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Oerskovia xanthineolytica bacteremia in an Immunocompromised patient with pneumonia
259
DIAGN MICROBIOLINFECTDIS 1994;18:259-261
CASE REPORT
Oerskovia xanthineolytica Bacteremia in an I m m u n o c o m p r o m i s e d Patient with P n e u m o n i a Clifford L. McDonald, Kimberly Chapin-Robertson, S. Reeves Dill, and Roy L. Martino
Oerskovia species, which are Nocardia-like bacteria that have rarely been found to cause human disease, are usually found in association with a foreign body with removal of the infected focus being necessary for cure. We present a case of Oerskovia xanthineolytica bacteremia in a patient with metastatic breast cancer, community-acquired pneumonia, and a tunneled
subcutaneous central venous catheter. Although the actual source of the bacteremia in this case is not proven, this patient's presentation with apparent lobar pneumonia and her improvement on antibiotics without catheter removal suggest that Oerskovia may be capable of causing primary pulmonary infection in the immunocompromised host.
INTRODUCTION
have been associated with a foreign body in immunocompromised hosts, requiring removal of the foreign body for cure. We report a case of a 54-year-old patient undergoing chemotherapy for metastatic breast cancer who had a community-acquired pneumonia and Oerskovia bacteremia.
Oerskovia species are pleomorphic, Gram-positive Nocardia-like bacteria that have only rarely been im-
plicated as pathogens in humans. The organism may be distinguished from Nocardia species by the colonies' bright yellow-pigmented appearance on agar, motility, and lack of partial acid fastness. Differentiation from Corynebacterium species can be aided by hydrolysis of esculin and motility. Oerskovia species include Oerskovia xanthineolytica and Oerskovia turbata. Oerskovia xanthineolytica can be distinguished by its ability to hydrolyze xanthine and hypoxanthine, production of acid from melibiose and raffinose, and growth at 42°C (Lechevalier, 1972). To date, there have been <10 reports of human disease caused by Oerskovia species (Rihs et al., 1990; Truant et al., 1992). Most of these infections From the Division of InfectiousDiseases (C.L.M., S.R.D.); the Department of Pathologyand Microbiology(K.C.-R.);and the Division of Hematology/Oncology(R.L.M.), Universityof South Alabama, Mobile, Alabama, USA. Address reprint requests to Dr. R.L. Martino, Division of Hematology/Oncology,Universityof South Alabama, 414 CC/CB, Mobile, AL 36688-0002, USA. Received 5 November 1993; revised and accepted 3 February 1994. © 1994 Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010 0732-8893/94/$7.00
CASE REPORT A 54-year-old white woman with a history of metastatic breast cancer was admitted with a 2-week history of cough productive of green sputum and 2- to 3-day history of right-sided, pleuritic chest pain, progressive shortness of breath, malaise, and chills with fever to 101°F (38.3°C) orally. Twelve days prior to admission, she complained to her doctor about only a mild cough productive of green sputum. At that time, her chest radiograph was normal, but she was neutropenic with a total white blood cell (WBC) count of 1000/mm 3 with 34% neutrophils. She was prescribed a 10-day course of lomefloxacin for bronchitis. Her condition worsened despite therapy, with development of shortness of breath, chest pain, and fever and chills. Her past medical history was significant for stage-Ill infiltrating ductal carcinoma of the right breast status post a right modified radical mastectomy with positive axillary lymph nodes 5 years
C.L. McDonald et al.
