Survival of Chlamydia trachomatis in different transport media and at different temperatures: diagnostic implications

We compared the survival of a laboratory strain of Chlamydia trachomatis serovar L-2 in different media and at different temperatures (room temperature, 4 degrees C, and -70 degrees C). At these temperatures the best storage medium was 2SP (0.2 mol/l sucrose in 0.02 mol/l phosphate buffer supplemented with 10% fetal calf serum). We used material obtained from patients to study the sensitivity of the culture method as a function of sample storage time and temperature. Compared with results on direct inoculation, material stored in 2SP for 48 hours gave 11% fewer positive cultures at 4 degrees C and 14% fewer at room temperature. Of samples which gave negative results on direct inoculation, 4% were positive after storage at 4 degrees C for 48 hours and 2% after storage at -70 degrees C for a week. As expected, the number of inclusion forming units in the original material proved to be important for the percentage of positive cultures among the stored samples.