Equine pulmonary aspergillosis with encephalitic, myocardial, and renal dissemination

Systemic aspergillosis associated with acute enterocolitis in foals

Aspergillosis is an uncommon disease in horses, but it can be fatal. We report two cases of systemic aspergillosis in foals that occurred in a short period in the same region of southern Brazil. In addition, a literature review of similar cases was also performed. Risk factors were attributed to an immunodepression by primary enterocolitis and corticosteroid treatment, the damage in the epithelium, and multiple antibacterial treatments, which allowed local fungal proliferation, tissue invasion and spread of infection, leading to death. Since the antemortem diagnosis of aspergillosis in foals is difficult, our report alerts equine veterinarians regarding the importance of suspecting and investigating fungal co-infections in complicated cases of enterocolitis.

Aspergillus Section Fumigati Pneumonia and Oxalate Nephrosis in a Foal

Equine pulmonary aspergillosis is a rare deep mycosis often due to the hematogenous spread of hyphae after gastrointestinal tract disease. We describe herein the main clinic-pathological findings observed in a foal, which spontaneously died after showing diarrhea and respiratory distress. Necropsy and histopathological investigations allowed to diagnose pulmonary aspergillosis, which likely developed after necrotic typhlitis-colitis. Biomolecular studies identified Aspergillus section Fumigati strain as the causative agent. Notably, severe oxalate nephrosis was concurrently observed. Occasionally, oxalate nephropathy can be a sequela of pulmonary aspergillosis in humans. The present case report suggests that the renal precipitation of oxalates can occur also in horses affected by pulmonary aspergillosis and could likely contribute to the fatal outcome of the disease.

Diphtheric aspergillosis tracheitis with gastrointestinal dissemination secondary to viral infections in a dairy calf

Diphtheric aspergillosis tracheitis is an uncommon syndrome described in human pathology, usually associated with immunosuppression in the affected individuals. Interestingly, no comparative/equivalent cases were found in domestic animals. This report describes the pathological and mycological findings associated with diphtheric aspergillosis tracheitis in an immunocompromised calf. The main pathological findings were diphtheric tracheitis and rhinitis, and necrotizing ruminitis associated with intralesional septate, acute branching fungal hyphae consistent with Aspergillus spp. Mycological culture and isolation confirmed the fungal hyphae as A. fumigatus due to characteristic features. Immunohistochemistry (IHC) assays identified intralesional antigens of bovine viral diarrhea virus (BVDV) and malignant catarrhal fever virus (MCFV) at the trachea and small intestine; IHC detected intralesional antigens of bovine alphaherpesvirus 1 (BoHV-1) only at the trachea. These findings confirmed the simultaneous occurrence of A. fumigatus with concomitant infections due to BVDV, MCFV, and BoHV-1 in this calf. Since ovine gammaherpesvirus-2 (OvHV-2) is the cause of MCF in Brail, it is likely that the intralesional MCFV antigens identified were those of OvHV-2. In this case, disseminated aspergillosis was probably associated with the undeveloped immunological status of the calf that was further impaired due to the combined immunodepressive effects of BVDV and BoHV-1 infections. Although BVDV and BoHV-1 are infectious disease pathogens frequently associated with the development of bovine respiratory disease (BRD) in feedlot and dairy cattle, the identification of intralesional OvHV-2-like antigens in several parts of the lungs suggest that this MCFV also played a role in the BRD-associated lesions identified in this calf.

•

An unusual presentation of fungal diphtheric tracheitis associated with Aspergillus fumigatus is described in a dairy calf.

•

A Malignant Catarrhal Fever Virus, most likely, OvHV-2, was associated with the development of pneumonia in this calf.

•

Simultaneous infections in dairy calves may be more frequent than previously reported.

•

OvHV-2 should be considered as a possible disease pathogen associated with the development of bovine respiratory disease.

•

The immunodepressive effects of BVDV and BoHV-1 were fundamental for the development of the fungal disease observed in this calf.

Causes and Pathology of Equine Pneumonia and Pleuritis in Southern Brazil

We document the causes and pathological findings in 50 cases of equine pneumonia and pleuritis in Southern Brazil. Suppurative (17/50), pyogranulomatous (14/50), aspiration (5/50), mycotic (4/50), bronchointerstitial (3/50), embolic (3/50) and eosinophilic granulomatous pneumonia (1/50) and pleuritis (3/50) were the main conditions identified. Streptococcus spp. were identified in 11 cases of suppurative pneumonia. Suppurative pneumonia was further divided into acute (8/17), subacute (6/17) and chronic (3/17) based on the morphological pattern of lesions. Rhodococcus equi was identified in all cases of pyogranulomatous pneumonia and exclusively affected young foals.

Aspergilose sistêmica em um cavalo - relato de caso

RESUMO O presente trabalho relata o caso de aspergilose sistêmica em um cavalo da raça Quarto de Milha. O animal apresentava quadro de emagrecimento progressivo e alopecia. Os parâmetros avaliados durante o exame clínico encontravam-se de acordo com os valores normais para a espécie. No hemograma verificou-se leucocitose por neutrofilia, sem desvio à esquerda, proteínas plasmáticas totais elevadas e aumento do fibrinogênio, indicando um processo inflamatório acompanhado de desidratação. Os exames bioquímicos séricos demonstraram aumento no valor da ureia. Apesar dos exames realizados e da terapia instituída com antibióticos de amplo espectro e suporte nutricional, após 51 dias de internamento o quadro clínico evoluiu para caquexia e decúbito permanente do paciente, o qual foi submetido à eutanásia seguida de necropsia. Com base nos achados nos exames necroscópico e histopatológico, diagnosticou-se infecção sistêmica por Aspergillus sp., acometendo pulmões, fígado, rins, peritônio parietal e encéfalo. Dentre os fatores predisponentes à relatada infecção fúngica sistêmica, destaca-se o status imunológico debilitado do paciente, possivelmente proporcionado por tratamentos prolongados com antibióticos e anti-inflamatórios esteroidais. O presente trabalho relata o primeiro caso descrito de arpergilose sistêmica no Brasil. O diagnóstico definitivo só foi possível após necropsia e histopatologia, visto que os sinais clínicos inespecíficos não foram determinantes para o diagnóstico em vida.

Gliotoxin--bane or boon?

Gliotoxin (GT) is the most important epidithiodioxopiperazine (ETP)-type fungal toxin. GT was originally isolated from Trichoderma species as an antibiotic substance involved in biological control of plant pathogenic fungi. A few isolates of GT-producing Trichoderma virens are commercially marketed for biological control and widely used in agriculture. Furthermore, GT is long known as an immunosuppressive agent and also reported to have anti-tumour properties. However, recent publications suggest that GT is a virulence determinant of the human pathogen Aspergillus fumigatus. This compound is thus important on several counts - it has medicinal properties, is a pathogenicity determinant, is a potential diagnostic marker and is important in biological crop protection. The present article addresses this paradox and the ecological role of GT. We discuss the function of GT as defence molecule, the role in aspergillosis and suggest solutions for safe application of Trichoderma-based biofungicides.