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Research Project: MALDI-TOF Mass Spectrometry as an Additional Tool for Vector-borne Disease Surveillance

Location: Research Programs

Project Number: 3022-32000-018-035-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 22, 2023
End Date: Aug 21, 2027

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-TOF MS) is a large biomolecule identification method extensively used in clinical bacteriology to identify bacterial pathogens from human samples. It has been successfully applied to medical entomology over the past few years and allowed the identification of arthropod vectors such as ticks, mosquitoes, fleas, live, sandflies, triatomines, bed bugs, etc. Species identification using MALDI-TOF MS is highly accurate and can be used to differentiate species belonging to the same complex (e.g., mosquito Gambiae complex). Furthermore, species identification has been refined to identify populations within species, allowing for precise and accurate surveillance of population changes. This project will develop Maldi-Tof protocols and reference sets for foreign vectors.

This project will generate databases for the identification of various arthropod vectors of interest and the detection of their associated pathogens. Non-infected arthropod collection samples stored will be used for the first stages of database development. Formally identified samples will be selected. Sanger sequencing will be used to identify arthropod species based on their Cox1, 12S, 18S and other genes validated for arthropod identification. Samples will be screened by qPCR for vector-borne pathogens prior to being subjected to MALDI-TOF mass spectrometry to generate spectra. The positive controls used for these assays will be generated from our UTMB collection of bacteria and viruses or provided by the CDC. Vectors collected overseas from East Africa (Kenya, Ethiopia, Uganda, Tanzania), West Africa (Senegal, Nigeria), and South America/the Caribbean (Venezuela, Martinique, Trinidad, Peru) will be collected. Samples will first be morphologically identified using relevant morphological keys and then subjected to MALDI-TOF mass spectrometry to generate spectra. They will also be screened for vector-borne pathogens to determine their infection status. Laboratory infected arthropods will be collected for MALDI-TOF MS analyses and used as controls. Data will be compiled and used to develop algorithms to identify vectors. Similar work will also be performed with US collected vectors to ensure non native ticks can be rapidly and accurately identified.