A Pediatric Case of Antibiotic-Associated Hemorrhagic Colitis Caused by Klebsiella Oxytoca

reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page Klebsiella oxytoca is a gram-negative member of the human fecal microbiota, which is detected in the intestine of about 1.6% to 9% of healthy subjects and thus considered to be a commensal member of the enteric microflora. 1 Recently, K. oxytoca has been recognized as the causative organism of antibiotic-associated hem-orrhagic colitis (AAHC) after the use of antibiotics, whereas some studies have shown that K. oxytoca is not associated with nonhemorrhagic antibiotic-associated diarrhea. 2,3 The characteristics of AAHC are sudden onset of bloody diarrhea and abdominal cramps after penicillin therapy that is considered to be critical for triggering dysbiosis as K. oxytoca exhibits a natural resistance to penicillins. 4 Here we describe a pediatric case of AAHC who initially presented with acute abdominal pain and bloody diarrhea after taking an antibiotic for traumatic dental injury. In addition, we conduct a literature review of previously reported cases of AAHC to clarify the characteristics from a clinical point of view. A previously healthy 14-year-old Japanese girl was admitted to our hospital with acute severe abdominal pain and frequent bloody diarrhea. She had been treated with 0.75 g oral amoxicillin (AMPC) daily without pro-biotics since she accidentally lost her teeth 3 days before the admission. She remained afebrile, and the positive findings on physical examination were limited to the abdomen: severe tenderness in the umbilical region without rebound and absent bowel sound. Laboratory examination was normal except for slightly elevated values of white blood cell count (12 400/µL) and C-reactive protein (0.95 mg/dL). An X-ray of the abdomen revealed distension of the small intestine, and ultra-sound study demonstrated thickening of the colon walls. Based on the physical examination, laboratory findings, and imaging studies, acute infectious enteritis was initially suspected. The fact that she did not have high fever and that white blood cell count and C-reactive protein level were not highly elevated suggested that severe bacterial infection was less likely, so symptomatic treatment including fluid and diet therapy was administered with discontinuation of AMPC. On the third day of hospitalization , the results of stool bacterial analysis collected on admission were established: Clostridium difficile toxin A and B were not detected by the cyto-toxin assay, nor was C. difficile itself isolated from the anaerobic stool culture. None of the …