This was on the 9th December 2024, at the Faculty of Science of the University of Yaoundé I, Cameroon.
Yvan Fotso with his supervisors
His study entitled “Identification of molecular markers of metabolic resistance to pyrethroids in malaria vectors in Yaoundé, Cameroon” earned him the highest distinction. The main aim of this research study was to develop a simple diagnostic test that can help in the early detection and the monitoring of metabolic resistance in field-caught Anopheles coluzzii and Anopheles gambiae mosquitoes. After identifying molecular markers for the rapid detection of resistance mediated by the CYP6P4 gene, Yvan Fotso showed a reduction in genetic diversity in favour of individuals carrying the T mutation at position 273 of a nrf2/MAF binding site in Anopheles gambiae. This mutation was found at a frequency of 100% in hyper-resistant specimens (R90) and 44% in hypersensitive specimens (S20). The candidate also identified a synonymous mutation in codon 168 (TGC->AGC) of the CYP6P4 gene with a frequency of 70% in the R90s and just 28% in the S20s, but with no sign of selection. However, no molecular marker associated with resistance was found in the CYP6M2 gene in the two species studied (Anopheles gambiae and Anopheles coluzzii), which is in line with the results of previous work, leaving the hypothesis of constitutive expression for this gene.
Dr Fotso Toguem obtained the highest distinction
Yvan Fotso also confirmed the temporal dynamics of permethrin resistance, as well as the expression of certain metabolic genes, which seems to be closely linked to seasonal anthropic activities favouring a selection pressure exerted on these malaria vectors at their breeding sites. In 45 minutes, the candidate presented a relevant summary of his work. He answered the jury’s questions satisfactorily. After deliberation, the jury decided to award Mr Fotso Toguem Yvan Gaétan the title of Doctor/Ph.D. in Biology of Animal Organisms, with a specialization in Parasitology and Ecology. For background, Dr. Yvan Fotso Toguem was one of the four Ph.D students selected within the Partnership for Increasing the Impact of Vector Control ( PIIVeC ) Programme, and mentored by Dr. Billy Tene. He was enrolled as a Ph.D student in Animal Biology, at the University of Yaoundé I (UYI) under the supervision of Prof Charles Wondji from Liverpool School of Tropical Medicine ( LSTM) and Prof Flobert Njiokou from UYI. This achievement marks the beginning of his career as a researcher in vector biology and genetics, with a focus on contributing to malaria elimination efforts in Cameroon and Africa.
