Production and viability of coccoid forms of Campylobacter jejuni

Abstract

Studies were conducted into the formation and physiological state of coccoid cells of a strain of the human and animal pathogen Campylobacter jejuni. It was found that growth phase and the presence of chloramphenicol did not affect the rate of shape transformation from spiral to coccoid, while nutrient limitation, aeration of the medium and the presence of free-radical scavengers had profound effects. Coccoid cells were found to reduce the tetrazolium salts INT (2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride) and CTC (5-cyano-2,3-ditolyl tetrazolium chloride) to their respective formazans and this was linked to cellular respiration. However, respiring coccoid cells could not sustain their existence in prolonged adverse conditions, and it was concluded that they represent a degenerative stage rather than a dormant state of the organism.

Identification of Campylobacter jejuni Genes Involved in the Response to Acidic pH and Stomach Transit

“…Of note, a pH of 4.5 does not support the growth of C. jejuni NCTC 11168 (36 and our unpublished observations). Unfavorable growth conditions can lead to morphological changes in C. jejuni, causing a shift from a spiral to a coccoid shape (22,62,86,99). Microscopic analysis of the samples used for microarray analysis did not reveal the formation of coccoids or any other morphological variants under our experimental conditions (Fig.…”

Development and Application of an Insertional System for Gene Delivery and Expression in Campylobacter jejuni

“…6A, panel 3). The coccoid cells are considered to be a degenerate bacterial form accumulated in cultures during prolonged incubation or are induced under unfavorable environmental conditions (6). We were interested to investigate if attached aggregates (biofilms) of bacteria provide a mechanism of protection from such conversion.…”

Putative mechanisms and biological role of coccoid form formation inCampylobacter jejuni

“…Coccoid cells have other characteristics besides the obvious feature of their shape. It was revealed that, despite the presence of flagella, coccoid cells of C. jejuni are non-motile [17,21]. The lack of motility could be a repercussion of the morphology.…”