{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T14:41:09Z","timestamp":1760366469118,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2022,1,6]],"date-time":"2022-01-06T00:00:00Z","timestamp":1641427200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004156","name":"Mahidol University","doi-asserted-by":"publisher","award":["01"],"award-info":[{"award-number":["01"]}],"id":[{"id":"10.13039\/501100004156","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>A point-of-care diagnostic for early and rapid diagnosis of scrub typhus caused by Orientia tsutsugamushi is required for prompt and proper treatment of patients presenting with undifferentiated febrile illnesses. In this study, an immunochromatographic antigen detection test kit (ICT AgTK) that targets the highly conserved O. tsutsugamushi 60 kDa GroEL chaperonin (heat shock protein 60) was developed. E. coli-derived recombinant GroEL expressed from DNA coding for the consensus sequence of 32 GroEL gene sequences extracted from the GenBank database was used to immunize rabbits and mice. Rabbit polyclonal antibodies (pAb) were used for preparing a gold-pAb conjugate, and the rGroEL-specific mouse monoclonal antibody was used as the antigen detection reagent at the ICT test line. In-house validation revealed that the ICT AgTK gave 85, 100 and 95% diagnostic sensitivity, specificity and accuracy, respectively, compared to the combined clinical features and standard IFA when tested on 40 frozen serum samples. The test kits correctly identified 10 scrub typhus samples out of 15 fresh plasma\/buffy coat samples of patients with febrile illnesses. For independent laboratory validation, the ICT AgTK was sent to one provincial hospital. The ICT AgTK utilized by the hospital medical technologist correctly identified six scrub typhus samples out of 20 serum samples of patients with fever, as confirmed by specific IgM\/IgG detection by IFA. The ICT AgTK is easy to perform with rapid turn-around time. It has the potential to be used as an important tool for on-site and early scrub typhus diagnosis by allowing testing of freshly collected samples (serum, plasma or buffy coat), especially in resource-limited healthcare settings.<\/jats:p>","DOI":"10.3390\/diagnostics12010136","type":"journal-article","created":{"date-parts":[[2022,1,7]],"date-time":"2022-01-07T01:15:26Z","timestamp":1641518126000},"page":"136","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["GroEL Chaperonin-Based Assay for Early Diagnosis of Scrub Typhus"],"prefix":"10.3390","volume":"12","author":[{"given":"Nitaya","family":"Indrawattana","sequence":"first","affiliation":[{"name":"Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pisinee","family":"Aiumurai","sequence":"additional","affiliation":[{"name":"Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitolgy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nawannaporn","family":"Sae-lim","sequence":"additional","affiliation":[{"name":"Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitolgy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Watee","family":"Seesuay","sequence":"additional","affiliation":[{"name":"Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitolgy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1154-6485","authenticated-orcid":false,"given":"Onrapak","family":"Reamtong","sequence":"additional","affiliation":[{"name":"Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manas","family":"Chongsa-nguan","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand"},{"name":"Faculty of Public Health and Environment, Pathumthani University, Pathum Thani 12000, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6973-8255","authenticated-orcid":false,"given":"Wanpen","family":"Chaicumpa","sequence":"additional","affiliation":[{"name":"Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitolgy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nitat","family":"Sookrung","sequence":"additional","affiliation":[{"name":"Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitolgy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"},{"name":"Biomedical Research Incubator Unit, Department of Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Xu, G., Walker, D.H., Jupiter, D., Melby, P.C., and Arcari, C.M. 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