[The ultrastructural study on the relationship between Chlamydia trachomatis and the host cell in adhesion and during...

Chlamydia trachomatis (C. trachomatis) is 0.4-0.5 microns in diameter in the EB stage, with the nucleoid located eccentrically within it. We studied the relationship between the eccentric nucleoid and the host cell surface under electron microscope, when C. trachomatis was in adhesion to the host cell and during and after invasion into the host cell. When C. trachomatis adheres to and invades a host cell, the eccentric nucleoid is located on the side distant from the host cell surface (44 of 66, 66%). The 1 x 3 chi-square test indicates that the difference is significant at p less than 0.001. After C. trachomatis invades a host cell, the eccentric nucleoid is located on the side close to the host cell surface (61 of 138, 44%). The 1 x 3 chi-square test shows the difference to be significant at p less than 0.001. However, since the latter (44%) is less than the former (66%). C. trachomatis revolves between adhesion and the completion of the invasion. The 2 x 3 chi-square test shows a significant difference at p less than 0.001.