Vol. 28, No. 12
JOURNAL OF CLINICAL MICROBIOLOGY. Dec. 1990. p. 2818-2819
0095-1137/90/122818-02$02.00/0 Copyright C 1990, American Society for Microbiology
Anaerobic Endocarditis Caused by Staphylococcus saccharolyticus T. ULF WESTBLOM,l* GEOFFREY J. GORSE,' THOMAS W. MILLIGAN,1"2 AND ANDREW H. SCHINDZIELORZ3 Department of Medicine, Division of Infectious Diseases,' and Department of Pathology,2 St. Louis University School of Medicine, St. Louis, Missouri 63104, and Department of Medicine, Division of Jnfectious Diseases, Yale University School of Medicine, New Haven, Connecticit 065203 Received 10 January 1990/Accepted 23 September 1990
The first case of infective endocarditis caused by the anaerobe Staphylococcus saccharolyticus is reported. The infection occurred in a previously healthy 61-year-old male with no known predisposing valvular heart disease. The patient was successfully treated with a combination of 2 g of nafcillin every 4 h and 90 mg of gentamicin every 8 h for 6 weeks.
(Patrick R. Murray, personal communication) with concentrations of antibiotics ranging from 1,000 to 0.015 ,ug/ml. Endpoint, inoculum standard, and MIC and MBC determinations were performed in accordance with the recommendations on methods for antimicrobial testing of anaerobic bacteria from the National Committee for Clinical Laboratory Standards. Quality control organism Staphylococcus aureus ATCC 29213 was included with each antibiotic tested. The patient was treated with a combination of 2 g of nafcillin every 4 h and 90 mg of gentamicin every 8 h for a total of 6 weeks. No precipitating event for his endocarditis could be established. The patient denied any recent dental procedures and had no evidence of ongoing oral infection. There was no history of recent skin lesions, except for peeling of the skin of his hands, which occurred 2 weeks after antibiotics had been initiated. The patient remained
Staphylococcus saccharolyticus is an anaerobic, grampositive coccus which is part of the bacterial skin flora (4). It was previously known as Peptococcus saccharolyticus, but oligonucleotide analysis of 16S rRNA has shown it to be, instead, a member of the genus Staphylococcus (7). Aerobic staphylococci are a common cause of bacterial endocarditis, while anaerobic bacteria only rarely give rise to this condition (6). There are no reports of anaerobic staphylococcal endocarditis in the literature. We now report the first such case. Case report. A 61-year-old male was admitted for evaluation of fever and weight loss. Six months earlier, he had noted the onset of a low-grade fever of around 100°F (37.8°C), occurring on a daily basis. This fever gradually became more pronounced and was accompanied by chills, typically occurring around midnight every day. He was seen in his physician's office, where laboratory evaluation, including blood cultures, was unremarkable. Because a murmur was noted, an echocardiogram was recommended but not performed at the time. One month before admission, his daily fevers were as high as 104°F (40°C) and he complained of fatigue and a 10-pound (ca. 4.5-kg) weight loss over the past 5 months. After changing physicians, he was given empiric treatment with ciprofloxacin. An echocardiogram performed at this time showed thickening of the mitral valve. When admitted to the hospital, the patient was afebrile and had stable vital signs. Physical examination was unremarkable, except for the presence of a grade 4 holosystolic murmur heard best at intercostal space 4 at the left sternal border and radiating to the axilla. No petechiae, splinter hemorrhages, Osler's nodes, or Janeway lesions were seen. Laboratory tests showed normochromic, normocytic anemia with a hemoglobin concentration of 10.4 g/dl, a platelet elevation of 547,000/mm3, and an erythrocyte sedimentation rate of 58 mm/h. Urinalysis showed a trace of blood by dipstick. Ciprofloxacin was discontinued, and three blood cultures were obtained. These were initially negative, but by day 10 all three showed growth of anaerobic cocci, identified as S. saccharolyticus (Table 1). The identity of the organism was independently verified by a second laboratory (courtesy of Wesley E. Kloos, Department of Genetics, North Carolina State University at Raleigh). Antimicrobial susceptibilities (Table 2) were determined by a broth dilution method using brain heart infusion broth containing 2% horse serum *
TABLE 1. Biochemical reactions of the isolated S. saccharolyticus Test
Result"
Catalase production.....................................................
