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E-hyun Shin - One of the best experts on this subject based on the ideXlab platform.
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Seasonal prevalence and species composition of mosquitoes and chigger mites collected from Daegu, Gunwi and Sangju in South Korea, 2014
Journal of Ecology and Environment, 2017Co-Authors: Moon Bo Choi, Wook-gyo Lee, E-hyun Shin, Bong Gu Song, Hyun Jun Kang, Sung-chan Yang, Ohseok KwonAbstract:Background As the habitat changes in Korea due to climate change, the emergence of disease-mediated vectors is increasing rapidly. Thus for the surveillance of mosquito- and chigger mite-borne disease, their seasonal prevalence and species composition were investigated at seven locations in Daegu, Gunwi and Sangju. Methods Mosquitoes were collected twice every month from five collection sites using a black light and BG sentinel traps in Daegu and Gunwi from April through November. Chigger mites were investigated twice per month from wild rodents caught with Sherman live traps in Gunwi and Sangju from April through May and September through November. Results A total of 2,361 female mosquitoes were collected. Cowshed (626 individuals, Trap index (TI) 44.7) and Kyungpook National University campus (846 individuals, TI 60.4) in Daegu had the highest number of mosquitoes in the black light and BG sentinel trap, respectively. The mosquitoes were collected more by BG sentinel trap than the black light trap. Nine mosquito species were trapped, and the Culex pipiens complex was the most commonly mosquito (1,397 individuals, 59.2%), followed by Anopheles sinensis (554 individuals, 23.5%). Anopheles sinensis (531 individuals, 51.9%) and Culex pipiens complex (1,142 individuals, 85.4%) were the most mosquitoes from black light and BG sentinel trap, respectively. In terms of seasonal prevalence, the highest abundance was in July, with 824 individuals collected. In chigger mites, eighty-one wild rodents of five species that are hosts of chigger mites were collected; among them, 53 and 25 individuals of Apodemus agrarius and Crocidura suaveolens , respectively were trapped. Leptotrombidium pallidum was a dominant species, with 2,467 individuals collected (67.8%). Conclusions The mosquito was the dominant species in Culex pipiens complex and the highest in July and August. Apodemus agrarius was most abundant in wild rats and Leptotrombidium pallidum was dominant in the collected chigger mites.
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2016Co-Authors: Kyu-sik Chang, Chan Park, Hee Il Lee, Mi-yeoun Park, See Profile, E-hyun ShinAbstract:tsutsugamushi in Leptotrombidium palpal
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RESEARCH ARTICLE Coincidence between Geographical Distribution of Leptotrombidium scutellare and Scrub Typhus Incidence in South Korea
2016Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42 % while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas thos
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Coincidence between geographical distribution of Leptotrombidium scutellare and scrub typhus incidence in South Korea
PloS one, 2014Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. L. pallidum could be another vector at all other parts of the Korean peninsula, including the eastern and northern regions that have a low level of scrub typhus incidence.
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Estimation of the genome sizes of the chigger mites Leptotrombidium pallidum and Leptotrombidium scutellare based on quantitative PCR and k-mer analysis.
Parasites & vectors, 2014Co-Authors: Ju Hyeon Kim, E-hyun Shin, Jong Yul Roh, Deok Ho Kwon, Young Ho Kim, Kyungjae Andrew Yoon, Seung-il Yoo, Seung-jae Noh, Junhyung Park, Mi-yeoun ParkAbstract:Background: Leptotrombidium pallidum and Leptotrombidium scutellare are the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. Before these organisms can be subjected to whole-genome sequencing, it is necessary to estimate their genome sizes to obtain basic information for establishing the strategies that should be used for genome sequencing and assembly. Method: The genome sizes of L. pallidum and L. scutellare were estimated by a method based on quantitative real-time PCR. In addition, a k-mer analysis of the whole-genome sequences obtained through Illumina sequencing was conducted to verify the mutual compatibility and reliability of the results. Results: The genome sizes estimated using qPCR were 191 ± 7 Mb for L. pallidum and 262 ± 13 Mb for L. scutellare. The k-mer analysis-based genome lengths were estimated to be 175 Mb for L. pallidum and 286 Mb for L. scutellare. The estimates from these two independent methods were mutually complementary and within a similar range to those of other Acariform mites. Conclusions: The estimation method based on qPCR appears to be a useful alternative when the standard methods, such as flow cytometry, are impractical. The relatively small estimated genome sizes should facilitate whole-genome analysis, which could contribute to our understanding of Arachnida genome evolution and provide key information for scrub typhus prevention and mite vector competence.
Mi-yeoun Park - One of the best experts on this subject based on the ideXlab platform.
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2016Co-Authors: Kyu-sik Chang, Chan Park, Hee Il Lee, Mi-yeoun Park, See Profile, E-hyun ShinAbstract:tsutsugamushi in Leptotrombidium palpal
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RESEARCH ARTICLE Coincidence between Geographical Distribution of Leptotrombidium scutellare and Scrub Typhus Incidence in South Korea
2016Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42 % while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas thos
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Coincidence between geographical distribution of Leptotrombidium scutellare and scrub typhus incidence in South Korea
PloS one, 2014Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. L. pallidum could be another vector at all other parts of the Korean peninsula, including the eastern and northern regions that have a low level of scrub typhus incidence.
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Estimation of the genome sizes of the chigger mites Leptotrombidium pallidum and Leptotrombidium scutellare based on quantitative PCR and k-mer analysis.
Parasites & vectors, 2014Co-Authors: Ju Hyeon Kim, E-hyun Shin, Jong Yul Roh, Deok Ho Kwon, Young Ho Kim, Kyungjae Andrew Yoon, Seung-il Yoo, Seung-jae Noh, Junhyung Park, Mi-yeoun ParkAbstract:Background: Leptotrombidium pallidum and Leptotrombidium scutellare are the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. Before these organisms can be subjected to whole-genome sequencing, it is necessary to estimate their genome sizes to obtain basic information for establishing the strategies that should be used for genome sequencing and assembly. Method: The genome sizes of L. pallidum and L. scutellare were estimated by a method based on quantitative real-time PCR. In addition, a k-mer analysis of the whole-genome sequences obtained through Illumina sequencing was conducted to verify the mutual compatibility and reliability of the results. Results: The genome sizes estimated using qPCR were 191 ± 7 Mb for L. pallidum and 262 ± 13 Mb for L. scutellare. The k-mer analysis-based genome lengths were estimated to be 175 Mb for L. pallidum and 286 Mb for L. scutellare. The estimates from these two independent methods were mutually complementary and within a similar range to those of other Acariform mites. Conclusions: The estimation method based on qPCR appears to be a useful alternative when the standard methods, such as flow cytometry, are impractical. The relatively small estimated genome sizes should facilitate whole-genome analysis, which could contribute to our understanding of Arachnida genome evolution and provide key information for scrub typhus prevention and mite vector competence.
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Transovarial Transmission of Orientia tsutsugamushi in Leptotrombidium palpale (Acari: Trombiculidae)
PLoS ONE, 2014Co-Authors: Eun Hee Shin, Wook-gyo Lee, Chan Park, Jong Yul Roh, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:Transovarial transmission of Orientia tsutsugamushi in colonies of Leptotrombidium palpale was studied in the parent and F1 and F2 generations. Both transovarial transmission and filial infection rates were 100% in the parent and F1 generations of Leptotrombidium palpale. The filial infection rate in the F1 generation was 100%, but it declined to 94.3% in the F2 progeny. The sex ratio of the F1 generation from infected L. palpale was 1∶0.8 (male:female) and the proportion of males was relatively high. This study is the first to report on the transovarial transmission of O. tsutsugamushi in L. palpale. High transovarial transmission rates in L. palpale suggest that this species might be one of the major vectors of tsutsugamushi disease in Korea.
Kenneth J. Linthicum - One of the best experts on this subject based on the ideXlab platform.
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Influence of Orientia tsutsugamushi Infection on the Developmental Biology of Leptotrombidium imphalum and Leptotrombidium chiangraiensis (Acari: Trombiculidae)
Journal of Medical Entomology, 2012Co-Authors: Siriporn Phasomkusolsil, Stephen P. Frances, Panita Tanskul, Pochaman Watcharapichat, Duangporn Phulsuksombati, Supaporn Ratanatham, Kriangkrai Lerdthusnee, Kenneth J. LinthicumAbstract:ABSTRACT Leptotrombidium chiangraiensis Tanskul & Linthicum, and Leptotrombidium imphalum Vercammen—Grandjean are important vectors of scrub typhus in rice field habitats in northern Thailand. The developmental biology of all stages of the life cycle of two generations of these species of mites infected with Orientia tsutsugamushi (Hayashi) and uninfected mites is reported. The development of the infected lines of both F1 and F2 L. chiangraiensis were significantly longer than their respective uninfected lines (P 150 fewer eggs than uninfected mites.
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Transmitting Orientia tsutsugamushi to Laboratory Mice KRIANGKRAI LERDTHUSNEE, NITTAYA KHLAIMANEE, TAWEESAK MONKANNA,
2011Co-Authors: Noppadon Sangjun, Kenneth J. Linthicum, Stephen P. Frances, Thomas M. Kollars, Siriporn Mungviriya, Russell E. Coleman, Bangkok ThailandAbstract:ABSTRACT Thirteen different laboratory colonies of Leptotrombidium chiggers [L. chiangraiensis Tanskul & Linthicum, L. deliense Walch and L. imphalum (Vercammen-Grandjean & Langston)] were evaluated for their ability to transmit Orientia tsutsugamushi (Hyashi) to mice. Of 4,372 transmission attempts using individual chiggers from all 13 colonies, 75 % (n � 3,275) successfully infected mice. Transmission rates for the individual chigger colonies ranged from 7 to 80%. Increasing the number of chiggers that fed on a given mouse generally increased transmission rates. Transmission of O. tsutsugamushi to mice by different generations (F1ÐF11) of certain chigger colonies was stable; however, transmission rates varied greatly in other colonies. Transmission rates (both vertical and horizontal) of several L. chiangraiensis colonies and the L. deliense colony were the highest, suggesting that these colonies may be useful for the development of a chigger-challenge model that can be used to evaluate the efÞcacy of candidate scrub typhus vaccines or therapeutic agents in laboratory mice. KEY WORDS Leptotrombidium chiangraiensis, Leptotrombidium deliense, Leptotrombidium imphalum, Orientia tsutsugamushi, chiggers, transmission In conducting the research described in this report, the investigators adhered to the “Guide for the Care and Use of Laboratory Animals ” as promulgated by the Committee on Care and Use o
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Transstadial and Transovarial Transmission of Orientia tsutsugamushi in Leptotrombidium imphalum and Leptotrombidium chiangraiensis (Acari: Trombiculidae)
Journal of Medical Entomology, 2009Co-Authors: Siriporn Phasomkusolsil, Stephen P. Frances, Panita Tanskul, Pochaman Watcharapichat, Duangporn Phulsuksombati, Supaporn Ratanatham, Kriangkrai Lerdthusnee, Kenneth J. LinthicumAbstract:Transovarial transmission of Orientia tsutsugamushi (Hayashi) in laboratory colonies of Leptotrombidium chiangraiensis Tanskul & Linthicum and Leptotrombidium imphalum (Vercammen-Grandjean & Langston) (Acari: Trombiculidae) was studied for two generations. In L. chiangraiensis, the transovarial and filial infection rate was 100% in each generation. Only infected females were produced. In L. imphalum, the transovarial infection rate of the parental generation was 100% but declined to 93.3% in the F1 generation. The overall filial infection rate was 100% in the F1 but was only 62.3% in the F2 generation. In infected lines, only infected females were produced in the F1 generation, but 1.5% of the F2 progeny were infected males. Lower rates of transovarial transmission in L. imphalum may be the cause of the lower natural infection rates found in nature.
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Redescription of Leptotrombidium (Leptotrombidium) imphalum (Acari: Trombiculidae), with observations on bionomics and medical importance in northern Thailand.
Journal of medical entomology, 1999Co-Authors: Panita Tanskul, Kenneth J. LinthicumAbstract:Leptotrombidium (Leptotrombidium) imphalum Vercammen-Grandjean & Langston is redescribed and illustrated. Specimens were collected from the rodents Rattus rattus, Rattus losea, and Bandicota indica in Chiangrai Province, northern Thailand. The species was found on hosts collected on dikes at the margins of rice fields and in adjacent fruit plantations and along irrigation canals, especially in areas covered with the grasses Imperata cylindrica (lalang grass) and Saccharum arudinaceum. The etiological agent of scrub typhus, Orientia (formerly Rickettsia) tsutsugamushi has been isolated from L. (L.) imphalum, rodent hosts, and patients who live and work in the same habitats.
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A new species of Leptotrombidium (Acari: Trombiculidae) collected in active rice fields in northern Thailand
Journal of medical entomology, 1997Co-Authors: Panita Tanskul, Kenneth J. LinthicumAbstract:Leptotrombidium (Leptotrombidium) chiangraiensis Tanskul & Linthicum is described and illustrated as new from specimens collected from the rodents Rattus rattus (L., 1758), Rattus argentiventer (Robinson & Kloss, 1916), Rattus losea (Swinhoe, 1870), and Bandicota indica (Bechstein, 1800) in Chiangrai Province, northern Thailand. The new species was collected in active rice fields and adjacent fruit plantation areas. The etiological agent of scrub typhus, Orientia (formerly Rickettsia) tsutsugamushi (Hayashi), has been isolated from patients who live and work in the same habitat where L. chiangraiensis is the predominant Leptotrombidium species.
Hee Il Lee - One of the best experts on this subject based on the ideXlab platform.
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2016Co-Authors: Kyu-sik Chang, Chan Park, Hee Il Lee, Mi-yeoun Park, See Profile, E-hyun ShinAbstract:tsutsugamushi in Leptotrombidium palpal
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RESEARCH ARTICLE Coincidence between Geographical Distribution of Leptotrombidium scutellare and Scrub Typhus Incidence in South Korea
2016Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42 % while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas thos
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Coincidence between geographical distribution of Leptotrombidium scutellare and scrub typhus incidence in South Korea
PloS one, 2014Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. L. pallidum could be another vector at all other parts of the Korean peninsula, including the eastern and northern regions that have a low level of scrub typhus incidence.
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Transovarial Transmission of Orientia tsutsugamushi in Leptotrombidium palpale (Acari: Trombiculidae)
PLoS ONE, 2014Co-Authors: Eun Hee Shin, Wook-gyo Lee, Chan Park, Jong Yul Roh, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:Transovarial transmission of Orientia tsutsugamushi in colonies of Leptotrombidium palpale was studied in the parent and F1 and F2 generations. Both transovarial transmission and filial infection rates were 100% in the parent and F1 generations of Leptotrombidium palpale. The filial infection rate in the F1 generation was 100%, but it declined to 94.3% in the F2 progeny. The sex ratio of the F1 generation from infected L. palpale was 1∶0.8 (male:female) and the proportion of males was relatively high. This study is the first to report on the transovarial transmission of O. tsutsugamushi in L. palpale. High transovarial transmission rates in L. palpale suggest that this species might be one of the major vectors of tsutsugamushi disease in Korea.
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detection of orientia tsutsugamushi the causative agent of scrub typhus in a novel mite species eushoengastia koreaensis in korea
Vector-borne and Zoonotic Diseases, 2011Co-Authors: Hee Il Lee, Chan Park, Bong Gu Song, Mi-yeoun Park, Soo Kyoung Shim, Eun Na Choi, Kyu Jam Hwang, E-hyun ShinAbstract:Abstract To identify potential vector species of scrub typhus in the Republic of Korea (ROK), chigger mites were harvested from wild rodents captured at nine localities in October 2005. The bodies of the chigger mites were individually punctured with a fine pin, squeezed out internal contents, and examined for Orientia tsutsugamushi DNA by nested polymerase chain reaction. The exoskeleton of associated chiggers was mounted on glass slides with polyvinylalcohol (PVA) medium for identification. Among 830 individuals belonging to 4 genera and 14 species, O. tsutsugamushi was detected from 22 chiggers of six species, with an overall infection rate of 2.7%. The infection rate was highest for Leptotrombidium palpale (5.3%), followed by Neotrombicula japonica (4.3%), Leptotrombidium scutellare (3.7%), Leptotrombidium orientale (3.6%), Eushoengastia koreaensis (1.9%), and Leptotrombidium pallidum (1.5%). This study first reported O. tsutsugamushi infection from N. japonica and E. koreaensis larvae in the ROK. The...
Jong Yul Roh - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Coincidence between Geographical Distribution of Leptotrombidium scutellare and Scrub Typhus Incidence in South Korea
2016Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42 % while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas thos
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Coincidence between geographical distribution of Leptotrombidium scutellare and scrub typhus incidence in South Korea
PloS one, 2014Co-Authors: Jong Yul Roh, Wook-gyo Lee, Chan Park, Eun Hee Shin, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:To clarify the geographical distribution of scrub typhus vectors in Korea, a survey of larval trombiculid mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. A total of 67,325 mites representing 4 genera and 14 species were collected from 783 trapped rodents, corresponding to a chigger index (number of chigger mites per rodent) of 86.0. The predominant mite species were Leptotrombidium pallidum (52.6%), Leptotrombiduim scutellare (27.1%), Leptotrombidium palpale (8.2%), Leptotrombidium orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Jeollabuk-Do (34.3%), Jeollanam-Do (49.0%), and Gyeongsangnam-Do (88%), were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. L. pallidum could be another vector at all other parts of the Korean peninsula, including the eastern and northern regions that have a low level of scrub typhus incidence.
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Estimation of the genome sizes of the chigger mites Leptotrombidium pallidum and Leptotrombidium scutellare based on quantitative PCR and k-mer analysis.
Parasites & vectors, 2014Co-Authors: Ju Hyeon Kim, E-hyun Shin, Jong Yul Roh, Deok Ho Kwon, Young Ho Kim, Kyungjae Andrew Yoon, Seung-il Yoo, Seung-jae Noh, Junhyung Park, Mi-yeoun ParkAbstract:Background: Leptotrombidium pallidum and Leptotrombidium scutellare are the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. Before these organisms can be subjected to whole-genome sequencing, it is necessary to estimate their genome sizes to obtain basic information for establishing the strategies that should be used for genome sequencing and assembly. Method: The genome sizes of L. pallidum and L. scutellare were estimated by a method based on quantitative real-time PCR. In addition, a k-mer analysis of the whole-genome sequences obtained through Illumina sequencing was conducted to verify the mutual compatibility and reliability of the results. Results: The genome sizes estimated using qPCR were 191 ± 7 Mb for L. pallidum and 262 ± 13 Mb for L. scutellare. The k-mer analysis-based genome lengths were estimated to be 175 Mb for L. pallidum and 286 Mb for L. scutellare. The estimates from these two independent methods were mutually complementary and within a similar range to those of other Acariform mites. Conclusions: The estimation method based on qPCR appears to be a useful alternative when the standard methods, such as flow cytometry, are impractical. The relatively small estimated genome sizes should facilitate whole-genome analysis, which could contribute to our understanding of Arachnida genome evolution and provide key information for scrub typhus prevention and mite vector competence.
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Transovarial Transmission of Orientia tsutsugamushi in Leptotrombidium palpale (Acari: Trombiculidae)
PLoS ONE, 2014Co-Authors: Eun Hee Shin, Wook-gyo Lee, Chan Park, Jong Yul Roh, Won Il Park, Bong Gu Song, Kyu-sik Chang, Hee Il Lee, Mi-yeoun Park, E-hyun ShinAbstract:Transovarial transmission of Orientia tsutsugamushi in colonies of Leptotrombidium palpale was studied in the parent and F1 and F2 generations. Both transovarial transmission and filial infection rates were 100% in the parent and F1 generations of Leptotrombidium palpale. The filial infection rate in the F1 generation was 100%, but it declined to 94.3% in the F2 progeny. The sex ratio of the F1 generation from infected L. palpale was 1∶0.8 (male:female) and the proportion of males was relatively high. This study is the first to report on the transovarial transmission of O. tsutsugamushi in L. palpale. High transovarial transmission rates in L. palpale suggest that this species might be one of the major vectors of tsutsugamushi disease in Korea.