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Florida Medical Entomology Laboratory

Florida Medical Entomology Laboratory

Dr. Derrick Mathias

Derrick Mathias

Assistant Professor


d.mathias@ufl.edu

Research Interests

Transmission cycles of vector-borne pathogens and parasites are complex and involve biological processes that occur at multiple scales, ranging from molecular interactions at the sub-cellular level to organismal interactions at the ecosystem level. For mosquito-borne agents, for example, successful transmission requires the presence and frequent interaction of both competent mosquitoes and competent hosts. For both types of organisms, competence further requires permissive immune systems and the ability of pathogens or parasites to infect specific cell types and develop (e.g., Plasmodium parasites) and/or replicate (e.g., arboviruses) as the case may be. On the vector side, competence is influenced by genetics of the vector, genetics of the pathogen or parasite, and non-genetic factors, which may be partitioned into internal (e.g., microbiota) and external (e.g., ambient temperature) factors.

Within the vector, competence-determining factors may be investigated by physiological compartment. For most mosquito-borne diseases, the causal agent enters the midgut lumen in a blood meal and gets transmitted horizontally to new hosts through saliva. For the agent to get from point A to B, it must negotiate a series of physiological barriers in the mosquito, which at a minimum include (i) infection of the midgut epithelium, (iii) replication and escape into the hemocoel (i.e., open circulatory system), (iii) infection of the salivary gland epithelium, and (iv) escape from salivary gland cells into the secretory cavity. My research program focuses on factors that cause variation in vector competence to address the question of why some blood-feeding insects and ticks are competent for a given agent, while others are not. Variation in vector competence is most pronounced between species or higher taxa (e.g., only anopheline mosquitoes transmit parasites that cause human malaria but rarely transmit arboviruses) but also occurs at the sub-species level within and between populations. My long-term objective is to use tools of molecular and evolutionary biology to tease apart genetic and non-genetic determinants of vector competence within populations and examine the extent to which competence-determining mechanisms are shared across vector-borne disease systems. Inherent in this strategy is the belief that investigating basic biology will yield insights that may be exploited to interrupt transmission cycles and control or prevent disease.

My lab primarily focuses mosquito-borne diseases, malaria in particular, but has begun to investigate arboviruses either endemic to the southeastern U.S. (epizootic hemorrhagic disease virus in white-tailed deer) or pose an imminent threat (Zika virus). For each disease system of interest I am asking a variety of questions that includes the list below.

Malaria:

  • Which molecules expressed on the Anopheles midgut surface are involved in Plasmodium infection of midgut epithelial cells? How conserved are these molecules among competent anopheline species? What role do they play in limiting competence among mosquito species compared to the innate immune response? Can the infection process be inhibited by antibodies or small molecules co-ingested in a blood meal that target vector-parasite interactions?
  • How are refractory phenotypes (i.e., resistant to parasite infection) genetically constructed in natural mosquito populations? How plastic are these phenotypes under various environmental conditions? How plastic are they for various strains and species of Plasmodium?
  • Does refractoriness to Plasmodium infection confer refractoriness to other parasites (e.g., filarial worms)?

Epizootic hemorrhagic disease:

  • Surveillance data on epizootic hemorrhagic disease virus (EHDV) and its potential vectors suggest that biting midge (family Ceratopogonidae) species other than Culicoides sonorensis are vectors of EHDV in the Southeast. Which of the Culicoides species native to the Southeast contribute to virus transmission?
  • Which molecules expressed on the Culicoides midgut surface are involved in virus infection of epithelial cells via endocytosis? How conserved are these molecules among competent ceratopogonid species? Can this process be inhibited by antibodies or small molecules co-ingested in a blood meal?

Zika virus:

  • Published studies of vector competence indicate that geographic origin of vector and virus strongly influence rates of dissemination and transmission. Which genes in the vector most influence competence for a given strain?
  • Like most mosquito-borne viruses, Zika virus has a single-stranded RNA genome with a relatively high mutation rate. Comparisons of strains from Africa and the Americas reveal divergence on the order of 10% at the nucleotide level and 4% at the amino acid level. How has this divergence influenced vector competence for North American mosquitoes? Can we identify amino acid substitutions in the genome that promote or limit adaptation to local vector populations?

