Campylobacter jejuni non-culturable coccoid cells

Lack of response of INT-407 cells to the presence of non-culturableCampylobacter jejuni

“…Many conflicting articles have been written on the existence and importance of non-culturable C. jejuni [ [5][6][7][8][9][10][11]. To further elucidate if non-culturable C. jejuni can be infective, the effect of adding non-culturable C. jejuni on the infectivity in INT-407 cells was studied instead of measuring the effect of non-culturable C. jejuni on their own.…”

“…A marked difference between studies is the temperature at which non-culturable C. jejuni were formed. While some authors did not find any infectivity of non-culturable C. jejuni formed at 4 xC [6][7][8], in all studies reporting on non-culturable C. jejuni causing infection, the non-culturable C. jejuni were formed at 4 xC [9][10][11], whereas in all experiments using higher temperatures no infectivity was found [5,8]. Interestingly Hazeleger et al [12] showed that non-culturable C. jejuni formed at 4 xC showed characteristics, including intracellular/extracellular ATP ratio and membrane fatty-acid composition, comparable to culturable C. jejuni, whereas nonculturable C. jejuni formed at 25 xC were clearly different.…”

“…Some authors showed that non-culturable C. jejuni were not infective in chicks, mice and human volunteers [5][6][7][8] while others demonstrated that nonculturable C. jejuni were colonizing chicks and mice [9][10][11]. The inconsistency in the literature about the infectivity of non-culturable C. jejuni might be the result of differences in methods, conditions and strains used.…”

Sources of Campylobacter Colonization in Broiler Chickens

“…There has been considerable debate as to whether such water-stressed bacteria retain infectivity. Although water-borne human outbreaks have been recorded (108), experimental animal studies have had variable success in demonstrating the infectivity of environmentally stressed C. jejuni (8,13,38,55,63,105), especially in chicks. One study (30) even suggested that the colonization potential of culturable C. jejuni for chicks is severely compromised by long-term exposure to water.…”

Acid and low temperature treatments on Salmonella Enteritidis inoculated in pork and its subsequent survival in simulated gastric fluid

“…First, aliquots of 5mL of pork homogenate were transferred to 10mL of SGF (pH 1.5) and incubated at 37°C. The SGF was prepared according to BEUMER et al (1992) and heated to 37°C prior to mixing with homogenate samples. The bacterial count was performed using the drop plate technique on TSA in triplicates.…”