Detection of Chlamydia trachomatis by using FITC-labeled monoclonal antibodies (MicroTrak method)

Abstract

The usefulness of FITC-labeled monoclonal antibodies (Micro TrakTM Culture Confirmation Testand Direct Specimen Test) for the detection of Chlamydia trachomatis from clinical specimens wasstudied. For examination of the specificity of Micro TrakTM method 15 reference strains (serovar A-Kand L1-L3) of C. trachomatis and one of Chlamydia psittaci were used. The reagents of Micro TrakTMmethod reacted strongly to all 15 strains of C. trachomatis but not to a strain of C. psittaci at all. A total of1034 clinical cases were tested for Micro TrakTM method. Culture Confirmation Test brought on thesame results for detection of chlamydial inclusions as Giemsa or iodine staining after cell culture ofspecimens. Number of inclusions detected from specimens by Culture Confirmation Test tended to morethan those by Giemsa or iodine staining method, and the inclusions stained with Micro TrakTM methodwere easier to be found out. Therefore, it would be concluded that Micro TrakTM Culture Confirmation Test is superior in detection of chlamydial inclusions to Giemsa or iodine staining which are now ususallyutilized. In Direct Specimen Test negative-coincidence ratio (number of negative-Direct Specimen Testcases in negative-culture cases/number of negative-culture cases) was 89.0%. This would show thatreactions of Micro TrakTM method in direct smears were almost specific to C. trachomatis organisms. Onthe other hand, positive-coincidence ratio (number of positive-Direct Specimen Test cases in positiveculturecases/number of positive-culture cases) was 69.7%. It is suggested that positive ratio isunequivocally influenced by the method for collection of specimens and for making direct smears, andthe experience of observation with fluorescence microscopy. Therefore, the carefulachievement andskillfulness of suitable method for detection of chlamydial organisms must bring better results. It mightbe suggested that Micro TrakTM Direct Specimen Test is a really rapid and easy-to-perform method fordetection of C. trachomatis and to be performed as a substitute method for cell culture method in clinicallaboratories.