Drug-Resistant Gram-Positive Cocci as Etiological Factors of Cardiac Implantable Electronic Device Infections-Data from the EXTRACT Registry.

INTRODUCTION

Bacterial multidrug resistance (MDR) drives treatment with expensive, toxic, or pharmacokinetically suboptimal antibiotics.

OBJECTIVES

To assess the prevalence of MDR Gram-positive cocci among isolates from cardiac implantable electronic device (CIED) infections at a Polish reference center.

METHODS

Data come from the "EXTRACT" registry (ClinicalTrials.gov ID NCT05775783), which covers 702 transvenous lead extraction procedures. Blood samples and intraoperative swabs were collected from participants with CIED infection.

RESULTS

From 209 cases with isolated pocket infection (PI) (107, 51.2%) or systemic infections (102, 48.8%), 263 Gram-positive cocci were cultured. They were: coagulase-negative staphylococci (CoNS) (177, 67.3%), Staphylococcus aureus (62, 23.6%), enterococci (15, 5.7%), streptococci (8, 3.0%), and others (1, 0.4%). The highest MDR rate was among CoNS (46.9%). CoNS exhibited methicillin resistance (MR-CoNS) in 55.9% with co-resistance to macrolides (73.2%), lincosamides (51.0%), fluoroquinolones (56.1%), aminoglycosides (41.4%), tetracyclines (29.6%), and co-trimoxazole (29.3%). Resistance to daptomycin (5.3%) and linezolid (2.0%) in MR-CoNS was rare. The frequency of MDR S. aureus was 8.1%. Methicillin resistance in S. aureus (MRSA, 6.5%) co-occurred with resistance to macrolides/lincosamides and fluoroquinolones (100% for both) or linezolid (25.0%). All MDR staphylococci were vancomycin-susceptible. High-level aminoglycoside resistance (HLAR) in Enterococcus faecalis (53.8%) was accompanied by levofloxacin co-resistance (66.7%). Conversely, E. faecium HLAR (50.0%) strains showed 100.0% β-lactam resistance. Vancomycin-resistant enterococci (VRE) accounted for 6.7%; the VRE E. faecium strain was tigecycline- and linezolid-susceptible. Among viridans group streptococci, β-lactam and lincosamides resistance was common (40.0% for both), with 50.0% of co-resistance.

CONCLUSIONS

Epidemiological data may improve the effectiveness of empirical antibiotic therapy for CIED-related infections.