Coagulase production................................................... Esculin hydrolysis....................................................... Nitrate reduction......................................................... Arginine utilization ...................................................... Urease production....................................................... Indole production........................................................ ,-Glucosidase production............................................. P-Glucuronidase production.......................................... P-Galactosidase production........................................... Acid production from: Glucose.................................................................. Arabinose ............................................................... Glycerol.................................................................
+ +
+
+
Lactose .................................................................. Maltose .................................................................. Mannitol ................................................................. Rhamnose ...............................................................
Salicin.................................................................... Sucrose .................................................................. Trehalose................................................................ Xylose ................................................................... Cellobiose ............................................................... Mannose................................................................. Raffinose ................................................................ Sorbitol .................................................................. -. Negative: +. positive.
Corresponding author. 2818
+ +
VOL. 28. 1990
NOTES
TABLE 2. Anaerobic susceptibility testing of S. sat-cchlaolvticuiis by broth dilution Antibiotics
Penicillin
Ampicillin Oxacillin Cephalothin Vancomycin Imipenem Gentamicin" Metronidazole Ciprofloxacin Clindamycin "
MIC (,ug/m)
MBC (0.g4m8)
0.015 0.015 0.015 0.015 0.015 0.015 0.48 250 0.12 0.012
0.48 0.015
().015 0.015 0.015 0.030 1.92 500 0.12 > 100
Determined under microaerophilic conditions (CanipyPak jar).
afebrile throughout hospitalization. A repeat echocardioshowed residual moderate-sized mitral valve vegetation of the posterior leaflet with mild mitral regurgitation. After discharge, the patient was followed up for more than 6 months in a clinic. He continued to do well and had no signs of recurrent infection. Discussion. Anaerobic endocarditis is a rare form of infective endocarditis. In two large studies with an aggregate total of 1,498 cases of endocarditis, only 3.8% were caused by anaerobic bacteria (5, 12). In recent years, the number of anaerobic isolates has increased while the number of culturenegative cases has decreased (5), indicating that improved laboratory techniques may play an important part in this apparent rise. In the early seventies, the most commonly encountered organisms were Bacteroides fi-agiis, Fusobacterium necrophorumn, and clostridial species (5, 8), while later reports found a higher number of anaerobic cocci (3, 10). Peptococcus species only rarely give rise to endocarditis. We are aware of only four previous cases. Cofsky and Seligman reported a case of fatal P. magnus endocarditis in an 18-year-old man (2). Singhi and co-workers described a case of Peptococcus species endocarditis in a 12-year-old boy with previous rheumatic heart disease (11). A third case was found without further clinical information as part of a review of 51 episodes of anaerobic bacteremia in an Indian university hospital (1). In the non-English literature, there is an additional case of late prosthetic valve endocarditis caused by a Peptococcus species (9). Our case is the first report of endocarditis caused by S. saccharolyticus. The course was subacute, and there was a favorable result of
