Indian Journal of Medical Microbiology, Vol. 29, No. 1, January-March, 2011, pp. 71-72
RA Swann, S Bhattacharya
Department of Microbiology, Leicester Royal Infirmary, LE1 5WW, United Kingdom
Correspondence Address: R A Swann, Department of Microbiology, Leicester Royal Infirmary, LE1 5WW, United Kingdom, email@example.com
Date of Submission: 24-Sep-2009
Code Number: mb11018
We report two cases of vancomycin-dependent Enterococcus faecium (VDE) bacteraemia [Figure - 1] a. and b. The first case was a 76-year-old, insulin-dependent diabetic man whose coronary artery bypass grafting was complicated by small bowel infarction and renal failure. Methicillin-resistant Staphylococcus aureus and Enterococcus sp. were cultured from urine and an abdominal drain site, respectively. He had received prolonged (18 days) treatment with intravenous vancomycin along with other agents (piperacillin-tazobactam, followed by ciprofloxacin, metronidazole, fluconazole) at the time VDE bacteraemia was detected.
The second case was a 39-year-old man who developed acute respiratory distress syndrome, renal failure and lung abscess, following diesel aspiration. He received extracorporeal membrane oxygenation (ECMO) for 29 days and ventilation for 40 days and was treated with ciprofloxacin and imipenem. Vancomycin-resistant Enterococcus sp. was isolated from a left groin cannula and left internal jugular central line site. VDE was subsequently detected from blood culture. Management in both cases consisted of withdrawal of vancomycin therapy and nursing of patients in isolation side rooms.
VDE arises following therapy with vancomycin. These strains have previously been isolated from stool, urine and blood cultures in seriously ill (burns, peritonitis, pancreatitis) or immunocompromised (transplantation) patients. , Nosocomial infection and outbreaks have been reported in bone marrow transplant units and such strains may be typed using pulsed field gel electrophoresis. , DNA sequencing has detected DDL gene mutation (e.g. P175L) or deletion (e.g. 1 bp deletion of d-Ala:d-Ala ligase gene or 18 bp deletion of VanSB gene) among VDE strains. ,, The growth of these fastidious organisms can be supported by vancomycin, ristocetin, DADA (d-Ala:d-Ala), but not necessarily by teicoplanin.  Spontaneous revertants away from vancomycin dependence can occur at a frequency of 1 in 10 6 .  Awareness of the existence of these strains is important, especially in the context of long-term vancomycin therapy and suspected presence of "nutritionally deficient" organisms.
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