Comparison of Chlamydia subgroup A detection from clinical specimens after 40 and 64 hours of incubation in 5-iodo-2-deoxyuridine-treated McCoy's cells.

The time course of formation of inclusion bodies produced by Chlamydia in 5-iodo-2-deoxyuridine (IUdR)-treated McCoy's cells was studied with the use of a known isolate of Chlamydia trachomatis D/UW-184/Ur and 47 frozen clinical urethral specimens previously shown to be either positive or negative for chlamydial inclusions after 3 days of incubation. Subsequent examination of 369 clinical specimens from the genitourinary tract over a 6-month period revealed 47 (13%) Chlamydia-positive cultures, all of which demonstrated inclusion bodies by iodine staining at 40 and 64 h postinoculation. Another 146 similar detected by iodine staining from 22 (15%). This study indicates that, although Chlamydia subgroup A inclusions are larger at 64 h, they can be readily detected from clinical specimens in IUdR-treated McCoy's cells at 40 h postinfection.