Molecular detection of Rickettsia species in ticks collected from the southwestern provinces of the Republic of Korea. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Noh, Yoontae; Lee, Yeong; Kim, Heung-Chul; Chong, Sung-Tae; Klein, Terry; Jiang, Ju; Richards, Allen; Lee, Hae; Kim, Su
• Is Part Of: Parasites & vectors. Volume 10:Issue 1(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-12
• Subjects: Rickettsia -- Spotted fever group rickettsiae -- Ixodid ticks -- 17 kDa antigen gene -- ompA; Parasitism -- Periodicals; Parasites -- Periodicals; Vector-pathogen relationships -- Periodicals; Animals as carriers of disease -- Periodicals; Insects as carriers of disease -- Periodicals; 616.96
• DOI: 10.1186/s13071-016-1955-x
• Languages: English
• ISSNs: 1756-3305

Abstract

Abstract Background Rickettsiae constitute a group of arthropod-borne, Gram-negative, obligate intracellular bacteria that are the causative agents of diseases ranging from mild to life threatening that impact on medical and veterinary health worldwide. Methods A total of 6, 484 ticks were collected by tick drag from June-October 2013 in the southwestern provinces of the Republic of Korea (ROK) (Jeollanam, n = 3, 995; Jeollabuk, n = 680; Chungcheongnam, n = 1, 478; and Chungcheongbuk, n = 331). Ticks were sorted into 311 pools according to species, collection site, and stage of development. DNA preparations of tick pools were assayed for rickettsiae by 17 kDa antigen gene andompA nested PCR (nPCR) assays and the resulting amplicons sequenced to determine the identity and prevalence of spotted fever group rickettsiae (SFGR). Results Haemaphysalis longicornis (4, 471; 52 adults, 123 nymphs and 4, 296 larvae) were the most commonly collected ticks, followed byHaemaphysalis flava (1, 582; 28 adults, 263 nymphs and 1, 291 larvae), andIxodes nipponensis (431; 25 adults, 5 nymphs and 401 larvae). The minimum field infection rate/100 ticks (assuming 1 positive tick/pool) was 0.93% for the 17 kDa antigen gene and 0.82% for theompA nPCR assays. The partial 17 kDa antigen andompA gene sequences from positive pools ofH. longicornis were similar to:Rickettsia sp. HI550 (99.4–100%), Rickettsia sp. FUJ98 (99.3–100%), Rickettsia sp. HIR/D91 (99.3–100%), andR. japonica (99.7%). One sequence of the partial 17 kDa antigen gene forH. flava was similar toRickettsia sp. 17kd-005 (99.7%), while seven sequences of the 17 kDa antigen gene obtained fromI. nipponensis ticks were similar toR. monacensis IrR/Munich (98.7–100%) andRickettsia sp. IRS3 (98.9%). Conclusions SFG rickettsiae were detected in three species of ixodid ticks collected in the southwestern provinces of the ROK during 2013. A number of rickettsiae have been recently reported from ticks in Korea, some of which were identified as medically important. Results from this study and previous reports demonstrate the need to conduct longitudinal investigations to identify tick-borne rickettsiae and better understand their geographical distributions and potential impact on medical and veterinary health, in addition to risk communication and development of rickettsial disease prevention strategies.