□ CASE REPORT □

CAPD Peritonitis Caused by Co- with Cellulosimicrobium cellulans (Oerskovia xanthineolytica)and Enterobacter cloacae: A Case Report and Literature Review

Jin Sug Kim 1, Tae Won Lee 1, Chun Gyoo Ihm 1,YuJinKim1, Song Mi Moon 1, Hee Joo Lee 2 and Kyung Hwan Jeong 1

Abstract

A 50-year-old woman with end-stage renal disease on continuous ambulatory peritoneal dialysis was ad- mitted with abdominal pain, fever and cloudy peritoneal fluid. The diagnosis was peritonitis, and the causa- tive were Cellulosimicrobium cellulans and Enterobacter cloacae. She was subsequently treated with the administration of intraperitoneal antibiotics and removal of the infected indwelling catheter. We herein re- port a case of Cellulosimicrobium cellulans and Enterobacter cloacae co-infection in a patient with peritoni- tis and review the relevant literature.

Key words: Oerskovia xanthineolytica, Cellulosimicrobium cellulans, Enterobacter cloacae, continuous ambulatory peritoneal dialysis, peritonitis, vancomycin

(Intern Med 54: 627-630, 2015) (DOI: 10.2169/internalmedicine.54.3261)

Introduction Case Report

Cellulosimicrobium cellulans (C. cellulans), formerly A 50-year-old woman with ESRD secondary to diabetes known as Oerskovia xanthineolytica, is a Gram-positive fila- mellitus was admitted to Kyung Hee University Medical mentous rod found primarily in soil and water. Infection Center, Seoul, South Korea via the emergency room due to with C. cellulans in humans is rare (1), with only approxi- abdominal pain. She had been undergoing CAPD for 15 mately 30 such case reports. These are more com- months and was on a regimen of 2-L exchanges three times mon in patients with a compromised immune function and/ per day. Her blood pressure was 160/90 mmHg, her heart or implanted medical devices, such as catheters, and few rate was 80 beats/min, her respiratory rate was 20 breaths/ cases have been reported as an uncommon cause of continu- min and; her temperature was 38.0℃. The peritoneal cathe- ous ambulatory peritoneal dialysis (CAPD) peritonitis. ter exit site was to the left of the midline and appeared nor- In this paper, we describe the case of a patient with end- mal. A laboratory investigation revealed the following find- stage renal disease (ESRD) who developed peritonitis ings: hemoglobin (Hb) =9.2 g/dL; hematocrit (Hct) =24.8%; caused by C. cellulans and Enterobacter cloacae (E. cloa- white blood cell count (WBC) =8,860/mm3 with a normal cae) due to an infected indwelling peritoneal dialysis cathe- differential; C-reactive protein (CRP) =9.7 mg/dL; and nor- ter. We also review the literature for other cases of mal liver enzymes (aspartate aminotransferase: 15 U/L, Oerskovia infection; and describe the common clinical fea- alanine aminotransferase: 11 U/L). A physical examination tures of these infections as well as implications for therapy. revealed a remarkable level of abdominal tenderness. The effluent peritoneal fluid was cloudy, with a WBC count of 12,500/mm3 (predominantly polymorphonuclear cells).

1Department of Internal Medicine, Kyung Hee University School of Medicine, Korea and 2Department of Laboratory Medicine, Kyung Hee University School of Medicine, Korea Received for publication May 12, 2014; Accepted for publication July 6, 2014 Correspondence to Dr. Kyung Hwan Jeong, [email protected]

627 Intern Med 54: 627-630, 2015 DOI: 10.2169/internalmedicine.54.3261

Figure 1. The API CORYNE system (bioMérieux, Lyon, France) identified the bacterium as Oer- skovia sp. The API Coryne biochemical strip keyed out the number 7572727, an excellent match for “Oerskovia xanthineolytica,” now known as Cellulosimicrobium cellulans.

