Growth characteristics of <b><i>C. trachomatis</i></b> L2 and the transformed strain expressing RSGFP, mCherry or CFP from the <i>incD</i> gene promoter.

<p>A–E HeLa cells were infected with the parental strain, <i>C. trachomatis</i> L2 (<b>A</b>), or the transformed strain harboring p2TK2-SW2 (<b>B</b>), p2TK2-SW2 IncDProm-RSGFP-IncDTerm (<b>C</b>), p2TK2-SW2 IncDProm-mCherry-IncDTerm (<b>D</b>) or p2TK2-SW2 IncDProm-CFP-IncDTerm (E) in the absence (No Pen.) or presence (10 U/ml Pen.) of penicillin. Samples were fixed 22 h and 33 h post infection and stained with the DNA dye Hoechst (<b>A</b>–<b>B</b>) (DNA, left panels) and antibodies against <i>Chlamydia</i> Major Outer Membrane Protein (MOMP) (<b>A</b>–<b>E</b>) (MOMP, middle panels) to visualize the inclusions. GFP (<b>C</b>), mCherry (<b>D</b>) and CFP (<b>E</b>) images are shown on the left panels. The merge images are shown on the right. Scale Bar: 25 µm. F. HeLa cells were infected with the parental strain, <i>C. trachomatis</i> L2 (L2), or the transformed strains harboring p2TK2-SW2 (2TK2), p2TK2-SW2 IncDProm-RSGFP-IncDTerm (RSGFP), p2TK2-SW2 IncDProm-mCherry-IncDTerm (Cherry) or p2TK2-SW2 IncDProm-CFP-IncDTerm (CFP) in the absence (Black bars, No Pen.) or in the presence of penicillin (Grey bars, 10 U/ml Pen.). The number of infectious particles (IFUs) recovered 48 h post infection was determined. ND: Not Detected.