Transmission potential of Rickettsia felis infection by Anopheles gambiae mosquitoes

• Published in: Proceedings of the National Academy of Sciences - PNAS 2015-06, Vol.112 (26), p.8088-8093
• Main Authors: Dieme, Constentin, Yassina Bechah, Cristina Socolovschi, Gilles Audoly, Jean-Michel Berenger, Ousmane Faye, Didier Raoult, Philippe Parola
• Format: Article
• Language: English
• Subjects: Animals; Anopheles - microbiology; Anopheles gambiae; Aquatic insects; Arthropoda; Arthropods; Bacteria; Biological Sciences; Disease Models, Animal; Disease transmission; epidemiology; Feces - microbiology; Felis; Female; Fever; Fluorescent Antibody Technique; Humans; Insect Vectors; Malaria; Mice; Mice, Inbred BALB C; Mosquitoes; Pathogens; patients; Rickettsia felis; Rickettsia felis - pathogenicity; Rickettsia Infections - microbiology; Rickettsia Infections - transmission; spotted fever; Sub-Saharan Africa; Vector-borne diseases
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1413835112

A growing number of recent reports have implicated Rickettsia felis as a human pathogen, paralleling the increasing detection of R. felis in arthropod hosts across the globe, primarily in fleas. Here Anopheles gambiae mosquitoes, the primary malarial vectors in sub-Saharan Africa, were fed with either blood meal infected with R. felis or infected cellular media administered in membrane feeding systems. In addition, a group of mosquitoes was fed on R. felis- infected BALB/c mice. The acquisition and persistence of R. felis in mosquitoes was demonstrated by quantitative PCR detection of the bacteria up to day 15 postinfection. R. felis was detected in mosquito feces up to day 14. Furthermore, R. felis was visualized by immunofluorescence in salivary glands, in and around the gut, and in the ovaries, although no vertical transmission was observed. R. felis was also found in the cotton used for sucrose feeding after the mosquitoes were fed infected blood. Natural bites from R. felis -infected An. gambiae were able to cause transient rickettsemias in mice, indicating that this mosquito species has the potential to be a vector of R. felis infection. This is particularly important given the recent report of high prevalence of R. felis infection in patients with “fever of unknown origin” in malaria-endemic areas. Significance Rickettsia felis is a ubiquitous, recently described human pathogen that has been identified as an important cause of unexplained fever in patients in sub-Saharan Africa. The epidemiology of R. felis infection, including its potential arthropod vectors, is poorly understood, however. The results of our experimental model of infection suggest that Anopheles gambiae mosquitoes, the primary malarial vectors in sub-Saharan Africa, have the potential to be vectors of R. felis infection.