strip identified the organism as number 7572727, Oerskovia xanthineolytica, now known as C. cellulans (2) (Fig. 1). On hospitalization day 12, a culture of the peritoneal fluid obtained on hospital days 9 and 10 yielded a Gram-positive organism identified microscopically and by 16S rRNA se- quencing as C. cellulans (Fig. 2). Although C. cellulans is a rare cause of human infection, we considered it to be a pathogen in this case due to the patient’s fever, elevated CRP level and leukocytosis despite the continuous admin- istration of intraperitoneal antibiotics and the persistence of the organism in subsequent peritoneal fluid cultures. There- fore, intraperitoneal vancomycin was administered in addi- Figure 2. Cellulosimicrobium cellulans Gram staining of a tion to ceftazidime and tobramycin. After C. cellulans was colony isolated on sheep blood agar. detected on a peritoneal fluid culture, the level of peritoneal WBCs increased to 261/mm3 (predominantly polymorphonu- clear cells). As C. cellulans is found primarily in soil and After performing a peritoneal fluid culture, the patient water, we attempted to determine the route of infection. was treated with intraperitoneal antibiotics, specifically cef- However, the patient lived in the city and stayed at home as tazidime and cefazolin. Two days after the start of antibiotic a housewife. She did not have any risk factors for contact therapy, the patient’s abdominal pain subsided and the peri- with soil or polluted water. toneal fluid became clear. On hospital day 4, a culture of After five days of treatment with intraperitoneal vancomy- the peritoneal fluid obtained on admission day revealed E. cin, a follow-up culture confirmed the elimination of all mi- cloacae, which was sensitive to ceftazidime, ciprofloxacin croorganisms, and the patient’s clinical symptoms resolved. and tobramycin and resistant to cefazolin. As a result, the In addition, the peritoneal WBC count decreased to less than antibiotic regimen was switched to intraperitoneal ceftaz- 100/mm3, without dominance of polymorphonuclear cells. idime and tobramycin. However, after 13 days of vancomycin (hospital day 25), C. Peritoneal fluid cultures obtained on hospital days 3 and 5 cellulans re-appeared on a peritoneal culture. The trough were free of organisms, as confirmed on an extended cul- level of vancomycin was 17.3 mg/mL, which satisfied the ture; therefore, treatment with intraperitoneal ceftazidime International Society of Peritoneal Dialysis guideline. Al- and tobramycin was continued. However, on hospital day 7, though the peritoneal WBC count did not increase, we con- the patient complained of a fever, with a body temperature sidered the antibiotic treatment to have failed due to bacte- of 38℃. Further laboratory tests showed an elevated CRP rial colonization of the surface of the peritoneal Tenckhoff level and leukocytosis. On hospital day 10, a culture of the catheter. Therefore, we decided to remove the catheter on peritoneal fluid (obtained on hospital day 7), which was in- day 27 hospitalization, and switch the treatment regimen to jected into a blood culture bottle [BacT/Alert blood culture hemodialysis. Consequently, a culture for bacteria on the system (bioMérieux, Lyon, France)], revealed organisms in- peritoneal catheter revealed C. cellulans, thus confirming itially identified as Gram-positive rods. In addition, cultures catheter infection to be the cause of the peritonitis. on blood agar showed yellow colonies within 24 hours of The intraperitoneal antibiotics were discontinued and van- incubation that were subsequently found to be catalase- comycin was administered intravenously for an additional positive and oxidase-negative. The API Coryne biochemical two weeks, while the patient continued to remain asympto-

628 Intern Med 54: 627-630, 2015 DOI: 10.2169/internalmedicine.54.3261

Figure 3. Brief summary of the patient’s clinical course and disease progression from admission. WBC: white blood cell count, CRP: C-reactive protein, HD: hospital day, E. cloacae: Enterobacter cloacae, IP: intraperitoneal, IV: intravenous

Discussion

The genus Cellulosimicrobium belongs to the suborder Micrococcineae,orderActinomycetales,classActinobacteria. It is composed of three , namely, C. cellulans, C. funkei and C. terreum (3, 4). These species are aerobic actinomycetes that appear as pleomorphic Gram-positive rods with rudimentary branching and exist naturally in soil, water and decaying plant material (5). They may be easily mistaken for Corynebacterium spp., common skin flora that may be considered contaminants on blood and other sterile body site cultures. Isolates from clinical specimens, -such as Figure 4. Growth of Cellulosimicrobium cellulans on a 5% blood and cerebrospinal fluid- found to be catalase-positive, sheep blood agar plate after 48 hours at 35°C under aerobic oxidase-negative and motile, producing a bright-yellow pig- conditions. The cultures on blood agar revealed yellow colonies ment, should be presumptively identified as Oerskovia spp., within 24 hours of incubation. This pigment is an important as the yellow pigment is a distinguishing characteristic of diagnostic characteristic. this species (Fig. 4). C. cellulans has been reported to be an uncommon cause of human infection, with only approximately 30 previous matic. case reports, including three of peritonitis (Table). The three No recurrence of abdominal signs or symptoms was noted previous cases of peritonitis caused by C. cellulans involved during the subsequent 12 months of follow-up. Fig. 3 pro- a 59-year-old diabetic woman, 70-year-old man and 13-year- vides a brief summary of the patient’s clinical course and old girl (6-8). All three patients were treated with intraperi- disease progression from the time of admission. toneal vancomycin, while the 59-year-old woman also re- ceived intramuscular tobramycin and oral doxycycline (6) and the man also received intramuscular gentamicin fol- lowed by the same antibiotics delivered intravenously upon

629 Intern Med 54: 627-630, 2015 DOI: 10.2169/internalmedicine.54.3261

Table. Oerskovia xanthineolytica CAPD Peritonitis Reported in the Medical Literature