gram
2819
treatment with bactericidal antibiotics. There was no evidence of underlying valvular heart disease, and the infection did not result in destruction of the valves. The source of the bacteremia is unknown but presumed to be the skin. We conclude that S. sacchiatrcolvticwus should be added to the list of organisms capable of causing infective endocarditis. Our experience shows that prolonged treatment with bactericidal antibiotics can result in effective recovery. Determination of whether this is representative of the true pathogenicity of the organism will have to await reports of other, similar infections. The technical assistance of Mary Ann DeGonia with broth dilution susceptibility testing was greatly appreciated. LITERATURE CITED 1. Babu, M. H., A. Mathai, V. K. Vishweshwaran, and P. G. Shivanada. 1987. Anaerobic bacteraemia. Indian J. Pathol. Microbiol. 30:247-253. 2. Cofsky, R. D., and S. J. Seligman. 1985. Peptococcus magnus endocarditis. South. Med. J. 78:361-362. 3. Dorsher, C. W., W. R. Wilson, and J. E. Rosenblatt. 1989. Anaerobic bacteremia and cardiovascular infections. p. 289310. In S. M. Finegold and W. L. George (ed.). Anaerobic infections in humans, lst ed. Academic Press, lnc., San Diego. Calif. 4. Evans, C. A., and K. L. Mattern. 1978. Individual differences in the bacterial flora of the skin of the forehead: Peptococcus saccharolyticus. J. Invest. Dermatol. 71:152-153. 5. Felner, J. M., and V. R. Dowell. 1970. Anaerobic bacterial endocarditis. N. Engl. J. Med. 283:1188-1192. 6. Gorbach, S. L., and J. G. Bartlett. 1974. Anaerobic infections (second of three parts). N. Engl. J. Med. 290:1237-1245. 7. Ludwig, W., K. Schleifer, G. E. Fox, E. Seewaldt, and E. Stackebrandt. 1981. A phylogenetic analysis of staphylococci, Peptococcus saccharolyticus and Micrococcus mucilaginosus. J. Gen. Microbiol. 125:357-366. 8. Nastro, L. J., and S. M. Finegold. 1973. Endocarditis due to anaerobic gram-negative bacilli. Am. J. Med. 54:482-496. 9. Reyes Bribiesca, R., and P. A. Reyes-Lopez. 1989. Etiology of infectious endocarditis at the Instituto Nacional de Cardiologia Ignacio Chavez from 1976 to 1986. Arch. lnst. Cardiol. Mex. 59:287-292. 10. Sapico, F. L., and R. J. Sarma. 1982. Infective endocarditis due to anaerobic and microaerophilic bacteria. West. J. Med. 137: 18-23. 11. Singhi, S. C., S. Singh, and P. S. Bidwi. 1988. Peptococcus endocarditis. Indian Pediatr. 25:876-878. 12. Weinstein, L., and R. H. Rubin. 1973. Infective endocarditis1973. Prog. Cardiovasc. Dis. 16:239-302.
JOURNAL OF CLINICAL MICROBIOLOGY. Dec. 1990. p. 2818-2819
0095-1137/90/122818-02$02.00/0 Copyright C 1990, American Society for Microbiology
Anaerobic Endocarditis Caused by Staphylococcus saccharolyticus T. ULF WESTBLOM,l* GEOFFREY J. GORSE,' THOMAS W. MILLIGAN,1"2 AND ANDREW H. SCHINDZIELORZ3 Department of Medicine, Division of Infectious Diseases,' and Department of Pathology,2 St. Louis University School of Medicine, St. Louis, Missouri 63104, and Department of Medicine, Division of Jnfectious Diseases, Yale University School of Medicine, New Haven, Connecticit 065203 Received 10 January 1990/Accepted 23 September 1990
The first case of infective endocarditis caused by the anaerobe Staphylococcus saccharolyticus is reported. The infection occurred in a previously healthy 61-year-old male with no known predisposing valvular heart disease. The patient was successfully treated with a combination of 2 g of nafcillin every 4 h and 90 mg of gentamicin every 8 h for 6 weeks.
