Enzyme-linked immunosorbent assay for the in-vitro detection of sensitivity of Chlamydia trachomatis to antimicrobial drugs.

A new method of testing antimicrobial activity in vitro against Chlamydia trachomatis by enzyme-linked immunosorbent assay (ELISA) was developed by using a monoclonal antibody reacting with the major outer membrane protein of C. trachomatis LGV2 serotype. ELISA was compared with standard iodine stain, with immunofluorescence assay (IFA) and immunoperoxidase assay (IPA) performed with the same monoclonal antibody as in the ELISA. The MICs and MBCs of rifampicin, oxytetracycline, erythromycin, chloramphenicol and cefazolin detected by ELISA were higher than those determined by iodine stain and slightly lower than those determined by IFA and IPA. Since ELISA was at least as informative as the previously described techniques, but more rapid and standardizable and easier to perform, the assay may be useful in measuring the antimicrobial drug susceptibility of C. trachomatis.