Human Immune Responses to Melioidosis and Cross-Reactivity to Low-Virulence Burkholderia Species, Thailand1.

Rongkard, Patpong; Kronsteiner, Barbara; Hantrakun, Viriya; Jenjaroen, Kemajittra; Sumonwiriya, Manutsanun; Chaichana, Panjaporn; Chumseng, Suchintana; Chantratita, Narisara; Wuthiekanun, Vanaporn; Fletcher, Helen A; +4 more... Teparrukkul, Prapit; Limmathurotsakul, Direk; Day, Nicholas PJ; Dunachie, Susanna J; (2020) Human Immune Responses to Melioidosis and Cross-Reactivity to Low-Virulence Burkholderia Species, Thailand1. EMERGING INFECTIOUS DISEASES, 26 (3). pp. 463-471. ISSN 1080-6040 DOI: https://doi.org/10.3201/eid2603.190206

Abstract

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.