Endophytic Streptomyces strains are potential sources for novel bioactive molecules. In this study, the diketopiperazine gancidin W (GW) was isolated from the endophytic actinobacterial genus Streptomyces, SUK10, obtained from the bark of Shorea ovalis tree, and it was tested in vivo against Plasmodium berghei PZZ1/100. GW exhibited an inhibition rate of nearly 80% at 6.25 and 3.125 μg kg−1 body weight on day four using the 4-day suppression test method on male ICR strain mice. Comparing GW at both concentrations with quinine hydrochloride and normal saline as positive and negative controls, respectively, 50% of the mice treated with 3.125 μg kg−1 body weight managed to survive for more than 11 months after infection, which almost reached the life span of normal mice. Biochemical tests of selected enzymes and proteins in blood samples of mice treated with GW were also within normal levels; in addition, no abnormalities or injuries were found on internal vital organs. These findings indicated that this isolated bioactive compound from Streptomyces SUK10 exhibits very low toxicity and is a good candidate for potential use as an antimalarial agent in an animal model.

Mosquito larval surveillance was carried out in a rice field in Tanjung Karang, Selangor, Malaysia to determine the diversity of breeding habitats of mosquito larvae and species composition of those mosquito larvae that bred in positive habitats within the study area. From 215 potential mosquito breeding habitats inspected, 93.90% outdoor containers and 6.10% indoor containers were positive with mosquito breeding. Artificial containers (71.95%) were favorable breeding habitats of mosquito larvae compared to natural containers (28.05%). Only Aedes albopictus Skuse (80.80%) and Culex quinquefasciatus Say (19.20%) larvae were collected from all positive breeding habitats. This result shows that Ae. albopictus is a predominant outdoor breeder in the study area and could also invade indoors. It is crucial to identify the mosquito species available in the study area and their habitats to ensure the effectiveness of vector control strategies conducted so that the transmission of any mosquito-borne diseases could be avoided or lessened.