Resumo Mieloencefalite protozoária equina (MPE) é uma doença neurológica causada por Sarcocystis neurona. Reação de imunofluorescência indireta (RIFI) tem sido utilizada para identificar a exposição de equinos à S. neurona no Brasil. Neste estudo, a RIFI foi utilizada para avaliar a presença de anticorpos IgG anti-Sarcocystis falcatula-like (Dal-CG23) e anti-S. neurona (SN138) no soro de 342 equinos de Campo Grande, Mato Grosso do Sul (Centro-oeste) e São Paulo, São Paulo (Sudeste), Brasil. O ponto de corte de 1:25 foi escolhido para maximizar a sensibilidade. Anticorpos IgG anti-S. neurona foram detectados em 239 cavalos (69,88%), enquanto anticorpos IgG anti-S. falcatula-like foram detectados em 177 cavalos (51,75%). O soro de 132 animais (38,59%) reagiu contra ambos os isolados. A ausência de reatividade foi evidenciada em 58/342 animais (16,95%). O baixo ponto de corte e a presença de gambás infectados com S. falcatula-like e Sarcocystis spp., nas regiões onde os equinos foram amostrados podem justificar a alta soroprevalência aqui observada. Devido à similaridade entre antígenos de superfície detectados nos imunoensaios, relatos de soropositividade contra S. neurona no Brasil podem resultar da exposição dos equinos a outras espécies de Sarcocystis. O papel de outras espécies de Sarcocystis como causa de doença neurológica em equinos no Brasil permanece incerto. MPE (MPE (RIFI S estudo antiSarcocystis anti falcatulalike falcatula like DalCG23 DalCG Dal CG23 CG (Dal-CG23 antiS. antiS anti-S SN138 SN (SN138 34 Grande Centrooeste Centro oeste (Centro-oeste Sudeste, Sudeste , (Sudeste) 125 1 25 1:2 sensibilidade 23 69,88%, 6988 69,88% 69 88 (69,88%) 17 51,75%. 5175 51,75% . 51 75 (51,75%) 13 38,59% 3859 38 59 (38,59% isolados 58342 58 58/34 16,95%. 1695 16,95% 16 95 (16,95%) spp spp. observada imunoensaios incerto DalCG2 CG2 (Dal-CG2 SN13 (SN13 3 (Sudeste 12 2 1: 698 69,88 6 8 (69,88% 517 51,75 5 7 (51,75% 38,59 385 (38,59 5834 58/3 169 16,95 9 (16,95% (Dal-CG SN1 (SN1 69,8 (69,88 51,7 (51,75 38,5 (38,5 583 58/ 16,9 (16,95 (SN 69, (69,8 51, (51,7 38, (38, 16, (16,9 (69, (51, (38 (16, (69 (51 (3 (16 (6 (5 ( (1

Abstract Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona. Immunofluorescence antibody tests (IFATs) have been widely used to identify exposure of horses to S. neurona in Brazil. Here we used IFAT to search for IgG antibodies against Sarcocystis falcatula-like (Dal-CG23) and S. neurona (SN138) in sera from 342 horses sampled in Campo Grande, Mato Grosso do Sul state (Midwestern), and São Paulo, São Paulo state (Southeastern), Brazil. The 1:25 cutoff value was chosen to maximize sensitivity of the test. IgG antibodies against S. neurona were detected in 239 horses (69.88%), whereas IgG antibodies against S. falcatula-like were detected in 177 horses (51.75%). Sera from 132 horses (38.59%) reacted against both isolates. Absence of reactivity was evidenced in 58/342 horses (16.95%). The lower cutoff used, and the presence of opossums infected with S. falcatula-like and Sarcocystis spp. in the regions where the horses were sampled, might justify the high seroprevalence observed here. Owing to the similarity among antigens targeted in immunoassays, reports on S. neurona-seropositive horses in Brazil may also derive from the exposure of horses to other Sarcocystis species. The role of other Sarcocystis species in causing neurological diseases in horses in Brazil remains unclear. EPM (EPM IFATs (IFATs S falcatulalike falcatula like DalCG23 DalCG Dal CG23 CG (Dal-CG23 SN138 SN (SN138 34 Grande Midwestern, Midwestern , (Midwestern) Southeastern, Southeastern (Southeastern) 125 1 25 1:2 test 23 69.88%, 6988 69.88% 69 88 (69.88%) 17 51.75%. 5175 51.75% . 51 75 (51.75%) 13 38.59% 3859 38 59 (38.59% isolates 58342 58 58/34 16.95%. 1695 16.95% 16 95 (16.95%) spp here immunoassays neuronaseropositive seropositive unclear DalCG2 CG2 (Dal-CG2 SN13 (SN13 3 (Midwestern (Southeastern 12 2 1: 698 69.88 6 8 (69.88% 517 51.75 5 7 (51.75% 38.59 385 (38.59 5834 58/3 169 16.95 9 (16.95% (Dal-CG SN1 (SN1 69.8 (69.88 51.7 (51.75 38.5 (38.5 583 58/ 16.9 (16.95 (SN 69. (69.8 51. (51.7 38. (38. 16. (16.9 (69. (51. (38 (16. (69 (51 (3 (16 (6 (5 ( (1

We used a colorimetric reverse dot blot hybridization (CRDH) assay to detect the presence of mutations in a specific region of the rpoB gene, associated with rifampin (RIF) resistance, in a panel of 156 DNAs extracted from 103 RIF-sensitive and 53 RIF-resistant cultures of Mycobacterium tuberculosis. When compared with the antimicrobial susceptibility test (AST), the sensitivity and specificity of the CRDH were 92.3% and 98.1%, respectively. When compared with sequencing, the sensitivity and specificity of the CRDH were 90.6% and 100%, respectively. To evaluate the performance of the assay directly in clinical specimens, 30 samples from tuberculosis patients were used. For these samples, the results of the CRDH were 100% consistent with the results of the AST and sequencing. These results indicate that the rate of concordance of the CRDH is high when compared to conventional methods and sequencing data. The CRDH can be successfully applied when a rapid test is required for the identification of RIF resistance in M. tuberculosis.

Resistance of beef cattle heifers to the cattle tick Boophilus microplus was evaluated by artificial infestation of 66 beef cattle heifers of the following genetic groups: 16 Nelore (NE), 18 Canchim x Nelore (CN), 16 Angus x Nelore (AN) and 16 Simmental x Nelore (SN). The animals, with a mean age of 16.5 months, were maintained with no chemical tick control in a Brachiaria decumbens pasture. Four artificial infestations with 20,000 B. microplus larvae were carried out 14 days apart and from day 18 to day 22 of each infestation the number of engorged female ticks (> 4.5 mm) was counted on the left side of each heifer. Data were analyzed as the percentage of return (PR = percentage of ticks counted relative to the number infested), transformed to (PR)¼, and as log10 (Cij + 1), in which Cij is the number of ticks in each infestation, using the least squares method with a model that included the effects of genetic group (GG), animal within GG (error a), infestation number (I), GG x I and the residual (error b). Results indicated a significant GG x I interaction, because AN and SN heifers had a higher percentage of return than CN and NE heifers, while CN heifers showed a higher percentage of return than the NE heifers only in infestations 3 and 4. Transformed percentages of return were NE = 0.35 ± 0.06, AN = 0.89 ± 0.06, CN = 0.54 ± 0.05 and SN = 0.85 ± 0.06.