Journal of Infection (1991) 22, 95-111
L e t t e r s to t h e E d i t o r E n d o c a r d i t i s c a u s e d by
Corynebacterium g r o u p D e
Accepted for publication 23 May I99o Sir,
Corynebacterium group D2 (CGD2) is a Gram-positive, catalase-positive, aerobic or facultatively anaerobic micro-organism belonging to the genus Corynebacterium. Characteristically C G D 2 , like Corynebacterium JK, is resistant to many antibiotics, but is unable to acidify carbohydrates and has a strong urease activity. 1 C G D 2 is commonly found on skin and mucous membranes of hospitalised patientsfl It has recently been recognised as causing urinary tract infection, pyelonephritis, and encrusted cystitis, mainly in patients who have been subjected to urological manipulation. ~ Other reported infections have been: pneumonia, 4 peritonitis in a patient on CAPD, wound infection and bacteraemia, s T o our knowledge C G D z , has never been reported as causing endocarditis. We describe an intravenous drug addict with an aortic and mitral valve endocarditis due to C G D 2 who required valvular replacement. A 24-year-old man with a IO years' history of parenteral drug addiction, was admitted to the hospital with high fever (40 °C), chills, and general malaise of I weeks' duration. T h e most noteworthy clinical findings were a grade I V / V I systolic-diastolic m u r m u r in the aortic area without signs of cardiac failure, a 4 cms hepatomegaly and a 6 cms splenomegaly. Laboratory tests on admission revealed a mild normocytic and normochromic anaemia with 6"0 x Io9/1 leucocytes and a normal differential count. A two-dimensional echocardiogram showed extensive vegetations on the aortic valve. These protruded into the exit site of the left ventricle. Aortic insufficiency was estimated as severe and was associated with slight mitral regurgitation. Six blood cultures were taken on admission and empirical therapy with Imipenen Iv (500 mg q.i.d.) and rifampin PO (300 mg b.i.d.) was started, and during the next few days his pyrexia improved. Staphylococcus epidermidis grew in one blood culture and Corynebacterium sp. in another two of six aerobic blood-culture bottles. At the time these isolates were considered as contaminants. A urine culture was negative. T e n days later, in six of six anaerobic blood cultures, typical diphtheroids were isolated on subculture. T h e y did not acidify carbohydrates and had a strong urease activity. On the basis of these data the micro-organism was identified as Corynebacterium group D2 (CGD2). T h e strain isolated was sensitive to Vancomycin and Imipenen but resistant to all aminoglycosides, erythromycin, penicillin, cephalosporins, t r i m e t h o p r i m / sulphamethoxazole and rifampin. T h r e e weeks after admission the patient developed acute ischaemic hemiplegia and as the blood cultures were still positive it was decided to replace the aortic and mitral valves. At operation aortic and mitral vegetations were observed. Cultures of the vegetations grew C G D 2 with the same sensitivity pattern as that of the previous isolates. After surgery antimicrobial therapy was changed and the patient received 4 weeks' of iv Vancomycin (500 mg q.i.d.). H e was discharged in good condition and with negative blood cultures. T h e most commonly reported human infection with coryneform micro-organisms is infective endocarditis over native or prosthetic valves. 6 In the minority of cases in which complete identification has been carried out, the species most commonly isolated in endocarditis has proved to be group JK, but infectious with C. pseudodiphtheriticum, C. xerosis, C. pyogenes and C. bovis7 have also been described. Clinical cure often required valvular replacement, although cure with antimicrobials
96
Letters to the Editor
alone has been reported in some cases, s Mortality rates in groups with and without prosthetic valves are approximately 5o and 25 % respectively. Corynebacterium is a rare cause of endocarditis in drug addicts. However, C G D 2 colonizes skin and mucous m e m b r a n e s and is therefore a potential cause of infective endocarditis in patients with repeated injection injuries. O u r case resembles others in that the first isolates were dismissed as contaminants, the blood cultures required prolonged incubation and a combination of surgery and antimicrobials was needed to achieve cure. 7,s In vitro testing indicates that Vancomycin, Norfloxacin and Ofloxacin are likely to be effective against C G D 2 . 9 T h e r e is little experience of I m i p e n e n in the treatment of Corynebacterium bacteraemia 1° but due to its high in vitro and in vivo activity m a y be an alternative to other antimicrobials which have greater toxicity. In patients whose clinical condition suggests infection, Corynebacterium should not be considered a contaminant without clear evidence that this is the case. C G D 2 can cause endocarditis on native valves and has a course similar to that caused by other corynebacteria.
