Cryptococcal phospholipase B antigen is not detected in serum of patients infected with Cryptococcus neoformans using a sandwich enzyme-linked immunosorbent assay.
Extracellular phospholipase B (PLB) is a virulence determinant of Cryptococcus neoformans and Cryptococcus gattii. In this study, we developed a sensitive enzyme-linked immunosorbent assay (ELISA) for PLB antigen with a detection limit of 3.9 ng mL(-1). PLB was detected in culture supernatants of C. neoformans and C. gattii. PLB, however, was not detected in sera of seven human patients and 10 feline patients with active cryptococcosis. Furthermore, none of five rats with extensive pulmonary C. gattii infection had a positive ELISA test result. In conclusion, cryptococcal PLB could not be detected in serum using a PLB antigen-based ELISA. Despite its sensitivity, this ELISA is of limited diagnostic value. Exploration of further extracellular molecules suitable for serodiagnosis of active cryptococcal infection is warranted.
Wu
Qi Xuan
QX
Centre for Infectious Diseases and Microbiology, Westmead Hospital, Westmead, New South Wales, Australia. qixuanw@icpmr.wsahs.nsw.gov.au
Chen
Sharon C A
SC
Santangelo
Rosemary T
RT
Martin
Patricia
P
Malik
Richard
R
Sorrell
Tania C
TC
D000818:Animals; D002415:Cats; D003453:Cryptococcosis / Q000097:blood* / Q000382:microbiology; D003455:Cryptococcus neoformans / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D008245:Lysophospholipase / Q000097:blood*; D051381:Rats; D012680:Sensitivity and Specificity
D007074:Immunoglobulin G; D008245:Lysophospholipase