DIAGNOSTIC POTENTIAL OF A SEROLOGICAL ASSAY FOR THE DIAGNOSIS OF ULCERANS DISEASE BASED ON THE PUTATIVE MYCOBACTERIUM ULCERANS TOXIN

Mycobacterium ulcerans infection is an important and potentially disfi guring disease of man, A rapid diagnostic assay for detection of this organism is required urgently Serological assays require a species-spe cific protein to ensure a high level of specificity and thus reduce th e occurrence of false positive results, As M. ulcerans had been report ed to produce a unique cytotoxin, it was thought that this would provi de an ideal antigen on which to base a serological assay for detection of M, ulcerans during infection. Crude culture filtrates, prepared by previously documented methods, were assayed for toxic activity by in- vitro cytotoxicity assays and in-vivo mouse footpad assays, To evaluat e the uniqueness of the cytotoxic factor, other species of mycobacteri a were also assayed, Analysis of these assays showed that similar biol ogical activity is present in various other mycobacterial species, Fur thermore, it was possible to neutralise this activity in all species t ested with a polyclonal antiserum raised against M. ulcerans. As the c ytotoxic factor was found not to be specific to M. ulcerans, it is unl ikely that a serological assay based on such a molecule will be of use .