Native mitral valve endocarditis associated with KPC producing Serratia marcescens bacteremia successfully treated with mitral valve replacement and ceftazidime-avibactam

Recurrent relapsing remitting Serratia marcescens infective endocarditis in a former drug-using patient

Unusual course of Serratia marcescens (SM) infectious endocarditis (IE) and literature review (2016-2024; 26 cases). A 44-year-old man, with chronic venous ulcers, presented 21/2 years after a MSSA tricuspid valve IE, a tricuspid and aortic valves SM IE . After 6 weeks of antibiotherapy (meropenem i.v., 2 g/6 h), he presented a relapse (same sensitivity pattern), complicated by tibio-peroneal trunk aneurysm. He underwent a biological tricuspid valve replacement. Fifteen months later, he presented a recurrent SM IE, (same sensitivity pattern), complicated by a popliteal artery aneurysm. An aortic-tricuspid bioprosthetic valve replacement was performed. At one-year, there was no sign infection. The occurrence of both relapsing and recurrence, and of infectious aneurysms in SM IE are highlighted. However, these findings must be interpreted with caution, due to the lack of molecular typing. Literature shows that a regimen combining a beta-lactam and either fluoroquinolone or an aminoglycoside seems to warrant a less mortality rate.

Gram-negative endocarditis: disease presentation, diagnosis and treatment

PURPOSE OF REVIEW

Gram-negative bacilli (GNB) cause between 1% and 10% of infective endocarditis (IE). Most episodes are caused by microorganisms of the Haemophilus spp., Aggregatibacter spp. Cardiobacterium spp., Eikenella spp., and Kingella spp (HACEK) group. The frequency of IE caused by non-HACEK (GNB-IE) has increased in recent years. Uncertainties persist regarding its best medical treatment and the appropriateness and timing of surgical treatment. In addition, there are new drugs with activity against multiresistant microorganisms, of which there is little experience in this disease. We review this topic by answering the most frequently asked questions that arise among our colleagues.

RECENT FINDINGS

HACEK microorganisms cause 1.5-2% of IE with only a 2% mortality. In contrast, non-HACEK GNB-IE accounts for 2.5-3% of all IE cases and is associated with nosocomial acquisition, advanced age, solid organ transplantation and 20-30% mortality. Drug addiction is important in areas with epidemic opioid abuse.

SUMMARY

The frequency of IE caused by GNB has been modified in recent years. HACEK episodes are no longer treated with ampicillin and aminoglycosides. In non-HACEK GNB-IE, combination therapy with a beta-lactam and a quinolone or aminoglycoside is recommended. The surgical indication and its value are evident in many patients. Management should rely on a collaborative group with experience in this disease.