I hepatitis exhibited similar degrees of apoptosis to controls; those with stage II lesions had variable apoptotic rates, ranging from mild to high, and in livers with more severe, stage III hepatitis, high levels of hepatocyte apoptosis was a feature. Statistical analyses indicated a positive association between the rate of apoptosis, the severity of the hepatitis and the amount of PCV2 DNA in the liver. Double immunolabelling for CCasp3 and PCV2 DNA revealed a predominance of cells labelling only for PCV2, followed by fewer cells labelling only for CCasp3, and the least number labelling for both. The findings suggest that apoptosis, possibly triggered by PCV2 infection and/or hepatic inflammation, plays a key role in the pathogenesis of hepatitis in pigs with naturally-occurring PMWS.

Association of bovine papillomavirus type 2 (BPV-2) and urinary bladder tumours in cattle from the Azores archipelago.

Urinary bladder tumours in cattle are caused by chronic ingestion of bracken fern and BPV-1/2 infection. The objective of the present study was to assess if BPV-2 was present in urinary bladder lesions from cattle with chronic enzootic haematuria (CEH) from the Azores archipelago (Portugal), in order to gain further information regarding the epidemiologic distribution of this virus. Samples were analysed using PCR specific primers for BPV-2 DNA and an immunohistochemistry for BPV E5 oncoprotein detection. We found a 28% incidence rate of BPV-2 DNA in different types of tumours and cystitis cases (13 out of 46 samples). Tested positive samples for PCR were also positive for the viral E5 oncoprotein; protein immunolabeling was mainly detected within the cytoplasm of urothelial cells, displaying a juxtanuclear distribution. This is the first report of BPV-2 detection in urinary bladder tumours associated with CEH in cattle from the Azores archipelago.

Apoptosis in lymphoid organs of pigs naturally infected by porcine circovirus type 2.

The objective of the present study was to evaluate the involvement of apoptosis in the development of post-weaning multisystemic wasting syndrome (PMWS) lymphoid-depletion lesions. Twenty-one pigs that were categorized into three different lesional severity stages (S1, n=5; S2, n=7; S3, n=9) and five healthy control pigs (stage S0) were used. From all pigs, samples of thymus, spleen, tonsil, ileum and superficial inguinal lymph node were processed for histological examination, in situ hybridization for porcine circovirus type 2 (PCV2) detection and cleaved caspase-3 (CCasp3) immunohistochemistry for detection of apoptotic cells. PCV2 was quantified in serum samples by using TaqMan real-time PCR. CCasp3 labelling was measured in the different morphological compartments of all lymphoid tissues, using an automated system for quantification. Differences between each tissue compartment and lesional stage were assessed, as well as the correlation between apoptosis, lesional stage and viral load. Overall, the results indicated that the more intense the lymphoid depletion, the lower the rate of apoptosis. In the thymus, the cortex was the area where differences between PMWS-affected and control animals were more evident; it was found that all PMWS-affected pigs had significantly lower rates of apoptosis than the controls. In the secondary lymphoid organs, B-cell areas presented higher rates of apoptosis; similar apoptotic rates were found in this compartment in control and S1 pigs. In S2 and S3, B-cell areas were lost and the apoptotic pattern observed was a diffusely distributed low rate of positive cells. Significantly lower rates of apoptosis between PMWS-affected pigs and the control group were already evident in S1 for the thymus, spleen, superficial inguinal lymph node and Peyer's patches, but not for the tonsils. Apoptotic rates in lymphoid tissues were correlated inversely with viral load in serum and with severity of lesions. In conclusion, the results indicate that apoptosis is not a remarkable feature in PMWS lymphoid lesion development.

Dynamics of porcine circovirus type 2 infection in a herd of pigs with postweaning multisystemic wasting syndrome.

OBJECTIVE: To determine the pattern of infection for porcine circovirus type 2 (PCV2) in a herd of pigs with postweaning multisystemic wasting syndrome (PMWS). ANIMALS: 29 sows and 250 pigs. PROCEDURE: Blood samples were collected from all 3-, 7-, and 12-week old pigs and 59 pigs at 28 weeks of age. Pigs that died during the study were necropsied. Porcine parvovirus and PCV2 antibodies were assayed. A polymerase chain reaction (PCR) was used to detect PCV2 genome in serum of selected pigs. RESULTS: The PMWS started when pigs were 8 weeks old, with a prevalence of 30% in 8- to 10-week-old pigs. Eighty-three pigs died during the period between 3 and 12 weeks of age. Microscopic lesions consistent with PMWS were observed, and PCV2 nucleic acid was detected (50 of 68 pigs). Antibodies to PCV2 decreased from 3 to 7 weeks of age, increased at 12 weeks of age, and were maintained until 28 weeks of age. One sow had a positive result for PCR of serum. Nine, 37 and 8 pigs had PCV2 genome in serum obtained at 7, 12, and 28 weeks of age, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with PCV2 coincided with severe clinical signs; however, infected 28-week-old pigs did not have evidence of disease. Immunity declined over time in young pigs. A long duration of PCV2 viremia was apparent in a high percentage of infected pigs, which may affect transmission and persistence of the virus in a herd.