Burkholderia cepacia is an aerobic, glucose–non-fermenting, gram-negative bacillus that mainly affects immunocompromised and hospitalized patients as well as those with chronic granulomatous disease and cystic fibrosis [1-3]. There have also been reports of B. cepacia causing endocarditis, infections of the central nervous system, and neonatal sepsis [2-4]. This organism is not normal human flora, and is usually found in hospital environments, such as in contaminated disinfectants, nebulizer solutions, medical devices, and on the skin of healthcare workers [3,5-7]. Recently, B. cepacia infections have increased because of increased use of broad-spectrum antimicrobial agents, longer duration of hospitalization and indwelling device-related infections [4,7,8]. This organism has high levels of resistance to many antimicrobial agents, and sulfamethoxazole-trimethoprim has been the drug of choice for treatment [1,4].

There have been rare reports of urinary tract infection (UTI) caused by B. cepacia. Hosts with predisposing factors, such as post renal transplant, vesico-ureteral reflux (VUR), neurogenic bladder, bladder irrigation, or use of contaminated medical devices, have been reported to be susceptible to B. cepacia UTI [9-11]. We sought to analyze the incidence, clinical manifestations, risk factors, antimicrobial sensitivity and outcomes of B. cepacia UTI in pediatric patients.

This retrospective study was conducted at Samsung Medical Center, a tertiary referral hospital in Seoul, Republic of Korea. Patients with urine culture-proven B. cepacia UTI between January 2000 and December 2014 were included in the retrospective analysis of medical records. Urinary tract infection was defined as a positive urine test plus at least one of the symptoms or signs of infection, including temperature > 38℃, dysuria, or costovertebral angle tenderness. A positive urine test was defined as a urine culture with ≥ 10⁵ colony forming units (CFU)/mL of B. cepacia from a urine sample collected either via catheter (if during the catheterization period), or by voiding (if the age was more than 3 years) or intermittent catheterization (if the age was less than 3 years). Collected data included gender, age, primary disease, risk factors, antimicrobial sensitivity and outcomes. Antimicrobial susceptibility was determined via VITEK 2 (Bio-Merieux, Durham, NC, USA) according to Clinical and Laboratory Standards Institute guideline. Result with intermediate was considered as resistance.

Burkholderia cepacia usually causes nosocomial infections in immunocompromised hosts, and the most common infectious focus is the respiratory tract, followed by intravascular catheters [2,3,8]. Burkholderia cepacia survives in moist environments, and outbreaks of B. cepacia infection have been described in association with contaminated nebulizers, indigo-carmine dye, mouthwash, and moisturizing body milk [3,5-7]. In our study, the incidence of B. cepacia in 2014 was relatively high, and surveillance cultures for intensive care unit environments were conducted; however, negative results were found.

There have been few reports of the characteristics of B. cepacia UTI. Affected patients often have predisposing factors, such as renal transplantation, prolonged bladder catheterization, or urethrocystoscopy [9-11]. In our study, predisposing host factors such as prolonged genitourinary catheterization, VUR, congenital heart disease, and immunocompromised status were suggested. Twelve of 14 patients with B. cepacia UTI had genitourinary catheterization such as bladder catheter, PCN, or double-J stents. Zeeshan et al. reported that VUR in a renal transplant recipient was a risk factor for B. cepacia UTI [11]. In our study, 4 patients (29%) showed VUR-related UTI in spite of prophylactic antimicrobial agents. VUR was also associated with other anomalies such as cloaca anomaly or chromosome abnormality. In cases of congenital heart disease, patients required prolonged pediatric intensive care unit stays and bladder catheterization, which increased their susceptibility to B. cepacia UTI. In addition, immunocompromised oncology patients have been reported to be susceptible to B. cepacia infection [8].

Burkholderia cepacia is a multidrug-resistant organism, and therapeutic options are limited [1]. Although trimethoprim-sulfamethoxazole has been the drug of choice, it is difficult to administer because of hypersensitivity, lack of availability, and resistance in some cases. Avgeri et al. reported that ceftazidime, meropenem, and piperacillin, either alone or in combination, may be used as alternative options in B. cepacia infections [1]. Patra et al. reported that piperacillin-tazobactam, ciprofloxacin, and trimethoprim-sulfamethoxazole, either alone or in combination, could result in complete recovery of B. cepacia sepsis in neonates. The highest susceptibility was observed with meropenem [4]. In our study, piperacillin-tazobactam, ceftazidime, trimethoprim-sulfamethoxazole, levofloxacin, and meropenem were used in the majority of cases. All patients experienced complete recovery from UTI. In our study, the highest susceptibility was observed with piperacillin-tazobactam and trimethoprim-sulfamethoxazole. Importantly, there was 100% resistance to amikacin and colistin. Even so, Li et al. reported a case of B. cepacia UTI after renal transplantation that required a graft nephrectomy because B. cepacia showed in vivo resistance to all available antimicrobial agents, and long-term use of piperacillin could not resolve the septic foci [9]. Because of such antimicrobial resistance, a combination of antimicrobial agents and surgical treatment in some cases may be required.

Burkholderia cepacia is a pathogen with intrinsic resistance to numerous antimicrobial agents that causes nosocomial UTI in pediatric patients with risk factors such as prolonged genitourinary catheterization, VUR, congenital heart disease, or malignancy. Prompt removal of catheters and appropriate antimicrobial therapy for B. cepacia UTI in high-risk patients can ensure complete recovery. In addition, a surveillance program for nosocomial infection in intensive care units is necessary to prevent B. cepacia infections.