Rare disease
CASE REPORT
Abiotrophia defectiva endocarditis Jodian Amor Pinkney,1 Rajeev Peeyush Nagassar,2 Karen Judith Roye-Green,3 Trevor Ferguson1 1
Department of Medicine, University Hospital of the West Indies, Kingston, Jamaica 2 Department of Microbiology, The Eastern Regional Health Authority, Sangre Grande, Trinidad and Tobago 3 Department of Microbiology, The University of the West Indies, Kingston, Jamaica Correspondence to Dr Jodian Amor Pinkney, [email protected] Accepted 28 November 2014
SUMMARY A previously healthy 27-year-old Jamaican man presented to the University Hospital of the West Indies with recurrent joint pain, remitting and relapsing fever, and shortness of breath. He was subsequently found to have Abiotrophia defectiva endocarditis. This was the first time this organism had been isolated at our institution. Despite culture directed antibiotics, his clinical course was quite severe with mitral regurgitation and congestive cardiac failure requiring mitral valve replacement. He recovered well postoperatively and is currently being followed at our outpatient cardiology clinic. This report highlights the severe presentation and often poor outcome associated with A. defectiva endocarditis and stresses that the outcome may be improved by early and appropriate surgical intervention. BACKGROUND
To cite: Pinkney JA, Nagassar RP, Roye-Green KJ, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014207361
Endocarditis due to Abiotrophia defectiva is quite rare, but accounts for up to 6% of streptococcal endocarditis and some cases of culture negative endocarditis.1–5 Previously, A. defectiva fell under the ‘umbrella’ group of nutritionally variant streptococci (NVS), which were initially described in 1961 by Freckle and Hirsch.6 7 In 1989, Bouvet et al used DNA–DNA hybridisation to divide NVS into Streptococcus defectivus and Streptococcus adjacens based on DNA homology.1 These were later transferred to a new genus, Abiotrophia, using 16s rRNA sequencing.8 Collins and Lawson9 have reclassified the genus Abiotrophia with A. defectiva as the only species in this genus. Classically, A. defectiva has been described as non-motile, Gram-positive cocci in chains that are catalase negative, pyridoxine dependent and exhibit satellitism.10 11 A. defectiva has been identified as part of the normal flora of the human oral cavity, gastrointestinal tract and urogenital tract.7 12 There is a propensity for these organisms to cause bacteraemia and infective endocarditis, but they have also been implicated in other infections such as sinusitis, osteomyelitis, corneal ulcers and scrotal abscesses.10 Although an uncommon cause of endocarditis, the clinical outcome can be severe, with need for early surgical intervention.13 This report describes the first case of A. defectiva infection identified in Jamaica, and highlights its propensity to cause endocarditis, the delays in identification and the fact that isolation may require more advanced microbiological diagnostic methods.
CASE PRESENTATION A 27-year-old man, with no prior history of illness, presented to his general practitioner with a
3-month history of intermittent fever, night sweats, joint pain, central chest pain, palpitations, shortness of breath and paroxysmal nocturnal dyspnoea. Two months prior, he had noticed clubbing of his fingers and toes and had transient ‘black and blue’ discolouration of the tip of the third digit of his left hand. There was no prior history of sore throat, dental procedures, skin rash, injection drug use or congenital heart disease. He had no history of travel outside of Jamaica. He had been prescribed a nonsteroidal anti-inflammatory drug by his general practitioner but this provided no relief. He was subsequently referred to the accident and emergency department of the University Hospital where a murmur was detected prompting referral to the cardiology clinic. At the cardiology clinic, physical examination revealed mucosal pallor and a grade three on six (III/VI) apical pansystolic murmur, in keeping with mitral regurgitation. A portable transthoracic echocardiogram was performed, which showed a 2.0 cm oscillating mass attached to the anterior mitral leaflet. The leaflet was flail and prolapsed into the left atrium. There was associated moderate posterior mitral regurgitation. The left ventricular systolic function was normal. Right ventricular systolic pressure (RVSP) was elevated at 50 mm Hg. The patient was then admitted with a presumptive diagnosis of infective endocarditis (IE). He was empirically started on ceftriaxone and gentamicin. On admission, his vital signs were within normal range. Laboratory findings on admission are found in table 1. Three sets of blood cultures were taken and all six bottles grew Gram-positive cocci. After 9 days of repeated attempts, A. defectiva was identified with low discrimination using the Vitek 2 system (bioMerieux). After identification of the organism, the patient had been switched to vancomycin only for suspected penicillin/cephalosporin resistance. The isolate was subsequently found to be sensitive to penicillin, ampicillin, coamoxiclav, ceftriaxone, gentamicin, erythromycin and vancomycin. The antibiograms of the six isolates were the same. As such, ceftriaxone was restarted with erythromycin, as gentamicin was not available at the time. Despite culture directed antibiotic therapy the patient’s condition gradually deteriorated, eventually resulting in severe congestive heart failure on day 16 of admission. He was treated with lisinopril 5 mg once daily and furosemide 20 mg once daily. A repeat echocardiogram showed an increase in the size of the oscillating vegetation from the previously seen 2.0–2.4 cm and an increase in
Pinkney JA, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2014-207361
1
Rare disease Table 1 Laboratory findings on admission
ESR CRP Antistreptolysin O VDRL HIV Urinalysis Serum Fe TIBC Percentage of saturation
On admission
Normal ranges
47 0.43 281↑ negative negative No abnormality 8 51 16
