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Fatal myocarditis associated with a Lancefield group B streptococcus
354
Letters to the Editor
Fatal Myocarditis Associated with a Lancefield Group B Streptococcus Sir, We report an unusual case of fatal myocarditis associated with a Lancefield group B streptococcus (serotype Ib). A previously fit 43-year-old woman presented with a 3-day history of malaise and 24 h of persistent central chest pain radiating to her back and left arm. Initial examination revealed a body temperature of 36 °C and a blood pressure of 80/60 mmHg, normal heart sounds and no signs of cardiac failure. Electrocardiography showed sinus rhythm with a heart rate of 110 beats per minute, ST segment elevation in leads I, II, aVL and V4-V6 and ST segment depression in leads III, V1 and V2. No pathological Q waves were present. Chest radiography was normal The total white blood cell count was 12.2 x 109/1 with a neutrophil count of 11.8 x 109/1. The serum creatine kinase concentration was 2 779 iu/1. The clinical impression was that of acute myocardial infarction and aspirin, heparin and glyceryl trinitrate were given. Thrombolytic therapy was not given in view of the delayed presentation. The chest pain persisted and repeat electrocardiography 24 h later showed no resolution of the ST segment changes. Transthoracic echocardiography revealed a 1 cm thick pericardial effusion together with right atrial diastolic collapse and a hypoechoic left ventricular wall. On transfer to the Wessex Cardiothoracic Centre, examination revealed a pulse of 140/minute, a blood pressure of 100/ 50 mmHg, a raised jugular venous pressure, marked pulsus paradoxus and a pericardial rub. Electrocardiography revealed low voltage QRS complexes and persistent widespread ST segment elevation. Emergency pericardiocentesis produced 400 ml of light brown purulent liquid containing numerous white blood cells and Gram-positive cocci. Intravenous therapy with rifampicin, netilmicin and flucloxacillin was started. Despite full support, the patient deteriorated and died. Culture of pericardial aspirate and blood produced a heavy growth of Lancefield group B 13-haemolytic streptococci capsular serotype Ib, sensitive to penicillin, erythromycin and ampicillin. No viruses were isolated from the pericardial aspirate. Autopsy revealed suppurative pericarditis together with widespread mottled discolouration of the left ventricular myocardium but no evidence of endocarditis. The three main epicardial coronary arteries all showed focal atheromatous luminal stenosis of up to 75% but no occlusive thrombus. The lungs showed vascular congestion and pulmonary oedema. No alternative primary infective sites were identified. Histological examination of myocardium revealed marked oedema and widespread myocyte necrosis with a severe, diffuse mixed inflammatory cell infiltrate (as classified according to the Dallas criteria ~) composed mainly of lymphocytes and plasma cells, with small numbers of neutrophils (Figure 1) and numerous Gram-positive cocci. These changes extended into the pericardium but not the endocardium. The appearances were interpreted as those of a bacterial myocarditis with an associated suppurative pericarditis. This patient initially presented with symptoms and signs highly suggestive of acute myocardial infarction. There were no specific clinical features to suggest an infective process, although in retrospect, the widespread distribution of the ST segment changes on electrocardiography would be relatively unusual for myocardial infarction and were perhaps more consistent with pericarditis. Nevertheless, this case highlights
Figure 1. Histological appearance of myocardium at postmortem. Haematoxylin and eosin stain, showing necrotic myocytes, interstitial oedema, an inflammatory cell infiltrate and colonies of bacteria.
