Abstract
Infective endocarditis caused by Abiotrophia defectiva is rarely encountered. A 67-year-old male transferred from a local hospital presented with severe dyspnea and pulmonary edema. Preoperative transthoracic echocardiography revealed severe mitral regurgitation with large vegetation. Blood cultures grew A. defectiva, a gram positive, nutritionally deficient streptococcus variant. Emergent mitral valve replacement through right thoracotomy was performed, and after completing six weeks of antibiotic combination therapy (vancomycin, ampicillin, and gentamicin), the patient recovered fully. Because of the need for prompt surgical treatment and long-term antibiotic therapy and lack of laboratory experience with the organism, physicians and laboratory workers should pay close attention to the possibility of A. defectiva infective endocarditis when gram positive cocci are detected in blood cultures. (Ann Clin Microbiol 2019;22:23-27)
Keywords
Abiotrophia defectiva Infective endocarditis Nutritionally variant streptococci
Acknowledgements
This work was supported by the annual clinical research grant from Pusan National University Yangsan Hospital.
Figures & Tables
Table 1. Summary of reported cases of
Pt. no. | Age (yr) | Sex | Pre-existing heart diseases | Other predisposing medical conditions | Identification methods of bacterium | Involved valves & surgery | Valve type | Antibiotics | Publication yr | References |
1 | 67 | M | No | No | MALDI-ToF/MS | MVR | Mechanical | VCM+AMP+GM | The current case | |
2 | 60 | M | Hypertrophic obstructive cardiomyopathy, hypertension | No | ND | Mitral valve/no surgery | - | CRO+GM | 2018 | 9 |
3 | 31 | M | No | Intravenous drug abuser | ND | MVR | Mechanical | AMP+GM | 2017 | 10 |
4 | 59 | F | Ventricular septal defect | No | ND | PVR, AVR, MVP, TAP | Bioprosthesis | CRO+AMP | 2017 | 11 |
5 | 18 | M | No | No | ND | AVR, MVR, Heart transplantation | Bioprosthesis | CRO+VCM | 2017 | 12 |
6 | 41 | M | Ventricular septal defect | ND | ND | PVR, AVR, MVR | Bioprosthesis | PG+GM | 2017 | 13 |
7 | 26 | F | No | Pregnancy(postpartum), fixed teeth brace | Vitek 2 Compact Analyzer | MVR | Mechanical | Broad spectrum antibiotics | 2017 | 14 |
8 | 52 | M | Mitral valve prolapse | Arterial hypertension | Polymerase chain reaction | MVR | Mechanical | AMP+GM | 2016 | 1 |
9 | 42 | F | Rheumatic heart disease | No | ND | AVR, MVR | ND | AMP/SB+GM | 2016 | 15 |
10 | 65 | M | Systolic/diastolic heart failure with intracardiac device (ICD) | No | MALDI-ToF/MS | Removal of ICD leads was impossible | - | PG+CM | 2016 | 16 |
11 | 50 | M | Myxomatous mitral valve/mitral insufficiency | Tooth extraction | Vitek 2, 16S rRNA sequencing | MVR | Bioprosthesis | VAN+GM | 2016 | 17 |
12 | 25 | F | Mitral valve prolapse/mitral insufficiency | Tooth extraction | Vitek 2, 16S rRNA sequencing | MVP | - | CRO+RIF+GM | 2016 | 17 |
13 | 62 | F | Rheumatic mitral stenosis/mitral valve regurgitation | Tooth extraction | MALDI-ToF/MS | MVR | Mechanical | VCM+GM | 2016 | 18 |
14 | 78 | M | Mitral regurgitation/ischemic heart disease | COPD, hypertension, hypercholesterolemia | ND | Mitral valve/no surgery | - | PG+GM | 2016 | 19 |
15 | 39 | F | No | Pregnancy (14th gestation week) | ND | MVR | Mechanical | AMP+GM | 2016 | 20 |
16 | 74 | M | No | No | ND | AVR, MVR | Mechanical | AMP | 2015 | 4 |
17 | 35 | M | Ventricular septal defect | ND | Culture negative, metagenomic analysis | PVR, AVR, MVR | ND | AMP/SB+GM | 2015 | 21 |