During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Com os objetivos de conhecer a ocorrência de anticorpos e identificar fatores de risco para a infecção por Toxoplasmagondii em cães, nas cidades de Lages e Balneário Camboriú, SC, amostras de sangue de 400 cães domiciliados foram processadas para a detecção de anticorpos contra T. gondii pela técnica da imunofluorescência indireta (RIFI). Dados referentes à raça, idade, sexo, tipo de dieta, ambiente, presença de gatos e acesso à rua foram obtidos por meio de questionário. Análise estatística foi realizada (teste de χ²). Dos 400 cães, 89 (22,3%) apresentaram anticorpos contra T. gondii. Dos cães de Lages, 52 (26%) foram positivos para T. gondii, enquanto os de Balneário Camboriú, 37 (18,5%)foram sororreagentes. Não foram observadas diferenças estatísticas entre as prevalências de T. gondii nos dois municípios. Maior ocorrência de sororreagentes para toxoplasmose foi verificada entre os cães sem raça definida (P = 0,002), que tinham acesso à rua (P = 0,003) e que recebiam dieta caseira (P = 0,028). Forte tendência para reagentes ao T. gondii foi observada entre os animais adultos, indicando exposição pós-natal ao agente, e entre os cães em contato com felinos.

The aim of this study was to identify the occurrence of antibodies and risk factors for infection for Toxoplasma gondii in dogs in the cities of Lages and Balneário Camboriú, Santa Catarina State, Brazil. Blood samples from 400 domiciliated dogs were processed for antibody detection against T. gondii by indirect immunofluorescence antibody test (IFAT). The following variables were obtained by questionnaire: breed, age, sex, diet, environment, presence of cats and street access. A Chi-Square test was performed to verify the association between the seroprevalence with the studied variables. From all evaluated dogs, 89 (22.3%) had antibodies against T. gondii. A total of 52 (26%) and 37 (18.5%) dogs were positive for T. gondii in Lages and Balneário Camboriú, respectively. No statistical differences were observed on the prevalences of T. gondii between both cities. Greater occurrences of seropositives for toxoplasmosis were observed in mixed-breed dogs (P = 0.002), who had access to the street (P = 0.003) and received homemade diet (P = 0.028). A strong trend for seropositivity against T. gondii was observed among adult dogs, indicating post-natal exposure, and among those that have previous contact with cats.

Com objetivo de observar os parâmetros biológicos de Amblyomma tigrinum, fêmeas ingurgitadas, coletadas de cães da cidade de Lages-SC, foram acondicionadas em placas de Petri, mantidas em câmara climatizada tipo BOD regulada à temperatura de 27 + 1º C, 80 + 10% UR e escotofase para realização da postura. Para o desenvolvimento das fases sucessivas do experimento, foram realizadas infestações em coelhos, por meio da técnica do saco de pano aderido à base das orelhas. Os períodos médios de eclosão, de ingurgitamento e de ecdise larval foram de 11,67; 5,93 e 10,96 dias, respectivamente. Os períodos médios de ingurgitamento e de ecdise ninfal foram de 12,40 e 16,27 dias respectivamente. Foi obtido o ingurgitamento de uma fêmea, com desprendimento no 22º dia. A longevidade foi de 75, 96 e 150 dias, para larvas, ninfas e adultos respectivamente.

To study the biological features of Amblyomma tigrinum, samples of engorged females collected from dogs in the city of Lages, SC, Brazil, were maintained in Petri dishes into an incubator at 27±1ºC and 80±10% RH, for egg laying. For the development of the subsequent experimental phases, artificial infestations were performed in rabbits using the technique of the cotton bag glued to the ear's base. The mean period of hatch, feeding and larval molt were 11.67, 5.93 and 10.96 days, respectively, whereas the mean period of feeding and nymph's molt were 12.40 and 16.27 days, respectively. Only one engorged female was obtained, with detachment observed on the 22nd day. The longevity periods for larvae, nymphs and adults were 75, 96 and 150 days respectively.