{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:49:52Z","timestamp":1789624192552,"version":"build-2803163510"},"reference-count":16,"publisher":"Springer Science and Business Media LLC","issue":"1","content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Malar J"],"published-print":{"date-parts":[[2013,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>\n              <jats:italic>Plasmodium knowlesi<\/jats:italic> is the fifth species identified to cause malaria in humans and is often misdiagnosed as <jats:italic>Plasmodium malariae<\/jats:italic> due to morphological similarities. The development of an inexpensive, serological detection method utilizing antibodies specific to <jats:italic>P. knowlesi<\/jats:italic> would be a valuable tool for diagnosis. However, the identification of specific antigens for these parasites remains a major challenge for generating such assays. In this study, surface protein containing an altered thrombospondin repeat domain (SPATR) was selected as a potentially specific antigen from <jats:italic>P. knowlesi<\/jats:italic>. Its multistage expression by sporozoites, asexual erythrocytic forms and gametocytes, along with its possible role in liver cell invasion, suggests that SPATR could be used as a biomarker for diagnosis of <jats:italic>P. knowlesi<\/jats:italic>.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>The <jats:italic>spatr<\/jats:italic> gene from <jats:italic>P. knowlesi<\/jats:italic> was codon optimized and cloned (<jats:italic>pkhspatr<\/jats:italic>). Recombinant <jats:italic>pk<\/jats:italic> HSPATR protein was expressed, purified, and evaluated for its sensitivity and specificity in immunoblot and ELISA-based assays for detecting <jats:italic>P. knowlesi<\/jats:italic> infection.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>The recombinant <jats:italic>pk<\/jats:italic> HSPATR protein allows sensitive detection of human <jats:italic>P. knowlesi<\/jats:italic> infection in serum samples by immunoblot and ELISA.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusions<\/jats:title>\n            <jats:p>With further research, recombinant <jats:italic>pk<\/jats:italic> HSPATR protein could be exploited as a marker for detection of <jats:italic>P. knowlesi<\/jats:italic> infection in humans. Therefore, this finding should contribute to the development of immunodiagnostic assays for the species-specific detection of malaria.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/1475-2875-12-182","type":"journal-article","created":{"date-parts":[[2013,6,4]],"date-time":"2013-06-04T10:46:37Z","timestamp":1370342797000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Cloning, expression, and immunocharacterization of surface protein containing an altered thrombospondin repeat domain (SPATR) from Plasmodium knowlesi"],"prefix":"10.1186","volume":"12","author":[{"given":"Vanitha","family":"Palaeya","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yee Ling","family":"Lau","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rohela","family":"Mahmud","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yeng","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mun Yik","family":"Fong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2013,6,4]]},"reference":[{"key":"2807_CR1","doi-asserted-by":"publisher","first-page":"e2026","DOI":"10.1371\/journal.pntd.0002026","volume":"7","author":"T William","year":"2013","unstructured":"William T, Rahman HA, Jelip J, Ibrahim MY, Menon J, Grigg MJ, Yeo TW, Anstey NM, Barber BE: Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia. 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