Antonio Pereira de Souza

Resistência de helmintos gastrintestinais de bovinos a anti-helmínticos no Planalto Catarinense

In order to estimate possible focus of resistance of bovine gastrointestinal helminths to ivermectin, levamisole phosphate and albendazole sulphoxide, 39 properties in the Santa Catarina Plateau were evaluated. In each location a mean number of 60 samples of feces was collected from animals between seven and 18 months of age, for the evaluation of the number of eggs per gram of feces (EPG), for culture and for larvae identification. Three groups with similar EPG mean were comprised, with the mean EPG being considered the group control. Animal from each group received a different subcutaneous treatment: a) 0.2mg kg-1 ivermectin, b) 5mg kg-1 levamisole phosphate, and c) 2.5mg kg-1 albendazole sulphoxide). The fecal evaluation, per group, was repeated seven days later. Resistance was considered when the efficacy of the drug was lesser than 95% and when the inferior limit of the confidence interval CI95% was lesser than 90%. From the properties examined, 82.1% presented animals with helminths resistant to ivermectin, 15.4% to levamisole phosphate, and 7.8% to albendazole sulphoxide. In only 10.3% of the properties the efficacy of all the anthelmintics was superior to 95%. Based on the generic diagnosis, through the larvae identification, Cooperia spp and Haemonchus spp were the prevailing resistant genus to ivermectin, Ostertagia spp, Cooperia spp and Trichostrongylus spp were associated with resistance to levamisole phosphate, and Cooperia spp. to albendazole sulphoxide.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil

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.

Epidemiologia das helmintoses gastrintestinais de ovinos no Planalto Catarinense

This work was developed for proposing a control strategy of sheep helminthes in the Santa Catarina Plateau. The prevalence, intensity and seasonal variation of gastrointestinal and pulmonary helminths in three farms of Lages, Sao Joaquim, and Campos Novos in Santa Catarina State, Brazil were assessed. Monthly, three tracer lambs were used by property. They had been previously housed for 30 days and suppressively treated by anthelmintics with different active ingredients followed by weekly parasitological examinations to assure the total elimination of parasitic infection. After this, they were taken back to their respective farms, where they grazed for 28 days and housed again for another 20 days. After this period, they were sacrificed for estimating the total worm burden, and 10% of abomasum and small intestine material was sampled as well as all the helminthes from the large intestine and the lungs. The heaviest Haemonchus contortus infection was registered from October to March. Trichostrongylus colubriformis and Trichostrongylus axei had increased rates through the experimental years, showing the peak from May to October of 1999. The most prevailing species in the abomasum were H. contortus (100%), T. axei (98.7%), T. colubriformis (1.3%), Teladorsagia circumcincta (100%) and Ostertagia ostertagi (100%); in the small intestine: T. colubriformis (100%), Cooperia punctata (69.1%), C. pectinata (18.4%), C. curticei (6.9%), C. oncophora (4.8%), C. spatulata (0.8%) and Nematodirus spathiger (100%). In the large intestine: Oesophagostomum venulosum (100%) and Trichuris ovis (100%). No worms were detected in the lungs.

Resistência de parasitos gastrintestinais de ovinos a alguns anti-helmínticos no estado de Santa Catarina, Brasil

Sixty-five sheep flocks were studied in Santa Catarina State to determine parasites resistance to anthelmintics based on ivermectin (0.2mg/kg), levamisole (10mg/kg), closantel (10mg/kg) and albendazole (10 mg/kg). The evaluation was carryed out when a particular sheep flock showed a control group with EPG (eggs per gram) level above 500. Larvae culture was also performed to allow the parasite identification. Four randomized groups of 10 animals were formed and treated with one of the four anthelmintic products. Faecal samples were collected of each group seven to ten days after the treatment, aiming to perform the eggs count and larvae identification. These results were compared with results of the control group. The anthelmintics were considered to present evidence of parasite resistance when the efficacy of the product was lower than 95%. From the total of 65 sheep flock studied, seventy-seven percent presented parasite resistance to ivermectin, with Haemonchus larvae only (100%); sixty-five percent to albendazole, with Haemonchus (74%), Ostertagia (15%) and Trichostrongylus (11%); thirteen percent to closantel, with Haemonchus (100%); and fifteen percent to levamisole, with Thichostrongylus (44%), Ostertagia (39%) and Haemonchus (17%). The results detected the presence of a multi-resistance to anthelminthics in the great majority of the sheep flocks of Santa Catarina State.

Resistance to cypermethrin and amitraz in Rhipicephalus (Boophilus) microplus on the Santa Catarina Plateau, Brazil

With the objective of evaluating Rhipicephalus (Boophilus) microplus resistance to cipermetrina and amitraz, were collected engorged tick females from cattle on 20 farms on the Santa Catarina Plateau, in southern Brazil, between January of 2004 and May of 2006. Were also received 20 groups of engorged R. (B.) microplus females, collected by cattle farmers requesting acaricidal efficacy (AE) testing. Were performed in vitro tests, which consisted of immersing engorged females in cypermethrin (0.015%) and in amitraz (0.025%). An AE >95% was considered indicative of effectiveness. Of the 20 collected groups, 18 (90%) showed cypermethrin resistance and 1 (5%) showed amitraz resistance. Of the 20 received groups, 19 (95%) showed cypermethrin resistance and 2 (10%) showed amitraz resistance. The AE of cypermethrin was found to be >95%, 85-94%, and 55-64%, respectively, in 4 (57.1%), 2 (28.6%), and 1 (14.3%) of 7 reference groups, collected in the 1997-2001 period. The AE of amitraz was >95% in all of those groups. Among the groups of specimens received for analysis in that period, the AE of amitraz was >95% in 6 (85.71%) and 75-84% in 1 (14.28%). R. (B.) microplus resistance to acaricides is increasing on the Santa Catarina Plateau.