CASE REPORT
Abiotrophia defectiva endocarditis Jodian Amor Pinkney,1 Rajeev Peeyush Nagassar,2 Karen Judith Roye-Green,3 Trevor Ferguson1 1
Department of Medicine, University Hospital of the West Indies, Kingston, Jamaica 2 Department of Microbiology, The Eastern Regional Health Authority, Sangre Grande, Trinidad and Tobago 3 Department of Microbiology, The University of the West Indies, Kingston, Jamaica Correspondence to Dr Jodian Amor Pinkney, [email protected] Accepted 28 November 2014
SUMMARY A previously healthy 27-year-old Jamaican man presented to the University Hospital of the West Indies with recurrent joint pain, remitting and relapsing fever, and shortness of breath. He was subsequently found to have Abiotrophia defectiva endocarditis. This was the first time this organism had been isolated at our institution. Despite culture directed antibiotics, his clinical course was quite severe with mitral regurgitation and congestive cardiac failure requiring mitral valve replacement. He recovered well postoperatively and is currently being followed at our outpatient cardiology clinic. This report highlights the severe presentation and often poor outcome associated with A. defectiva endocarditis and stresses that the outcome may be improved by early and appropriate surgical intervention. BACKGROUND
To cite: Pinkney JA, Nagassar RP, Roye-Green KJ, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014207361
Endocarditis due to Abiotrophia defectiva is quite rare, but accounts for up to 6% of streptococcal endocarditis and some cases of culture negative endocarditis.1–5 Previously, A. defectiva fell under the ‘umbrella’ group of nutritionally variant streptococci (NVS), which were initially described in 1961 by Freckle and Hirsch.6 7 In 1989, Bouvet et al used DNA–DNA hybridisation to divide NVS into Streptococcus defectivus and Streptococcus adjacens based on DNA homology.1 These were later transferred to a new genus, Abiotrophia, using 16s rRNA sequencing.8 Collins and Lawson9 have reclassified the genus Abiotrophia with A. defectiva as the only species in this genus. Classically, A. defectiva has been described as non-motile, Gram-positive cocci in chains that are catalase negative, pyridoxine dependent and exhibit satellitism.10 11 A. defectiva has been identified as part of the normal flora of the human oral cavity, gastrointestinal tract and urogenital tract.7 12 There is a propensity for these organisms to cause bacteraemia and infective endocarditis, but they have also been implicated in other infections such as sinusitis, osteomyelitis, corneal ulcers and scrotal abscesses.10 Although an uncommon cause of endocarditis, the clinical outcome can be severe, with need for early surgical intervention.13 This report describes the first case of A. defectiva infection identified in Jamaica, and highlights its propensity to cause endocarditis, the delays in identification and the fact that isolation may require more advanced microbiological diagnostic methods.
CASE PRESENTATION A 27-year-old man, with no prior history of illness, presented to his general practitioner with a
3-month history of intermittent fever, night sweats, joint pain, central chest pain, palpitations, shortness of breath and paroxysmal nocturnal dyspnoea. Two months prior, he had noticed clubbing of his fingers and toes and had transient ‘black and blue’ discolouration of the tip of the third digit of his left hand. There was no prior history of sore throat, dental procedures, skin rash, injection drug use or congenital heart disease. He had no history of travel outside of Jamaica. He had been prescribed a nonsteroidal anti-inflammatory drug by his general practitioner but this provided no relief. He was subsequently referred to the accident and emergency department of the University Hospital where a murmur was detected prompting referral to the cardiology clinic. At the cardiology clinic, physical examination revealed mucosal pallor and a grade three on six (III/VI) apical pansystolic murmur, in keeping with mitral regurgitation. A portable transthoracic echocardiogram was performed, which showed a 2.0 cm oscillating mass attached to the anterior mitral leaflet. The leaflet was flail and prolapsed into the left atrium. There was associated moderate posterior mitral regurgitation. The left ventricular systolic function was normal. Right ventricular systolic pressure (RVSP) was elevated at 50 mm Hg. The patient was then admitted with a presumptive diagnosis of infective endocarditis (IE). He was empirically started on ceftriaxone and gentamicin. On admission, his vital signs were within normal range. Laboratory findings on admission are found in table 1. Three sets of blood cultures were taken and all six bottles grew Gram-positive cocci. After 9 days of repeated attempts, A. defectiva was identified with low discrimination using the Vitek 2 system (bioMerieux). After identification of the organism, the patient had been switched to vancomycin only for suspected penicillin/cephalosporin resistance. The isolate was subsequently found to be sensitive to penicillin, ampicillin, coamoxiclav, ceftriaxone, gentamicin, erythromycin and vancomycin. The antibiograms of the six isolates were the same. As such, ceftriaxone was restarted with erythromycin, as gentamicin was not available at the time. Despite culture directed antibiotic therapy the patient’s condition gradually deteriorated, eventually resulting in severe congestive heart failure on day 16 of admission. He was treated with lisinopril 5 mg once daily and furosemide 20 mg once daily. A repeat echocardiogram showed an increase in the size of the oscillating vegetation from the previously seen 2.0–2.4 cm and an increase in
Pinkney JA, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2014-207361
1
Rare disease Table 1 Laboratory findings on admission
ESR CRP Antistreptolysin O VDRL HIV Urinalysis Serum Fe TIBC Percentage of saturation
On admission
Normal ranges
47 0.43 281↑ negative negative No abnormality 8 51 16
