Pathogenic properties of Campylobacter jejuni: assay and correlation with clinical manifestations

Abstract

The pathogenic properties of 20 strains of Campylobacter jejuni isolated from persons with clearly defined clinical manifestations were determined. Cell-free broth filtrates were examined for (i) enterotoxin production by Chinese hamster tissue culture assay and an enzyme-linked immunosorbent assay (ELISA) employing GM1 ganglioside and affinity-purified antiserum to Escherichia coli heat-labile toxin, (ii) cytotoxin production by Vero and HeLa cell tissue culture lines, and (iii) their ability to cause fluid secretion in rat ligated ileal loops. Viable bacteria were examined for invasive properties by an ELISA with the immunoglobulin fraction of antiserum to Formalin-killed bacteria of an invasive strain, and by their effect on fluid secretion and morphology in rat ligated ileal loops. None of the eight isolates obtained from asymptomatic carriers had any detectable pathogenic properties. All six strains isolated from persons with bloody invasive-type diarrhea elaborated a cytotoxin; their viable bacteria had high titers in the ELISA for invasive properties and caused fluid secretion in ligated ileal loops, although consistent morphologic abnormalities and evidence of mucosal invasion, examined by immunofluorescence techniques, were not detected. All six strains isolated from persons with watery secretory-type diarrhea produced an enterotoxin, one elaborated a cytotoxin, and broth filtrates of all strains caused fluid secretion in ligated ileal loops; viable bacteria had low titers in the ELISA for invasive properties and evoked fluid secretion in ligated loops by means of enterotoxin production. These observations show (i) that a correlation exists between the pathogenic properties of the infective C. jejuni strain and gastrointestinal manifestations in the infected host, and (ii) that these pathogenic properties can be identified by in vitro assays, including ELISAs.

Adhesion to and invasion of HEp-2 cells by Campylobacter spp

“…Occasionally, rounding of HEp-2 cells was observed during the 6-h infection period. Infection of HEp-2 cells with C. jejuni and C. coli strains has been reported to cause cytopathic effects as cell rounding, loss of adherence, and death after 24 to 48 h of incubation (24,38).…”

Heat-labile and heat-stable haemolysins of Campylobacter jejuni

“…Recent pathogenicity studies showed that some diarrhoeal strains of C. jejuni produce a cytotoxin either singly or along with a cytotonic toxin [3]. Other phenomena attributed to the pathogenesis of C. jejuni are colonisation and invasion of gut mucosa [4][5][6][7][8][9]. The interplay of the various virulence determinants of the pathogen in the disease process is unclear, but bacteraemia, infiltration and destruction of gut epithelial cells resulting in bloody diarrhoea indicates that a cytolytic process plays a part.…”

Altered synthetic response of Campylobacter jejuni to cocultivation with human epithelial cells is associated with enhanced internalization

“…However, it has also been proposed that disease involves translocation of the bacterium across the intestinal epithelium, with resultant tissue damage and inflammation (31). This latter proposal is based upon examinations of rectal biopsy specimens from C. jejuni-infected patients and, more recently, by the demonstration of the ability of C. jejuni to bind to and enter cultured epithelial cells (1,2,7,9,16,17,19,21). Although the relevance of the internalization of C. jejuni by cultured epithelial cells to in vivo behavior is largely presumptive, some evidence does suggest that such in vitro models may be useful in the elucidation of pathogenic mechanisms associated with C. jejuni enteritis.…”