FIG. 1.

Parallel assessments of infectivity of C. trachomatis serovar L2 (CT-L2), C. trachomatis serovar D (CT-D), and C. psittaci (Cp) for each CHO cell mutant. Infectivity for monolayers of each cell line was tested in triplicate for each chlamydial strain. At approximately 48 h postinfection, chlamydial inclusions were detected by immunofluorescence and enumerated by counting inclusions. Similar data were obtained by using sequence-confirmed C. psittaci 6BC_PF. Qualitative estimates of attachment for C. trachomatis serovar L2 are indicated as no binding (NB) by a scale of 1+ to 4+ when cell-associated binding was detected, where 1+ represents approximately 10 elementary bodies apparently associated with cell surfaces and 4+ represents many elementary bodies bound with entire staining of the cells.