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Detection of Clostridium difficile and its toxin A [TcdA] in stool specimens from hospitalised patients

100%

Wroblewska M. M., Swoboda-Kopec E., Rokosz A., Nurzynska G., Bednarska A., Luczak M.

Polish Journal of Microbiology

2005

tom 54

nr 2

The study has been carried out to determine the frequency of C. difficile recovery in stool cultures and the rate of C. difficile toxin A detection in faecal specimens of patients with nosocomial diarrhoea. Clinical specimens comprised 4414 stool samples collected from 1998 to 2002 from adult patients hospitalised in different wards of a university-affiliated hospital (1200 beds) and suspected of C. difficile-associated disease (CDAD). There have been 1308 (29.6%) specimens positive for C. difficile culture (15.1% in 1998, 29.5% in 1999, 33.8% in 2000, 31.2% in 2001 and 32.0% in 2002). The highest number of C. difficile strains was cultured from stool samples of patients hospitalised in the haematology/oncology ward (51.1% of all isolates), neurology (8.3%), nephrology (8.0%), gastrointestinal surgery (7.0%) and neurosurgery (6.2%) wards. The testing for C. difficile toxin A yielded 847 (19.2%) positive samples and 3567 (80.8%) toxin A-negative results. The percentage of C. difficile toxin A-positive samples was 29.4% in 1998, 17.5% in 1999, 23.2% in 2000, 17.1% in 2001 and 15.0% in 2002. In the analysed period we observed an increase in the number of stool specimens tested for C. difficile and an increase in the number of C. difficile culture-positive samples. A decrease in the number of C. difficile toxin A-positive samples was noted in the last 2 years of the study. This phenomenon may be due to an improved antibiotic policy of the hospital.

Co-infection of hamsters with toxin A or toxin B-deficient Clostridium difficile strains

84%

Szczesny A., Martirosian G., Cohen S., Silva J.,Jr.

Polish Journal of Microbiology

2005

tom 54

nr 4

Male Syrian hamsters (Mesocricetus auratus) were used to study interactions between different toxin deficient strains of C. difficile. After sensitization with clindamycin, hamsters were intragastrically co-infected with the appropriate dilutions corresponding to 100, 1000 and 10,000 cells of four (toxin A or B-deficient) C. difficile strains (8864, P-829, W-38 and W-74). In addition, a group of hamsters was infected with C. difficile VPI 10463, a reference toxigenic strain. Colonization and mortality was observed within 48 hours in the group of hamsters infected with the reference toxigenic strain. No clinical disease was observed in the groups of hamsters co-infected with the toxin A or B-deficient strains. Re-infection of these hamsters (co-infected with toxin deficient isolates) with C. difficile VPI 10463 resulted in clinical disease and death suggesting that these strains do not confer protection against infection with a toxigenic strain. Macroscopic and microscopic observations of the cecum of re-infected hamsters demonstrated uniformly multiple large hemorrhagic areas without pseudomembranes. Hamsters infected with as few as 100-500 cells of the toxigenic strain - VPI 10463 alone demonstrated pseudomembranes and multiple hemorrhages. These results suggest that even though the toxin deficient strains did not prevent re-infection with a toxigenic strain of C. difficile, they may play a role in the histopathologic changes after re-infections in the hamster model. Further studies with a larger number of hamsters and C. difficile strains of various molecular profiles are required to better understand the interaction between these strains.

Ograniczanie wyników

2 Polish Journal of Microbiology

1 Bednarska A.

1 Cohen S.

1 Luczak M.

1 Martirosian G.

1 Nurzynska G.

1 Rokosz A.

1 Silva J.,Jr.

1 Swoboda-Kopec E.

1 Szczesny A.

1 Wroblewska M. M.

2 2005

Wyniki wyszukiwania

Detection of Clostridium difficile and its toxin A [TcdA] in stool specimens from hospitalised patients

Co-infection of hamsters with toxin A or toxin B-deficient Clostridium difficile strains