- Email: [email protected]
Empyema caused by Ralstonia pickettii in a hemodialysis patient
Case Report
Empyema Caused by Ralstonia pickettii in a Hemodialysis Patient Todd S. Wills, M.D.,1 Joanna Lopez,2 and Alicia R. Billington,3 1Assistant Professor of Internal Medicine, Division of Infectious Diseases and International Medicine, University of South Florida College of Medicine, Tampa, Florida, 2Undergraduate, University of Miami, Coral Gables, Florida, 3Undergraduate, Cornell University, Ithaca, New York
Introduction Ralstonia pickettii is a gram-negative, oxidase-positive bacillus. Bacteremia has been reported in association with invasive devices, as well as contaminated intravenous solutions. Although it is typically a low-virulence organism, we report a case of an empyema caused by R. pickettii in a patient requiring chronic hemodialysis.
Case Report A 41-year-old man with multiple medical problems presented to the emergency room with vomiting, diarrhea, and fever. His medical history was notable for diabetes mellitus, end-stage renal disease requiring hemodialysis for 18 months, and chronic pancreatitis with pseudocysts requiring drainage twice previously. His initial physical examination revealed a temperature of 103.5ºF; blood pressure, 150/76 mm Hg; respiratory rate, 19 breaths/min; and pulse, 120 beats/min. Blood cultures drawn on admission grew coagulasenegative staphylococci. The patient’s hemodialysis catheter was removed, and his fever initially resolved; however, fever returned within 10 days. Evaluation for a source of the fever demonstrated a left-sided pleural effusion on chest X ray. A thoracic CT scan revealed a loculated effusion and reactive lymphadenopathy. A thoracentesis
Mailing Address: Todd S. Wills, M.D., Division of Infectious Diseases, Tampa General Hospital, Box 1289, Tampa, FL 33601. Tel.: 813-844-4187. Fax: 813844-7605. E-mail: [email protected]
Clinical Microbiology Newsletter 29:7,2007
was performed, and the pleural fluid grew R. pickettii. The effusion persisted despite chest tube drainage, and surgical decortication was eventually performed. The patient received an antibiotic course of intravenous cefepime for 28 days and oral ciprofloxacin for 42 days. A repeat thoracic CT scan performed 1 month later revealed resolution of the pleural effusion and lymphadenopathy. The patient remained free of fevers and respiratory symptoms following treatment.
Discussion R. pickettii was first isolated in 1973 and included in the genus Pseudomonas. The species name pickettii was given to this aerobic, non-fermentative, gramnegative bacterium, recognizing M.J. Pickett, who first collected the strains (1). The rod-shaped organism was reclassified in the Burkholderia and then the Ralstonia genera, receiving its current name in 1995 in tribute to E. Ralston, the American biologist who first described R. pickettii (2). R. pickettii is often confused with other similar bacteria, increasing the difficulty of classifying and treating the pathogen. Despite the complexity of identifying R. pickettii, several nosocomial outbreaks have been attributed to the bacterium. The organism has been isolated in sputum cultures of cystic fibrosis patients (3), infected intravenous catheter sites (4), and in the blood of patients receiving intravenous infusions contaminated with the organism (5). This is the first documented case of an empyema caused by R. pickettii. R. pickettii is an emerging pathogen, © 2007 Elsevier
with most infections described in hospital settings. It is ubiquitous in nature and is found naturally in soil and groundwater. Several characteristics of the bacterium are used to aid in its identification. The organism is an oxidase- and catalase-positive bacterium that exists primarily as single cells or short chains. The optimal temperature for growth of R. pickettii is 35°C. Even under these conditions, the rate of growth is low, with characteristic, barely apparent, opaque colonies growing after 1 day of incubation (6). R. pickettii is often misidentified as related species, including Pseudomonas fluorescens and Burkholderia cepacia (7), all of which initially were classified in the genus Pseudomonas. Definitive