Spirochaetes

Spi·ro·chae·tes (spi″ro-keґtēz) 1. a phylum of bacteria consisting of gram-negative, highly flexible, helical cells that are motile by protoplasmic flagella; organisms are chemo-organotrophic and may be anaerobic, microaerophilic, facultatively anaerobic, or aerobic. Members are free-living or associated with animal hosts; some are pathogenic. It contains the single class Spirochaetes. 2. the sole class of the order Spirochaetes. It contains the single order Spirochaetales.