260
prior to this admission. Despite adjuvant chemotherapy and tamoxifen, she developed locally recurrent disease 1 year after diagnosis and metastatic disease 3 years later. Chemotherapy resulted in initial stabilization of her disease. However, 5 months prior to the present admission, progressive disease in bone and liver became evident, and the patient agreed to another course of palliative chemotherapy. Her Groshong catheter was placed in the left subclavian vein 4 months before admission, and her most recent course of chemotherapy was given 31 days before admission. On admission, the patient's temperature was 100.2°F (37.9°C) orally, pulse 115, and other vital signs were normal. She had no oral lesions. No heart murmurs or gallops were present. There were decreased breath sounds in the right lower lung field with crackles present. The Groshong catheter exit site was unremarkable, and the abdominal exam was normal. Her WBC count was 10,900/mm 3 with a predominance of polymorphonuclear leukocytes. A urinalysis revealed moderate pyuria and bacteruria with many epithelial cells. A urine culture grew 10,000-50,000 colony-forming units/ml of mixed Gram-positive flora. A computerized tomogram of the chest and abdomen performed just prior to admission to assess disease status demonstrated right lower lobe consolidation with a small right pleural effusion. The sputum Gram stain was an inadequate sample with ~25 WBCs per low-power field and numerous squamous epithelial cells. The patient was begun on cefuroxime 750 mg intravenously (i.v.) every 8 h for a community-acquired pneumonia. Over the next 48 h, her temperature normalized and her pulmonary symptoms resolved. On hospital day 3, blood cultures from the day of admission (one drawn peripherally and two via the central catheter) were growing Gram-positive rods. The patient was switched to vancomycin 1 g i.v. every 12 h. On hospital day 5, a venogram through the catheter was performed, the results of which were normal. The three sets of blood cultures were submitted in BACTEC blood culture bottles with growth detected at 36 h in the aerobic bottles from all three sets using a BACTEC 660 blood-culturing system (Becton-Dickinson, Cockeysville, MD, USA). Isolates from all three cultures were identical with Gram stains from the bottles s h o w i n g Grampositive rods with possible branching. A partial acid-fast stain was negative. Pellets obtained from centrifuging the broth from the BACTECbottles were subcultured onto routine media. Growth at 24 h on the aerobic blood agar showed yellow-pigmented colonies that were nonhemolytic and catalase positive. A Corynestrip (API, Plainview, NY, USA) was inoculated according to the manufacturer's instructions and incubated for 18 h at 35°C in air. The
Corynestrip was interpreted as an Oerskovia species (excellent identification) based on the code compendium generated. Susceptibility test results were generated by both disk diffusion testing as well as broth dilution testing for minimum inhibitory concentrations (MICs) using a Sensititre plate (Radiometer, Westlake, OH, USA). The results of susceptibility tests generated from each of these methods were in agreement. The MICs are listed in Table 1. The isolate was subsequently sent to the Alabama State Laboratory for specific species identification. Based on the isolate's ability to hydrolyze xanthine and hypoxanthine as well as its ability to grow at 42°C, it was identified as Oerskovia xanthineolytica. The patient received a 14-day course of i.v. vancomycin without catheter removal. Repeat blood cultures on day 4 of vancomycin therapy as well as at 48 and 72 h after the completion of therapy were all negative. Clearing of the pulmonary infiltrate on a follow-up outpatient chest radiograph was documented. The patient's condition has been followed for 6 months as an outpatient without recurrent bacteremia. DISCUSSION
Oerskovia species are Gram-positive organisms that demonstrate branching and filamentous morphology when grown on solid media. The organism may fragment into small, motile rodlike elements when they are recovered in liquid media. First described by Orskov in 1938 as a motile Nocardia species, it was originally isolated from soil and later dry-grass cuttings (Lechevalier, 1972). Although it is an organism of low virulence, a total of 35 human clinical isolates of Oerskovia species were submitted to the Centers for Disease Control in Atlanta, Georgia, over a 20-year period prior to 1977, yet clinical deTABLE 1
Minimum Inhibitory Concentrations (MICs)
Antibiotic Penicillin Ampicillin Oxacillin Cephalothin Erythromycin Clindamycin Ciprofloxacin Tetracycline TMP-SMXa Vancomycin Gentarnicin Imipenem Rifampin Chloramphenicol
MIC (p~g/ml) 2 4 > 32 4 1 2 1 1 <0.25/4.75 <0.5 2 2 <0.5 <4
aTrimethoprim-sulfamethoxazole.