(Patrick R. Murray, personal communication) with concentrations of antibiotics ranging from 1,000 to 0.015 ,ug/ml. Endpoint, inoculum standard, and MIC and MBC determinations were performed in accordance with the recommendations on methods for antimicrobial testing of anaerobic bacteria from the National Committee for Clinical Laboratory Standards. Quality control organism Staphylococcus aureus ATCC 29213 was included with each antibiotic tested. The patient was treated with a combination of 2 g of nafcillin every 4 h and 90 mg of gentamicin every 8 h for a total of 6 weeks. No precipitating event for his endocarditis could be established. The patient denied any recent dental procedures and had no evidence of ongoing oral infection. There was no history of recent skin lesions, except for peeling of the skin of his hands, which occurred 2 weeks after antibiotics had been initiated. The patient remained
Staphylococcus saccharolyticus is an anaerobic, grampositive coccus which is part of the bacterial skin flora (4). It was previously known as Peptococcus saccharolyticus, but oligonucleotide analysis of 16S rRNA has shown it to be, instead, a member of the genus Staphylococcus (7). Aerobic staphylococci are a common cause of bacterial endocarditis, while anaerobic bacteria only rarely give rise to this condition (6). There are no reports of anaerobic staphylococcal endocarditis in the literature. We now report the first such case. Case report. A 61-year-old male was admitted for evaluation of fever and weight loss. Six months earlier, he had noted the onset of a low-grade fever of around 100°F (37.8°C), occurring on a daily basis. This fever gradually became more pronounced and was accompanied by chills, typically occurring around midnight every day. He was seen in his physician's office, where laboratory evaluation, including blood cultures, was unremarkable. Because a murmur was noted, an echocardiogram was recommended but not performed at the time. One month before admission, his daily fevers were as high as 104°F (40°C) and he complained of fatigue and a 10-pound (ca. 4.5-kg) weight loss over the past 5 months. After changing physicians, he was given empiric treatment with ciprofloxacin. An echocardiogram performed at this time showed thickening of the mitral valve. When admitted to the hospital, the patient was afebrile and had stable vital signs. Physical examination was unremarkable, except for the presence of a grade 4 holosystolic murmur heard best at intercostal space 4 at the left sternal border and radiating to the axilla. No petechiae, splinter hemorrhages, Osler's nodes, or Janeway lesions were seen. Laboratory tests showed normochromic, normocytic anemia with a hemoglobin concentration of 10.4 g/dl, a platelet elevation of 547,000/mm3, and an erythrocyte sedimentation rate of 58 mm/h. Urinalysis showed a trace of blood by dipstick. Ciprofloxacin was discontinued, and three blood cultures were obtained. These were initially negative, but by day 10 all three showed growth of anaerobic cocci, identified as S. saccharolyticus (Table 1). The identity of the organism was independently verified by a second laboratory (courtesy of Wesley E. Kloos, Department of Genetics, North Carolina State University at Raleigh). Antimicrobial susceptibilities (Table 2) were determined by a broth dilution method using brain heart infusion broth containing 2% horse serum *
TABLE 1. Biochemical reactions of the isolated S. saccharolyticus Test
Result"
Catalase production.....................................................
Coagulase production................................................... Esculin hydrolysis....................................................... Nitrate reduction......................................................... Arginine utilization ...................................................... Urease production....................................................... Indole production........................................................ ,-Glucosidase production............................................. P-Glucuronidase production.......................................... P-Galactosidase production........................................... Acid production from: Glucose.................................................................. Arabinose ............................................................... Glycerol.................................................................
+ +
+
+
Lactose .................................................................. Maltose .................................................................. Mannitol ................................................................. Rhamnose ...............................................................
Salicin.................................................................... Sucrose .................................................................. Trehalose................................................................ Xylose ................................................................... Cellobiose ............................................................... Mannose................................................................. Raffinose ................................................................ Sorbitol .................................................................. -. Negative: +. positive.
Corresponding author. 2818
+ +
VOL. 28. 1990
NOTES
TABLE 2. Anaerobic susceptibility testing of S. sat-cchlaolvticuiis by broth dilution Antibiotics
Penicillin
Ampicillin Oxacillin Cephalothin Vancomycin Imipenem Gentamicin" Metronidazole Ciprofloxacin Clindamycin "
MIC (,ug/m)
MBC (0.g4m8)
0.015 0.015 0.015 0.015 0.015 0.015 0.48 250 0.12 0.012
0.48 0.015
().015 0.015 0.015 0.030 1.92 500 0.12 > 100
Determined under microaerophilic conditions (CanipyPak jar).
