Aspectos epidemiológicos da infecção por Hepatozoon spp.(Apicomplexa: hepatozoidae) em cães de áreas rurais do Estado de São Paulo, Brasil e caracterização molecular de isolados

Hepatozoon canis é um protozoário que infecta cães e é transmitido pela ingestão do carrapato Rhipicephalus sanguineus. Existem duas espécies distintas de Hepatozoon que infectam cães, H. canis e H. americanum. O diagnóstico de rotina é realizado pelo encontro de gamontes em esfregaço sangüíneo corados por Giemsa. O objetivo desse estudo foi verificar a prevalência de infecção em cães de áreas rurais, comparar a sensibilidade da técnica de esfregaço sangüíneo com a reação da polimerase em cadeia (PCR), e caracterizar a espécie de Hepatozoon spp. que infecta cães no Brasil. Foram realizados esfregaços sangüíneos de sangue periférico e de sangue da veia jugular. O exame por esfregaço sangüíneo detectou 17 animais positivos (11,33%), sendo 14/150 (9,3%) em esfregaços de sangue capilar (ponta de orelha), e 7/150 (4,7%) em esfregaços de sangue da veia jugular. O diagnóstico pela PCR detectou 80/150 (53,3%) amostras positivas. Carrapatos das espécies Rhipicephalus sanguineus e Amblyomma sp. foram encontrados em 36/150 (24%) dos cães, em porcentagens iguais. As espécies identificadas para o gênero Amblyomma foram: A. cajennense, A. ovale . Análises dos dados demonstraram que técnica de PCR foi mais sensível do que o exame por esfregaço sangüíneo. A espécie de Hepatozoon identicada nas amostras de cães no Brasil foi o H. canis.Hepatozoon canis is a protozoan that infects dogs and is transmitted by the ingestion of the brown dog tick, Rhipicephalus sanguineus. Two distinct species of Hepatozoon genus can infect dogs, H. canis and H. americanum. Routine tests to detect the disease are based in direct examination of gametocytes on Giemsa stained blood smears. The purpose of this study was the investigation of disease prevalence in rural area dogs, comparison the blood smear examination to PCR in diagnostic tests, and characterize the Hepatozoon species implicated in the infection of Brazilian dogs. Blood smear examination was undertaken with blood collected by puncture of the cephalic vein and ear margin capillary bed. This technique detected 17 positive animals (11.33%), 14 out 150 (9.3%) in peripherical blood and 7 out 150 (4.7%) in cephalic vein blood. PCR tests detected 80 out 150 (53.3%) positive animals. Rhipicephalus sanguineus and Amblyomma sp. were found in 36 out 150 of the dogs (24%), in equal proportions. The identified species for Amblyomma genus were A. cajennense, A. ovale. Data analysis showed that PCR was much more sensitive compared to blood smear examination. Hepatozoon species identified in the subjects was H. canis

Molecular and parasitological survey of Hepatozoon canis (Apicomplexa : Hepatozoidae) in dogs from rural area of São Paulo state, Brazil

Hepatozoon canis is a protozoan that infects dogs and is transmitted by the ingestion of the brown dog tick, Rhipicephalus sanguineus. Two distinct species of Hepatozoon genus can infect dogs, H. canis and H. americanum. Routine tests to detect the disease are based on direct examination of gametocytes on Giemsa-stained blood smears. The objectives of this study were the investigation of infection prevalence in rural area dogs, the comparison of diagnostics by blood smear examination and polymerase chain reaction (PCR), and the association of infection with tick infestation. Blood smears, collected by puncture of the cephalic vein and ear margin capillary bed from 150 dogs, were examined. This technique detected 17 positive animals (11.3%), with 14 (9.3%) in peripheral blood and seven (4.7%) in cephalic vein blood. PCR tests detected 80 (53.3%) positive animals. R. sanguineus and Amblyomma spp. were found in 36 of the dogs (24%), in equal proportions. The identified species for Amblyomma genus were A. cajennense and A. ovale. Data analysis showed that PCR was much more sensitive when compared to blood smear examination. Hepatozoon species was previously identified as closely related to H. canis

