COMPARISON OF 2 PANELS OF MONOCLONAL-ANTIBODIES FOR DETERMINATION OF CHLAMYDIA-TRACHOMATIS SEROVARS

A panel of monoclonal antibodies was developed for serovar typing of c linical isolates of Chlamydia trachomatis. The panel could distinguish all 15 established serovars from one another, although the hybridomas of the panel were developed by fusions of myeloma cells and spleen ce lls from mice immunized with antigen derived from the urogenital serov ars D to L3. The typing assay was based on a dot enzyme immunoassay, a nd the monoclonal antibodies that were included in the panel reacted s trongly in this assay. A collection of 289 clinical isolates from The Netherlands was typed. The observed serovar frequency distribution was 51 isolates of serovar D (17.6%), 103 isolates of serovar E (35.6%), 62 isolates of serovar F (21.5%), 28 isolates of serovar G (9.9%), 14 isolates of serovar H (4.8%), 2 isolates of serovar I' (0.7%), 20 isol ates of serovar J (6.9%), and 9 isolates of serovar K (3.1%). These re sults were confirmed by typing these isolates with a panel of monoclon al antibodies purchased from the Washington Research Foundation, Seatt le. No strain variation was observed within serovar D with both panels . However, restriction fragment length polymorphism analysis of the ge ne encoding the major outer membrane protein showed that 32 isolates w ere similar to the prototype D and 17 were similar to the variant D-. The two others showed a new restriction pattern. Our panel of monoclon al antibodies contained one monoclonal antibody that divided the serov ar G isolates into two groups. This differentiation was confirmed by r estriction fragment length polymorphism analysis, confining this diffe rence to a known sequence variation in variable domain TV, These data support the subdivision of serovar G into serovars G (prototype strain UW-57) and Ga (prototype strain IOL-238).