Native valve endocarditis due to coagulase-negative staphylococci. Clinical and microbiologic features

Area of Science:

• Infectious Diseases
• Cardiology
• Microbiology

Background:

• Native valve endocarditis (NVE) is a serious infection.
• Coagulase-negative staphylococci (CoNS) are increasingly recognized as pathogens in NVE.
• Many patients with CoNS NVE have underlying valvular or congenital heart disease.

Purpose of the Study:

• To investigate the clinical presentation, complications, and outcomes of NVE caused by CoNS.
• To evaluate the antibiotic susceptibility patterns of CoNS isolates from patients with endocarditis.
• To highlight the importance of identifying CoNS in blood cultures as a potential indicator of endocarditis.

Main Methods:

• Retrospective study of 21 patients with NVE due to CoNS.
• Clinical data collection on patient demographics, comorbidities, presentation, complications, and treatment.
• Microbiologic analysis of CoNS isolates, including antibiotic susceptibility testing.

Main Results:

• Frequent complications observed, including arterial emboli (5/21), conduction abnormalities (9/21), and congestive heart failure (8/21).
• High cure rates achieved with both medical (10/12) and surgical (7/9) management.
• All isolates were susceptible to vancomycin; antibiotic resistance (methicillin, gentamicin, rifampin) was noted, often linked to nosocomial infections.

Conclusions:

• CoNS in blood cultures should not be dismissed as contamination and may signify life-threatening endocarditis.
• Careful antibiotic selection, including testing for cryptic beta-lactam resistance, and management of intracardiac complications are vital for successful treatment.
• Valve replacement may be frequently necessary in managing CoNS endocarditis.