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. 2012;7(10):e48254.
doi: 10.1371/journal.pone.0048254. Epub 2012 Oct 30.

Rickettsia species in African Anopheles mosquitoes

Cristina Socolovschi  1 , Frédéric Pages, Mamadou O Ndiath, Pavel Ratmanov, Didier Raoult
Affiliations

Rickettsia species in African Anopheles mosquitoes

Cristina Socolovschi et al. PLoS One. 2012.

Expression of concern in

Abstract

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.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Minimum evolutionary tree using a bootstrap analysis for the putative novel Rickettsia species.
The nearest GenBank sequences (showed at the end of the Rickettsia name) were aligned using the multi-sequence alignment ClustalX and BioEdit programs. The phylogenetic tree was constructed using parsimony and maximum-likelihood methods.
Figure 2
Figure 2. The spatial distribution of Plasmodium falciparum entomological inoculation rate (PfEIR) and Rickettsia felis infection incidence.
2010 Malaria Atlas Project, available under the Creative Commons Attribution 3.0 Unported License .
See this image and copyright information in PMC

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