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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 Ricketisia 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. [ABSTRACT FROM AUTHOR]

We investigated the prevalence of Bartonella infections in ticks, mites and small mammals (rodents, insectivores and weasels) collected during 2001 through 2004, from various military installations and training sites in Korea, using PCR and sequence analysis of 16S rRNA, 23S rRNA and groEL heat shock protein genes. The prevalence of Bartonella spp. was 5.2% (n = 1,305 sample pools) in ticks, 19.1% (n = 21) in mesostigmatid mites and 13.7% (n = 424 individuals) in small mammals. The prevalence within the family Ixodidae was, 4.4% (n = 1,173) in Haemaphysalis longicornis (scrub tick), 2.7% (n = 74) in H. flava, 5.0% (n = 20) in Ixodes nipponensis, 11.1% (n = 9) in I. turdus, 33.3% (n = 3) in I. persulcatus and 42.3% (n = 26) in Ixodes spp. ticks. In rodents, the prevalence rate was, 6.7% (n = 373) in Apodemus agrarius (striped field mouse) and 11.1% (n = 9) in Eothenomys regulus (Korean red-backed vole) and in an insectivore,Crocidura lasiura, 12.1% (n 33). Neither of the two weasels were positive for Bartonella spp. Phylogenetic analysis based on amino acid sequence of a portion of the groEL gene amplified from one A. agrarius spleen was identical to B. elizabethae species. We demonstrated the presence of Bartonella DNA in H. longicornis, H. flava and I. nipponensis ticks, indicating that these ticks should be added to the growing list of potential tick vectors and warrants further detailed investigations to disclose their possible roles in Bartonella infection cycles. [ABSTRACT FROM AUTHOR]

Genomic DNAs extracted from 1,288 Haemaphysalis longicornis ticks collected from grass vegetation and various animals from nine provinces of Korea were subjected to screening by genus-specific (Ehrlichia spp. or Anaplasma spp.) real-time TaqMan PCR and species-specific (E. chaffeensis) nested-PCR based on amplification of 16S rRNA gene fragments. In all, 611 (47.4%) ticks tested positive for genus-specific amplification of 116 bp fragment of 16S rRNA of Ehrlichia spp. or Anaplasma spp. Subsequently, 396 bp E. chaffeensis-specific fragment of 16S rRNA was amplified from 4.2% (26/611) tick samples. The comparison of the nucleotide sequence of 16S rRNA gene from one tick (EC-PGHL, GeneBank accession number AY35042) with the sequences of 20 E. chaffeensis strains available in the database showed that EC-PGHL was 100% identical or similar to the Arkansas (AF416764), the Sapulpa (U60476) and the 91HE17 (U23503) strains. The phylogenetic analysis also revealed that the E. chaffeensis EC-PGHL formed a single cluster with the above strains. This is the first study to report molecular detection and phylogenetic analysis of E. chaffeensis from H. longicornis ticks in Korea. The implicit significance of E. chaffeensis infection in H. longicornis ticks in Korea is discussed. [ABSTRACT FROM AUTHOR]