Derrick Mathias

Assistant Professor


d.mathias@ufl.edu

  • MPH, John Hopkins Bloomberg School of Public Health, 2010
  • Ph.D., University of Oregon, 2006
  • B.S., University of Memphis, 1996

Derrick Mathias

Assistant Professor


d.mathias@ufl.edu

Recent Publications

  • Oforka LC, Adeleke MA, Anikwe JC, Hardy NB, Mathias DK, Makanjuola WA, Fadamiro HY. 2017. Poor genetic differentiation but clear cytoform divergence among cryptic species in Simulium damnosum complex (Diptera: Simuliidae). Systematic Entomology (in press)
  • Pastrana-Mena R*, Mathias DK*, Delves MJ, King JG, Yee R, Rajaram K, Verotta L, Dinglasan RR. 2016.  A malaria transmission-blocking natural product derivative prevents Plasmodium zygote-to-ookinete maturation in the mosquito midgut. ACS Chemical Biology 11(12):3461-3472.
  • Balaich JN, Mathias DK, Torto B, Jackson BT, Tao D, et al. 2016. The non-artemisinin sesquiterpene lactones parthenin and parthenolide block Plasmodium falciparum sexual stage transmission. Antimicrobial Agents and Chemotherapy 60(4):2108-2117.
  • Atkinson SC, Armistead JS, Mathias DK, Sandeu MM, Tao D, et al. 2015. The Anopheles-midgut APN1 structure reveals a new malaria transmission–blocking vaccine epitope. Nature Structural and Molecular Biology 22(7):532-539.
  • Ruecker A, Mathias DK, Straschil U, Churcher TS, Dinglasan RR, et al. 2014. A male and female gametocyte functional viability assay to identify biologically relevant malaria transmission-blocking drugs. Antimicrobial Agents and Chemotherapy 58(12):7292-7302.
  • Mathias DK, Jardim JG, Parish LA, Armistead JS, Trinh HV, et al. 2014. Differential roles of an anopheline midgut GPI-anchored protein in mediating Plasmodium falciparum and Plasmodium vivax ookinete invasion. Infection, Genetics and Evolution 28:635-647.
  • Tao D, Ubaida-Mohien C, Mathias DK, King JG, Pastrana-Mena R, et al. 2014. Sex-partitioning of the Plasmodium falciparum stage V gametocyte proteome provides insight into falciparum-specific cell biology. Molecular and Cellular Proteomics 13:2705-2724.
  • Armistead JA, Morlais I, Mathias DK, Jardim JG, Joy J, et al. 2014. Antibodies to a single, conserved epitope in Anopheles APN1 inhibit universal transmission of Plasmodium falciparum and Plasmodium vivax malaria. Infection and Immunity 82(2):818-829.
  • Mathias DK*, Pastrana-Mena R*, Ranucci E, Tao D, Ferruti P, et al. 2013. A small molecule glycosaminoglycan mimetic blocks Plasmodium invasion of the mosquito midgut. PLoS Pathogens 9(11): e1003757.
  • Ubaida Mohien C, Colquhoun DR, Mathias DK, Gibbons JG, Armistead JS, et al. 2013. A bioinformatic approach for integrated transcriptomic and proteomic comparative analyses of model and non-sequenced anopheline vectors of human malaria parasites. Molecular and Cellular Proteomics 12:120-131.
  • Mathias DK, Plieskatt JL, Armistead JS, Bethony JM, Abdul-Majid KB, et al. 2012. Expression, immunogenicity, histopathology, and potency of a mosquito-based malaria transmission-blocking recombinant vaccine. Infection and Immunity 80(4):1606-1614.
  • Mathias DK, Ochomo E, Atieli F, Ombok M, Bayoh N, et al. 2011. Spatial and temporal variation in the kdr allele L1014S in Anopheles gambiae s.s. and phenotypic variability in susceptibility to insecticides in western Kenya. Malaria Journal 10:10.
  • Bayoh MN, Mathias DK, Odiere MR, Mutuku FM, Kamau L, et al. 2010. Anopheles gambiae s.s.:  historical population decline associated with regional distribution of insecticide-treated bed nets in western Nyanza Province, Kenya. Malaria Journal 9:62.

*Denotes equal contribution by authors.

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Barry Alto

Associate Professor

Mosquito Ecology - Disdease Transmission
bwalto@ufl.edu
Appointments, Awards, and Professional Service:
  • 2016-present, Editorial Board, Entomological Society of America (Environmental Entomology).
  • 2015-present, Board of Directors (Member-at-Large), Florida Mosquito Control Association.
  • 2014, Richard Jones Outstanding New Faculty Research Award, Institute of Food and Agricultural Sciences, University of Florida.
  • 2011-2014, Editorial Board (served as chair in 2014), Entomological Society of America (Journal of Medical Entomology).
  • 2011-2014, Faculty Assembly representative, Institute of Food and Agricultural Sciences, University of Florida.
  • 2014-present, Institute of Food and Agricultural Sciences Faculty Research Advisory Group, University of Florida.