Interpretation Resistant Resistant Resistant Susceptible Moderately susceptible Moderately susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible
Oerskovia Bacteremia
tails were not available (Sottnek et al., 1977). These included five heart valve or cardiac isolates, nine blood isolates, and one cerebrospinal fluid isolate as well as isolates from various other sites. Eight case reports in which Oerskovia species were implicated as causing disease in humans have been published, including four cases with bacteremia. The first seven of these have been reviewed (Rihs et al., 1990). Since their review, one case of Oerskovia xanthineolytica bacteremia has been reported complicating a patient hospitalized for bleeding esophageal varices and methicillin-resistant Staphylococcus bacteremia without an identified focus of infection (Truant et al., 1992). Nearly all previous reports, similar to our case, occurred in immunocompromised hosts. In at least six of the previous eight cases, this organism gained entry into the body through the presence of foreign bodies, including a homograft heart valve, a metallic object lodged in the eye, a ventriculoperitoneal shunt, a peritoneal catheter, and two cases associated with long-term central venous catheters. The cases without related foreign bodies include the case of bacteremia noted above without an identified focus (Truant et al., 1992) and the case of a patient who underwent nephrectomy for a pyogenic infection associated with impacted stones (Cruickshank et al., 1979). In five of the six foreign-body infections, cure occurred with removal of the foreign body. The case in which cure was effected without foreign-body removal was a bacteremia following infusion of contaminated home total parenteral nutrition solution
261
through a long-term central venous catheter (Guss and Ament, 1989). It seems unlikely that an established catheter infection was present in that case. Another case of Oerskovia bacteremia (O. turbata) that was more clearly venous catheter related failed antibiotic therapy alone, requiring catheter removal (LeProwse et al., 1989). That case was treated with amikacin after the organism was initially misidentifled as Nocardia and the patient had a known allergy to sulfonamide drugs. The last four reported cases of human infection (including this case) have been successfully treated with vancomycin. The etiology of the Oerskovia bacteremia in the present case cannot be determined with certainty since lower respiratory tract cultures were not obtained. However, positive blood cultures in the setting of acute pneumonia are considered definitive proof of the etiology of an associated pneumonia (Donowitz and Mandell, 1990). The fact that our patient grew an organism that is not usually pathogenic may be explained by her metastatic breast cancer, chemotherapy, and preceding neutropenia. A catheter-associated bacteremia cannot be excluded especially since less virulent organisms, including Oerskovia, can cause bacteremia in this setting. Catheter-associated bacteremia, however, does not explain our patient's acute lobar pneumonia, and two simultaneous infections would have to be postulated. In addition, the bacteremia cleared easily without catheter removal and has not recurred in 6 months. We feel that Oerskovia species may be identified in the future as rare causes of pneumonia in other immunocompromised hosts.
REFERENCES Cruickshank JG, Gawler AH, Shaldon C (1979) Oerskovia species: rare opportunistic pathogens. J Med Microbiol 12:513-515. Donowitz GR, Mandell GL (1990) Acute pneumonia. In Principles and Practice of Infectious Diseases. Eds, GL Mandell, RG Douglas, and JE Bennett. New York: Churchill Livingston, pp 540-555. Guss WJ, Ament ME (1989) Oerskovia infection caused by contaminated home parenteral nutrition solution. Arch Intern Med 149:1457-1458. Lechevalier MP (1972) Description of a new species, Oerskovia xanthineolytica, and emendation of Oerskovia Prauser et al. Int ] Syst Bacteriol 22:260-264. LeProwse CR, McNeil MM, McCarty JM (1989) Catheter-
related bacteremia caused by Oerskovia turbata. J Clin Microbiol 27:571-572. Rihs JD, McNeil MM, Brown JM, Yu VL (1990) Oerskovia xanthineolytica implicated in peritonitis associated with peritoneal dialysis: case report and review of Oerskovia infections in humans. ] Clin Microbiol 28:1934-1937. Sottnek FO, Brown JM, Weaver RE, Carroll GF (1977) Recognition of Oerskovia species in the clinical laboratory: characterization of 35 isolates. Int J Syst Bacterio127:263270. Truant AL, Satishchandran V, Eisensteadt R, Richman P, McNeil MM (1992) Oerskovia xanthineolytica and methicillin-resistant Staphylococcus aureus in a patient with cirrhosis and variceal hemorrhage. Eur J Clin Microbiol Infect Dis 11:950-951.
