C-152. Comparison of Chlamydia Growth in Three Different Strains of Female Tissue Culture Cells

T. Komoda1, A. Fuji1, H. Bannai1, H. Akita2, S. Iwata3, Y. Sato4, K. Sunakawa5;
1Kyorin Univ., Tokyo, JAPAN, 2St.-Marianna Univ. Sch. of Med., Yokohama City Seibu Hosp., Kanagawa, JAPAN, 3Natl. Tokyo Med. Ctr., Tokyo, JAPAN, 4Ota Fuji Heavy Industry Hosp., Gunma, JAPAN, 5Kitasato Inst. for Life Sci., Kitasato Univ., Tokyo, JAPAN.

Background: To get a clue of persistent serum IgA antibody in women patients with Chlamydia trachomatis infection after antibiotic treatment, minimal inhibitory concentrations of antibiotics (MIC) and growth of C. trachomatis were examined using three different cell strains as in vitro models. Methods: The cell strains derived from uterine cervix (HeLa229), endometrium (RL95-2) and ovary (A2789) cells were grown for 24 hours in 24 well-tissue culture plates coated in poly-L-lysine. An in- house polymerase chain reaction (real-time PCR) method was established and used for evaluation of Chlamydia growth in each cell. C. trachomatis serovar D (1×104 IFU) was used for infection with assisting centrifugation and cultured. Twenty-four, 48, 72 and 96 hours later, the cells were fixed with methanol and/or were collected together with the medium. The former were stained with immunoperoxidase assay for inclusion counting and the extraction reagent was added to the later cells to get Chlamydia DNA. Results: Real-time PCR assay reflects the number of inclusions formed in the cells. The number of inclusions formed in HeLa 229 cells was higher than in RL95-2 cells and than in A2780 cells. However, more DNA copies were detected in A2780 cells than in the other two cell strains, suggesting that the inclusion bodies formed in A2780 cells comprehend many Chlamydia organisms. It was also found that MICs measured in RL95-2 cells were two to four times higher than that of HeLa 229 cells and A2780 (MIC: HeLa 229 cell: EM, CAM, DOXY for 0.031; LVFX: 0.025, TFLX:0.125; RL95-2 cells: 0.063, 0.063, 0.063, 0.25, 0.5; A2780 cell: 0.031, 0.06, 0.031, 0.25, 0.125(μg/ml)). Conclusion: Results may suggest that it is easier for C. trachomatis organisms to exist in the endometrium and ovary cells than in uterine cervical cells.