title: Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector.
abstract: Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24 hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats.
authors.affiliation: The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden.
authors.forename: Stina
authors.initials: S
authors.lastname: Bäckman
authors.affiliation: The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Näslund
authors.affiliation: The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Forsman
authors.affiliation: The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden.
authors.forename: Johanna
authors.initials: J
authors.lastname: Thelaus
mesh_terms: D000818:Animals; D009033:Culicidae / Q000382:microbiology*; D017753:Ecosystem; D005604:Francisella tularensis / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007303:Insect Vectors / Q000382:microbiology*; D007814:Larva / Q000382:microbiology; D051379:Mice; D014406:Tularemia / Q000235:genetics / Q000382:microbiology / Q000635:transmission*; D014871:Water Microbiology