Characterization of clinical Campylobacter jejuni isolates with special emphasis on lipooligosaccharide locus class, putative virulence factors and host response

Abstract

Recent studies have indicated a role of the lipooligosaccharide (LOS) of Campylobacter jejuni in the severe neurological Guillain Barré syndrome, as well as in development of more severe symptoms of acute enteritis. We evaluated the role of the LOS locus class in C. jejuni infection among 163 enteritis patients. The prevalence of LOS locus classes differed according to the origin of the isolates. Furthermore, LOS locus classes A and B were significantly associated with susceptibility or resistance to ciprofloxacin and doxycycline. However, our results do not corroborate earlier findings that isolates with potential to sialylate LOS might be associated with more severe symptoms of enteritis. Instead, in an infection model, such isolates gave weaker epithelial IL-8 responses than nonsialylated isolates. Absence of the iron transport protein encoded by the gene ceuE as well as the putative fucose permease gene cj0486 was associated with increased in vitro IL-8 secretion.

Lipooligosaccharide locus classes and putative virulence genes among chicken and human Campylobacter jejuni isolates

“…The LOS locus class C was the most common in both sources followed by the classes E and H, which is in line with the results from other studies on human isolates [5, 8, 15]. By a combined analysis of LOS locus classes and the Sma I restriction patterns, we sought to identify potential differences in transmission of isolates with different LOS locus classes between the Swedish chickens and humans as well as from unknown sources.…”

“…In this material however, the prevalence of fucP was only slightly higher than 50 % among the human and chicken isolates. In our previous studies we found this particular gene to be present in 49 % of isolates from enteritis patients and in 23 % of isolates from bacteremia patients in Finland [2, 8]. Together these results suggest that L-fucose utilization by fucP hardly is a prerequisite for colonization of chickens or for causing infections in humans.…”

“…Some studies have also proposed that C. jejuni strains with sialylated LOS might be involved in more severe symptoms of enteritis as well as invasive infection [5, 13, 14]. However in previous studies, we have not been able to find any associations between such strains and severe enteritis or with invasive infection in patients [7, 8]. The prevalence of C. jejuni strains with genes for sialylation of LOS among enteritis patients seems to vary between 50 and 60 % [5, 8, 15].…”

“…However in previous studies, we have not been able to find any associations between such strains and severe enteritis or with invasive infection in patients [7, 8]. The prevalence of C. jejuni strains with genes for sialylation of LOS among enteritis patients seems to vary between 50 and 60 % [5, 8, 15]. Although poultry is an important source of Campylobacter infection in many countries, very little is known about the distribution of LOS locus classes among C. jejuni from broiler flocks reared for consumption [15, 16].…”

Scientific Opinion on the evaluation of molecular typing methods for major food‐borne microbiological hazards and their use for attribution modelling, outbreak investigation and scanning surveillance: Part 1 (evaluation of methods and applications)

“…Although C. jejuni has a limited ability to metabolize sugars, the organism possesses a large number of enzymes involved in the biosynthesis of carbohydrates which are then incorporated into its peptidoglycan (PG), lipooligosaccharides (LOS), capsular polysaccharides (CPS) and both N-and O-linked glycoproteins. Recent studies have indicated a role of the lipooligosaccharide (LOS) of C. jejuni in virulence, particularly the severe neurological Guillain Barré syndrome (Ellström et al, 2013;Pike et al, 2013). LOS and CPS are also involved in the interaction between Campylobacter and the human innate and acquired immune system.…”