identification may be facilitated through use of a PCR assay with a primer obtained from the 16S rRNA gene of R. pickettii (3). Common-source outbreaks of R. pickettii, a water-based organism, have been reported. Kahan et al. described a cluster of R. pickettii bacteremias traced to contaminated distilled water used to prepare a chlorhexidine solution for intravenous-site sterilization (8). In 1985, Verschraegen et al. reported on several cases of pseudobacteremia in which the primary source of contamination was 0.05% chlorhexidine aqueous solution used when drawing blood for culture (1). More recently, Maki et al. described a cluster of nosocomial R. pickettii bacteremias ultimately linked to fentanyl citrate vials contaminated through narcotic theft by health care personnel (5). Human infection unrelated to conta0196-4399/00 (see frontmatter)
55
minated solutions is rare. Isolation of the organism in culture alone is often attributed to laboratory contamination rather than to infection. True infection is more likely when treatment targeting the organism and/or removal of an infected source is associated with clinical improvement. A recently reported case of R. pickettii venous catheter infections in a pediatric oncology unit described clinical improvement only with catheter removal and appropriate antimicrobial therapy (4). In this case, isolation of R. pickettii in culture from a sterile site coupled with clinical improvement following decortication and targeted antimicrobial therapy increases the likelihood that the organism was a true pathogen. Antimicrobial susceptibility patterns reported for R. pickettii vary widely. In this case, the R. pickettii isolate was susceptible to ceftazidime, cefoperazone, ciprofloxacin, imipenem, mezlocillin, and piperacillin. The pathogen was resistant to amikacin, aztreonam, gentamicin, tobramycin, ticarcillin, and ticarcillin/clavulanic acid. The isolate’s resistance to all aminoglycosides tested is unusual for a gram-negative bacterium.
56
0196-4399/00 (see frontmatter)
In this case, the empyema was successfully treated by using oral ciprofloxacin for 6 weeks and intravenous cefepime for 28 days. R. pickettii is an emerging pathogen in the hospital setting. Although the organism is of low virulence and has not yet been reported as a cause of death, nosocomial outbreaks related to common water sources are of particular concern to hospital epidemiologists. This case demonstrates an R. pickettii infection in the absence of an obvious nosocomial source. It is possible that such de novo cases will become more common with the increasingly complex care for patients with multiple co-morbidities. References 1. Verschraegen, G. et al. 1985. Pseudomonas pickettii as a cause of pseudobacteremia. J. Clin. Microbiol. 21:278-279. 2. Yabuuchi, E. et al. 1995. Transfer of two Bulkholderia and an Alcaligenes species to Ralstonia gen. nov.: proposal of Ralstonia pickettii (Ralston, Palleroni and Doudoroff 1973) comb. nov., Ralstonia solanacearum (Smith 1896) comb. nov. and Ralstonia eutropha (Davis 1969)
© 2007 Elsevier
comb. nov. Microbiol. Immunol. 39:897-904. 3. Coenye, T., P. Vandamme, and J.J. LiPuma. 2002. Infection by Ralstonia pickettii in cystic fibrosis patients: identification of R. pickettii and R. mannitolilytica by polymerase chain reaction. Emerg. Infect. Dis. 8:692-696. 4. Kismet, E. et al. 2005. Two cases of Ralstonia pickettii bacteremias in a pediatric oncology unit requiring removal of the Port-A-Caths. J. Pediatr. Hematol. Oncol. 27:37-38. 5. Maki, D. et al. 1991. Nosocomial Pseudomonas pickettii bacteremias traced to narcotic tampering. JAMA 265:981-986. 6. Bruins, M.R., S. Kapil, and F.W. Oehme. 2000. Pseudomonas pickettii: a common soil and groundwater aerobic bacteria with pathogenic and biodegradation properties. Ecotoxicol. Environ. Safety 47:105-111. 7. Riley, P.S. and R.E. Weaver. 1975. Recognition of Pseudomonas pickettii in the clinical laboratory: biochemical characterization of 62 strains. J. Clin. Microbiol. 1:61-64. 8. Kahan, A. et al. 1983. Nosocomial infections by chlorhexidine solution contaminated with Pseudomonas pickettii (biovar Va-1). J. Infect. 7:256-263.