Babesia spp. infection in dogs from rural areas of São Paulo State, Brazil

The status of Babesia spp. infection in dogs from rural areas of São Paulo State, Brazil was Studied. For this, l 50 animals were examined by blood smears and by PCR; the presence of tick infestation was also investigated. By the blood smear examination, 3 animals (2%) were detected positive and by PCR for Babesia spp. 12 (8%) were positive, with bands Visualized in 450 bp. Rhipicephalus sanguineus or Amblyomma spp. were found on 36 (24%) of the 150 dogs. Amblyomma species found were A. cajennense (9/36-25%) and A. ovale (9/36-25%). It was not possible to correlate the presence of R. sanguineus and the infection with Babesia spp. The sequencing of four positive samples demonstrated close identity with B. canis vogeli already characterized in Brazil.A presença de infecção por Babesia spp. em cães de áreas rurais do Estado de São Paulo, Brasil foi investigada. Para tanto, 150 cães foram examinados por técnicas parasitológicas de esfregaços sanguíneos e moleculares (PCR), e também, foi verificada a presença de carrapatos nestes animais. Pela análise de esfregaços sanguíneos, 3 (2%) dos cães estavam infectados, enquanto pela PCR, 12 (8%) dos animais foram positivos com bandas aproximadas de 450 pares de base (pb). Foram observados 36 (24%) cães infestados com Rhipicephalus sanguineus ou com Amblyomma spp. As espécies de Amblyomma observadas foram A. cajennense (25%) e A. ovale (25%). Não foi possível correlacionar a presença de R. sanguineus com a infecção por Babesia spp. O seqüenciamento de quatro amostras positivas demonstrou alta identidade com B. canis vogeli, já caracterizada no Brasil

Morphological, morphometric, and molecular characterization of Hepatozoon spp. (Apicomplexa, Hepatozoidae) from naturally infected Caudisona durissa terrifica (Serpentes, Viperidae)

Hepatozoon spp. are the most frequent intracellular protozoa in snakes. Considering the variety of parasites infecting specimens of Caudisona durissa terrifica and the divergent data in literature where only two species, Hepatozoon romani and Hepatozoon capsulata, are described, the aim of this study was to morphologically, morphometrically, and molecularly characterize Hepatozoon spp. from some naturally infected specimens of C. durissa terrifica, and observe changes caused by these protozoa in parasitized erythrocytes. Four snakes were examined. Two of them had two morphological distinct gamonts, while the other two had only one type of gamont. The six distinct gamonts were provisionally named gamonts A, B, C, D, E, and F. Statistical analysis, however, confirmed the existence of only four parasite populations, those which were capable of inducing significant alterations in determined red blood cells variables. Attempts to infect Aedes aegypti and Culex quinquefasciatus mosquitoes were done for each snake specimen. Some mosquitoes became infected and oocysts were recovered and measured. The detection of Hepatozoon DNA was obtained with success but the molecular characterization was unable to differentiate species of the samples, with respect to the fragment studied.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Investigation of tick vectors of Hepatozoon canis in Brazil

Hepatozoon canis is a common apicomplexan parasite of dogs. In Brazil, in addition to Rhipicephalus sanguineus, Amblyomma ovate, Amblyomma cajennense, and Rhipicephalus (Boophilus) microplus have been suggested to act as vectors. The present study aimed to evaluate, under controlled conditions, the acquisition of H. canis by A. ovate, R. sanguineus, and A. cajennense after feeding on naturally infected dogs. Cytological and histophatological examinations were performed to recover oocysts and other sporogonic stages of the protozoan from the experimentally infected nymphs and adults. None of the R. sanguineus (n = 30) or A. cajennense nymphs (n = 15) that were dissected after feeding on H. canis naturally infected dogs became infected by the hemoparasite. Likewise, none of the R. sanguineus (n = 165) and A. cajennense (n = 114) adult ticks that were fed as nymphs on dogs demonstrated infection. Additionally, A. cajennense adult ticks were incapable of acquiring the infection, since no parasite was found in 62 adults that fed on H. canis-infected dogs. With regard to A. ovate ticks, 2 different infestations were carried out. Firstly, a dog with naturally occurring hepatozoonosis was infested with A. ovate adults originating from Rondonia, Brazil. Ticks fed to full engorgement. A total of 31 adults was collected from the dog and dissected on the third day after natural detachment. Oocysts were detected in 13 (42%) of the ticks. The second experimental infestation was carried out using adult ticks originating from Sao Paulo, Brazil. Surprisingly, of the 103 dissected ticks, only one (1%) contained oocysts in the hemocoel. No other sporogonic stage was found. Results indicate that different strains of A. ovate ticks may exist in Brazil with different susceptibilities to pathogens. Furthermore, it is possible that R. sanguineus and A. cajennense have little or no importance in the transmission of H. canis in rural areas of Brazil. (C) 2013 Elsevier GmbH. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP