Clostridium difficile in a geriatric unit: a prospective epidemiological study employing a novel S-layer typing method

Abstract

Clostridium difficile is the major identifiable cause of antibiotic-associated diarrhoea in the UK. The aim of this study was to employ traditional culture, toxin detection and a novel typing method to determine the level of C. difficile colonization and disease in a population of elderly patients and to investigate the association between strains in the patients and their environment. Three hundred and ninety patients between 62 and 101 years of age admitted to a geriatric unit in the Royal Victoria Hospital (RVH), Edinburgh, were investigated for the presence of C. difficile. C. difficile was cultured from 100 (26 %) patients using pre-reduced cycloserine-cefoxitin egg yolk agar, and toxin(s) was detected in the faeces of 34 of these patients using the Techlab ELISA test kit for the detection of C. difficile toxins A and/or B. Toxin(s) was detected in a further 18 patients from whom no C. difficile was detected in culture. Of the patients in whom C. difficile was detected, 49 % had diarrhoea, with the highest proportion of patients with diarrhoea being both culture-and toxin-positive for C. difficile. Environmental sampling of the patient environment yielded C. difficile from 14 % of samples. The organism was most frequently isolated from floors, sluice-rooms and toilet areas. The variation in the molecular mass of the C. difficile S-layer proteins was exploited as the basis of a novel typing method for C. difficile. Isolates from patients in the RVH were given a four-digit 'S-type' number based on their S-layer protein profile. A total of seven S-types were identified, with one type, toxigenic S-type 5236, accounting for 73 % of all clinical isolates and 91 % of environmental isolates.

Effects of sub-MIC concentrations of antibiotics on growth of and toxin production by Clostridium difficile

“…Strain 338a is of S-type 5236 (ribotype 1) and was present in 78 % of cases of C. difficile diarrhoea in a geriatric unit in the Royal Victoria Hospital, Edinburgh (McCoubrey et al, 2003). Strains were grown from spores stored in cooked meat broth [anaerobic investigation medium (AIM) with cooked meat particles (Brown et al, 1996)].…”

Molecular characterization of Clostridium difficile clinical isolates in a geriatric hospital

“…It has already been reported that C. difficile surface proteins display a high variability (Péchiné et al, 2005). McCoubrey et al (2003) studied the variation in the molecular mass of the C. difficile S-layer proteins and identified seven S types among 100 isolates. The C. difficile S layer is composed of two proteins of variable size: a higher-molecular-mass protein of 48-56 kDa encoded by the conserved 39-terminal part of the slpA gene and a lower-molecular-mass protein of 36-45 kDa encoded by the variable 59-terminal part of the gene.…”

“…They described a good correlation between the two methods and proposed PCR-RFLP on the fliC gene as an additional typing method. Previous reports have also described the variability of the S-layer protein (SlpA) among C. difficile isolates (Calabi et al, 2001;Kato et al, 2005;McCoubrey et al, 2003). Karjalainen et al (2002) suggested that genotyping based on slpA gene studies could be useful for typing strains.…”

The CFD driven optimisation of a modified venturi for cavitational activity

“…Stool carriage of C. difficile reaches 16%–35% in hospitalized inpatients, with percentages proportional to the duration of hospital stay and exposure to antibiotics 26, 27. CDAD is characterized by a progression from an uncolonized state to C. difficile colonization, followed by toxin production 28. This process, in part, depends on the specific strain of C. difficile, as well as the immune status of the host.…”