Rickettsia conorii entry into Vero cells.
The entry of rickettsiae into eukaryotic cells is mediated by an induced phagocytosis, but rickettsiae have never been observed in a closed phagocytic vacuole. In this study, Rickettsia conorii entry into Vero cells was observed by transmission electron microscopy during a period of 3 to 20 min after bacterium-cell contact. The entry occurred within 3 min after bacterium-cell contact, and R. conorii was observed in the process of engulfment, within a phagocytic vacuole, or free in the cytosol. Escape from the phagosome is a very rapid step since phagosome lysis was only occasionally observed. By 12 min, 90% of bacteria were internalized and half were free in the cytosol. This report confirms that rickettsiae penetrate nonphagocytic cells by induced phagocytosis and is the first demonstration of rickettsiae within a complete phagocytic vacuole.
Teysseire
N
N
Unité des Rickettsies, Centre National de la Recherche Scientifique EP J 0054, Faculté de Médecine, la Timone, France.
Boudier
J A
JA
Raoult
D
D
D000818:Animals; D002451:Cell Compartmentation; D002522:Chlorocebus aethiops; D003600:Cytosol / Q000648:ultrastructure; D008854:Microscopy, Electron; D010587:Phagocytosis; D010588:Phagosomes / Q000648:ultrastructure; D012281:Rickettsia / Q000254:growth & development* / Q000648:ultrastructure; D013997:Time Factors; D014709:Vero Cells / Q000648:ultrastructure