Toxoplasma gondii antibodies on domiciled cats from Lages municipality, Santa Catarina State, Brazil.

Sera were collected from 300 domiciled cats from the municipality of Lages, Southern Brazil, to determine the prevalence of Toxoplasma gondii antibodies and risk factors associated. Tests for T. gondii antibodies were performed using indirect immunofluorescent antibody test (IFAT). Positive reactions with titers ≥1:64 were found in 43 (14.33%) cats. A significant number of seropositive cats were ≥6 month old (p = 0.03758) and had access to the streets or/and rural areas (p = 0.04185). The results indicate that T. gondii is widespread in cats in Lages with a prevalence of 14.33%.

Epidemiologia de Oestrus Ovis (Diptera: Oestridae) em ovinos no Planalto Catarinense

An experiment has been carried out in the Santa Catarina Plateau to recommend a proposal for a strategy of Oestrus ovis, infestation in sheep. The prevalence, intensity and seasonal variation of O. ovis larvae in three farms of Lages, Sao Joaquim, and Campos Novos municipalities in the Santa Catarina State, Brazil, were assessed from october 1997 to september 2001. Three tracer lambs per property were used monthly. They had been previously housed for 30 days and suppressively treated with different active ingredients and taken to their respective farms, where they grazed for 28 days and housed again for another 20 days. After this period, they were sacrificed to collected O. ovis larvae from paranasal sinus. No infested animals with larvae of O. ovis were observed at monthly average temperatures inferior to 9.8°C. Heavier infestations occurred in spring and summer, mainly in Lages and in Campos Novos. These results suggest that strategic treatment should be done in the beginning of spring and in the end of summer.

Canine tegumentar leishmaníasis in the town of Balneário Camboriú in the State of Santa Catarina

INTRODUCTION The increase in American tegumentary leishmaniasis (ATL) cases in 2005 was due to an outbreak that occurred in the towns of Itapema and Balneário Camboriú. This study aimed to determine the possible presence of infection by Leishmania sp in domestic dogs living in an endemic focus of ATL in the town of Balneário Camboriú and verify the existence of a correlation between the humoral and cellular immune responses, the presence of suggestive lesions and positivity in direct parasitological exams. METHODS A total of 275 dogs were evaluated, examined according to clinic aspects, the development of delayed hypersensitivity to Immunoleish antigens and serological responses to the indirect immunofluorescence reaction and immunoenzymatic assay. RESULTS Seven dogs presented suspect lesions, but Leishmania was not detected using the direct parasitological method. The serological result was 5.8% positivity using the IIFR technique, 6.2% by ELISA and 1.8% using the intradermal test. The total number of dogs positive for ATL using the serological exams and/or intradermal test was 24, indicating prevalence of 8.7% for ATL. CONCLUSIONS Further studies are required to evaluate the participation of dogs in the epidemiological chain of ATL in Balneário Camboriú.

Prevalência de anticorpos anti-Babesia equi em eqüinos no Planalto Catarinense

Serum samples from 397 horses were examined by the indirect immunofluorescence technique. The blood samples were taken from horses of various ages, breeds and both sexes, bred and born in the Santa Catarina State, Brazil, in the counties of Lages, Sao Joaquim, Bom Jardim da Serra, Campos Novos, Anita Garibaldi, Curitibanos e Correia Pinto. The results indicated a prevalence of 50.38% of positive animals for B. equi at the 1:40 serum dilution. In different counties studied, the prevalence positive animals varied from 18.51% to 64.70%.

Neospora spp. antibodies in horses from two geographical regions of the state of Santa Catarina, Brazil

The aims of this study were to determine occurrences of Neospora spp. IgG antibodies in horses from two geographical regions of the state of Santa Catarina, southern Brazil, and identify risk factors for infection. Analyses were performed on 615 samples using the immunofluorescent antibody test (IFAT ≥ 1:50). Out of the 615 samples, 25 (4.1%) were positive for Neospora spp. The titers for Neospora spp. were distributed as follows: 1:50 (13), 1:100 (eight), 1:200 (three) and 1:400 (one). Out of the 311 samples taken in the mountain region, eight were positive (2.6%). Among the samples from the coastal region (304), 17 had Neospora spp. antibodies, thus indicating occurrence of 5.6%. Although no statistically significant difference was observed (P = 0.06704), the prevalence among animals of the coast was 2.2 times higher than that of the mountain region. Contact with dogs and/or cattle (P = 0.007596) were identified as risk factor for Neospora spp. infection.