DIAGN MICROBIOLINFECTDIS 1994;18:259-261
CASE REPORT
Oerskovia xanthineolytica Bacteremia in an I m m u n o c o m p r o m i s e d Patient with P n e u m o n i a Clifford L. McDonald, Kimberly Chapin-Robertson, S. Reeves Dill, and Roy L. Martino
Oerskovia species, which are Nocardia-like bacteria that have rarely been found to cause human disease, are usually found in association with a foreign body with removal of the infected focus being necessary for cure. We present a case of Oerskovia xanthineolytica bacteremia in a patient with metastatic breast cancer, community-acquired pneumonia, and a tunneled
subcutaneous central venous catheter. Although the actual source of the bacteremia in this case is not proven, this patient's presentation with apparent lobar pneumonia and her improvement on antibiotics without catheter removal suggest that Oerskovia may be capable of causing primary pulmonary infection in the immunocompromised host.
INTRODUCTION
have been associated with a foreign body in immunocompromised hosts, requiring removal of the foreign body for cure. We report a case of a 54-year-old patient undergoing chemotherapy for metastatic breast cancer who had a community-acquired pneumonia and Oerskovia bacteremia.
Oerskovia species are pleomorphic, Gram-positive Nocardia-like bacteria that have only rarely been im-
plicated as pathogens in humans. The organism may be distinguished from Nocardia species by the colonies' bright yellow-pigmented appearance on agar, motility, and lack of partial acid fastness. Differentiation from Corynebacterium species can be aided by hydrolysis of esculin and motility. Oerskovia species include Oerskovia xanthineolytica and Oerskovia turbata. Oerskovia xanthineolytica can be distinguished by its ability to hydrolyze xanthine and hypoxanthine, production of acid from melibiose and raffinose, and growth at 42°C (Lechevalier, 1972). To date, there have been <10 reports of human disease caused by Oerskovia species (Rihs et al., 1990; Truant et al., 1992). Most of these infections From the Division of InfectiousDiseases (C.L.M., S.R.D.); the Department of Pathologyand Microbiology(K.C.-R.);and the Division of Hematology/Oncology(R.L.M.), Universityof South Alabama, Mobile, Alabama, USA. Address reprint requests to Dr. R.L. Martino, Division of Hematology/Oncology,Universityof South Alabama, 414 CC/CB, Mobile, AL 36688-0002, USA. Received 5 November 1993; revised and accepted 3 February 1994. © 1994 Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010 0732-8893/94/$7.00
CASE REPORT A 54-year-old white woman with a history of metastatic breast cancer was admitted with a 2-week history of cough productive of green sputum and 2- to 3-day history of right-sided, pleuritic chest pain, progressive shortness of breath, malaise, and chills with fever to 101°F (38.3°C) orally. Twelve days prior to admission, she complained to her doctor about only a mild cough productive of green sputum. At that time, her chest radiograph was normal, but she was neutropenic with a total white blood cell (WBC) count of 1000/mm 3 with 34% neutrophils. She was prescribed a 10-day course of lomefloxacin for bronchitis. Her condition worsened despite therapy, with development of shortness of breath, chest pain, and fever and chills. Her past medical history was significant for stage-Ill infiltrating ductal carcinoma of the right breast status post a right modified radical mastectomy with positive axillary lymph nodes 5 years
C.L. McDonald et al.
