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Updated: May 17, 2026
An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
Published on: October 11, 2022
RETRACTED: Rickettsia species in African Anopheles mosquitoes
Cristina Socolovschi1, Frédéric Pages, Mamadou O Ndiath
1Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France.
Background:
There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology.
Methodology/Principal Findings:
Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d'Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d'Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d'Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region.
Conclusion:
R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity.
Insights
Rickettsia felis bacteria were found in Anopheles mosquitoes in Africa, suggesting mosquitoes may spread this infection. A new Rickettsia species, closely related to R. felis, was also identified in these mosquitoes.
Area of Science:
- Medical Entomology
- Bacteriology
- Molecular Biology
Background:
- Rickettsia felis infection is more prevalent in febrile individuals in Sub-Saharan Africa, particularly during the rainy season.
- Mosquitoes exhibit high vectorial capacity and their abundance may contribute to rickettsial epidemiology.
Purpose of the Study:
- To investigate the presence and diversity of Rickettsia species in Anopheles mosquitoes in West and Central Africa.
- To determine the potential role of Anopheles mosquitoes in the transmission of Rickettsia in the region.
Main Methods:
- Quantitative and traditional PCR assays were employed to detect rickettsial DNA in Anopheles mosquitoes collected from Côte d'Ivoire, Gabon, and Senegal.
- Sequence analysis of specific Rickettsia genes (gltA, ompB, ompA, sca4) and BLAST analysis were performed for genetic characterization.
Main Results:
- Rickettsial DNA was detected in 1.5% of 848 Anopheles mosquitoes.
- Rickettsia felis was identified in one Anopheles gambiae molecular form S mosquito.
- A novel Rickettsia species, genetically similar to R. felis, was found in An. gambiae molecular form S and An. melas mosquitoes. This new species showed 99.71% gltA sequence similarity to a previously identified Rickettsia strain from a febrile patient in Senegal.
Conclusions:
- Rickettsia felis was detected for the first time in Anopheles gambiae molecular form S, a primary African malaria vector.
- The discovery of R. felis and a new Rickettsia species in mosquitoes highlights the need for further research into African rickettsial epidemiology, including bacterial isolation, vector capacity, animal reservoirs, and human pathogenicity.
