Utility of polyclonal antibodies binding to specific epitopes of Burkholderia pseudomallei

Abstract

Burkholderia pseudomallei (B. pseudomallei) is a major causative agent of melioidosis in endemic areas such as Southeast Asia and Northern Australia. Rapid diagnosis is required for appropriate treatments in septicemic melioidosis. In this study, we aimed to evaluate the specific polyclonal antibody (pAb) to B. pseudomallei for potentially use in the development of diagnostic assays and pathogenesis studies. In determination the cross reaction of the pAb to other bacteria by indirect ELISA, the pAb to B. pseudomallei has no cross-reactivity with other bacteria. In contrast, the pAb reacted with 24 clinical isolates of B. pseudomallei-extracted antigens. By ELISA, the pAb to B. pseudomallei could be used to detect secreted antigens in 3 hour culture supernatants of 1.5 x 10⁴ cfu/ml B. pseudomallei. In addition, opsonization of the bacteria with the pAbs could enhance bacterial internalization by U937-derived macrophages when compared with bacterial culture alone. The mechanism of these observations, however, needs to be further investigated. In conclusion, we suggest that the pAbs to B. pseudomallei can be potentially used for development of diagnosis method and pathogenesis study.