afebrile throughout hospitalization. A repeat echocardioshowed residual moderate-sized mitral valve vegetation of the posterior leaflet with mild mitral regurgitation. After discharge, the patient was followed up for more than 6 months in a clinic. He continued to do well and had no signs of recurrent infection. Discussion. Anaerobic endocarditis is a rare form of infective endocarditis. In two large studies with an aggregate total of 1,498 cases of endocarditis, only 3.8% were caused by anaerobic bacteria (5, 12). In recent years, the number of anaerobic isolates has increased while the number of culturenegative cases has decreased (5), indicating that improved laboratory techniques may play an important part in this apparent rise. In the early seventies, the most commonly encountered organisms were Bacteroides fi-agiis, Fusobacterium necrophorumn, and clostridial species (5, 8), while later reports found a higher number of anaerobic cocci (3, 10). Peptococcus species only rarely give rise to endocarditis. We are aware of only four previous cases. Cofsky and Seligman reported a case of fatal P. magnus endocarditis in an 18-year-old man (2). Singhi and co-workers described a case of Peptococcus species endocarditis in a 12-year-old boy with previous rheumatic heart disease (11). A third case was found without further clinical information as part of a review of 51 episodes of anaerobic bacteremia in an Indian university hospital (1). In the non-English literature, there is an additional case of late prosthetic valve endocarditis caused by a Peptococcus species (9). Our case is the first report of endocarditis caused by S. saccharolyticus. The course was subacute, and there was a favorable result of
gram
2819
treatment with bactericidal antibiotics. There was no evidence of underlying valvular heart disease, and the infection did not result in destruction of the valves. The source of the bacteremia is unknown but presumed to be the skin. We conclude that S. sacchiatrcolvticwus should be added to the list of organisms capable of causing infective endocarditis. Our experience shows that prolonged treatment with bactericidal antibiotics can result in effective recovery. Determination of whether this is representative of the true pathogenicity of the organism will have to await reports of other, similar infections. The technical assistance of Mary Ann DeGonia with broth dilution susceptibility testing was greatly appreciated. LITERATURE CITED 1. Babu, M. H., A. Mathai, V. K. Vishweshwaran, and P. G. Shivanada. 1987. Anaerobic bacteraemia. Indian J. Pathol. Microbiol. 30:247-253. 2. Cofsky, R. D., and S. J. Seligman. 1985. Peptococcus magnus endocarditis. South. Med. J. 78:361-362. 3. Dorsher, C. W., W. R. Wilson, and J. E. Rosenblatt. 1989. Anaerobic bacteremia and cardiovascular infections. p. 289310. In S. M. Finegold and W. L. George (ed.). Anaerobic infections in humans, lst ed. Academic Press, lnc., San Diego. Calif. 4. Evans, C. A., and K. L. Mattern. 1978. Individual differences in the bacterial flora of the skin of the forehead: Peptococcus saccharolyticus. J. Invest. Dermatol. 71:152-153. 5. Felner, J. M., and V. R. Dowell. 1970. Anaerobic bacterial endocarditis. N. Engl. J. Med. 283:1188-1192. 6. Gorbach, S. L., and J. G. Bartlett. 1974. Anaerobic infections (second of three parts). N. Engl. J. Med. 290:1237-1245. 7. Ludwig, W., K. Schleifer, G. E. Fox, E. Seewaldt, and E. Stackebrandt. 1981. A phylogenetic analysis of staphylococci, Peptococcus saccharolyticus and Micrococcus mucilaginosus. J. Gen. Microbiol. 125:357-366. 8. Nastro, L. J., and S. M. Finegold. 1973. Endocarditis due to anaerobic gram-negative bacilli. Am. J. Med. 54:482-496. 9. Reyes Bribiesca, R., and P. A. Reyes-Lopez. 1989. Etiology of infectious endocarditis at the Instituto Nacional de Cardiologia Ignacio Chavez from 1976 to 1986. Arch. lnst. Cardiol. Mex. 59:287-292. 10. Sapico, F. L., and R. J. Sarma. 1982. Infective endocarditis due to anaerobic and microaerophilic bacteria. West. J. Med. 137: 18-23. 11. Singhi, S. C., S. Singh, and P. S. Bidwi. 1988. Peptococcus endocarditis. Indian Pediatr. 25:876-878. 12. Weinstein, L., and R. H. Rubin. 1973. Infective endocarditis1973. Prog. Cardiovasc. Dis. 16:239-302.
