Insecticidal activities of Streptomyces sp. KSF103 ethyl acetate extract against medically important mosquitoes and non-target organisms

Abstract

A potentially novel actinobacterium isolated from forest soil, Streptomyces sp. KSF103 was evaluated for its insecticidal effect against several mosquito species namely Aedes aegypti, Aedes albopictus, Anopheles cracens and Culex quinquefasciatus. Mosquito larvae and adults were exposed to various concentrations of the ethyl acetate (EA) extract for 24 h. Considerable mortality was evident after the EA extract treatment for all four important vector mosquitoes. Larvicidal activity of the EA extract resulted in LC50 at 0.045 mg/mL and LC90 at 0.080 mg/mL for Ae. aegypti; LC50 at 0.060 mg/mL and LC90 at 0.247 mg/mL for Ae. albopictus; LC50 at 2.141 mg/mL and LC90 at 6.345 mg/mL for An. cracens; and LC50 at 0.272 mg/mL and LC90 at 0.980 mg/mL for Cx. quinquefasciatus. In adulticidal tests, the EA extract was the most toxic to Ae. albopictus adults (LD50 = 2.445 mg/mL; LD90 = 20.004 mg/mL), followed by An. cracens (LD50 = 5.121 mg/mL; LD90 = 147.854 mg/mL) and then Ae. aegypti (LD50 = 28.873 mg/mL; LD90 = 274.823 mg/mL). Additionally, the EA extract exhibited ovicidal activity against Ae. aegypti (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), Ae. albopictus (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), and An. cracens (LC50 = 0.715 mg/mL; LC90 = 6.956 mg/mL), evaluated up to 168 h post-treatment. It displayed no toxicity on the freshwater microalga Chlorella sp. Beijerinck UMACC 313, marine microalga Chlorella sp. Beijerinck UMACC 258 and the ant Odontoponera denticulata. In conclusion, the EA extract showed promising larvicidal, adulticidal and ovicidal activity against Ae. aegypti, Ae. albopictus, An. cracens, and Cx. quinquefasciatus (larvae only). The results suggest that the EA extract of Streptomyces sp. KSF103 has the potential to be used as an environmental-friendly approach in mosquito control. The current study would serve as an initial step toward complementing microbe-based bioinsecticides for synthetic insecticides against medically important mosquitoes.

Insecticidal potential of Streptomyces sp. dichloromethane extracts against the cactus cochineal Dactylopius opuntiae (Cockerell)

“…Streptomyces secondary metabolites are considered a significant new-generation pesticide by IPM practitioners due to their specific toxicity and favorable non target organism and ecological profile (Schneider et al, 2004). In addition, the use of Streptomyces secondary metabolites has gained public acceptance due to its minimal impact on ecosystems and humans, as well as other non-target organisms (Chen et al, 2023). Microbial insecticides are highly valuable because of their extremely low toxicity to non-target animals and humans (Dhanasekaran and Thangaraj, 2014).…”

Antiviral Activities of Streptomyces KSF 103 Methanolic Extracts against Dengue Virus Type-2

“…Negative and positive ion modes were used with the UHPLC-MS. Four different compounds were reported to exhibit potential antiviral properties based on similar molecular features of known compounds (Table 3). Aminocaproic acid [22,23] C6H13NO2…”

“…In a recent study, Streptomyces KSF 103 was isolated from soil sediments of a primary forest in Jerantut, Pahang, Malaysia [ 23 ]. An ethyl acetate extract of strain KSF 103 possessed potent insecticidal activities against Aedes and Culex mosquito sp.…”

“…An ethyl acetate extract of strain KSF 103 possessed potent insecticidal activities against Aedes and Culex mosquito sp. [ 23 ]. Here, the effects of Streptomyces KSF 103 ME on DENV-2 replication were investigated.…”