* Servicio de Medicina Interna I t Hospital General, Gregorio Maraa6n, Dr. Esquerdo~ 46, 280o7 Madrid, Spain
ft. Ena* ft. Berenguert T. Pel6ezt E. Bouzat
References I. Kelly MC, Smith ID, Anstey RJ, Thornley JH, Rennie RP. Rapid identification of antibiotic-resistant corynebacteria with the API 2oS system, ff Clin Microbiol I984; I9: 245-247. 2. Soriano F, Rodriguez-Tudela JL, Fermindez-Roblas R, Aguado JM, Santamaria M. Skin colonization by Corynebacterium group D2 and JK in hospitalized patients, ff Clin Microbiol I988; 26: I878-I880. 3. Aguado JM, Ponte C, Soriano F. Bacteriuria with a multiply resistant species of Corynebacterium (Corynebacterium group D2): an unnoticed cause of urinary tract infection. ff Infect Dis I987; 156: I44-r5o. 4. Jacobs NF, Perlino CA. Diphtheroid pneumonia. South Med ff I979; 72: 475-476. 5. Van Bosterhaut B, Claeys G, Gigi J, Wauters G. Isolation of Corynebacterium group D2 from clinical specimens. Bur ff Clin Microbiol I987; 6: 418-419. 6. Van Scoy RE, Cohen SN, Geraci JE, Washington JA. Coryneform bacterial endocarditis. Mayo Clin Proc I977; 52: 216--219. 7. Lipsky BA, Goldberger AC, Tompkins LS, Plorde JJ. Infections caused by nondiphtheria corynebacteria. Rev Infect Dis I982; 4: I22o--I235. 8. Murray BE, Karchmer AW, Moellering RC. Diphtheroid prosthetic valve endocarditis. Am ff Med I98o; 69: 838-848. 9. Soriano F, Ponte C, Santamaria M, Torres A, Fermindez-Roblas R. Susceptibility of urinary isolates of Corynebacteriurn group D2 to fifteen antimicrobials and acetohidroxamic acid. J Antimicrob Chemother I987; zo: 349-355. Io Eron LJ. Imipenen/cilastatin therapy of bacteremia. Am ff Med I985; 78 (Suppl 6A): 95-99.
L e t t e r s to t h e E d i t o r E n d o c a r d i t i s c a u s e d by
Corynebacterium g r o u p D e
Accepted for publication 23 May I99o Sir,
Corynebacterium group D2 (CGD2) is a Gram-positive, catalase-positive, aerobic or facultatively anaerobic micro-organism belonging to the genus Corynebacterium. Characteristically C G D 2 , like Corynebacterium JK, is resistant to many antibiotics, but is unable to acidify carbohydrates and has a strong urease activity. 1 C G D 2 is commonly found on skin and mucous membranes of hospitalised patientsfl It has recently been recognised as causing urinary tract infection, pyelonephritis, and encrusted cystitis, mainly in patients who have been subjected to urological manipulation. ~ Other reported infections have been: pneumonia, 4 peritonitis in a patient on CAPD, wound infection and bacteraemia, s T o our knowledge C G D z , has never been reported as causing endocarditis. We describe an intravenous drug addict with an aortic and mitral valve endocarditis due to C G D 2 who required valvular replacement. A 24-year-old man with a IO years' history of parenteral drug addiction, was admitted to the hospital with high fever (40 °C), chills, and general malaise of I weeks' duration. T h e most noteworthy clinical findings were a grade I V / V I systolic-diastolic m u r m u r in the aortic area without signs of cardiac failure, a 4 cms hepatomegaly and a 6 cms splenomegaly. Laboratory tests on admission revealed a mild normocytic and normochromic anaemia with 6"0 x Io9/1 leucocytes and a normal differential count. A two-dimensional echocardiogram showed extensive vegetations on the aortic valve. These protruded into the exit site of the left ventricle. Aortic insufficiency was estimated as severe and was associated with slight mitral regurgitation. Six blood cultures were taken on admission and empirical therapy with Imipenen Iv (500 mg q.i.d.) and rifampin PO (300 mg b.i.d.) was started, and during the next few days his pyrexia improved. Staphylococcus epidermidis grew in one blood culture and Corynebacterium sp. in another two of six aerobic blood-culture bottles. At the time these isolates were considered as contaminants. A urine culture was negative. T e n days later, in six of six anaerobic blood cultures, typical diphtheroids were isolated on subculture. T h e y did not acidify carbohydrates and had a strong urease activity. On the basis of these data the micro-organism was identified as Corynebacterium