the capacity for infectious diseases clinically to mimic noninfectious processes. Lancefield group B streptococci are being increasingly recognized as important h u m a n pathogens. 2 Seven capsular serotypes are currently recognized (Ia, Ib, II, III, IV, V and VI)) Group B streptococci are almost always sensitive to penicillin, although the minimum inhibitory concentration may be higher than that for Group A streptococci. 4 Group B streptococci are most commonly associated with serious neonatal infections including meningitis and septicaemia, due to vertical transmission from the mother. 5 Most neonatal infections appear to be associated with serotype III, while a wide variety of serotypes may infect older children and adults. 34 The most common group B streptococcal infections in adults are pneumonia, infective endocarditis, pyelonephritis, skin and soft tissue infections and puerperal fever, 4' 6, 7 which may be acquired in hospital s and usually occurs in association with underlying diseases, including diabetes mefiitus, malignancy, HIV infection, genitourinary disorders and liver disease. 4'67 The mortality rate in adult infection (38-70%) is higher than that of neonatal infection (15%). 5'8 Cardiac infection due to Group B streptococci usually manifests as endocarditis, most commonly in immunocompromised patients. 9 Primary myocarditis associated with Group B streptococci is extremely rare, with only one previously described case occuring in an otherwise fit 29-year-old Turkish m a n ) ° In our case there was no evidence of a primary endoearditis, and although pericarditis was present, the destructive infective process was centered on the myocardium. A mixed inflammatory cell infiltrate may be observed in bacterial myocarditis 1but an underlying viral myocarditis cannot be entirely excluded, although no viruses were isolated from the pericardial aspirate. This case highlights the ability of Lancefield group B streptococci to cause life-threatening infection in adults who possess no clear predisposing factors for serious infection with unusual organisms. Such infections may progress quickly and be associated with a fatal outcome.
Letters to the Editor
Acknowledgement We thank Dr J Morgan for his permission to report this case. A. C. B a t e m a n 1, M. Richards 2, A. P. Pallett 3 Departments of 1Histopathology, 2Microbiology and 3Wessex Cardiothoracic Centre, Southampton GeneraI Hospital, Tremona Road, Southampton S 0 1 6 6YD, U.K.
References 1 Aretz HT. Billingham ME, Edwards WD et aI. Myocarditis. A histopathologic definition and classification. Am J Cardiovasc Pathol 1986; 1 : 3 14. 2 Eykyn SJ, Young SEJ, Cookson BD. Increased community-acquired septicaemic infection with group B streptococci in adults (letter). Lancet 1991; 338: 446. 3 Wessels MR, Klasper DL. The changing spectrum of group B streptococcal disease. N Engl f Med 1993; 328: 1843-1844. 4 Bayer AS, Chow AW, Anthony BF, Guze LB. Serious infections in adults due to group B streptococci. Am J Med 1976; 61: 498-503. 5 Opal SM, Cross A, Palmer M. Almazan R. Group B streptococcal sepsis in adults and infants. Arch lntern Med 1986; 148: 641-645. 6 Lerner PI, Gopalakrishna KV, Wolinsky E, McHenry MC, Tan J8, Rosenthal M. Group B streptococcus (S. agalactiae) bacteraemia in adults: analysis of 32 cases and review of the literature. Medicine 1977; 56: 457-473. 7 Farley MM, Harvey RC, Stull T et al. A population-based assessment of invasive disease due to group B streptococcus in nonpregnant adults. N Engl [ Med 1993; 328: 1807-1811. 8 Gallagher PG, Watanakunahorn C. Group B streptococcal bacteraemia in a community teaching hospital. Am J Med 1985; 78: 795-800. 9 Scully BE, Spriggs D, Neu HC. Streptococcus agalactiae (group B) endocarditis - a description of twelve cases and review of the literature. Infection 1987; 15: 169-176. 10 Von Kurnatowski HA, Sierra-Callejas JL, Henkel W, Diederich KW. Foudroyant t0dlich verlaufende myokarditis durch streptokold;en der gruppe B. Dtsch reed Wschr 1977; 103: 439-441.
