Due to the phylogenetic similarity between Leishmania spp. and Trypanosoma cruzi (T. cruzi), serological cross-reactions and false-positive results are quite common. This study aimed to elucidate canine leishmaniasis and trypanosomiasis diagnosis by the indirect fluorescent antibody test (IFAT) on serum samples, and direct parasitological examination and polymerase chain reaction (PCR) in liver and spleen samples. One hundred dogs from Zoonosis Control Center (ZCC) in Bauru, SP, an endemic area for visceral leishmaniasis (VL), and 100 dogs from the Dog Warden Service in Botucatu, SP, a nonendemic area for VL, were studied. IFAT showed positive results for Leishmania spp. in 65% of canine serum samples from Bauru while 40% of the samples were positive for T. cruzi by this test. All samples from Botucatu were negative for leishmaniasis in IFAT, and only 4% were positive for T. cruzi. Out of 200 serum samples tested, 33 (16.5%) showed positive serological results for both the parasites. Direct parasitological examination and PCR found, respectively, 59% and 76% of the liver samples and 51% and 72% of the spleen samples of dogs from Bauru positive for Leishmania spp. Twenty-six (78.8%) of 33 dogs that showed anti-Leishmania spp. and anti-T. cruzi antibodies also tested positive by direct parasitological examination and PCR for Leishmania spp., which indicates that these dogs presented leishmaniasis. No liver or spleen sample from the 200 dogs analyzed showed a positive PCR result for T. cruzi. These findings support the occurrence of cross-reactions between Leishmania spp. and T. cruzi in IFAT; they also corroborate the need for simultaneous PCR and/or parasitological examination to establish canine leishmaniasis (CL) diagnosis.

A leishmaniose visceral (LV) é uma zoonose causada por protozoários do gênero Leishmania. O cão é o principal reservatório do parasito, especialmente em áreas urbanas. A Reação de Imunofluorescência Indireta (RIFI) é comumente empregada para o diagnóstico da leishmaniose visceral canina (LVC), baseada na detecção de anticorpos contra o parasito. Entretanto, reações cruzadas com Trypanosoma cruzi podem ocorrer à sorologia. Com o objetivo de avaliar as reações cruzadas entre os antígenos de Leishmania spp. e de T.cruzi, foram colhidas 150 amostras de sangue de cães positivos para LVC em inquérito epidemiológico e os soros foram testados pela RIFI. Os cães foram submetidos à eutanásia no Centro de Controle de Zoonoses de Bauru (SP), área endêmica para LV. Outras 150 amostras de sangue de cães foram colhidas em Botucatu (SP), área não endêmica para LV, e os soros foram também testados pela RIFI. Os soros de cães procedentes de Bauru resultaram positivos, tanto para Leishmania spp. quanto para T.cruzi, demonstrando uma grande incidência de reações cruzadas, reforçando a necessidade da confirmação diagnóstica por outras técnicas. As amostras de soros de cães procedentes de Botucatu (SP), pela técnica de RIFI, demonstraram baixa prevalência de resultados positivos para Leishmania spp. e para T.cruzi. Entretanto, apesar do reduzido número de resultados positivos à sorologia para ambos parasitos, a investigação sorológica e epidemiológica para LV e doença de Chagas em cães de Botucatu deve ser mantida, considerando a importância do cão como reservatório doméstico no contexto destas zoonoses.

Considering the bactericide action of the propolis and the fact that this compound is allowed for use in organic dairies, Brazilian researchers developed the nanoestructured propolis, a new perspective for bovine mastitis treatment. The aim of the present study was to evaluate the safety of this nanopropolis formulation in dairy cows from an organic farm in Botucatu-SP Brazil. A volume of 10 mL nanopropolis was administered by intramammary route in four cows, during three consecutive days. Animals were clinically evaluated after treatments and no local and/or systemic adverse reactions were verified. The use of nanopropolis did not interfered on SCC values neither on milk production rates on treated cows. It was possible to conclude that the evaluated nanopropolis formulation is safe for intramammary treatment of mastitis cases in dairy herds.

Article history Dairy farming is an important social and economic activity in the Midwest region of Santa Catarina State, Brazil. However, despite technological advances in the productive chain, mastitis is still considered the main disease of dairy herds, due its high economic impact. Bacterial pathogens are the main cause of this disease and failures in the treatment of clinical cases are attributed in part to the antimicrobial resistance of these pathogens. As an alternative, in vitro antimicrobial susceptibility tests of strains isolated from bovine mastitis cases have been carried out; the information generated contributes to strategic treatment measures, and also to the control of microorganism resistance. Therefore, the aims of the present study were to evaluate the etiology and in vitro antimicrobial susceptibility profiles of bacterial strains isolated from cases of bovine mastitis in dairy herds from the Midwest region of Santa Catarina State, Brazil. For this purpose, 345 milk samples were collected from 70 herds located in 16 different municipalities. The main pathogens isolated were: staphylococci (55.9%), streptococci (34.8%), Corynebacterium spp. (7.8%) and Escherichia coli (1.4%). The resistance rates of staphylococcus strains to ampicillin and to gentamicin were lower (24.9%) and higher (33%), respectively, than those obtained in other Brazilian studies. The resistance profiles of streptococcus strains were similar to those described in the literature, while Corynebacterium spp., showed high resistance rates to tetracycline (85.2%). Moreover, a considerable prevalence of staphylococcus (27.5%) and streptococcus (11.7%) multiresistant strains was verified. These data reinforce the need for regional characterization of microorganisms.

Corynebacterium bovis is a mastitis-causing microorganism responsible for economic losses related to decrease in milk production. The aim of the study was identify Corynebacterium spp. strains recovered from milk samples of subclinical mastitis by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Samples were collected during a 10-mo mastitis-monitoring program in a high-production dairy farm. In this study, 80 strains were analyzed; from these 54 (67.5%) were identified at species level as Corynebacterium bovis, 24 (31.2%) isolates were identified at the genus level as Corynebacterium spp., and only 1 (1.35%) isolated had unreliable identification. Results demonstrated that MALDI-MS could be an important technique for the identification of Corynebacterium spp. in milk.