Bacteria: A novel source for potent mosquito feeding-deterrents

Area of Science:

• Microbiology
• Chemical Ecology
• Vector Biology

Background:

• Entomopathogenic bacteria, including Xenorhabdus species, produce secondary metabolites with known antibiotic and insecticidal properties.
• Novel applications of these bacterial metabolites, particularly in vector control, remain largely unexplored.

Purpose of the Study:

• To investigate the potential of extracellular metabolites from Xenorhabdus budapestensis as mosquito feeding deterrents.
• To identify the specific compounds responsible for the observed feeding-deterrent activity.

Main Methods:

• In vitro cultivation of Xenorhabdus budapestensis to obtain extracellular metabolites.
• Bioassays to assess the feeding-deterrent activity of metabolite fractions against Aedes aegypti, Anopheles gambiae, and Culex pipiens.
• Chemical analysis to identify the active compounds within the deterrent fraction.

Main Results:

• A mixture of compounds from X. budapestensis exhibited potent feeding-deterrent activity against three major mosquito vectors.
• The active fraction was significantly enriched in compounds consistent with fabclavines.
• The deterrent activity of the fabclavine-rich fraction was comparable to or superior to DEET and picaridin.

Conclusions:

• Extracellular metabolites from Xenorhabdus budapestensis, likely fabclavines, possess significant mosquito feeding-deterrent properties.
• These findings suggest a potential for developing novel, biologically derived mosquito repellents and feeding-deterrents from bacterial sources.