Miniature Cell Formation in Chlamydia psittaci

Abstract

In an electron microscope study on the developmental cycle of the goat pneumonitis strain of Chlamydia psittaci in L cells, it was observed that miniature reticulate bodies, measuring approximately 0.2 μm in diameter and surrounded by double unit membranes, were produced infrequently from normal-sized reticulate bodies through a “budding”-like process. As little as 0.1 μg of penicillin per ml greatly increased the frequency of the miniature reticulate body formation.

Production of outer membrane blebs during chlamydial replication

“…Retrospective examination of our own thin sections of C trachomatis serotype E grown in McCoy cells [5], and other published electron micrographs of C. psittaci strains grown in both L cells and yok sac explants [ 1,6,7] revealed vesicles similar to those observed in the present study. The large number and consistent appearance of these single-membrane vesicles that can be seen in chlamydial inclusions propagated in various host cell systems and fixed un-105 der a variety of conditions make it very unlikely that they arise either as f'lxation artefacts, or are derived from the host cell.…”

“…These vesicles could be distinguished from the miniature reticulate bodies described by Tanami and Yamada [6] by the lack of any intravesicular contents and by the limiting single unit membrane, rather than the double unit membrane which surrounds both normal and miniature reticulate bodies. Both single-membrane vesicles and miniature reticulate bodies could be seen in the inclusions of L2 examined after 24 h in culture (Fig.…”

Ultrastructure of Chlamydia pneumoniae in cell culture

“…The dense bodies could be seen budding from the protoplast of RBs into their periplasmic space as described by Chi et al [3]. These bodies corresponded to miniature cells or minute forms described earlier [11,12]. The cells could have distorted shape (Fig.…”

“…psittaci-type (see [9][10][11][12]). The inclusions were devoid of glycogen and contained different developmental forms of chlamydia: reticulate bodies (RBs), elementary bodies (EBs), and intermediate bodies (IBs).…”

Biosynthesis and disulfide cross-linking of outer membrane components during the growth cycle of Chlamydia trachomatis

“…However, this conclusion assumes that the MOMP that is made during the cycle remains associated with the chlamydiae. Another possibility is that some of the MOMP is released from the RB outer membrane, possibly within the blebs that have been reported by many investigators (17,20).…”