[Morphological changes of Campylobacter jejuni and Campylobacter coli under various culture conditions and the...

The morphological transformation from the spiral form to the coccoidal form Campylobacter jejuni and Campylobacter coli was studied under various conditions by such techniques as electron microscopy, SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and chemical analyses. The conversion from the spiral form to the coccoidal form of Campylobacter in microaerophilic cultivation occurred in about 50% of the cells in 48 h and in about 90% of the cells in 72 h. At higher temperatures (37 C and 42 C) under aerophilic conditions, the spiral-form cells converted easily to the coccoidal form in phosphate-buffered saline. Electron-microscopic studies revealed that the envelopes of the coccoidal-form cells were soft in comparison with those of the spiral-form cells. The LPS and protein contents of the cells reached the highest levels after cultivation for 48 h under microaerophilic condition. The 33 K and 28 K polypeptide contents of 24-h and 48-h cultures were higher than those of 72-h and 96-h cultures.