Accepted for publication 25 September 1997
Incidence of ~-Iactamase Production by Oral Aerobic/ anaerobic Flora from Patients Admitted for Elective Tonsillectomy Sir, R e c u r r e n t tonsillitis is a m a j o r cause of morbidity. The purpose of the present study was to d e t e r m i n e the bacterial flora of r e c u r r e n t l y inflamed tonsils in children w i t h tonsillitis. 1 The frequency of 13-1actamase producing micro-organisms was also reported. Tonsils were r e m o v e d from paediatric patients admitted for elective tonsillectomy. Forty patients aged 4 - 1 5 were studied (one tonsil from each child). They suffered from r e c u r r e n t tonsillitis defined as at least five episodes per year in the previous 2 years or six to seven episodes in 1 year with previous episodes of tonsillitis in the preceding year. None h a d received antimicrobial t h e r a p y for at least 1 week before surgery. Each episode m u s t h a v e been characterized by one or more of the following: (a) oral t e m p e r a t u r e > 3 8 ° C ; (b) enlarged tender
355
Table I. Aerobic/anaerobic tonsillar isolates obtained from 40 patients admitted for elective tonsillectomy Organism
a. Aerobic isolates a-haemolytic Streptococci Streptococcus pneumoniae Neisseria Spp. [3-haemolytic Streptococci (S. pyogens group A) Staphylococcus aureus Coagulase-negative Staphylococci Haemophilus influenza b. Anaerobic isolates Anaerobic Grmn-negative cocci Anaerobic Gram-positive rod/cocci Peptostreptococcus Spp Fusobacterium necrophorum Anaerobic Gram-negative: Pigmented Non-pigmented
Total number of isolates Surface Core 65 2 17 10
72 3 3 8
29 (18) 15 (3) 6 (2)
40 (27) 7 (2) 2 (1)
21 2 19 49 (6)
15 14 28 35 (10)
43 (7) 61 (31)
31 (8) 69 (23)
Figures in parenthesis indicate [Mactamase-producing strains.
cervical lymphnodes w i t h episodes of tonsillitis or persistent nodes after the episode of tonsillitis ; or (c) tonsillar exudate on examination. Immediately after excision, the tonsils were placed in a sterile container; one of the tonsils was placed in a sterile Petri dish a n d held by forceps. The surface of the tonsil was r u b b e d t h o r o u g h l y with a sterile cotton swab. One side of the tonsil was cauterized with a sterile scalpel a n d a n incision was m a d e t h r o u g h t h a t area, cutting the tonsil in half. The core of the tonsil was t h e n swabbed w i t h a sterile cotton swab a n d b o t h swabs plated out o n aerobic a n d anaerobic media. Specimens were inoculated onto 5% sheep blood, chocolate a n d MacConkey's a g a r plate (Oxoid). Plates were i n c u b a t e d at 37 °C aerobically (MacConkey's) or u n d e r 5% CO2 (5% sheep's blood a n d chocolate) a n d e x a m i n e d at 2 4 a n d 48 h. For anaerobic culture, the material was plated o u t onto pre-reduced vitamin Kl-enriched Schaedlen's blood agar, a n anaerobic blood agar c o n t a i n i n g k a n a m y c i n a n d vancomycin, a n d anaerobic blood agar c o n t a i n i n g colistin a n d nalidixic acid. The anaerobic plates were i n c u b a t e d in anaerobic jars a n d e x a m i n e d at 48 a n d 96 h. Bacteria were identifed using c o n v e n t i o n a l methods as previously described. 2 13-1actamase production was studied on freshly g r o w n colonies using the c h r o m o g e n i c cephalosporin, nitrocefin (Unipath.). The organisms causing chronic a n d r e c u r r e n t upper respiratory tract infections tend to form a heterogeneous group, comprising b o t h aerobic bacteria a n d Gram-positive a n d negative anaerobes, fn the present study mixed aerobic a n d anaerobic flora were obtained from almost all patients (Table I). A comparison between the core a n d surface specimens showed t h a t in m a n y instances, organisms t h a t were recovered from core cultures were also isolated from surface cultures. A total of 2 7 9 aerobic a n d 3 8 6 anaerobic isolates were recovered. It r e m a i n s controversial w h e t h e r these mixed groups of bacteria interact synergistically, e n h a n c i n g a n d prolonging the intensity of infections. 3 The role of anaerobic organisms, especially their proposed ability to protect susceptible organisms by the production of 13-1actamases a n d haemolytic streptococci, h a s been
