Bacterial septicemia and herpesvirus infection in Antarctic fur seals (Arctocephalus gazella) stranded in the São Paulo coast, Brazil.

In August 2021, two juvenile male Antarctic fur seals (Arctocephalus gazella) stranded in the southeastern Brazilian coast and were referred to rehabilitation centers. The animals presented increased body temperature, prostration, respiratory distress and despite treatment died. A necropsy following a standardized protocol was performed, and formalin-fixed tissues were processed for microscopic examination. Samples were screened for morbillivirus, herpesvirus, and Brucella spp. by molecular analyses (PCR, RT-PCR). Bacteriological culture was performed in samples collected from the lungs, trachea, and lymph nodes of both cases. The main histopathologic findings were of infectious nature, including multifocal necrotizing and fibrinous mixed interstitial pneumonia, bronchiolitis, and bronchitis, with intralesional myriad bacteria associated with vascular fibrinoid necrosis. Pseudomonas aeruginosa was isolated from tracheal and lung swabs of Case 1, and Klebsiella oxytoca was found in nostril swabs, tracheobronchial lymph nodes, and lung of Case 2. Gammaherpesvirus infection was detected in both cases, and the sequences retrieved were classified into the genus Percavirus. All tested samples were PCR-negative for Brucella spp. and morbillivirus. We hypothesize that the deficient immunological status in association with starvation predisposed the reactivation of herpesvirus and secondary bacterial co-infections. To the authors' knowledge, this is the first molecular detection of herpesvirus in an Antarctic pinniped. These findings reinforce that Otariid gammaherpesvirus circulating in the Southern Hemisphere are likely endemic in the Arctocephalus genus. This report contributes to the current knowledge of health aspects affecting wild pinnipeds, especially in the poorly studied Antarctic species.

Direct PCR of lesions suggestive of sporotrichosis in felines / [PCR direta de lesões sugestivas de esporotricose em gatos]

A esporotricose é uma doença emergente e a incidência de esporotricose zoonótica tem aumentado, principalmente no Brasil; a maioria dos casos está relacionada à transmissão de gatos infectados. O diagnóstico definitivo da esporotricose felina é feito por cultura fúngica; no entanto, aguardar o longo período de cultura pode atrasar o início do tratamento. O objetivo deste estudo foi detectar e determinar as espécies de Sporothrix por PCR realizado diretamente das lesões de gatos, provenientes de área endêmica, nos quais a esporotricose fazia parte do diagnóstico diferencial. Um total de 87,1% dos casos foi positivo por PCR ou cultura fúngica para Sporothrix; 81,4% foram confirmados como S. brasiliensis por PCR, 71,4% por isolamento e 65,7% pelos dois métodos. Em conclusão, a análise direta por PCR de lesões sugestivas de esporotricose em gatos é um bom método para confirmar a infecção e determinar as espécies de Sporothrix, garantindo um diagnóstico rápido; esse método tem uma boa concordância com o isolamento fúngico.(AU)

Evaluation of Cytopathological Techniques for the Diagnosis of Canine Visceral Leishmaniosis with Lymph Node Samples.

The identification of the parasite in cytological smears of lymph node aspirates is a widely applied technique for the direct diagnosis of Leishmania spp. infection, especially in endemic areas. Although very specific, this method has limited sensitivity, and improving the technique would be highly desirable. This study aimed to evaluate the efficacy of conventional smear cytology (SC), liquid-based cytology (LBC), cell block (CB) stained with haematoxylin and eosin (HE) and immunocytochemistry (ICC), and formalin-fixed paraffin wax-embedded tissue immunohistochemistry (FFPE-IHC) compared with serology and polymerase chain reaction for the diagnosis of canine visceral leishmaniosis (CVL) in lymphoid tissue. The use of a preservative medium and centrifugation for cytological samples reduced the number of unsatisfactory artefacts/background. Moreover, LBC allowed excellent cellular preservation and the application of ancillary techniques, such as CB and ICC. SC was the most accurate morphological diagnostic method (45.0%). CB-ICC alone or associated with SC demonstrated significantly higher sensitivity (70.0% and 72.0%, respectively) when compared with SC alone (34.00%). CB-ICC was found to be more effective in the detection of infected animals with mild clinical signs, similar to FFPE-IHC. The specificity and positive predictive value were similar between all methods. Finally, the detection limit for CB-ICC and SC + CB-ICC was identical (18.46 amastigotes/mm2). Our study suggests that CB-ICC is a promising tool for improvement of the cytopathological diagnosis of CVL and may be applied in routine epidemiological screening.

Multicentric cutaneous keratoacanthomas in a free-living marmoset (Callithrix sp.).

Cutaneous neoplasia is common in non-human primates. We describe the gross and microscopic features of multicentric cutaneous keratoacanthomas in a free-living marmoset (Callithrix sp.). Immunohistochemistry for human papillomavirus and herpes simplex virus type I and simplex virus type II was negative. Keratoacanthomas should be included in the differential diagnosis for cutaneous masses in non-human primates.

Parotid Salivary Gland Basal Cell Adenocarcinoma in a Big-eared Opossum (Didelphis aurita).

The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum (Monodelphis domestica) and the Virginia opossum (Didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum (Didelphis aurita) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums.

Spontaneous pulmonary adenosquamous carcinoma in a free-living black capuchin monkey (Sapajus nigritus).

Pulmonary neoplasia is rare among wild New World primates. We report the gross, microscopical, and immunohistochemical features of a primary multicentric pulmonary adenosquamous carcinoma in a free-living black capuchin monkey (Sapajus nigritus). Herein, the spectrum of pulmonary neoplasms in non-human primates is widened and briefly reviewed.

Hepatocellular carcinoma in a free-living marmoset (Callithrix sp.) with concomitant biliary trematodiasis.

Hepatocellular carcinoma (HCC) is rare in New World primates. We report the gross, microscopical, and immunocytochemical features of a spontaneous HCC in a free-living marmoset (Callithrix sp.). Hepatitis B and C virus and aflatoxin immunohistochemistry were negative; however, concomitant intra- and extrahepatic biliary trematodiasis could have played a role.

Liquid-based cytology and cell block immunocytochemistry in veterinary medicine: comparison with standard cytology for the evaluation of canine lymphoid samples.

Liquid-based Cytology (LBC) consists of immediate wet cell fixation with automated slide preparation. We applied LBC, cell block (CB) and immunocytochemistry to diagnose canine lymphoma and compare results with conventional cytology. Samples from enlarged lymph nodes of 18 dogs were collected and fixed in preservative solution for automated slide preparation (LBC), CB inclusion and immunophenotyping. Two CB techniques were tested: fixed sediment method (FSM) and agar method (AM). Anti-CD79a, anti-Pax5, anti-CD3 and anti-Ki67 were used in immunocytochemistry. LBC smears showed better nuclear and nucleolar definition, without cell superposition, but presented smaller cell size and worse cytoplasmic definition. FSM showed consistent cellular groups and were employed for immunocytochemistry, while AM CBs presented sparse groups of lymphocytes, with compromised analysis. Anti-Pax-5 allowed B-cell identification, both in reactive and neoplastic lymph nodes. Our preliminary report suggests that LBC and FSM together may be promising tools to improve lymphoma diagnosis through fine-needle aspiration.