The Role of Klebsiella Oxytoca in Antibiotic-Associated Colitis and Determination of Antibiotic-Sensitivity Pattern in Clinical Isolates

Klebsiella oxytoca is recently described as the causative organism for antibiotic-associated hemorrhagic colitis. The condition occurs mainly after treating with beta-lactamase antibiotics، cephalosporins، quinolone which is frequently used in the treatment of infectious diseases of all ages. The patients with hemorrhagic colitis typically have abdominal pain and almost always، bloody diarrhea. The aim of this study was to determine the prevalence of Klebsiella oxytoca in patient with colitis and the of antibiotic-sensitivity pattern in clinical isolates. In this cross-sectional study، population consisted of hospitalized patients with the history of diarrhea or dysentery and taking antibiotics for 1 week to 2 months. Fecal samples were collected، inoculated into Cary-Blair transport medium and transferred to the microbiology laboratory of Pasteur Institute (Iran). Klebsiella oxytoca strains were identified by standard microbiology tests. Isolated bacteria using specific primers for polygalacturonase (pehX) gene were confirmed by polymerase chain reaction (PCR). The antibiotic resistance patterns of isolates were investigated using Kirby-Bauer disk diffusion method on Muller-Hinton agar and the results were evaluated according to CLSI (Clinical and Laboratory Standards Institute) recommendations. 311 stool specimens from patients with diarrhea or bloody diarrhea during 18 months (June 2011 to January 2013) were studied. Forty strains of Klebsiella oxytoca isolated by microbiology standard methods and were confirmed by PCR. The prevalence of Klebsiella oxytoca was 52. 5% among children، 22. 5% among women and 25% among men. Out of 40 isolates، 30. 6% was isolated from the patients with dysentery compared to 69. 4% from the patients with diarrhea and history of taking antibiotics. The results of antibiotic susceptibility pattern revealed that clinical isolates of Klebsiella oxytoca shown high sensitivity to amikacin (98%)، ertapenem (98%)، imipenem (93%) and meropenem (93%). The most resistance were to amoxicillin (85%)، ampicillin (80%)، ticarcillin (55%)، and cotrimoxazole (30%). The results indicated that infection with Klebsiella oxytoca in patients with antibiotic-associated colitis or hemorrhagic colitis should be considered further.