Clinical Microbiology Newsletter 29:7,2007
Empyema Caused by Ralstonia pickettii in a Hemodialysis Patient Todd S. Wills, M.D.,1 Joanna Lopez,2 and Alicia R. Billington,3 1Assistant Professor of Internal Medicine, Division of Infectious Diseases and International Medicine, University of South Florida College of Medicine, Tampa, Florida, 2Undergraduate, University of Miami, Coral Gables, Florida, 3Undergraduate, Cornell University, Ithaca, New York
Introduction Ralstonia pickettii is a gram-negative, oxidase-positive bacillus. Bacteremia has been reported in association with invasive devices, as well as contaminated intravenous solutions. Although it is typically a low-virulence organism, we report a case of an empyema caused by R. pickettii in a patient requiring chronic hemodialysis.
Case Report A 41-year-old man with multiple medical problems presented to the emergency room with vomiting, diarrhea, and fever. His medical history was notable for diabetes mellitus, end-stage renal disease requiring hemodialysis for 18 months, and chronic pancreatitis with pseudocysts requiring drainage twice previously. His initial physical examination revealed a temperature of 103.5ºF; blood pressure, 150/76 mm Hg; respiratory rate, 19 breaths/min; and pulse, 120 beats/min. Blood cultures drawn on admission grew coagulasenegative staphylococci. The patient’s hemodialysis catheter was removed, and his fever initially resolved; however, fever returned within 10 days. Evaluation for a source of the fever demonstrated a left-sided pleural effusion on chest X ray. A thoracic CT scan revealed a loculated effusion and reactive lymphadenopathy. A thoracentesis
Mailing Address: Todd S. Wills, M.D., Division of Infectious Diseases, Tampa General Hospital, Box 1289, Tampa, FL 33601. Tel.: 813-844-4187. Fax: 813844-7605. E-mail: [email protected]
Clinical Microbiology Newsletter 29:7,2007
was performed, and the pleural fluid grew R. pickettii. The effusion persisted despite chest tube drainage, and surgical decortication was eventually performed. The patient received an antibiotic course of intravenous cefepime for 28 days and oral ciprofloxacin for 42 days. A repeat thoracic CT scan performed 1 month later revealed resolution of the pleural effusion and lymphadenopathy. The patient remained free of fevers and respiratory symptoms following treatment.
Discussion R. pickettii was first isolated in 1973 and included in the genus Pseudomonas. The species name pickettii was given to this aerobic, non-fermentative, gramnegative bacterium, recognizing M.J. Pickett, who first collected the strains (1). The rod-shaped organism was reclassified in the Burkholderia and then the Ralstonia genera, receiving its current name in 1995 in tribute to E. Ralston, the American biologist who first described R. pickettii (2). R. pickettii is often confused with other similar bacteria, increasing the difficulty of classifying and treating the pathogen. Despite the complexity of identifying R. pickettii, several nosocomial outbreaks have been attributed to the bacterium. The organism has been isolated in sputum cultures of cystic fibrosis patients (3), infected intravenous catheter sites (4), and in the blood of patients receiving intravenous infusions contaminated with the organism (5). This is the first documented case of an empyema caused by R. pickettii. R. pickettii is an emerging pathogen, © 2007 Elsevier
with most infections described in hospital settings. It is ubiquitous in nature and is found naturally in soil and groundwater. Several characteristics of the bacterium are used to aid in its identification. The organism is an oxidase- and catalase-positive bacterium that exists primarily as single cells or short chains. The optimal temperature for growth of R. pickettii is 35°C. Even under these conditions, the rate of growth is low, with characteristic, barely apparent, opaque colonies growing after 1 day of incubation (6). R. pickettii is often misidentified as related species, including Pseudomonas fluorescens and Burkholderia cepacia (7), all of which initially were classified in the genus Pseudomonas. Definitive identification may be facilitated through