Jpn. J. Infect. Dis., 68, 50–54, 2015 Original Article Bacteremia Caused by Pseudomonas luteola in Pediatric Patients Gulsum Iclal Bayhan1*, Saliha Senel2,4, Gonul Tanir1, and Sengul Ozkan3 1Department of Pediatric Infectious Disease, 2Department of Pediatrics, and 3Department of Clinical Microbiology and Infectious Disease, Dr. Sami Ulus Maternity and Children's Health Education and Research Hospital; and 4Department of Pediatrics, Yƒldƒrƒm Beyazit University, Ankara, Turkey SUMMARY: Pseudomonas luteola has rarely been reported as a human pathogen. The clinical mani- festations of P. luteola bacteremia and its susceptibility to antibiotics have not been characterized. This retrospective study was conducted at a 382-bed tertiary care center in Turkey. During the 9-year study period, 7 patients (5 females and 2 males) were diagnosed with P. luteola bacteremia. Six of these patients had hospital-acquired bacteremia, whereas 1 patient had community-acquired P. luteola infec- tion. All patients had monomicrobial bacteremia. Antimicrobial susceptibility testing revealed that all strains of P. luteola were sensitive to amikacin, gentamicin, trimethoprim-sulfamethoxazole, and meropenem, and that all strains were resistant to piperacillin-tazobactam, aztreonam, and colistin. In conclusion, we believe that P. luteola can cause both community- and hospital-acquired bacteremia. Amikacin, gentamicin, trimethoprim-sulfamethoxazole, and meropenem were effective against P. lu- teola in the present study. tion of antibiotic treatment because of clinical deterio- INTRODUCTION ration or antibiogram results, duration of antibiotic Pseudomonas luteola, which is also called Chryseo- treatment, and treatment outcome. monas luteola, is a nonfermenting gram-negative bac- P. luteola bacteremia was diagnosed based on the iso- terium that was previously classified in US Centers for lation of bacterium in 1 peripheral blood cultures. Disease Control and Prevention group Ve-1. P. luteola Bacteremia was considered hospital-acquired if it oc- is rarely reported as human pathogen, and the literature curred 48 h after hospital admission. Community- includes only a few cases of infection by this bacterium acquired infection was defined as bacteremia that oc- (1,2). The present study aimed to determine the clinical curred within the first 48 h after hospital admission characteristics, antibiotic susceptibility, treatment regi- without exposure to a healthcare facility. Bacterial mens, and outcomes in 7 pediatric patients with P. lu- growth was detected in blood cultures using a teola bacteremia. BacT/Alert3D automated system (bioMerieux,Á Marcy l'Etoile, France). The organism with slow growth and the presence of small yellow-orange colonies on eosin MATERIALS AND METHODS methylene blue agar and blood agar after 48 h incuba- This study was conducted at Dr. Sami Ulus Maternity tion were considered in the identification process. It was and Children's Health and Diseases Research and Edu- identified as catalase-positive and oxidase-negative in cation Hospital, a 382-bed tertiary care center in standard biochemical tests. It utilized glucose, man- Ankara, Turkey. The study included patients aged 1 nitol, and maltose oxidatively; hydrolyzed esculin; and month–18 years who developed P. luteola bacteremia reduced nitrates to nitrites. It did not decarboxylate ly- between January 2005 and November 2013. The sine, did not hydrolyze urea, and did not produce in- patients' medical records were reviewed. The following doles. Identification of P. luteola was performed using variables were analyzed patients' age and gender, pri- the Vitek 2 (bioMerieux) automated system. The suscep- mary diagnosis, peripheral blood leukocyte count and tibility of bacterial isolates to antimicrobial agents was serum C-reactive protein (CRP) level at the time blood initially determined via the routine disk diffusion culture was obtained, use of total parenteral nutrition, method, according to the guidelines of the Clinical and central vascular access and mechanical ventilation for Laboratory Standards Institute's guideline for other ＞48 h, duration of hospitalization prior to bacteremia, non-Enterobacteriaceae (3). Bacterial isolates were test- number of positive blood cultures, antimicrobial sus- ed using the following antimicrobials: amikacin; gen- ceptibility profile, empirical antibiotic regimen, altera- tamicin; aztreonam; ceftriaxone; ceftazidime; cefoper- azone-sulbactam; ciprofloxacin; imipenem; piperacil- Received February 3, 2014. Accepted June 16, 2014. lin; piperacillin-tazobactam; and trimethoprim-sul- J-STAGE Advance Publication November 25, 2014. famethoxazole. Statistical analysis was performed using DOI: 10.7883/yoken.JJID.2014.051 SPSS v.15.0 for Windows (SPSS, Inc., Chicago, IL, *Corresponding author: Mailing address: Department of USA). Pediatric Infectious Disease, Dr. Sami Ulus Maternity and Children's Health Education and Research Hospital, RESULTS Babur caddesi, No: 44 (06080), Altindag, Ankara, Turkey. Tel: ＋90 312 305 65 45, Fax: ＋90 312 317 03 53, E-mail: During the 9-year study period, 7 patients (5 females gibayhan＠gmail.com and 2 males) were diagnosed with P. luteola bacteremia. 