Letters to the Editor
Fatal Myocarditis Associated with a Lancefield Group B Streptococcus Sir, We report an unusual case of fatal myocarditis associated with a Lancefield group B streptococcus (serotype Ib). A previously fit 43-year-old woman presented with a 3-day history of malaise and 24 h of persistent central chest pain radiating to her back and left arm. Initial examination revealed a body temperature of 36 °C and a blood pressure of 80/60 mmHg, normal heart sounds and no signs of cardiac failure. Electrocardiography showed sinus rhythm with a heart rate of 110 beats per minute, ST segment elevation in leads I, II, aVL and V4-V6 and ST segment depression in leads III, V1 and V2. No pathological Q waves were present. Chest radiography was normal The total white blood cell count was 12.2 x 109/1 with a neutrophil count of 11.8 x 109/1. The serum creatine kinase concentration was 2 779 iu/1. The clinical impression was that of acute myocardial infarction and aspirin, heparin and glyceryl trinitrate were given. Thrombolytic therapy was not given in view of the delayed presentation. The chest pain persisted and repeat electrocardiography 24 h later showed no resolution of the ST segment changes. Transthoracic echocardiography revealed a 1 cm thick pericardial effusion together with right atrial diastolic collapse and a hypoechoic left ventricular wall. On transfer to the Wessex Cardiothoracic Centre, examination revealed a pulse of 140/minute, a blood pressure of 100/ 50 mmHg, a raised jugular venous pressure, marked pulsus paradoxus and a pericardial rub. Electrocardiography revealed low voltage QRS complexes and persistent widespread ST segment elevation. Emergency pericardiocentesis produced 400 ml of light brown purulent liquid containing numerous white blood cells and Gram-positive cocci. Intravenous therapy with rifampicin, netilmicin and flucloxacillin was started. Despite full support, the patient deteriorated and died. Culture of pericardial aspirate and blood produced a heavy growth of Lancefield group B 13-haemolytic streptococci capsular serotype Ib, sensitive to penicillin, erythromycin and ampicillin. No viruses were isolated from the pericardial aspirate. Autopsy revealed suppurative pericarditis together with widespread mottled discolouration of the left ventricular myocardium but no evidence of endocarditis. The three main epicardial coronary arteries all showed focal atheromatous luminal stenosis of up to 75% but no occlusive thrombus. The lungs showed vascular congestion and pulmonary oedema. No alternative primary infective sites were identified. Histological examination of myocardium revealed marked oedema and widespread myocyte necrosis with a severe, diffuse mixed inflammatory cell infiltrate (as classified according to the Dallas criteria ~) composed mainly of lymphocytes and plasma cells, with small numbers of neutrophils (Figure 1) and numerous Gram-positive cocci. These changes extended into the pericardium but not the endocardium. The appearances were interpreted as those of a bacterial myocarditis with an associated suppurative pericarditis. This patient initially presented with symptoms and signs highly suggestive of acute myocardial infarction. There were no specific clinical features to suggest an infective process, although in retrospect, the widespread distribution of the ST segment changes on electrocardiography would be relatively unusual for myocardial infarction and were perhaps more consistent with pericarditis. Nevertheless, this case highlights
Figure 1. Histological appearance of myocardium at postmortem. Haematoxylin and eosin stain, showing necrotic myocytes, interstitial oedema, an inflammatory cell infiltrate and colonies of bacteria.
