Two-Dimensional Protein Profiles and Fatty-Acid Compositions in Coccoid Forms of Campylobacter jejuni

It is generally known that campylobacter cells are transformed from the normal spiral form into a coccoid form under unfavourable conditions (Fig. 1). This coccoid form, which is evident at both growth and environmental temperatures,8 is not culturable using available techniques. However, it may play a role in survival of campylobacters during the contamination cycle comparable to the situation in Vibrio, Salmonella, Legionella and Shigella species for which transformations to a viable nonculturable form and reversions have been described.5 The transition to the nonculturable coccoid form in C. jejuni is influenced by temperature and medium composition2 and occurs above and below the minimum growth temperature of 32°C.8 To explore whether formation of cocci is an active process, both protein profiles and fatty-acid compositions of spirals and cocci formed at 4°C and 25°C were compared and the effects of protein synthesis inhibition and DNA damage were determined.