use of a PCR assay with a primer obtained from the 16S rRNA gene of R. pickettii (3). Common-source outbreaks of R. pickettii, a water-based organism, have been reported. Kahan et al. described a cluster of R. pickettii bacteremias traced to contaminated distilled water used to prepare a chlorhexidine solution for intravenous-site sterilization (8). In 1985, Verschraegen et al. reported on several cases of pseudobacteremia in which the primary source of contamination was 0.05% chlorhexidine aqueous solution used when drawing blood for culture (1). More recently, Maki et al. described a cluster of nosocomial R. pickettii bacteremias ultimately linked to fentanyl citrate vials contaminated through narcotic theft by health care personnel (5). Human infection unrelated to conta0196-4399/00 (see frontmatter)
55
minated solutions is rare. Isolation of the organism in culture alone is often attributed to laboratory contamination rather than to infection. True infection is more likely when treatment targeting the organism and/or removal of an infected source is associated with clinical improvement. A recently reported case of R. pickettii venous catheter infections in a pediatric oncology unit described clinical improvement only with catheter removal and appropriate antimicrobial therapy (4). In this case, isolation of R. pickettii in culture from a sterile site coupled with clinical improvement following decortication and targeted antimicrobial therapy increases the likelihood that the organism was a true pathogen. Antimicrobial susceptibility patterns reported for R. pickettii vary widely. In this case, the R. pickettii isolate was susceptible to ceftazidime, cefoperazone, ciprofloxacin, imipenem, mezlocillin, and piperacillin. The pathogen was resistant to amikacin, aztreonam, gentamicin, tobramycin, ticarcillin, and ticarcillin/clavulanic acid. The isolate’s resistance to all aminoglycosides tested is unusual for a gram-negative bacterium.
56
0196-4399/00 (see frontmatter)
In this case, the empyema was successfully treated by using oral ciprofloxacin for 6 weeks and intravenous cefepime for 28 days. R. pickettii is an emerging pathogen in the hospital setting. Although the organism is of low virulence and has not yet been reported as a cause of death, nosocomial outbreaks related to common water sources are of particular concern to hospital epidemiologists. This case demonstrates an R. pickettii infection in the absence of an obvious nosocomial source. It is possible that such de novo cases will become more common with the increasingly complex care for patients with multiple co-morbidities. References 1. Verschraegen, G. et al. 1985. Pseudomonas pickettii as a cause of pseudobacteremia. J. Clin. Microbiol. 21:278-279. 2. Yabuuchi, E. et al. 1995. Transfer of two Bulkholderia and an Alcaligenes species to Ralstonia gen. nov.: proposal of Ralstonia pickettii (Ralston, Palleroni and Doudoroff 1973) comb. nov., Ralstonia solanacearum (Smith 1896) comb. nov. and Ralstonia eutropha (Davis 1969)
© 2007 Elsevier
comb. nov. Microbiol. Immunol. 39:897-904. 3. Coenye, T., P. Vandamme, and J.J. LiPuma. 2002. Infection by Ralstonia pickettii in cystic fibrosis patients: identification of R. pickettii and R. mannitolilytica by polymerase chain reaction. Emerg. Infect. Dis. 8:692-696. 4. Kismet, E. et al. 2005. Two cases of Ralstonia pickettii bacteremias in a pediatric oncology unit requiring removal of the Port-A-Caths. J. Pediatr. Hematol. Oncol. 27:37-38. 5. Maki, D. et al. 1991. Nosocomial Pseudomonas pickettii bacteremias traced to narcotic tampering. JAMA 265:981-986. 6. Bruins, M.R., S. Kapil, and F.W. Oehme. 2000. Pseudomonas pickettii: a common soil and groundwater aerobic bacteria with pathogenic and biodegradation properties. Ecotoxicol. Environ. Safety 47:105-111. 7. Riley, P.S. and R.E. Weaver. 1975. Recognition of Pseudomonas pickettii in the clinical laboratory: biochemical characterization of 62 strains. J. Clin. Microbiol. 1:61-64. 8. Kahan, A. et al. 1983. Nosocomial infections by chlorhexidine solution contaminated with Pseudomonas pickettii (biovar Va-1). J. Infect. 7:256-263.
Clinical Microbiology Newsletter 29:7,2007