Immunoblot analysis to demonstrate antigenic variability of clinical isolated. Pseudomonas pseudomallei.

ABSTRACT

Pseudomonas pseudomallei (Ps.ps.) is the causative organism of melioidosis, and is widely distributed in Southeast Asia and Northern Australia. Clinical manifestations range from subclinical infection to fulminant septicemia. To demonstrate the antigenic variability of Ps.ps., 62 clinical isolates from 31 blood, 13 sputum, 9 pus, 3 urine and 6 body fluid culture specimens were studied by SDS-PAGE and immunoblotting. In SDS-PAGE, there were approximately 20 antigenic components with molecular weights ranging from 14 to 66 kilodaltons (KD) which suggested that there was antigenic variability among these 62 clinical isolates of Ps.ps. Attempts to correlate immunoblot profiles with clinical illness or sources of specimens were not successful but 6 common antigens were identified with molecular weight of 17.5, 21, 33, 34, 40 and 45 KD, respectively. Among these antigens, the 45 KD component was recognised by all patients' sera. Thus, the 45 KD protein antigen may be useful for the future approach in immunodiagnosis of melioidosis.