title: Plasmodium falciparum infection increases Anopheles gambiae attraction to nectar sources and sugar uptake.
abstract: Plasmodium parasites are known to manipulate the behavior of their vectors so as to enhance transmission. From an evolutionary standpoint, behavior manipulation by the parasite should expose the vector to limited risk of early mortality while ensuring sufficient energy supply for both it and the vector. However, it is unknown whether this vector manipulation also affects vector-plant interaction and sugar uptake. Here, we show that the attraction of Anopheles gambiae s.s. to plant odors increased by 30% and 24% after infection with the oocyst and sporozoite stages of Plasmodium falciparum, respectively, while probing activity increased by 77% and 80%, respectively, when the vectors were infected with the two stages of the parasite. Our data also reveal an increased sugar uptake at the oocyst stage that decreased at the sporozoite stage of infection compared to uninfected An. gambiae, with depletion of lipid reserves at the sporozoite stage. These results point to a possible physiological adjustment by An. gambiae to P. falciparum infection or behavior manipulation of An. gambiae by P. falciparum to enhance transmission. We conclude that the nectar-seeking behavior of P. falciparum-infected An. gambiae appears to be modified in a manner governed by the vector's fight for survival and the parasite's need to advance its transmission.
authors.affiliation: International Centre of Insect Physiology and Ecology, Box 30772, Nairobi 00100, Kenya.
authors.forename: Vincent O
authors.initials: VO
authors.lastname: Nyasembe
authors.affiliation: Center for Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, 1700 Southwest 23 Drive, Gainesville, FL 32608, USA.
authors.forename: Peter E A
authors.initials: PEA
authors.lastname: Teal
authors.affiliation: International Centre of Insect Physiology and Ecology, Box 30772, Nairobi 00100, Kenya.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sawa
authors.affiliation: Center for Chemical Ecology, Department of Entomology, Pennsylvania State University, University Park, Pennsylvania, PA 16802, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Tumlinson
authors.affiliation: International Centre of Insect Physiology and Ecology, Box 30772, Nairobi 00100, Kenya; Center for Development Research, University of Bonn, Walter-Flex-Straße 3, 53113 Bonn, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Borgemeister
authors.affiliation: International Centre of Insect Physiology and Ecology, Box 30772, Nairobi 00100, Kenya. Electronic address: btorto@icipe.org.
authors.forename: Baldwyn
authors.initials: B
authors.lastname: Torto
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology* / Q000502:physiology; D050260:Carbohydrate Metabolism; D002241:Carbohydrates; D005247:Feeding Behavior; D057048:Plant Nectar; D010963:Plasmodium falciparum
chemical_list: D002241:Carbohydrates; D057048:Plant Nectar