260
prior to this admission. Despite adjuvant chemotherapy and tamoxifen, she developed locally recurrent disease 1 year after diagnosis and metastatic disease 3 years later. Chemotherapy resulted in initial stabilization of her disease. However, 5 months prior to the present admission, progressive disease in bone and liver became evident, and the patient agreed to another course of palliative chemotherapy. Her Groshong catheter was placed in the left subclavian vein 4 months before admission, and her most recent course of chemotherapy was given 31 days before admission. On admission, the patient's temperature was 100.2°F (37.9°C) orally, pulse 115, and other vital signs were normal. She had no oral lesions. No heart murmurs or gallops were present. There were decreased breath sounds in the right lower lung field with crackles present. The Groshong catheter exit site was unremarkable, and the abdominal exam was normal. Her WBC count was 10,900/mm 3 with a predominance of polymorphonuclear leukocytes. A urinalysis revealed moderate pyuria and bacteruria with many epithelial cells. A urine culture grew 10,000-50,000 colony-forming units/ml of mixed Gram-positive flora. A computerized tomogram of the chest and abdomen performed just prior to admission to assess disease status demonstrated right lower lobe consolidation with a small right pleural effusion. The sputum Gram stain was an inadequate sample with ~25 WBCs per low-power field and numerous squamous epithelial cells. The patient was begun on cefuroxime 750 mg intravenously (i.v.) every 8 h for a community-acquired pneumonia. Over the next 48 h, her temperature normalized and her pulmonary symptoms resolved. On hospital day 3, blood cultures from the day of admission (one drawn peripherally and two via the central catheter) were growing Gram-positive rods. The patient was switched to vancomycin 1 g i.v. every 12 h. On hospital day 5, a venogram through the catheter was performed, the results of which were normal. The three sets of blood cultures were submitted in BACTEC blood culture bottles with growth detected at 36 h in the aerobic bottles from all three sets using a BACTEC 660 blood-culturing system (Becton-Dickinson, Cockeysville, MD, USA). Isolates from all three cultures were identical with Gram stains from the bottles s h o w i n g Grampositive rods with possible branching. A partial acid-fast stain was negative. Pellets obtained from centrifuging the broth from the BACTECbottles were subcultured onto routine media. Growth at 24 h on the aerobic blood agar showed yellow-pigmented colonies that were nonhemolytic and catalase positive. A Corynestrip (API, Plainview, NY, USA) was inoculated according to the manufacturer's instructions and incubated for 18 h at 35°C in air. The
Corynestrip was interpreted as an Oerskovia species (excellent identification) based on the code compendium generated. Susceptibility test results were generated by both disk diffusion testing as well as broth dilution testing for minimum inhibitory concentrations (MICs) using a Sensititre plate (Radiometer, Westlake, OH, USA). The results of susceptibility tests generated from each of these methods were in agreement. The MICs are listed in Table 1. The isolate was subsequently sent to the Alabama State Laboratory for specific species identification. Based on the isolate's ability to hydrolyze xanthine and hypoxanthine as well as its ability to grow at 42°C, it was identified as Oerskovia xanthineolytica. The patient received a 14-day course of i.v. vancomycin without catheter removal. Repeat blood cultures on day 4 of vancomycin therapy as well as at 48 and 72 h after the completion of therapy were all negative. Clearing of the pulmonary infiltrate on a follow-up outpatient chest radiograph was documented. The patient's condition has been followed for 6 months as an outpatient without recurrent bacteremia. DISCUSSION
Oerskovia species are Gram-positive organisms that demonstrate branching and filamentous morphology when grown on solid media. The organism may fragment into small, motile rodlike elements when they are recovered in liquid media. First described by Orskov in 1938 as a motile Nocardia species, it was originally isolated from soil and later dry-grass cuttings (Lechevalier, 1972). Although it is an organism of low virulence, a total of 35 human clinical isolates of Oerskovia species were submitted to the Centers for Disease Control in Atlanta, Georgia, over a 20-year period prior to 1977, yet clinical deTABLE 1
Minimum Inhibitory Concentrations (MICs)
Antibiotic Penicillin Ampicillin Oxacillin Cephalothin Erythromycin Clindamycin Ciprofloxacin Tetracycline TMP-SMXa Vancomycin Gentarnicin Imipenem Rifampin Chloramphenicol
MIC (p~g/ml) 2 4 > 32 4 1 2 1 1 <0.25/4.75 <0.5 2 2 <0.5 <4
aTrimethoprim-sulfamethoxazole.
