Serological diagnosis of gonorrhoea using gonococcal pili as antigen

The studies described in the following chapters were performed in an attempt to contribute to a solution of the problems mentioned in chapter two. For the purpose of these studies, material had to be collected from patients and several techniques had to be developed. Material and techniques were then used to study a number of specific problems concerning the serological diagnosis of gonorrhoea.' 1. Almost the entire material was collected from patients attending the STD clinic of the Rotterdam University Hospital Dijkzigt. Gonococci were isolated from all patients with gonorrhoea, and stored. Sera were collected from patients with and without gonorrhoea. The patients were divided into well-defined groups on the basis of history, sex and diagnosis. Blood samples were obtained on the day of the first examination (D 1) and on at least one other day (D2), generally 11-22 days after Dl. More than two sera were collected from some patients. 2. For serodiagnostic purposes an ELISA was developed, using a purified gonococcal pilus preparation from a single strain as antigen. The sera were also submitted to two tests routinely used elsewhere: an IHA using a pilus antigen from another gonococcal strain (used at the Statens Seruminstitut, Denmark), and a GCFT using a crude extract from a single gonococcal strain as antigen, (used at the National Health Institute, Bilthoven, The Netherlands). 3. The first objective of this study was to evaluate the sensitivity and specificity of the abovementioned ELISA as applied to sera from various groups of patients. After application of the IHA and the GCFT to the same sera, the results were compared with those of the ELISA. 4. Next, the influence of the choice of gonococcal pilus antigen on the sensitivity and specificity of the serological test was studied. 5. Finally, a study was made of the contribution of the ELISA to the diagnosis of gonorrhoea when this test was applied to females without complaints who attended the STD clinic for examination