(P03) A Case of Multi-Drug Resistant Raoultella Ornithinolytica Urinary Tract Infection

Introduction: Raoultella ornithinolytica (R. ornithinolytica) is a gram-negative aerobic rod, previously classified as Klebsiella ornithinolytica. It is a rare causative agent of human disease. We describe a case of a resident at a skilled nursing facility with urinary tract infection secondary to this pathogen.

Case Description: A 58-year-old female with Parkinson’s disease, rheumatoid arthritis (RA) and lung disease, asthma, macular degeneration, hypertension, atrial fibrillation, hyperlipidemia, depression and osteoporosis; no known antibiotic allergies; who was a long term care skilled nursing facility resident complained of urinary urgency and frequency of two days’ duration.

The patient was afebrile with normal vital signs. Abnormalities noted on physical examination were bilateral upper extremity contractures, in keeping with RA. Abdominal exam excluded bladder and costovertebral angle tenderness. Laboratory studies revealed a normal leukocyte count (4890 cells/microliter) and serum creatinine level (0.61 mg/dL). Urinalysis (UA) was reported with 5-10 white blood cells (reference range: 0-4/hpf), moderate leukocyte esterase and was positive for nitrites. No bacteria were reported on the UA. Urine culture was resulted as >100,000 cfu/mL Raoultella ornithinolytica and 20000-50000 cfu/mL Escherichia coli. Antibiotic sensitivities for R. ornithinolytica were listed as sensitive to ceftazidime, ceftriaxone, piperacillin-tazobactam, meropenem and tobramycin. The organism was resistant to ampicillin, amoxicillin-clavulanate, cefazolin, cefuroxime, ciprofloxacin, levofloxacin, gentamicin, nitrofurantoin, tetracycline (tetra) and trimethoprim-sulfamethoxazole (TMP-SMX). E. coli was resistant only to ampicillin, TMP-SMX and tetra.
The patient was successfully treated with intramuscular ceftriaxone 1gram daily for 7 days with complete resolution of symptoms upon completion of therapy.

Discussion: R. ornithinolytica is an emerging Enterobacterium that can result in human infections, notably urinary tract infections, hepatobiliary disease, blood stream and respiratory tract infections. It is an uncommon pathogen in the post-acute setting and providers must be aware of the possibility of its multi-drug resistant nature. Select literature on this organism points to occurrence in immunocompromised hosts, which was not in the case in our patient. Enhanced barrier precautions must be implemented along with effective antimicrobial therapy.