Peritonitis Due to Providencia stuartii

Editor:

Providencia stuartii is a gram-negative bacterium belonging to the Enterobacteriaceae family (1). Providencia stuartii is a frequent cause of urinary tract infections in hospitalized and nursing home patients with long-term in dwelling urinary catheters. This strain shows resistance to both disinfectants and multiple antimicrobial drugs (2). P. stuartii is nosocomially diffuse, especially in chronic care units and geriatric and neurological wards, where it is frequently predominant and could cause such severe infections as fatal bacteremia (3). Peritonitis remains a major complication of peritoneal dialysis (PD), accounting for considerable mortality and hospitalization among PD patients (4). Additionally, gram-negative peritonitis is often more severe and resistant and is associated with worse outcomes (5). Detection of etiologic agents of the peritonitis is an important diagnostic step. Herein we report a case of life-threatening peritonitis due to P. stuartii. This is the first case report of peritonitis due to a Providencia strain in a PD patient.

A 73-year-old female patient was on PD for end-stage renal disease secondary to type II diabetes. She had been on PD for 8 months and was admitted to hospital with abdominal pain and fever. In her physical examination, abdominal palpation revealed general pain and tenderness. Appearance of her peritoneal fluid was cloudy. In her laboratory examination, C-reactive protein was 6.3 mg/dL, white blood cell count (WBC) was 13700/ μL (with 82% neutrophils and 17% lymphocytes), and hemoglobin was 9.7 g/dL. Her peritoneal fluid contained 800 WBC/mm³ (with 80% neutrophils) and standard dialysate culture technique was performed. Gram stain was negative. Thereafter we started intraperitoneal cefazolin and gentamicin empirically without the need for catheter removal. Peritoneal fluid culture was found to be negative. Despite empirical treatment, the patient's clinical condition deteriorated. On the second day of the treatment, the patient was febrile (39.8°C) and abdominal pain was increased. Peritoneal fluid was examined again with the same technique. Laboratory investigations revealed a septic hemogram with 20000 WBC/μL and C-reactive protein level of 12 mg/dL. Peritoneal fluid analysis revealed 2500 WBC/mm³, with 82% neutrophils. Cefazolin was changed to vancomycin and gentamicin was continued. The following day, the fluid WBC were elevated to 3600/high-power field. The patient's Tenckhoff catheter was removed but signs of peritonitis persisted on physical examination.

After 3 days the culture bottle flagged positive and the bacterium was identified as Providencia stuartii. Antibiotic sensitivity testing showed resistance to beta-lactam antibiotics and to all aminoglycosides except amikacin (4). Amikacin was started according to the antibiogram. No clinical or laboratory improvement was observed on the second day of amikacin administration. Despite treatment, the patient's clinical condition deteriorated and she died on the fourth day of medical therapy.

The genus Providencia includes urease-producing gram-negative bacilli that are responsible for a wide range of human infections. Providencia species have been isolated from urine (most common), stool, and blood, as well as from sputum, skin, and wound cultures (1–3,6,7). To the best to our knowledge, there are no reports of cases of peritonitis due to P. stuartii or other strains of Providencia. However, we think this agent might lead to culture-negative peritonitis because of difficulty of culture techniques. Susceptibility testing for P. stuartii is extremely important because many Providencia species may be resistant to multiple antibiotics (7). This could further explain the unresponsiveness of patients to previously administered empirical antibiotic treatment.

In conclusion, this is the first case report of peritonitis due to any Providencia species. It is clear that P. stuartii has great potential to cause significant community-acquired and nosocomial infections. Providencia stuartii should be kept in mind in resistant culture-negative peritonitis in PD patients. As seen in this present case, P. stuartii may cause serious, invasive, and rapidly progressing infections.