title: Identification of rickettsiae from wild rats and cat fleas in Malaysia.
abstract: Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting.
authors.affiliation: Department of Medical Microbiology, Tropical Infectious Diseases Research and Education Centre, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: S T
authors.initials: ST
authors.lastname: Tay
authors.forename: A S
authors.initials: AS
authors.lastname: Mokhtar
authors.forename: K C
authors.initials: KC
authors.lastname: Low
authors.forename: S N
authors.initials: SN
authors.lastname: Mohd Zain
authors.forename: J
authors.initials: J
authors.lastname: Jeffery
authors.forename: N
authors.initials: N
authors.lastname: Abdul Aziz
authors.forename: K L
authors.initials: KL
authors.lastname: Kho
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002950:Citrate (si)-Synthase / Q000235:genetics*; D058251:Ctenocephalides / Q000382:microbiology*; D005260:Female; D008296:Malaysia; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000662:veterinary; D051381:Rats; D012281:Rickettsia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012282:Rickettsia Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012376:Rodent Diseases / Q000453:epidemiology* / Q000382:microbiology; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins; D002950:Citrate (si)-Synthase
keywords: Cat fleas; Malaysia; reservoirs; rickettsioses; wild rats