The objective of the present study was to determine the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene of Haemonchus contortus from various sheep flocks in eastern Amazon, and to identify management practices that may favor the emergence of resistance to anthelmintic drugs in the same area. In total, 305 specimens of H. contortus were collected from sheep at 12 farms located in the state of Pará. An allele-specific PCR was performed to detect the F200Y polymorphism, and questionnaires were used to obtain information about the farms and flocks. All genotypes were detected as follows: 31% of the parasites were RR, 37% of the parasites were SR, and 32% were SS. The completed questionnaires revealed that all farms employed semi-intensive farming systems, performed suppressive anthelmintic treatment, and based their choice of drug on cost and availability rather than on any knowledge regarding drugs that remained effective on their property. It can thus be concluded that the SNP in codon 200 of the β-tubulin isotype 1 gene is present in the H. contortus populations from eastern Amazon, and that a series of management practices that favor the emergence of anthelmintic resistance are employed on these farms.

The continuous use of synthetic insecticides for controlling the arboviral vector Aedes aegypti has led to the natural selection of mosquito populations resistant to different chemical groups. Thus, plant-derived compounds have emerged as a viable alternative for vectorcontrol. This study determined whether the crude methanolic extract (CME) from leaves of Clibadium surinamense has larvicidal activity against Ae. aegypti. Third- and fourth-instar Ae. Aegyptilarvae were kept in recipients containing 99 mL of water and 1mL of ethanol-diluted CMEat concentrations of 250, 500, 750, and 1000 ppm. The control group contained 99 mL of water and 1 mL of ethanol. Three trials were performed in triplicate for each group.After 24 hours of treatment, the LC50 and LC90 values were determined to be 283 and 430 ppm, respectively, according to one-way analysis of variance. In conclusion, we have demonstrated for the first time that the CME from leaves of C. surinamense show larvicidal activity against Ae. aegypti under laboratory conditions.