the capacity for infectious diseases clinically to mimic noninfectious processes. Lancefield group B streptococci are being increasingly recognized as important h u m a n pathogens. 2 Seven capsular serotypes are currently recognized (Ia, Ib, II, III, IV, V and VI)) Group B streptococci are almost always sensitive to penicillin, although the minimum inhibitory concentration may be higher than that for Group A streptococci. 4 Group B streptococci are most commonly associated with serious neonatal infections including meningitis and septicaemia, due to vertical transmission from the mother. 5 Most neonatal infections appear to be associated with serotype III, while a wide variety of serotypes may infect older children and adults. 34 The most common group B streptococcal infections in adults are pneumonia, infective endocarditis, pyelonephritis, skin and soft tissue infections and puerperal fever, 4' 6, 7 which may be acquired in hospital s and usually occurs in association with underlying diseases, including diabetes mefiitus, malignancy, HIV infection, genitourinary disorders and liver disease. 4'67 The mortality rate in adult infection (38-70%) is higher than that of neonatal infection (15%). 5'8 Cardiac infection due to Group B streptococci usually manifests as endocarditis, most commonly in immunocompromised patients. 9 Primary myocarditis associated with Group B streptococci is extremely rare, with only one previously described case occuring in an otherwise fit 29-year-old Turkish m a n ) ° In our case there was no evidence of a primary endoearditis, and although pericarditis was present, the destructive infective process was centered on the myocardium. A mixed inflammatory cell infiltrate may be observed in bacterial myocarditis 1but an underlying viral myocarditis cannot be entirely excluded, although no viruses were isolated from the pericardial aspirate. This case highlights the ability of Lancefield group B streptococci to cause life-threatening infection in adults who possess no clear predisposing factors for serious infection with unusual organisms. Such infections may progress quickly and be associated with a fatal outcome.
Letters to the Editor
Acknowledgement We thank Dr J Morgan for his permission to report this case. A. C. B a t e m a n 1, M. Richards 2, A. P. Pallett 3 Departments of 1Histopathology, 2Microbiology and 3Wessex Cardiothoracic Centre, Southampton GeneraI Hospital, Tremona Road, Southampton S 0 1 6 6YD, U.K.
References 1 Aretz HT. Billingham ME, Edwards WD et aI. Myocarditis. A histopathologic definition and classification. Am J Cardiovasc Pathol 1986; 1 : 3 14. 2 Eykyn SJ, Young SEJ, Cookson BD. Increased community-acquired septicaemic infection with group B streptococci in adults (letter). Lancet 1991; 338: 446. 3 Wessels MR, Klasper DL. The changing spectrum of group B streptococcal disease. N Engl f Med 1993; 328: 1843-1844. 4 Bayer AS, Chow AW, Anthony BF, Guze LB. Serious infections in adults due to group B streptococci. Am J Med 1976; 61: 498-503. 5 Opal SM, Cross A, Palmer M. Almazan R. Group B streptococcal sepsis in adults and infants. Arch lntern Med 1986; 148: 641-645. 6 Lerner PI, Gopalakrishna KV, Wolinsky E, McHenry MC, Tan J8, Rosenthal M. Group B streptococcus (S. agalactiae) bacteraemia in adults: analysis of 32 cases and review of the literature. Medicine 1977; 56: 457-473. 7 Farley MM, Harvey RC, Stull T et al. A population-based assessment of invasive disease due to group B streptococcus in nonpregnant adults. N Engl [ Med 1993; 328: 1807-1811. 8 Gallagher PG, Watanakunahorn C. Group B streptococcal bacteraemia in a community teaching hospital. Am J Med 1985; 78: 795-800. 9 Scully BE, Spriggs D, Neu HC. Streptococcus agalactiae (group B) endocarditis - a description of twelve cases and review of the literature. Infection 1987; 15: 169-176. 10 Von Kurnatowski HA, Sierra-Callejas JL, Henkel W, Diederich KW. Foudroyant t0dlich verlaufende myokarditis durch streptokold;en der gruppe B. Dtsch reed Wschr 1977; 103: 439-441.
