First report of Rickettsia felisin China

Abstract

BackgroundRickettsia felis is a recently described flea-borne spotted fever group Rickettsia that is an emerging human pathogen. Although there is information on the organism from around the world, there is no information on the organism in China.MethodsWe used a commercial ELISA to detect antibodies reactive against R. felis in blood samples and developed a PCR to detect the gltA of the organism in blood samples and external parasites.ResultsWe found reactive antibodies in people (16%; 28/180), dogs (47%; 128/271) and cats (21%; 19/90) and positive PCRs with DNA from people (0.1%; 1/822), dogs (0.8%; 8/1,059), mice (10%; 1/10), ticks (Rhipicephalus sanguineus; 10%; 15/146), lice (Linognathus setosus; 16%; 6/37), fleas (Ctenocephalides felis felis; 95%; 57/60) and mosquitoes (Anopheles sinensis, Culex pipiens pallens; 6%; 25/428), but not from cats (0/135) or canine fecal swabs (0/43).ConclusionsThis is the first report of R. felis in China where there is serological and/ or PCR evidence of the organism in previously reported [people, dogs, cats, ticks (Rhipicephalus sanguineus), fleas (Ctenocephalides felis felis) and mosquitoes (Anopheles sinensis, Culex pipiens pallens)] and novel species [mice and lice (Linognathus setosus)].Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0682-1) contains supplementary material, which is available to authorized users.

Rickettsia in mosquitoes, Yangzhou, China

“…Since the first reports that rickettsiae could be propagated in mosquito cell lines, 9, 10 there has been growing evidence that mosquitoes can be infected with the organisms. 1, 2, 3, 4, 5 Our study provides further information on Rickettsia species in mosquitoes, in particular the common house mosquito Cx. pipiens that occurs widely in temperate areas of the world and feeds most commonly on a wide variety of bird species but also occasionally on people and a wide range of mammals.…”

“…and Mansonia uniformis in Africa, 1, 2, 3 and Anopheles sinensis and Culex pipiens in China. 4 Further, it has been shown that Anopheles gambiae can be infected with R. felis and transmit the organism during feeding, indicating it might be a potential vector. 5 Finally, a new Rickettsia species has been found in An.…”

“…pipiens in China. 4 To gather more data on Rickettsia species in mosquitoes in China, we studied convenience samples of mosquitoes from Yangzhou and report our findings below.…”

“…pipiens males and females and the Aedes albopictus were pooled separately (15 per pool) in 600 μL of RNA/DNA Stabilization Reagent for Blood/Bone Marrow (Roche Molecular Biochemicals, Indianapolis, IN, USA) and stored at −80 °C. The DNA was extracted from the pooled mosquitoes as described before 4 and tested for Rickettsia with a gltA -based FRET-PCR and a nested-PCR as described before. 4 To further characterize the Rickettsia found in the positive mosquito pools, we used multilocus sequence typing (MLST) with primers against the gltA which we developed (forward primer: 5'-ATG AGC AGA ATG CTT CTA CTT CAA CA-3'; reverse primer: 5'-ATT TTC TCT CAA TAA AAT ATT CAT CTT TAA G-3'), and those previously described for ompA , ompB and sca4 .…”

“…The DNA was extracted from the pooled mosquitoes as described before 4 and tested for Rickettsia with a gltA -based FRET-PCR and a nested-PCR as described before. 4 To further characterize the Rickettsia found in the positive mosquito pools, we used multilocus sequence typing (MLST) with primers against the gltA which we developed (forward primer: 5'-ATG AGC AGA ATG CTT CTA CTT CAA CA-3'; reverse primer: 5'-ATT TTC TCT CAA TAA AAT ATT CAT CTT TAA G-3'), and those previously described for ompA , ompB and sca4 . 3, 6, 7 A FRET-PCR targeting the mammalian hydroxymethylbilane synthase (HMBS) gene 8 and a regular PCR we designed to amplify the avian HMBS gene (forward primer: 5'-TTA GCA GTG GAA GTT CGT GCC AA-3' reverse primer: 5'-AGG GAC ACT ACA GCC ACC CTC CT-3') were used to determine whether mosquitoes had ingested a blood meal.…”