There are many extraction methods available to purify bacterial DNA. PCR efficiency can vary depending on the quantity and quality of the template DNA used. This study evaluated the efficiency, quality, cost and rapidness of two in-house protocols, silica particles and Chelex-100 resin, for the extraction of twenty Salmonella isolates from boot swabs. The aim of this experiment was to compare the extraction methods for Salmonella spp. detection. DNA extraction was performed for each method and subjected to real-time PCR amplification. The amounts and integrity of DNA were determined using spectrophotometry and agarose gel electrophoresis, and the efficiency measured with real-time PCR. Limit of Detection (LOD) was determined with serial dilutions of a S. Typhimurium reference strain resulting in linear regression coefficients of R 2=0.992 (efficiency 119.31) for silica and R 2=0.958 (efficiency 93.33) for Chelex, with LOD of 10 -4 for both. Silica particles method resulted in higher DNA yield, 85.01 ± 59.11 compared to 50.74 ± 12.95 and 260/280 ratio, 1.77 ± 0.02 versus 1.63 ± 0.13. DNA integrity was superior using silica, gel showed a unique band higher than 2.000 bp, while Chelex-100 was imperceptive or degraded. Regarding PCR results, the mean quantification cycle (Cq) for silica was 17.08 ± 0.73 and Chelex-100, 17.64 ±0.56 (suggesting lower DNA values). Results showed that both methods were effective for the DNA extraction of Salmonella, once PCR resulted positive for all samples, efficiency was higher for silica. Chelex-100 resin was performed in less time at a lower cost.

Via a One Health approach, this study concomitantly assessed the susceptibility of humans and dogs to Trypanosoma cruzi infections on three islands and in two mainland seashore areas of southern Brazil. Human serum samples were tested using an enzyme-linked immunosorbent assay (ELISA) to detect anti-T. cruzi antibodies, while dog serum samples were tested using indirect fluorescent antibodies in an immunofluorescence assay (IFA). Seropositive human and dog individuals were also tested using quantitative polymerase chain reaction (qPCR) in corresponding blood samples. Overall, 2/304 (0.6%) human and 1/292 dog samples tested seropositive for T. cruzi by ELISA and IFA, respectively, and these cases were also molecularly positive for T. cruzi by qPCR. Although a relatively low positivity rate was observed herein, these cases were likely autochthonous, and the individuals may have been infected as a consequence of isolated events of disturbance in the natural peridomicile areas nearby. Such a disturbance could come in the form of a fire or deforestation event, which can cause stress and parasitemia in wild reservoirs and, consequently, lead to positive triatomines. In conclusion, T. cruzi monitoring should always be conducted in suspicious areas to ensure a Chagas disease-free status over time. Further studies should also consider entomological and wildlife surveillance to fully capture the transmission and spread of T. cruzi on islands and in seashore mainland areas of Brazil and other endemic countries.