Affiliations: [a] Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany | [b] Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany | [c] Helmholtz Center for Infection Research, Braunschweig, Germany
Correspondence:
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Corresponding author: Dr. Maximilian Pichlmaier MA, Department for Cardiac Surgery, University Hospital Munich, Marchioninistr. 15, 81377 Munich, Germany. Tel.: +49 89 7095 2930; Fax: +49 89 7095 3465; E-mail: maximilian.pichlmaier@med.uni-muenchen.de.
Abstract: Background:Asymptomatic bacterial colonisation of medical implants is increasingly recognised. The role of the often unusual bacteria is usually unknown however. Objective and methods:During a three-year period, patients presenting with clinically evident CIED lead endocarditis and/or pocket infections were included in a prospective database. Using 16s DNA analysis and sequencing, devices and pockets of consecutive patients with evident CIED infection were examined for the presence of bacterial species in addition to the ones grown in conventional culture in order to characterise their clinical role. Results:During the study 77 of a total of 409 consecutive operations involving the explantation of a CIED were performed for clinically evident infection. 71 were included in the study and conventional extended culture and 16s DNA analysis performed and compared. In 42.3% of the patients bacteria were identified by DNA analysis in addition to the culture of the supposedly causative organisms. Conclusion:DNA analysis is more sensitive than conventional culture of swabs in detecting any, or indeed multiple bacterial strains in CIED infection. This may in future influence treatment strategies as e.g. the cohabitation of different strains seems common and is not reflected by classical culture results. Spread of infection along the leads was clearly demonstrated and this strongly supports the recommendation of complete removal of all CIED components in every form of CIED infection. The more unusual bacteria demonstrated here do not appear to play a significant clinical role as suspected earlier.