50 Bacteremia Caused by Pseudomonas luteola The mean age of the patients was 44 ± 40.8 months pies and alterations to the treatment regimens based on (median: 24 months; range: 11–105 months). All the results of drug susceptibility testing of P. luteola iso- patients were febrile when blood was obtained for cul- lates are presented in Table 2. ture. Two patients had a central vascular catheter at the Recurrent P. luteola bacteremia occurred in 1 patient time of bacteremia, and 1 patient was receiving mechan- (case no. 4). Although this patient was being followed- ical ventilation before P. luteola bacteremia developed. up in the hospital for a diagnosis of Miller-Dieker syn- Three patients (42.8z) had leukocytosis (＞15,000 leu- drome, fever and respiratory distress developed, and kocytes/mL), and 5 patients (71.4z) had an elevated respiratory support with mechanical ventilation was re- CRP level (＞10 mg/dL) at the time of obtain blood cul- quired. His CRP level and leukocyte count were ex- ture. All patients had monomicrobial bacteremia, as tremely elevated, and chest radiography revealed there were no cases of concomitant microorganism in- bilateral infiltration. Colistin was added to the initial fection. The clinical characteristics of 7 patients with P. antibiotic treatment following a diagnosis of nosocomi- luteola bacteremia are shown in Table 1. al pneumonia. P. luteola was cultured in blood that was Six patients had hospital-acquired bacteremia, with a obtained at the beginning of the patient's febrile period. median interval from hospitalization to the develop- After 48 h, P. luteola was again isolated in the second ment of bacteremia of 13 days, whereas 1 patient had blood culture while the patient was receiving colistin community-acquired P. luteola infection; she had pro- treatment. As colistin-resistant P. luteola was identified tein-losing enteropathy and presented with a fever of in both blood cultures, colistin was withdrawn, and the 38.39C, vomiting, and diarrhea. Initial empirical thera- patient was treated with imipenem. Table 1. Summary of demographic data, comorbidities, clinical characteristics, and length of hospital stay of 7 patients with Pseudomonas luteola bacteremia Age Hospitalization Single/multiple Acquired Clinical positive blood Case (mo)/ Year Primary disease source TPN/CVL/MV situation day on positive Gender culture obtained culture 1 105/F 2011 Miller Fisher syndrome Hospital －/－/－ Bacteremia 13 Single 2 11/F 2011 Congenital hypophospatasia, Hospital / / Bacteremia 126 Single malnutrition － － ＋ 3 14/F 2011 Protein-losing enteropathy Community －/－/－ Bacteremia 0 Single 4 72/M 2011 Miller-Dieker syndrome Hospital / / Pneumonia, 49 2 ＋ ＋ － bacteremia 5 19/F 2010 Infantile spasm Hospital －/－/－ Bacteremia 7 Single 6 29/M 2010 Tetralogy of Fallot Hospital －/＋/－ Bacteremia 10 Single 7 86/F 2007 Meningomyelocele Hospital －/－/－ Bacteremia 24 Single TPN, total parenteral nutrition; CVL, central vascular line; MV, mechanic ventilation. Table 2. Summary of treatment regimen, treatment duration, and outcome Empirical antibiotic Appropriate/ Antibiotic Treatment Case First-line antibiotic treatment during Inappropriate treatment after Outcome treatment bacteremia therapy culture result duration 1 CTX, CD IMP App IMP 23 Survived 2 CAZ, COLI, LZD IMP App IMP 24 Died 3 CTR, AK IMP App IMP 10 Survived 4 PTZ, VA COLI Inapp IMP 34 Survived 5 CEF MERZ App MERZ 14 Survived 6 AS IMP App IMP 7 Survived 7 VA, AK MERZ App MERZ 21 Discharge App/Inapp, appropriate/inappropriate; CTRX, ceftriaxone; CD, clindamycin; CAZ, ceftazidime; COLI, colistin; LZD, linezolid; AK, amikacin; PTZ, piperacillin-tazobactam; VA, vancomycin; AS, ampicillin-sulbactam; MERZ, meropenem; IMP, imipenem. Table 3. Antimicrobial susceptibility of Pseudomonas luteola isolates Case PI AZT CAZ CTX CP IMP STX AK PTZ GM CPZ COLI 1RRRSSSSSRSRR 2RRRNSSSSRSNN 3NRRNRSSSRSRR 4RRRSSSSSRSNR 5SRRNSSSSRSSR 6NRRSSSSSNSNN 7SNSSSSSSNSNN PI, piperacillin; AZT, aztreonam; SXT, trimethoprim-sulfamethoxazole; CP, ciprofloxacin; GM, gentamicin; CPZ, cephoperazon-sulbac- tam; N, not performed; R, resistant; S, susceptible. 51 Antimicrobial susceptibility testing illustrated that all oped P. luteola bacteremia on the 126th day of hospi- strains of P. luteola were sensitive to amikacin, gen- talization died. Although this patient