Metabolic Capacity and Pathogenic Properties of the Intestinal Coliforms in Patients with Ulcerative Colitis

Abstract

An automated microplates system for biochemical fingerprinting of bacteria (the PhP-syslem) was used to measure the metabolic activities of the faecal coliform populations from ulcerative colitis (UC) patients (n=19), their healthy household relatives (n= 17) and healthy unrelated individuals (n = 20). The metabolic fingerprint obtained for each coliform population was used to calculate a metabolic capacity (MC)-value for that population. Similarities between metabolic fingerprints were measured as correlation coefficients (r) and the mean correlation coefficients (^rmean) were taken to indicate homogeneity within each group. Coliforms from patients had higher MC-values (mean ± SD = 0.841 ±01) than those from healthy controls (0.764 ±0136; P < 001). whereas no significant difference was observed between the MC-values of the coliforms from patients and their healthy relatives. Homogeneity among metabolic fingerprints of coliform populations from patients (r_mean = 0.336) and their relatives (0.377) was lower than that from healthy unrelated controls (0.644; P < 0.001 for both groups). Klebsiella spp. with adhesive properties were found in 10 patients (53 per cent) and in three relatives (18 per cent) but in no healthy controls. Similarly strains with mannose-resistant haemagglutination and haemolytic activity were also found more often among patients than among healthy controls. Coliforms from patients with total colitis had higher MC-values (mean ±SD = 0.886±0.07) than those from left-sided colitis (0.81±0.115; P < 0.05) and also possessed more virulence factors. The MC-assay used in this study proved to be a meaningful way of characterising coliform populations in patients with UC.

Key Words:

• Metabolic capacity
• Coliforms
• Pathogenic properties
• Ulcerative colitis