Reference Age Sex Underlying Site of Treatment Foreign body conditions infection Removed? (6) 59 F DM, ESRD Peritonitis IP Vanco, No IM TOB, Oral DOX (7) 70 M ESRD Peritonitis IP Vanco, Yes IM GM (8) 13 F ESRD Peritonitis IP Vanco No Current 50 F DM, ESRD Peritonitis IP CFZ, Yes case IP TOB IP & IV Vanco DM: diabetes mellitus, ESRD: end-stage renal disease, IP: intraperitonia, IM: intramuscular, Vanco: vancomycin, TOB: tobramycin, DOX: doxycycline, GM: gentamicin, CFZ: ceftazidime catheter removal (7), whereas the 13-year-old girl’s symp- References toms resolved completely with vancomycin alone. (8) Although C. cellulans was not cultured on early admis- 1. McNeil MM, Brown JM. The medically important aerobic actino- sion in the present study, we believe that the patient had mycetes: epidemiology and microbiology. Clin Microbiol Rev 7: been co-infected with E. cloacae. Infection with a relatively 357-417, 1994. 2. Rowlinson MC, Bruckner DA, Hinnebusch C, Nielsen K, Deville small number of C. cellulans organisms may delay the diag- JG. Clearance of cellulosimicrobium cellulans bacteremia in a nosis. Although most case of CAPD peritonitis may be at- child without central venous catheter removal. J Clin Microbiol tributed to a single organism, multiple organisms are some- 44: 2650-2654, 2006. times identified, referred to as poly-microbial peritonitis. In 3. Schumann P, Weiss N, Stackebrandt E. Reclassification of Cellu- previous studies, the prevalence of poly-microbial peritonitis lomonas cellulans (Stackebrandt and Keddie 1986) as Cellulosimi- crobium cellulans gen. nov., comb. nov. Int J Syst Evol Microbiol in CAPD patients has been reported to be 10-16% (9). Poly- 51: 1007-1010, 2001. microbial peritonitis usually has a poor outcome with a sig- 4. Brown JM, Steigerwalt AG, Morey RE, Daneshvar MI, Romero nificantly high frequency of hospitalization, catheter loss LJ, McNeil MM. Characterization of clinical isolates previously and permanent hemodialysis transfer (10). However, recent identified as Oerskovia turbata: proposal of Cellulosimicrobium large-scale studies have revealed that most patients with funkei sp. nov. and emended description of the genus Cellulosimi- crobium. Int J Syst Evol Microbiol 56: 801-804, 2006. poly-microbial peritonitis exhibit a good response to antibi- 5. Lechevalier MP. Description of a new species, Oerskovia xan- otics (11). Poly-microbial peritonitis resulting from contami- thineolytica, and emendation of Oerskovia prauser et al. Int J Syst nation generally resolves with antibiotic therapy without Bacteriol 22: 260-264, 1972. catheter removal, unless the catheter is the source of the in- 6. Borra S, Kleinfeld M. Peritonitis caused by Oerskovia xan- fection (12). thineolytica in a patient on chronic ambulatory peritoneal dialysis Although the present patient was asymptomatic following (CAPD). Am J Kidney Dis 27: 458, 1996. 7. Rihs JD, McNeil MM, Brown JM, Yu VL. Oerskovia xan- the initial treatment and received intraperitoneal vancomycin thineolytica implicated in peritonitis associated with peritoneal di- continuously, C. cellulans was identified in the peritoneal alysis: case report and review of Oerskovia infections in humans. fluid collected after many days of hospitalization. We be- J Clin Microbiol 28: 1934-1937, 1990. lieved the catheter to be the source of the infection, and re- 8. Lujan-Zilbermann J, Jones D, DeVincenzo J. Oerskovia xan- moval of the Tenckhoff catheter was consequently required thineolytica peritonitis: case report and review. Pediatr Infect Dis J 18: 738-739, 1999. in order to resolve the infection. 9. Kim GC, Korbet SM. Polymicrobial peritonitis in continuous am- With the increase in the number of immunocompromised bulatory peritoneal dialysis patients. Am J Kidney Dis 36: 1000- patients and the popularity of long-term indwelling catheters 1008, 2000. and prostheses, the potential for infections with opportunis- 10. Barraclough K, Hawley CM, McDonald SP, et al. Polymicrobial tic pathogens deserves further attention. In patients in whom peritonitis in peritoneal dialysis patients in Australia: predictors, treatment, and outcomes. Am J Kidney Dis 55: 121-131, 2010. C. cellulans is isolated, we recommend the administration of 11. Lin YC, Lin WP, Huang JY, Lee SY. Polymicrobial peritonitis fol- vancomycin therapy and removal of infected indwelling de- lowing colonoscopic polypectomy in a peritoneal dialysis patient. vices, if possible, in order to achieve a complete recovery. Intern Med 51: 1841-1843, 2012. 12. Li PK, Szeto CC, Piraino B, et al. Peritoneal dialysis-related in- The authors state that they have no Conflict of Interest (COI). fections recommendations: 2010 update. Perit Dial Int 30: 393- 423, 2010.

Ⓒ 2015 The Japanese Society of Internal Medicine http://www.naika.or.jp/imonline/index.html

630