Accepted for publication 25 September 1997
Incidence of ~-Iactamase Production by Oral Aerobic/ anaerobic Flora from Patients Admitted for Elective Tonsillectomy Sir, R e c u r r e n t tonsillitis is a m a j o r cause of morbidity. The purpose of the present study was to d e t e r m i n e the bacterial flora of r e c u r r e n t l y inflamed tonsils in children w i t h tonsillitis. 1 The frequency of 13-1actamase producing micro-organisms was also reported. Tonsils were r e m o v e d from paediatric patients admitted for elective tonsillectomy. Forty patients aged 4 - 1 5 were studied (one tonsil from each child). They suffered from r e c u r r e n t tonsillitis defined as at least five episodes per year in the previous 2 years or six to seven episodes in 1 year with previous episodes of tonsillitis in the preceding year. None h a d received antimicrobial t h e r a p y for at least 1 week before surgery. Each episode m u s t h a v e been characterized by one or more of the following: (a) oral t e m p e r a t u r e > 3 8 ° C ; (b) enlarged tender
355
Table I. Aerobic/anaerobic tonsillar isolates obtained from 40 patients admitted for elective tonsillectomy Organism
a. Aerobic isolates a-haemolytic Streptococci Streptococcus pneumoniae Neisseria Spp. [3-haemolytic Streptococci (S. pyogens group A) Staphylococcus aureus Coagulase-negative Staphylococci Haemophilus influenza b. Anaerobic isolates Anaerobic Grmn-negative cocci Anaerobic Gram-positive rod/cocci Peptostreptococcus Spp Fusobacterium necrophorum Anaerobic Gram-negative: Pigmented Non-pigmented
Total number of isolates Surface Core 65 2 17 10
72 3 3 8
29 (18) 15 (3) 6 (2)
40 (27) 7 (2) 2 (1)
21 2 19 49 (6)
15 14 28 35 (10)
43 (7) 61 (31)
31 (8) 69 (23)
Figures in parenthesis indicate [Mactamase-producing strains.
cervical lymphnodes w i t h episodes of tonsillitis or persistent nodes after the episode of tonsillitis ; or (c) tonsillar exudate on examination. Immediately after excision, the tonsils were placed in a sterile container; one of the tonsils was placed in a sterile Petri dish a n d held by forceps. The surface of the tonsil was r u b b e d t h o r o u g h l y with a sterile cotton swab. One side of the tonsil was cauterized with a sterile scalpel a n d a n incision was m a d e t h r o u g h t h a t area, cutting the tonsil in half. The core of the tonsil was t h e n swabbed w i t h a sterile cotton swab a n d b o t h swabs plated out o n aerobic a n d anaerobic media. Specimens were inoculated onto 5% sheep blood, chocolate a n d MacConkey's a g a r plate (Oxoid). Plates were i n c u b a t e d at 37 °C aerobically (MacConkey's) or u n d e r 5% CO2 (5% sheep's blood a n d chocolate) a n d e x a m i n e d at 2 4 a n d 48 h. For anaerobic culture, the material was plated o u t onto pre-reduced vitamin Kl-enriched Schaedlen's blood agar, a n anaerobic blood agar c o n t a i n i n g k a n a m y c i n a n d vancomycin, a n d anaerobic blood agar c o n t a i n i n g colistin a n d nalidixic acid. The anaerobic plates were i n c u b a t e d in anaerobic jars a n d e x a m i n e d at 48 a n d 96 h. Bacteria were identifed using c o n v e n t i o n a l methods as previously described. 2 13-1actamase production was studied on freshly g r o w n colonies using the c h r o m o g e n i c cephalosporin, nitrocefin (Unipath.). The organisms causing chronic a n d r e c u r r e n t upper respiratory tract infections tend to form a heterogeneous group, comprising b o t h aerobic bacteria a n d Gram-positive a n d negative anaerobes, fn the present study mixed aerobic a n d anaerobic flora were obtained from almost all patients (Table I). A comparison between the core a n d surface specimens showed t h a t in m a n y instances, organisms t h a t were recovered from core cultures were also isolated from surface cultures. A total of 2 7 9 aerobic a n d 3 8 6 anaerobic isolates were recovered. It r e m a i n s controversial w h e t h e r these mixed groups of bacteria interact synergistically, e n h a n c i n g a n d prolonging the intensity of infections. 3 The role of anaerobic organisms, especially their proposed ability to protect susceptible organisms by the production of 13-1actamases a n d haemolytic streptococci, h a s been