group D2 (CGD2). T h e strain isolated was sensitive to Vancomycin and Imipenen but resistant to all aminoglycosides, erythromycin, penicillin, cephalosporins, t r i m e t h o p r i m / sulphamethoxazole and rifampin. T h r e e weeks after admission the patient developed acute ischaemic hemiplegia and as the blood cultures were still positive it was decided to replace the aortic and mitral valves. At operation aortic and mitral vegetations were observed. Cultures of the vegetations grew C G D 2 with the same sensitivity pattern as that of the previous isolates. After surgery antimicrobial therapy was changed and the patient received 4 weeks' of iv Vancomycin (500 mg q.i.d.). H e was discharged in good condition and with negative blood cultures. T h e most commonly reported human infection with coryneform micro-organisms is infective endocarditis over native or prosthetic valves. 6 In the minority of cases in which complete identification has been carried out, the species most commonly isolated in endocarditis has proved to be group JK, but infectious with C. pseudodiphtheriticum, C. xerosis, C. pyogenes and C. bovis7 have also been described. Clinical cure often required valvular replacement, although cure with antimicrobials
96
Letters to the Editor
alone has been reported in some cases, s Mortality rates in groups with and without prosthetic valves are approximately 5o and 25 % respectively. Corynebacterium is a rare cause of endocarditis in drug addicts. However, C G D 2 colonizes skin and mucous m e m b r a n e s and is therefore a potential cause of infective endocarditis in patients with repeated injection injuries. O u r case resembles others in that the first isolates were dismissed as contaminants, the blood cultures required prolonged incubation and a combination of surgery and antimicrobials was needed to achieve cure. 7,s In vitro testing indicates that Vancomycin, Norfloxacin and Ofloxacin are likely to be effective against C G D 2 . 9 T h e r e is little experience of I m i p e n e n in the treatment of Corynebacterium bacteraemia 1° but due to its high in vitro and in vivo activity m a y be an alternative to other antimicrobials which have greater toxicity. In patients whose clinical condition suggests infection, Corynebacterium should not be considered a contaminant without clear evidence that this is the case. C G D 2 can cause endocarditis on native valves and has a course similar to that caused by other corynebacteria.
* Servicio de Medicina Interna I t Hospital General, Gregorio Maraa6n, Dr. Esquerdo~ 46, 280o7 Madrid, Spain
ft. Ena* ft. Berenguert T. Pel6ezt E. Bouzat
References I. Kelly MC, Smith ID, Anstey RJ, Thornley JH, Rennie RP. Rapid identification of antibiotic-resistant corynebacteria with the API 2oS system, ff Clin Microbiol I984; I9: 245-247. 2. Soriano F, Rodriguez-Tudela JL, Fermindez-Roblas R, Aguado JM, Santamaria M. Skin colonization by Corynebacterium group D2 and JK in hospitalized patients, ff Clin Microbiol I988; 26: I878-I880. 3. Aguado JM, Ponte C, Soriano F. Bacteriuria with a multiply resistant species of Corynebacterium (Corynebacterium group D2): an unnoticed cause of urinary tract infection. ff Infect Dis I987; 156: I44-r5o. 4. Jacobs NF, Perlino CA. Diphtheroid pneumonia. South Med ff I979; 72: 475-476. 5. Van Bosterhaut B, Claeys G, Gigi J, Wauters G. Isolation of Corynebacterium group D2 from clinical specimens. Bur ff Clin Microbiol I987; 6: 418-419. 6. Van Scoy RE, Cohen SN, Geraci JE, Washington JA. Coryneform bacterial endocarditis. Mayo Clin Proc I977; 52: 216--219. 7. Lipsky BA, Goldberger AC, Tompkins LS, Plorde JJ. Infections caused by nondiphtheria corynebacteria. Rev Infect Dis I982; 4: I22o--I235. 8. Murray BE, Karchmer AW, Moellering RC. Diphtheroid prosthetic valve endocarditis. Am ff Med I98o; 69: 838-848. 9. Soriano F, Ponte C, Santamaria M, Torres A, Fermindez-Roblas R. Susceptibility of urinary isolates of Corynebacteriurn group D2 to fifteen antimicrobials and acetohidroxamic acid. J Antimicrob Chemother I987; zo: 349-355. Io Eron LJ. Imipenen/cilastatin therapy of bacteremia. Am ff Med I985; 78 (Suppl 6A): 95-99.
