Avaliação da eficácia do fipronil em Rhipicephalus (Boophilus) microplus em tratamentos consecutivos

A realização deste trabalho teve como objetivo avaliar a eficácia do fipronil em Rhipicephalus (Boophilus) microplus, durante e após 14 tratamentos, no período de dezembro de 2006 a abril de 2009. O experimento foi realizado em uma propriedade rural do município de Lages, SC, utilizando-se 20 bovinos mestiços charolês mantidos em campo nativo, naturalmente infestados com R. (B.) microplus. A cada 14 dias, foram realizadas contagens das fêmeas de carrapato, maior ou igual a 4,5mm. Os animais foram tratados com fipronil 1mg/kg via pour on, quando a média do número de carrapatos foi igual ou superior a 40 fêmeas. Ao final do experimento, para análise da eficácia do fipronil 1%, foi realizado o teste de estábulo, utilizando 10 animais infestados com larvas provenientes de teleóginas coletadas de bovinos da propriedade. Os animais foram randomizados, de acordo com a produção inicial de teleóginas, estabelecendo-se dois grupos: controle (n=5) e tratado (n=5). A redução da média do número de fêmeas de R. (B.) microplus nas contagens após tratamentos foi de 100% nos três primeiros, com um leve declínio até o sexto tratamento. No sétimo tratamento a redução foi de 91,3%. Ao final do experimento a eficácia do fipronil 1%, avaliada pelo teste de estábulo, na redução do número de teleóginas, foi de 79,3%. A porcentagem média de inibição de reprodução calculada foi de 22,47%. Concluiu-se que, após seis tratamentos com fipronil, média de um a cada 2,7 meses, o princípio ativo deve ser substituído e que, após 14 tratamentos, o R. (B.) microplus adquiriu resistência parcial a esse carrapaticida

Toxoplasma gondii in milk of naturally infected dairy ewes on west mesoregion of Santa Catarina state, Brazil

ABSTRACT This study aimed to detect Toxoplasma gondii in the milk of dairy sheep in the Western mesorregion of state of Santa Catarina by bioassay (22 milk samples from eight ewes seropositive; IFA ≥256) and PCR [for the detection of agent in the brains of mice inoculated on bioassay and directly from milk (108 samples from 42 seropositive ewes (IFA, ≥64) in different lactation periods)]. T. gondii DNA was detected in mice brains inoculated with milk from eight sheep (a sample of the 45th day of lactation and seven in the collection of 90th day) and directly from the milk in samples of the second collection (90 days) in five animals. Taking into account both assays, from a total of 42 ewes in lactation and seropositive for T. gondii, 30.95% (13/42) of the animals presented evidences of T. gondii presence in milk. Positive PCR samples were sequenced and the results confirmed ≥97% identity with the membrane antigen P22 gene of T. gondii. The results showed that T. gondii is present in the milk of sheep, representing a possible source of infection to humans through the consumption of milk "in natura" and/or derivatives, besides the possibility of lactogenic transmission to lambs

Genotyping of Toxoplasma gondii isolates from naturally infected Gallus domesticus in Santa Catarina state, Brazil

ABSTRACT Toxoplasmosis is a widespread zoonosis that can infect warm-blooded animals including birds and humans, and chickens are considered to be indicators of environmental contamination. In Brazil, Toxoplasma gondii has a non-clonal population structure composed of three lineages (I, II, and III), presenting high recombination, and resulting in wide genetic diversity. This study aimed to genetically characterize T. gondii isolates from naturally infected chickens (Gallus domesticus) in Santa Catarina state, southern Brazil region. Sera from 133 free-range chickens were analyzed by an immunofluorescence assay (IFA) to detect IgG antibodies against T. gondii. Brain and heart from 30 positive animals, based on IFA (≥ 1:64), were used to isolate the parasite using a mouse bioassay. Strain genotyping was performed by PCR-RFLP using 12 genetic markers (SAG1, 5´-3´SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3). The results were classified according to the genotypes based on the ToxoDB (http://toxodb.org/toxo/). Of 133 chicken sera analyzed, 84 (63.16%) were positive, with antibody titers ranging from 16 to 1024. Eleven isolates were obtained from mouse bioassay (Ck3, Ck32, Ck35, Ck56, Ck63, Ck89, Ck102, Ck103, Ck125, Ck127, and Ck128). Genotyping revealed six genotypes; three were classified as #26, #53, and #120, and three (NEO1, NEO2, and NEO3) were had not been previously described. No clonal lineages of type I, II, or III were identified. The present study confirms the high genetic diversity of T. gondii in Brazil

Antibodies against rickettsiae from spotted fever groups in horses from two mesoregions in the state of Santa Catarina, Brazil

Bacteria of the Rickettsia genus are agents of Brazilian Spotted Fever (BSF), a zoonotic disease which is difficult to diagnose, evolves quickly and can result in death. Antibodies against Rickettsia spp. in horses were studied, by means of Indirect Immunofluorescence Assay (IFAT ≥64), in 150 blood samples taken from animals in two Santa Catarina mesoregions (Planalto Serrano and Vale do Itajaí). The overall occurrence of Rickettsia spp. antibodies in horses was 18.66%, with cross-reactivity occurring in all positive samples for at least two of the species tested. Separately, according to the species, 25 (16.66%) samples were positive for R. rickettsii, 15 (10%) for R. parkeri, 22 (14.66%) for R. amblyommii, 23 (15.33%) for R. rhipicephali, 16 (10.66%) for R. bellii and 19 (12.66%) for R. felis. Only two animals resulted in a conclusive serodiagnosis, one for R. bellii and the other for R. rickettsii, at maximum dilutions of 1:4096 and 1:512, respectively. The occurrence of antibodies against Rickettsia spp. in horses from two mesoregions in the state of Santa Catarina indicates the movement of BSF agents in these sentinel animals and confirms the importance of studying spotted fever in the state of Santa Catarina

Amblyomma calcaratum parasitando tamanduá-bandeira (Myrmecophaga tridactyla) em São Paulo Amblyomma calcaratum parasitizing giant anteater (Myrmecophaga tridactyla) in the State of São Paulo, Brazil

<abstract language="eng">Ocurrence of Amblyomma calcaratum parasitizing giant anteater (Myrmecophaga tridactyla) is described in the State of São Paulo, Brazil