Toxin A negative/toxin B positive Clostridium difficile strains isolated from patients with diarrhoea in a tertiary hospital in Athens

Abstract number: 1135_161

Malamou-Lada H., Kafkoula-Alevizou H., Karampoyia-Karafillidis P., Strouza A.


During the last five years, toxin A negative/toxin B positive (A–B+) Clostridium difficile (Cd) strains were isolated in Asia, Canada and Europe. No A–B+ Cd strains have been isolated from patients in Greece so far. The aim of this study is to present five cases of diarrhoea caused by A–B+ strains in our hospital, over a two year period.


Over the last two years, we prospectively examined 913 stool samples obtained from patients with diarrhoea for the presence of Cd and its toxins A&B. Culture for Cd was performed on cycloserine–cefoxin blood agar and the strains were identified by conventional methods. Toxin A was detected from stools by an ELISA assay (Vidas, bioMérieux) and a chromatographic assay (Color Pac, BD). Toxigenicity of the isolated strains was examined using Color Pac test for toxin A and Premier toxins A&B test (Meridian, USA) for toxins A&B. Cd strains negative by Color Pac and positive by Premier test were considered A–B+. The MIC's of the A–B+ isolates to antibiotics were determined using E-test (AB Biodisk, Sweden).


Cd was isolated in 70/913 (8%) stool samples. Toxin A was detected in 79/913 (8.6%) samples. Five of 70 (7%) Cd strains were A–B+, two (3%) were A–B– and 63 (90%) were A+B+. The A–B+ strains were isolated from five patients (age range 50–85 years), hospitalized in different wards of the hospital during 2003 (4 patients) and 2004 (1 patient). All patients had more than one risk factors to develop Cd associated diarrhoea such as antibiotic therapy (3), malignancies (2), chemotherapy (2), advanced age (4). All five A–B+ strains were resistant to clindamycin, three were resistant to penicillin, but all were sensitive to vancomycin and metronidazole.


This is the first report of isolation A–B+ Cd strains from hospitalised Greek patients with diarrhoea. The strains were resistant to clindamycin and all the patients had high risk factors to develop Cd associated diarrhoea. Laboratories should apply diagnostic assays to detect both toxins A&B, especially in patients with risk factors to develop Cd intestinal infections.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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