Interpretation Resistant Resistant Resistant Susceptible Moderately susceptible Moderately susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible Susceptible
Oerskovia Bacteremia
tails were not available (Sottnek et al., 1977). These included five heart valve or cardiac isolates, nine blood isolates, and one cerebrospinal fluid isolate as well as isolates from various other sites. Eight case reports in which Oerskovia species were implicated as causing disease in humans have been published, including four cases with bacteremia. The first seven of these have been reviewed (Rihs et al., 1990). Since their review, one case of Oerskovia xanthineolytica bacteremia has been reported complicating a patient hospitalized for bleeding esophageal varices and methicillin-resistant Staphylococcus bacteremia without an identified focus of infection (Truant et al., 1992). Nearly all previous reports, similar to our case, occurred in immunocompromised hosts. In at least six of the previous eight cases, this organism gained entry into the body through the presence of foreign bodies, including a homograft heart valve, a metallic object lodged in the eye, a ventriculoperitoneal shunt, a peritoneal catheter, and two cases associated with long-term central venous catheters. The cases without related foreign bodies include the case of bacteremia noted above without an identified focus (Truant et al., 1992) and the case of a patient who underwent nephrectomy for a pyogenic infection associated with impacted stones (Cruickshank et al., 1979). In five of the six foreign-body infections, cure occurred with removal of the foreign body. The case in which cure was effected without foreign-body removal was a bacteremia following infusion of contaminated home total parenteral nutrition solution
261
through a long-term central venous catheter (Guss and Ament, 1989). It seems unlikely that an established catheter infection was present in that case. Another case of Oerskovia bacteremia (O. turbata) that was more clearly venous catheter related failed antibiotic therapy alone, requiring catheter removal (LeProwse et al., 1989). That case was treated with amikacin after the organism was initially misidentifled as Nocardia and the patient had a known allergy to sulfonamide drugs. The last four reported cases of human infection (including this case) have been successfully treated with vancomycin. The etiology of the Oerskovia bacteremia in the present case cannot be determined with certainty since lower respiratory tract cultures were not obtained. However, positive blood cultures in the setting of acute pneumonia are considered definitive proof of the etiology of an associated pneumonia (Donowitz and Mandell, 1990). The fact that our patient grew an organism that is not usually pathogenic may be explained by her metastatic breast cancer, chemotherapy, and preceding neutropenia. A catheter-associated bacteremia cannot be excluded especially since less virulent organisms, including Oerskovia, can cause bacteremia in this setting. Catheter-associated bacteremia, however, does not explain our patient's acute lobar pneumonia, and two simultaneous infections would have to be postulated. In addition, the bacteremia cleared easily without catheter removal and has not recurred in 6 months. We feel that Oerskovia species may be identified in the future as rare causes of pneumonia in other immunocompromised hosts.
REFERENCES Cruickshank JG, Gawler AH, Shaldon C (1979) Oerskovia species: rare opportunistic pathogens. J Med Microbiol 12:513-515. Donowitz GR, Mandell GL (1990) Acute pneumonia. In Principles and Practice of Infectious Diseases. Eds, GL Mandell, RG Douglas, and JE Bennett. New York: Churchill Livingston, pp 540-555. Guss WJ, Ament ME (1989) Oerskovia infection caused by contaminated home parenteral nutrition solution. Arch Intern Med 149:1457-1458. Lechevalier MP (1972) Description of a new species, Oerskovia xanthineolytica, and emendation of Oerskovia Prauser et al. Int ] Syst Bacteriol 22:260-264. LeProwse CR, McNeil MM, McCarty JM (1989) Catheter-
related bacteremia caused by Oerskovia turbata. J Clin Microbiol 27:571-572. Rihs JD, McNeil MM, Brown JM, Yu VL (1990) Oerskovia xanthineolytica implicated in peritonitis associated with peritoneal dialysis: case report and review of Oerskovia infections in humans. ] Clin Microbiol 28:1934-1937. Sottnek FO, Brown JM, Weaver RE, Carroll GF (1977) Recognition of Oerskovia species in the clinical laboratory: characterization of 35 isolates. Int J Syst Bacterio127:263270. Truant AL, Satishchandran V, Eisensteadt R, Richman P, McNeil MM (1992) Oerskovia xanthineolytica and methicillin-resistant Staphylococcus aureus in a patient with cirrhosis and variceal hemorrhage. Eur J Clin Microbiol Infect Dis 11:950-951.