Emerging Infectious Diseases (Mar 2020)

Human Immune Responses to Melioidosis and Cross-Reactivity to Low-Virulence Burkholderia Species, Thailand

  • Patpong Rongkard,
  • Barbara Kronsteiner,
  • Viriya Hantrakun,
  • Kemajittra Jenjaroen,
  • Manutsanun Sumonwiriya,
  • Panjaporn Chaichana,
  • Suchintana Chumseng,
  • Narisara Chantratita,
  • Vanaporn Wuthiekanun,
  • Helen A. Fletcher,
  • Prapit Teparrukkul,
  • Direk Limmathurotsakul,
  • Nicholas P.J. Day,
  • Susanna J. Dunachie

DOI
https://doi.org/10.3201/eid2603.190206
Journal volume & issue
Vol. 26, no. 3
pp. 463 – 471

Abstract

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Melioidosis is a neglected tropical disease with an estimated annual mortality rate of 89,000 in 45 countries across tropical regions. The causative agent is Burkholderia pseudomallei, a gram-negative soil-dwelling bacterium. In Thailand, B. pseudomallei can be found across multiple regions, along with the low-virulence B. thailandensis and the recently discovered B. thailandensis variant (BTCV), which expresses B. pseudomallei–like capsular polysaccharide. Comprehensive studies of human immune responses to B. thailandensis variants and cross-reactivity to B. pseudomallei are not complete. We evaluated human immune responses to B. pseudomallei, B. thailandensis, and BTCV in melioidosis patients and healthy persons in B. pseudomallei–endemic areas using a range of humoral and cellular immune assays. We found immune cross-reactivity to be strong for both humoral and cellular immunity among B. pseudomallei, B. thailandensis, and BTCV. Our findings suggest that environmental exposure to low-virulence strains may build cellular immunity to B. pseudomallei.

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