Detection of Leishmania infantum amastigotes in neutrophil from peripheral blood in a naturally infected dog / Detecção de formas amastigotas de Leishmania infantum em neutrófilos do sangue periférico de cão naturalmente infectado

Abstract Canine visceral leishmaniasis (CVL) is a zoonotic disease of high lethality caused by Leishmania infantum in the Americas. In the infected dog, the amastigotes are scarce in blood, especially in the late phase of the disease. This study aimed to report a rare case of L. infantum amastigotes found in neutrophils from peripheral blood of a naturally infected dog in terminal phase of CVL, also describing its clinical status before and after treatment with miltefosine 2%. The dog, which presented as polysymptomatic and with classical signs and symptoms of CVL was submitted to the following tests: Dual Path Platform (DPP) rapid test, ELISA and parasitological examination of peripheral blood. Hematological and biochemical parameters were obtained before and after treatment. All diagnostic tests were positive for CVL. The identification of L. infantum amastigotes inside neutrophils from peripheral blood was confirmed through microscopy, and the species was confirmed by molecular analysis. At the end of the treatment, peripheral parasitemia was not detected, and improvements were observed in clinical and laboratorial parameters. Finally, this atypical finding can be used as example to raise discussions about the real immunological role of neutrophils in late phases of CVL and its clinical/therapeutic implications.

Resumo A leishmaniose visceral canina (LVC) é uma doença zoonótica de alta letalidade causada por Leishmania infantum nas Américas. No cão infectado, as formas amastigotas são escassas no sangue, principalmente na fase tardia da doença. Este estudo teve como objetivo relatar um caso raro de amastigotas de L. infantum encontradas em neutrófilos do sangue periférico de um cão naturalmente infectado e terminal da LVC, descrevendo também seu estado clínico antes e após o tratamento com miltefosina a 2%. O cão, que se apresentou como polissintomático e com sinais e sintomas clássicos da LVC foi submetido aos seguintes testes: teste rápido Dual Path Platform (DPP), ELISA e exame parasitológico de sangue periférico. Os parâmetros hematológicos e bioquímicos foram obtidos antes e após o tratamento. Todos os testes diagnósticos foram positivos para LVC. A identificação de formas amastigotas de L. infantum, dentro de neutrófilos do sangue periférico foi confirmada por microscopia, e a espécie foi confirmada por análise molecular. Ao final do tratamento, não foi detectada parasitemia periférica, observando-se melhora dos parâmetros clínicos e laboratoriais. Por fim, esse achado atípico pode ser usado como exemplo para levantar discussões sobre o real papel imunológico dos neutrófilos nas fases tardias da LVC e suas implicações clínicas/terapêuticas.

ULTRASTRUCTURAL CHANGES IN Schistosoma mansoni MALE WORMS AFTER in vitro INCUBATION WITH THE ESSENTIAL OIL OF Mentha x villosa Huds

Introduction: The essential oil Mentha x villosa (MVEO) has a wide range of actions, including antibacterial, antifungal, antiprotozoal and schistosomicidal actions. The present study aimed to investigate the ultrastructural changes of MVEO on the tegument of adult Schistosoma mansoni. Materials and Methods: Different concentrations of MVEO were tested on S. mansoni adult worms in vitro. Ultrastructural changes on the tegument of these adult worms were evaluated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: The MVEO caused the death of all worms at 500 μg mL-1 after 24 h. After 24h of 500 μg mL-1 MVEO treatment, bubble lesions were observed over the entire body of worms and they presented loss of tubercles in some regions of the ventral portion. In the evaluation by TEM, S. mansoni adult worms treated with MVEO, 500 μg mL-1, presented changes in the tegument and vacuoles in the syncytial matrix region. Glycogen granules close to the muscle fibers were visible. Conclusion: The ability of MVEO to cause extensive ultrastructural damage to S. mansoni adult worms correlates with its schistosomicidal effects and confirms earlier findings with S. mansoni.