Fatal toxoplasmosis in an immunosuppressed domestic cat from Brazil caused by Toxoplasma gondii clonal type I

Abstract

The objective of the study was to report on a fatal case of feline toxoplasmosis with coinfection with the feline leukemia virus (FeLV). A domestic cat (Felis silvestris catus) presented intense dyspnea and died three days later. In the necropsy, the lungs were firm, without collapse and with many white areas; moderate lymphadenomegaly and splenomegaly were also observed. The histopathological examination showed severe necrotic interstitial bronchopneumonia and mild necrotic hepatitis, associated with intralesional cysts and tachyzoites of Toxoplasma gondii that were positive by anti-T. gondii immunohistochemical (IHC) evaluation. The bone marrow showed chronic myeloid leukemia and the neoplastic cells were positive by anti-FeLV IHC evaluation. DNA extracted from lungs was positive for T. gondii by PCR targeting REP-529. T. gondii was characterized by PCR-RFLP and by the microsatellites technique. ToxoDB-PCR-RFLP #10, i.e. the archetypal type I, was identified. Microsatellite analysis showed that the strain was a variant of type I with two atypical alleles. This was the first time that a T. gondii clonal type I genotype was correlated with a case of acute toxoplasmosis in a host in Brazil.Keywords: Felis silvestris catus, FeLV, genotyping, immunohistochemistry, microsatellite markers. ResumoO objetivo deste estudo foi relatar um caso de toxoplasmose felina fatal com coinfecção com o vírus da leucemia felina (FeLV). Um gato doméstico (Felis silvestris catus) apresentou intensa dispneia e morreu três dias depois. Na necropsia, observaram-se pulmões firmes, não colabados e com múltiplas áreas brancas, além de linfoadenomegalia e esplenomegalia moderadas. No exame histopatológico, evidenciaram-se broncopneumonia intersticial necrótica acentuada e hepatite necrótica discreta associada a cistos e taquizoítas de T. gondii intralesionais positivos na imuno-histoquímica (IHC) anti-T. gondii. Evidenciou-se ainda, na medula óssea, leucemia mieloide crônica com IHC anti-FeLV positiva nas células neoplásicas. O DNA extraído dos pulmões foi positivo para T. gondii por meio da PCR-REP-529. T. gondii foi caracterizado por PCR-RFLP e pela técnica de microssatélites. Foi identificado o genótipo ToxoDB-PCR-RFLP #10, i.e., o arquétipo tipo I. A análise por microssatélites mostrou que a cepa era uma variante do tipo I, com dois alelos atípicos. Esta é a primeira vez que T. gondii clonal tipo I foi relacionado com um caso agudo de toxoplasmosis em um hospedeiro no Brasil.

Clinical Toxoplasmosis in Dogs and Cats: An Update

“…Generalized toxoplasmosis in immunocompetent and immunosuppressed cats, involving acute interstitial pneumonia, acute and multifocal necrotizing hepatitis, non-suppurative meningoencephalitis with glial granuloma, moderate lymphadenomegaly, and splenomegaly, have been reported (37–40). In addition, cutaneous manifestations with nodules that may ulcerate are sometimes related to feline immunosuppression (40–42).…”

“…Vast literature has been published since initial studies (1, 3, 62) exposed that viral infections in dogs and cats may predispose to clinical toxoplasmosis; however, the results are not conclusive. A few cases of feline clinical toxoplasmosis combined with feline immunodeficiency virus (FIV) (63) and feline leukemia virus (FeLV) (40) have been described. During experimental infections, challenge with FIV triggered the disease and predisposed cats to acute generalized toxoplasmosis (64), but later studies on the general population did not identify the same association (65).…”

New prevalence surveillance of Toxoplasma gondii among rodents and stray cats by ELISA avidity and nested PCR methods, Northeast of Iran

“…A simple ELISA method used in toxoplasmosis analysis detects presence of the antibodies in these hosts. The molecular method is positively associated with the ELISA avidity method and can contribute to the health of the region (Jung et al 2017;Must et al 2017;Pena et al 2017;Wang et al 2018a, b, d;Wang et al 2017). Prevention of the congenital toxoplasmosis in rodents and stray cats has been based mainly on serological tests for anti-Toxoplasma antibodies.…”

Doenças infecciosas e parasitárias no contexto brasileiro

“…A doença é significativa em felinos que adquirem a infecção de forma congênita (HARTMANN et al, 2013). Entretanto, gatos portadores podem apresentar a infecção aguda com a reativação dos cistos de T. gondii quando imunossuprimidos, seja por uso de imunossupressores, como os glicocorticóides ou ciclosporinas (HARTMANN et al, 2013), ou decorrente de doenças imunossupressoras como a FIV (vírus da imunodeficiência felina) (MUNHOZ et al, 2017) ou FeLV (vírus da leucemia felina) (PENA et al, 2017).…”