Left-sided native valve Staphylococcus aureus endocarditis

Despite improved diagnostic tools and expanded treatment options, left-sided native valve endocarditis caused by Staphylococcus aureus infection remains a serious and destructive disease. The high morbidity and mortality, however, can be reduced by early recognition, correct diagnosis, and appropriate treatment. In the following article, we discuss the clinical presentation, diagnostic workup and treatment of infective endocarditis, thereby reviewing the current guidelines. Blood cultures and echocardiography are the cornerstones of diagnosis in identifying infective endocarditis but are no substitute for clinical judgement. The modified Duke criteria may facilitate the diagnostic process, but clinical evaluation remains crucial.     

Successful treatment of MRSA native valve endocarditis with oral linezolid therapy: a case report

Staphylococcal endocarditis is potentially fatal and is now the most common cause of infective endocarditis with a mortality rate of 25-47% [Hecht SR, Berger M. Right-sided endocarditis in intravenous drug users: prognostic features in 102 episodes. Ann Intern Med 1992;117:560-6]. Its treatment requires maintenance of bactericidal level of antibiotics for prolonged periods to attain a culture-negative state. Although intravenous vancomycin is currently the drug of choice for methicillin resistant Staphylococcus aureus (MRSA) endocarditis, we present a case treated successfully with oral linezolid for 4 weeks due to a lack of venous access.     

An unusual right-sided endocarditis: a case report of eustachian valve endocarditis

Thienopyridines and aspirin are beneficial in patients undergoing bare-metal stent implantation, and aspirin and clopidogrel treatment have also been proved effective after drug-eluting stent (DES) implantation. However, despite the common substitution of clopidogrel with ticlopidine because of cost or patient intolerance, there are no data on the comparison of ticlopidine vs. clopidogrel after DES implantation. We hereby compare ticlopidine vs. clopidogrel after paclitaxel-eluting stent implantation in subjects enrolled in the prospective multicenter Taxus in Real-life Usage Evaluation (TRUE) Study. Across the 505 analyzed patients (112 treated with ticlopidine and 393 with clopidogrel), similar rates of early and mid-term (7 months) adverse thrombotic events were found with either antiplatelet regimen, with the notable exception of 2 cases of late stent thrombosis in patients who had prematurely withdrawn ticlopidine treatment just 3 months after the procedure. These findings thus support the overall safety and effectiveness of ticlopidine after DES implantation, and also confirm the increased risk of late thrombosis when premature withdrawal of thienopyridines occurs.     

Staphylococcus lugdunensis native tricuspid valve endocarditis: a case report and review of literature

Coagulase negative staphylococci are skin commensals and are generally disregarded as contaminants in clinical specimens. Repeated isolation of coagulase negative staphylococci in blood cultures should warrant a species identification to recognize unusually virulent organisms that demand aggressive treatment, such as Staphylococcus lugdunensis. Staphylococcus lugdunensis is known to cause a wide variety of infections, including a predominant left-sided endocarditis. We report a rare case of native tricuspid valve Staphylococcus lugdunensis endocarditis in a non-intravenous drug user and include a brief literature review.     

Treatment of infective endocarditis caused by methicillin-resistant Staphylococcus aureus: teicoplanin versus vancomycin in a retrospective study

Infective endocarditis caused by methicillin-resistant Staphylococcus aureus (MRSA) is increasing. Vancomycin and teicoplanin are 2 intravenous glycopeptides appropriate for its treatment. There is no human study comparing teicoplanin and vancomycin for the treatment of MRSA endocarditis. Between 1996 and 2006, 51 MRSA endocarditis patients were treated at the authors' hospital. There were 29 patients with nosocomial infection; 15 were treated with teicoplanin. Teicoplanin was used as the first therapeutic agent in 3 patients because of renal insufficiency. Vancomycin was used as the first therapeutic agent in 12 patients. Treatment was changed to teicoplanin because of adverse reactions in 10 and persistent bacteremia in 2 patients. Early operation was performed in 2 patients because of persistent MRSA bacteremia. Overall, 7 patients died in hospital. There was no statistically significant difference in hospital mortality rate (42% vs 47%) and bacteriologic failure rate (34% vs 40%) between 36 patients treated with vancomycin and 15 patients treated with teicoplanin. Teicoplanin can be an alternative therapy of MRSA infective endocarditis.     

Treatment failure of methicillin-resistant Staphylococcus aureus endocarditis with linezolid

We report a case of methicillin-resistant Staphylococcus aureus endocarditis treated by vancomycin and cotrimoxazole switched to oral linezolid alone with a complete resolution of the vegetation. Two months after discontinuation of treatment, the patient presented a relapse confirmed by pulsed-field gel electrophoresis involving the same linezolid-susceptible strain and rapidly died.     

Community-associated methicillin-resistant Staphylococcus aureus endocarditis 'down under': case series and literature review

Infective endocarditis is a common complication of Staphylococcus aureus bacteraemia, but literature reports of community-associated methicillin-resistant S. aureus (CA-MRSA) endocarditis are relatively uncommon and mostly comprise intravenous drug users (IVDUs) with the USA300 strain. We report 5 cases of CA-MRSA endocarditis in previously healthy young Australian adults, 4 in IVDUs. Morbidity was high with frequent septic emboli; 3 patients required cardiac surgery and 1 patient died. Typing revealed the 2 most common Australian strains, the Panton-Valentine leukocidin (PVL)-positive ST93 (Queensland) strain and the PVL-negative ST1 (WA-MRSA-1) strain.     

