1Meziani, Z., 1Hassaine, H., and 2Belhachemi, F.
1Laboratory of Applied Microbiology in Food, Biomedical and Environment (LAMAABE), University of Tlemcen, Algeria
2Department of Cardiology, Hospital of Tlemcen, Algeria
*Correspondence to: zahera_fd@yahoo.fr; 00213553406801
Abstract:
Background: The significant increase in the use of implantable cardiac devices (ICDs) has been accompanied by biofilm formation and increase rate of infection on the devices. The purpose of our study is to describe the clinical and microbiological findings of infection of ICDs in the cardiology units of western Algeria hospitals.
Methodology: All patients with clinical diagnosis of ICD infections or infective endocarditis upon removal of their ICDs from December 2012 to August 2014 in cardiology units of 4 Algerian hospitals were included in the study. Each element of the ICD pocket and lead was separately sonicated in sterile saline, inoculated onto Chapman and MacConkey agar plates and incubated aerobically at 37oC for colony count after 24 hours. Biochemical identification of the bacteria isolates was made by API 20E, API 20 NE and API Staph, and confirmed by Siemens Healthcare Diagnostics WalkAway® 96 Plus System. Antibiotic susceptibility testing on each isolate was performed by the disk diffusion method on Mueller Hinton agar. Biofilm formation was detected by Congo Red Agar (CRA) and Tissue Culture Plate (TCP) methods, and hydrophobicity of the bacterial cell was determined by the MATH protocol.
Results: Over a period of twenty-one months, 17 ICDs were removed from patients with post-operative infections; 6 (35.3%) had early infection of ICD and 11 (64.7%) had late ICD infection. Fifty-four bacterial strains were isolated and identified, with coagulase-negative staphylococci being the predominant bacteria with 46.3% (25/54). There was no significant association between hydrophobicity and antimicrobial resistance in the 54 isolates but there is positive correlation between biofilm production and antimicrobial resistance, with the strongest biofilm producers resistant to more than one antibiotic. Four independent predictors of infection of resynchronization devices were reported; reoperation, multi-morbidity, long procedure, and ICD implantation.
Conclusion: Our study is the first in Algeria to describe microbiological characteristics of ICD infection. The bacteria in the biofilm were protected, more resistant and tolerated high concentrations of antibiotics and thus played a major role in the development of ICD infections. Despite the improvements in ICD design and implantation techniques, ICD infection remains a serious challenge.
Keywords: implantable cardiac devices, staphylococci, resistance, biofilm, hydrophobicity Continue reading “Infections of implantable cardiac devices by biofilm forming bacteria in western Algeria hospitals”