Clinical features, fungal load, coinfections, histological skin changes, and itraconazole treatment response of cats with sporotrichosis caused by Sporothrix brasiliensis

Elaine Waite De Souza,Rodrigo Caldas Menezes,Raquel De Vasconcellos Carvalhaes De Oliveira,Cintia De Moraes Borba,Isabella Dib Ferreira Gremião,Rosely Maria Zancopé-Oliveira,Ingeborg Maria Langohr,Camila Rocha Da Cunha,Manoel Marques Evangelista Oliveira,Sandro Antonio Pereira,Luisa Helena Monteiro De Miranda

doi:10.1038/s41598-018-27447-5

Elaine Waite De Souza, Rodrigo Caldas Menezes + Show 9 more

Open Access

https://doi.org/10.1038/s41598-018-27447-5

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Abstract

Zoonotic sporotrichosis caused by the fungus Sporothrix brasiliensis is usually severe in cats. This study investigated the associations between clinical features, fungal load, coinfections, histological skin changes, and response to itraconazole in cats with sporotrichosis caused by S. brasiliensis. Fifty-two cats with skin lesions and a definitive diagnosis of sporotrichosis were treated with itraconazole for a maximum period of 36 weeks. The animals were submitted to clinical examination and two subsequent collections of samples from the same skin lesion for fungal diagnosis and histopathology, as well as serology for feline immunodeficiency (FIV) and leukaemia (FeLV) viruses. Thirty-seven (71%) cats were clinically cured. Nasal mucosa lesions and respiratory signs were associated with treatment failure. Cats coinfected with FIV/FeLV (n = 12) had a lower neutrophil count in the lesion. A high fungal load in skin lesions was linked to young age and treatment failure, as well as to a longer time of wound healing, poorly formed granulomas and fewer neutrophils, macrophages and lymphocytes in these lesions. These results indicate that itraconazole is effective, but nasal mucosal involvement, respiratory signs and high fungal loads in skin lesions are predictors of treatment failure that will assist in the development of better treatment protocols for cats.

Highlights

Sporotrichosis is a widely distributed worldwide mycosis that usually affects the skin and subcutaneous tissue of humans and several animal species, but that can spread to other organs[1,2,3]
Difficult-to-treat forms of sporotrichosis are common in cats, little is known about predictors of the treatment response in animals with sporotrichosis caused by S. brasiliensis
Treatment failure does not seem to be associated with infection with feline immunodeficiency virus (FIV) or feline leukaemia virus (FeLV)[16]

Summary

Introduction

Sporotrichosis is a widely distributed worldwide mycosis that usually affects the skin and subcutaneous tissue of humans and several animal species, but that can spread to other organs[1,2,3]. Difficult-to-treat forms of sporotrichosis are common in cats, little is known about predictors of the treatment response in animals with sporotrichosis caused by S. brasiliensis This fungal species is considered the most virulent within the genus Sporothrix[19,20] and may be associated with the high frequency of severe lesions in the nasal mucosa and of upper respiratory signs in cats from Rio de Janeiro[3,16]. These previous studies have not identified the species S. brasiliensis because phenotypical and molecular characterization of the fungus was not performed[3,16,17] These studies have not evaluated the association between clinical features, fungal load, coinfection with FIV/FeLV and histological skin changes before and during the treatment as predictors of itraconazole treatment response in cats[3,16,17]. The aim of this study was to investigate for the first time the associations between clinical features, fungal load, coinfection with FIV/FeLV, histological skin changes, and treatment response to itraconazole as predictors of outcome in cats with sporotrichosis caused by S. brasiliensis

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