Histopathologic Changes, Ultrastructure, and Molecular Characterization of an Adenovirus in a Sun Conure (Aratinga solstitialis).

In this case report, we describe the pathologic changes and the ultrastructural and molecular characteristics of an adenovirus in a sun conure (Aratinga solstitialis) that presented with a history of sudden death. On histologic examination, there was multifocal hepatic and splenic necrosis. Within some hepatocytes and unidentified cells in the spleen, renal interstitial fibroblasts, and ovarian stroma were intranuclear amphophilic inclusion bodies. Electron microscopy of affected tissue showed intranuclear icosahedral viral particles with an inner capsid (29.2-33.8 nm in diameter) and an outer capsid (70.2-71.7 nm in diameter). Next-generation sequencing and BLAST analysis of complementary DNA synthesized from RNA extracted from formalin-fixed tissues showed an adenovirus, designated sun conure adenovirus (SCAdv). A DNA in situ hybridization (ISH) probe, constructed from the SCAdv and similar sequences from GenBank, was also positive in the intranuclear inclusion bodies, whereas standard ISH for psittacine adenovirus 1 was negative. These results show that ancillary diagnostic testing, such as next-generation sequencing, even using formalin-fixed, paraffin-embedded tissues, along with ISH, can be useful in identifying additional, unknown viruses that show similar pathology to commonly known viruses but do not show up as positive on routine diagnostic tests.

Reporte de caso- Cambios histopatológicos, ultraestructura y caracterización molecular de un adenovirus en una cotorra solar (Aratinga solstitialis). En este reporte de caso, se describen los cambios patológicos y las características ultraestructurales y moleculares de un adenovirus en una cotorra solar (Aratinga solstitialis) que se presentó con un historial de muerte súbita. En el examen histológico, hubo necrosis hepática y esplénica multifocal. Dentro de algunos hepatocitos y células no identificadas en el bazo, los fibroblastos intersticiales renales y en el estroma ovárico se encontraron cuerpos de inclusión anfofílicos intranucleares. La microscopía electrónica del tejido afectado mostró partículas víricas intranucleares icosaédricas con una cápside interna (de 29.2 a 33.8 nm de diámetro) y una cápside externa (de 70.2 a 71.7 nm de diámetro). Mediante el análisis de secuenciación de segunda generación y por la Herramienta de Búsqueda de Alineaciones Local Básica (con siglas en inglés BLAST) del ADN complementario sintetizado a partir de ARN extraído de tejidos fijados con formalina mostraron un adenovirus, denominado adenovirus de cotorra solar (SCAdv). Se construyó una sonda de ADN para hibridación in situ (ISH), a partir de la secuencia del virus SCAdv y de secuencias similares de GenBank, que generó reacción positiva en los cuerpos de inclusión intranucleares, mientras que la hibridación in situ estándar para el adenovirus I de psitácidos fue negativa. Estos resultados muestran que las pruebas de diagnóstico complementarias, como la secuenciación de segunda generación, utilizando tejidos fijados con formalina e incluidos en parafina junto con la hibridación in situ pueden ser útiles para identificar virus adicionales desconocidos que muestran una patología similar a los virus comúnmente conocidos, pero que no se detectan con las pruebas diagnósticas de rutina.

Apparent attachment of Campylobacter and Salmonella to broiler breeder rooster spermatozoa.

It has been demonstrated that horizontal and vertical transmission of Salmonella and Campylobacter can occur in broiler breeder flocks. The mechanism of this transmission is still unclear. Previously negative broiler breeder flocks have been reported to become positive with Salmonella, Campylobacter, or both after the introduction of "spike" roosters at 45 wk of age. To determine whether the rooster semen is a possible source of transmission to hens for colonization, we evaluated the association of both Salmonella and Campylobacter spp. to segments (head, midpiece, and tail) of individual spermatozoa after artificial inoculation. Salmonella typhimurium, Salmonella heidelberg, and Salmonella montevideo, or Campylobacter jejuni (in 0.85% saline) was added to a freshly collected (by abdominal massage) aliquot of pooled semen from roosters housed in individual cages. The semen and bacteria solutions were incubated 1 h at room temperature. Samples were fixed using Karnosvsky and Zamboni fixatives for 24 h prior to centrifuging and rinsing in 0.1 M cacodylate x HCl buffer. Individual aliquot samples were then subjected to both scanning (JSM-5800) and transmission (JEM-1210) electron microscopy. The scanning electron microscopy showed that Salmonella was associated with all 3 segments (head, midpiece, and tail) of the spermatozoa and apparently equally distributed. Campylobacter was mainly associated with the midpiece and tail segments; few isolates were located on the head segment. The transmission electron microscopy showed apparent attachment of Salmonella and Campylobacter to the spermatozoa.

Immunogold for detection of avian leukosis/sarcoma virus in formalin-fixed heart and kidney.

Immunoprobes are used in the qualitative and semi-quantitative demonstration of antigens in clinical samples. In the present study, an immunogold method has been used for routine and rapid detection of avian leukosis/sarcoma virus (AL/SV) in sections of formalin-fixed chicken heart and kidney. Application of this ultrastructural indirect immunogold labelling technique (IILT) will enable pathologists to obtain a definitive diagnosis of avian AL/SV infection when inclusions or putative viral particles are observed by light or electron microscopy. IILT also may be used in research on AL/SV infections.

Ultrastructure of the gastrocnemius tendon and sheath from broilers infected with reovirus.

Gastrocnemius tendon and sheath from male broilers infected with reovirus at 1 day of age were evaluated ultrastructurally at 1, 2, 3, 4, 5, 10, 15, and 20 weeks postinoculation (PI). Although virus particles were not identified, degenerative changes in sheath and tendon fibroblasts were characterized by cytoplasmic vacuolization, disruption of membranes, and loss of ribosomes from rough endoplasmic reticulum, mitochondrial degeneration, and cell disruption.