1. Chlamydiae is the most common bacterial STD in the United States and 2.86 million chlamydiae infections are reported annually.

2. Heat-inactivated Chlamydiae produced an early agglutination of macrophages with leakage of lysosomal acid phosphatase, disintegration of neutral red-stained lysosomes, as well as a progressive irreversible damage of the macrophage.

3. Chlamydiae belonging to Subgroup A occur in both the normal male urethra and in patients with urethro-adnexitis, which means thatChlamydiae must be attributed with a significant pathogenetic role in certain cases of abacterial urethroadnexitis.