title: Tick-borne rickettsial pathogens in ticks and small mammals in Korea.
abstract: In order to investigate the prevalence of tick-borne infectious agents among ticks, ticks comprising five species from two genera (Hemaphysalis spp. and Ixodes spp.) were screened using molecular techniques. Ticks (3,135) were collected from small wild-caught mammals or by dragging/flagging in the Republic of Korea (ROK) and were pooled into a total of 1,638 samples (1 to 27 ticks per pool). From the 1,638 tick samples, species-specific fragments of Anaplasma phagocytophilum (1 sample), Anaplasma platys (52 samples), Ehrlichia chaffeensis (29 samples), Ehrlichia ewingii (2 samples), Ehrlichia canis (18 samples), and Rickettsia rickettsii (28 samples) were amplified by PCR assay. Twenty-one pooled and individual tick samples had mixed infections of two (15 samples) or three (6 samples) pathogens. In addition, 424 spleen samples from small captured mammals (389 rodents, 33 insectivores, and 2 weasels) were screened for selected zoonotic pathogens. Species-specific DNA fragments of A. phagocytophilum (110 samples), A. platys (68 samples), E. chaffeensis (8 samples), E. ewingii (26 samples), E. canis (51 samples), and Rickettsia sp. (22 samples) were amplified by PCR assay. One hundred thirty small mammals had single infections, while 4, 14, and 21 striped field mice (Apodemus agrarius) had mixed infections of four, three, and two pathogens, respectively. Phylogenetic analysis based on nucleotide sequence comparison also revealed that Korean strains of E. chaffeensis clustered closely with those from China and the United States, while the Rickettsia (rOmpA) sequences clustered within a clade together with a Chinese strain. These results suggest that these agents should be considered in differential diagnosis while examining cases of acute febrile illnesses in humans as well as animals in the ROK.
authors.affiliation: Bio-Safety Research Institute and College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Korea.
authors.forename: Chul-Min
authors.initials: CM
authors.lastname: Kim
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Yi
authors.forename: Do-Hyeon
authors.initials: DH
authors.lastname: Yu
authors.forename: Mi-Jin
authors.initials: MJ
authors.lastname: Lee
authors.forename: Mae-Rim
authors.initials: MR
authors.lastname: Cho
authors.forename: Atul R
authors.initials: AR
authors.lastname: Desai
authors.forename: Smriti
authors.initials: S
authors.lastname: Shringi
authors.forename: Terry A
authors.initials: TA
authors.lastname: Klein
authors.forename: Heung-Chul
authors.initials: HC
authors.lastname: Kim
authors.forename: Jin-Won
authors.initials: JW
authors.lastname: Song
authors.forename: Luck-Ju
authors.initials: LJ
authors.lastname: Baek
authors.forename: Sung-Tae
authors.initials: ST
authors.lastname: Chong
authors.forename: Monica L
authors.initials: ML
authors.lastname: O'guinn
authors.forename: John S
authors.initials: JS
authors.lastname: Lee
authors.forename: In-Yong
authors.initials: IY
authors.lastname: Lee
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Janet
authors.initials: J
authors.lastname: Foley
authors.forename: Joon-Seok
authors.initials: JS
authors.lastname: Chae
mesh_terms: D000709:Anaplasma / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004536:Ehrlichia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D018884:Ixodes / Q000382:microbiology; D007723:Korea; D008322:Mammals / Q000382:microbiology*; D051189:Murinae / Q000382:microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D017282:Tick-Borne Diseases / Q000175:diagnosis / Q000382:microbiology; D013987:Ticks / Q000382:microbiology*
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial