Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 May;84(1):171-182.
doi: 10.1007/s10493-021-00609-3. Epub 2021 Apr 7.

Screening and genotyping of Orientia tsutsugamushi from field-collected on-host chiggers (Acari: Prostigmata) recovered from a positive scrub typhus locality in Kelantan, Malaysia

F C L Ernieenor  1 , M J NorJaiza  2 , A Fadillah  3 , J Canedy  3 , A Mariana  3
Affiliations

Screening and genotyping of Orientia tsutsugamushi from field-collected on-host chiggers (Acari: Prostigmata) recovered from a positive scrub typhus locality in Kelantan, Malaysia

F C L Ernieenor et al. Exp Appl Acarol. 2021 May.

Abstract

Orientia tsutsugamushi is the causative agent of scrub typhus vectored by larval stages of trombiculid mites (chiggers) that occur in most tropical regions of Southeast Asia. A total of 242 chiggers extracted from eight small mammals captured from a positive scrub typhus locality in Kelantan, Malaysia, were screened for the presence of O. tsutsugamushi. The chiggers were grouped in 16 pools for extraction of DNA prior to screening of O. tsutsugamushi based on the nucleotide sequence of 56-kDa type specific antigen (TSA) gene using nested polymerase chain reaction. Two species of on-host chiggers were identified, the one, Leptotrombidium deliense, much more dominant (94.8%) than the other, Ascoshoengastia sp. (5.2%). The pathogen was detected in two pools (12.5%) of L. deliense recovered from Rattus rattus and Tupaia sp. The 56-kDa TSA gene sequence analysis revealed the O. tsutsugamushi harboured in those chiggers were Karp prototype strain with high similarity (99.3%). Findings of this study strongly supported the existence of scrub typhus infections in certain parts of Malaysia which agrees with previous local reports. Moreover, this study highlighted the pressing need of a large-scale close observation of O. tsutsugamushi DNA sequences from chiggers that can probably be collected from other positive scrub typhus localities to precisely provide the distribution and prevalence of this zoonotic pathogen.

Keywords: 56-kDa TSA gene; Chigger; Orientia tsutsugamushi; Scrub typhus.

PubMed Disclaimer

References

    1. Bonell A, Lubell Y, Newton PN, Crump JA, Paris DH (2017) Estimating the burden of scrub typhus: a systematic review. PLoS Negl Trop Dis 11(9):e0005838 - PubMed - PMC
    1. Brown GW, Robinson DM, Huxsoll DL, Ng TS, Lim KJ (1976) Scrub typhus: a common cause illness in indigenous populations. Trans R Soc Trop Med Hyg 70(5–6):444–448 - PubMed
    1. Chaisiri K, Cosson JF, Morand S (2017) Infection of rodents by Orientia tsutsugamushi, the agent of scrub typhus, in relation to land use in Thailand. Trop Med Infect Dis 2(4):53 - PMC
    1. Chaisiri K, Christina-Gill A, Stekolnikov AA, Hinjoy S, McGarry JW, Darby AC, Morand S, Makepeace BL (2019) Ecological and microbiological diversity of chigger mites, including vectors of scrub typhus, on small mammals across stratified habitats in Thailand. Animal Microbiome 1:18 - PubMed - PMC
    1. Chakraborty S, Sarma N (2017) Scrub typhus: an emerging threat. Indian J Dermatol 62(5):478–485 - PubMed - PMC

LinkOut - more resources