Accession Number : ADA552256


Title :   Genotype Diversity and Distribution of Orientia tsutsugamushi Causing Scrub Typhus in Thailand


Descriptive Note : Journal article


Corporate Author : NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD


Personal Author(s) : Ruang-areerate, Toon ; Jeamwattanalert, Pimmada ; Rodkvamtook, Wuttikorn ; Richards, Allen L ; Sunyakumthorn, Piyanate ; Gaywee, Jariyanart


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a552256.pdf


Report Date : Jul 2011


Pagination or Media Count : 7


Abstract : Scrub typhus, caused by antigenically disparate isolates of Orientia tsutsugamushi, is a widely distributed mite-borne human disease in the Asia Pacific region. Information regarding the heterogeneity of the immunodominant 56-kDa type-specific antigen (TSA) gene is crucial for the design and evaluation of scrub typhusspecific diagnostic assays and vaccines. Using indirect immunofluorescence assays (IFA) and PCR assays, 0.tsutsugamushi was detected samples from rodents and patients with fever of unknown origin obtained from six provinces of Thailand during 2004 to 2007. Sequences were determined for a fragment of the 56-kDa TSA gene, and the relationship between these sequences and those previously determined were assessed. The phylogenetic analyses of partial 56-kDa TSA gene sequences demonstrated wide diversity and distribution of 0. tsutsugamushi genotypes in Thailand. Furthermore, the genetic diversity grouped the scrub typhus agents into two commonly and five infrequently found genotypes within six provinces of Thailand. The two most commonly found genotypes of 0. tsutsugamushi described in this study do not associate with the prototype strains that are widely used for the design and evaluation of diagnostic assays and vaccine candidates. Thus, these new genotypes should be considered for future scrub typhus assay and vaccine development.


Descriptors :   *ANTIGENS , *GENES , *RICKETTSIA TSUTSUGAMUSHI , *SCRUB TYPHUS , ASIA , DISEASES , FEVERS , FLUORESCENCE , GENETICS , HETEROGENEITY , IMMUNOLOGY , PATIENTS , RODENTS , SAMPLING , VACCINES


Subject Categories : Genetic Engineering and Molecular Biology
      Medicine and Medical Research
      Microbiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE