Antibiotic-associated haemorrhagic colitis caused by Klebsiella oxytoca

Abstract number: P1938

Orth D., Naim A., Ehrlenbach S., Grif K., Würzner R.

Objectives:Klebsiella oxytoca has been isolated from stool samples of patients with Clostridium difficile-negative antibiotic-associated hemorrhagic colitis. However, the pathogenic role of this organism has not been fully elucidated yet.

The aim of our study was to investigate the presence of toxin producing Klebsiella oxytoca in patients with antibiotic-associated hemorrhagic colitis.

Methods: 2500 stools specimens from patients with the clinical diagnosis antibiotic-associated hemorrhagic colitis and 85 stool specimens of a healthy control group were examined in the period from June to November 2007 in the Tyrol (Austria).

The specimens were cultured on MacConkey agar and investigated for the presence of K. oxytoca by standard microbial procedures. The cytotoxic effect of K. oxytoca strains was tested on Hep-2 cells and Vero cells, the amount of cytotoxicity was determined by Lactat-Dehydrogenase release. The Klebsiella strains were characterized phenotypically by antibiotic susceptibility testing and were typed by Pulsed-Field Gel-Electrophoresis. In addition, all stool samples were investigated for Clostridium difficile toxin by ELISA.

Results: 119 of 2500 stool specimens (4.8%) of patients with antibiotic-associated hemorrhagic colitis yielded K. oxytoca. In the control group only 2 of 85 specimens (2.4%) were positive for K. oxytoca. The rate of cytotoxic strains among K. oxytoca was 46% in patients with antibiotic-associated hemorrhagic colitis compared with none in the healthy control group. In addition we could demonstrate that Vero cells are superior to Hep-2 cells for investigating K. oxytoca strains for toxin production.

Eleven percent of the stool specimens were positive for Clostridium difficile toxin.

Conclusions: Our study demonstrates that beside Clostridium difficile cytotoxigenic K. oxytoca are a causative agent of antibiotic-associated hemorrhagic colitis. Thus, cytotoxigenic K. oxytoca should be included in routine microbiologic diagnostic of stool specimens. Furthermore we recommend Vero cells for determination of the cytotoxic effect of K. oxytoca strains.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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