Successful treatment of Staphylococcus aureus bacterial endocarditis in a renal transplant recipient

We report the successful treatment of Staphylococcus aureus endocarditis in a renal transplant recipient with preservation of his renal allograft. A 44‐year‐old man presented to the emergency room with sudden onset of fevers and rigors 7 weeks after renal transplantation. Infective endocarditis was diagnosed by Duke's Criteria (Durack et al. New criteria for the diagnosis of infective endocarditis. Am J Med 1994: 96: 200–209) with multiple positive blood cultures for S. aureus and a mitral valve vegetation on transesophageal echocardiogram. He was treated with intravenous antibiotics for 6 weeks with continuation of his immunosuppression. He has remained clinically stable for over 5 years. Although the treatment of S. aureus endocarditis in immunosuppressed transplant patients has traditionally resulted in loss of their allograft, prompt diagnosis and appropriate antibiotics with continued immunosuppressive therapy resulted in a successful outcome and allograft preservation in this case.     

Prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis and Micrococcus species successfully treated with rifampicin combined with other antibiotics

Two patients with prosthetic valve endocarditis due to methicillin-resistant Gram-positive cocci (Staphylococcus epidermidis and Micrococcus spp.) are described. They were successfully treated with rifampicin combined first with an aminoglycoside and later with co-trimoxazole or co-trimoxazole plus vancomycin. The addition of rifampicin to these antibiotics resulted in enhanced serum bactericidal activity. High doses of rifampicin (1200-1800 mg) for 7-8 weeks did not cause any serious side-effect. Surgery was not required. During surveillance for more than 2 years endocarditis did not recur.     

Emergence of teicoplanin resistance during therapy of Staphylococcus aureus endocarditis

Serial isolates of Staphylococcus aureus showing two- to eightfold increases in teicoplanin minimum inhibitory concentrations (MICs) and twofold or less increases in MICs of other glycopeptides were recovered from the blood of a patient with endocarditis in whom drug therapy was unsuccessful. Comparable resistance emerged during teicoplanin treatment of rabbits with endocarditis caused by the original susceptible parent strain. For the parent strain, spontaneous resistance to teicoplanin at concentrations of 2-10 times the MIC was detected in vitro at frequencies of 10(-7) to 10(-9). Similar results were found for isolates of S. aureus from other geographic locations. Resistance was constitutive and not plasmid mediated, and its acquisition was not associated with changes in cytoplasmic membrane proteins. Teicoplanin was less effective than vancomycin at inhibiting peptidoglycan synthesis in resistant strains, suggesting that there is differential interference with the access of teicoplanin to or interaction with its target(s). Alternatively, teicoplanin and vancomycin may differ in some detail(s) of their mechanism of action against S. aureus.     

Testicular swelling with pneumonia and septicaemia: a rare presentation of right-sided endocarditis

As far as we are aware, right-sided bacterial endocarditis has not previously been described as presenting with systemic illness and testicular swelling. We report a teenager who presented with this unusual combination as a consequence of right-sided endocarditis. He presented with high fever, with chills and rigor, along with painful enlargement of the left testicle, a productive cough with progressive breathlessness, and joint pains. His blood culture was positive for Staphylococcus aureus, and a computerised tomographic scan of the chest revealed multiple pulmonary emboluses. Ultrasound of the testicles showed features of inflammation, and an echocardiogram revealed a vegetation on the tricuspid valve.     

Nosocomial methicillin-resistant Staphylococcus aureus endocarditis with splenic abscess in a pregnant woman

A 36-year-old, 7-week-gravida patient with catheter-related nosocomial infective endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA) is presented in this paper. The patient was admitted to our hospital because of carbon monoxide intoxication. After 14 days, MRSA catheter-related bacteremia developed. The central venous catheter was immediately removed, and teicoplanin therapy was started. Because of persistent fever, leukocytosis, and high C-reactive protein values, endocarditis was suspected. A transesophageal echocardiogram revealed 19-mm vegetation on her mitral valve, confirming the diagnosis of endocarditis. Gentamicin and rifampicin were added to the therapy regimen, and the dose of teicoplanin was increased to 12 mg/kg-day. After 8 days, a splenic abscess was detected by ultrasonography. Vegetation excision, mitral valve replacement by open-heart surgery and splenectomy were performed in the same operation. Antibiotherapy was continued for 6 weeks after surgery, and the patient's condition improved. The development of endocarditis could be prevented by proper clinical practices.     

Successful salvage therapy with daptomycin after linezolid and vancomycin failure in a liver transplant recipient with methicillin-resistant Staphylococcus aureus endocarditis

Abstract: Infective endocarditis is a rare complication affecting solid organ transplant recipients. Staphylococcus aureus is a common cause of infective endocarditis accounting for about 30% of cases. We present a case of nosocomial methicillin-resistant S. aureus endocarditis with persistent bacteremia, in a patient following orthotopic liver transplantation. We were unable to eradicate this infection with primary linezolid therapy or with secondary treatment with combined vancomycin and rifampicin, but successfully treated it with daptomycin, in addition to tricuspid and aortic valve replacement.