Electron microscopy of the coccoid form of Campylobacter jejuni.

Confluent cultures of Campylobacter jejuni incubated for 24 and 48 h each were examined by electron microscopy. Although the 24-h-old cells exhibited typical curved morphology, the 48-h-old cells showed rounded morphology with a loss of cell integrity. This appeared to be an autolytic process that occurred very rapidly after the culture became mature. These results confirm previous evidence that the coccoid form of this organism is a degenerate state.