Prosthetic Valve Endocarditis Caused by Metallo-β-Lactamase-ProducingPseudomonas Aeruginosa

‘TAVR Infected Pseudomonas Endocarditis’: a case report

Pseudomonas aeruginosa (P. aeruginosa) rarely causes infective endocarditis (IE), previously reported for approximately 3% of all patients with IE.¹ Most commonly, the infection occurs in intravenous drug users (IVDU) as right-sided endocarditis, noting presentations of P. aeruginosa IE without history of intravenous drug to be extremely rare, finding only a few cases reported in the literature. However there are increasing reports of cardiovascular implantable electronic device–related and prosthetic heart valve infections caused by this pathogen in non-IVDUs.² This report will focus on the clinical presentation, management, and outcome of P. aeruginosa endocarditis in an 89-year-old patient with a transcatheter aortic valve replacement (TAVR). Medical management was pursued due to the patient’s underlying comorbidities. Long-term suppressive antibiotic therapy with delafloxacin was successful in maintaining negative blood cultures, despite an allergy to levofloxacin and ciprofloxacin.

Non-nosocomial healthcare-associated left-sided Pseudomonas aeruginosa endocarditis: a case report and literature review

Background

With the development of invasive medical procedures, an increasing number of healthcare-associated infective endocarditis cases have been reported. In particular, non-nosocomial healthcare-associated infective endocarditis in outpatients with recent medical intervention has been increasingly identified.

Case presentation

A 66-year-old man with diabetes mellitus and a recent history of intermittent urethral self-catheterization was admitted due to a high fever. Repeated blood cultures identified Pseudomonas aeruginosa, and transesophageal echocardiography uncovered a new-onset severe aortic regurgitation along with a vegetative valvular structure. The patient underwent emergency aortic valve replacement surgery and was successfully treated with 6 weeks of high-dose meropenem and tobramycin. Historically, most cases of P. aeruginosa endocarditis have occurred in the right side of the heart and in outpatients with a history of intravenous drug abuse. In the case presented, the repeated manipulations of the urethra may have triggered the infection. Our literature review for left-sided P. aeruginosa endocarditis showed that non-nosocomial infection accounted for nearly half of the cases and resulted in fatal outcomes as often as nosocomial cases. A combination therapy with anti-pseudomonal beta-lactams or carbapenems and aminoglycosides may be the preferable treatment. Medical treatment alone may be effective, and surgical treatment should be carefully considered.

Conclusions

We presented a rare case of native aortic valve endocarditis caused by P. aeruginosa. This case illustrates the importance of identifying the causative pathogen(s), especially for outpatients with a recent history of medical procedures.

Pseudomonas aeruginosa infective endocarditis in patients who do not use intravenous drugs: Analysis of risk factors and treatment outcomes

BACKGROUND

Infective endocarditis (IE) due to Pseudomonas aeruginosa is rare and accounts for only about 3% of all patients with this disease. Most infections are associated with the use of intravenous drugs. Patients with P. aeruginosa-related IE who do not use intravenous drugs are extremely rare. We carried out a review of the literature to identify the nature and risk factors of this disease.

METHODS

Patients with IE reported between 1993 and 2013 were reviewed by searching the Medline database using the keywords "endocarditis" and "Pseudomonas aeruginosa". All of the patients included met the definition of the modified Duke criteria.

RESULTS

Twenty-seven patients in 22 reports were reviewed. IE associated with health care accounted for 20 patients (74%). The mean age of the patients was 53.4 years and there was a predominance of men (81.5%). Native valve endocarditis was seen in 20 (74.1%) patients. Surgery for infection control was performed in 15 (55.6%) patients and the mortality rate in patients who underwent surgery was 33.3% (five patients). A relapse of IE after adequate treatment was seen in nine (33.3%) patients. The mortality rate in all 27 patients was 28.6% (2/7) for those with community-acquired IE and 40% (8/20) for those with IE associated with health care. Univariate analysis showed a higher mortality rate in patients aged >60 years and in those whose source of endocarditis was related to a prosthetic device.

CONCLUSION

P. aeruginosa endocarditis has substantial morbidity and mortality. It is characterized by easy relapse and is highly associated with prosthetic devices.

Controlling the spread of carbapenemase-producing Gram-negatives: therapeutic approach and infection control

Although the rapid spread of carbapenemase-producing Gram-negatives (CPGNs) is providing the scientific community with a great deal of information about the molecular epidemiology of these enzymes and their genetic background, data on how to treat multidrug-resistant or extended drug-resistant carbapenemase-producing Enterobacteriaceae and how to contain their spread are still surprisingly limited, in spite of the rapidly increasing prevalence of these organisms and of their isolation from patients suffering from life-threatening infections. Limited clinical experience and several in vitro synergy studies seem to support the view that antibiotic combinations should be preferred to monotherapies. But, in light of the data available to date, it is currently impossible to quantify the real advantage of drug combinations in the treatment of these infections. Comprehensive clinical studies of the main therapeutic options, broken down by pathogen, enzyme and clinical syndrome, are definitely lacking and, as carbapenemases keep spreading, are urgently needed. This spread is unveiling the substantial unpreparedness of European public health structures to face this worrisome emergency, although experiences from different countries-chiefly Greece and Israel-have shown that CPGN transmission and cross-infection can cause a substantial threat to the healthcare system. This unpreparedness also affects the treatment of individual patients and infection control policies, with dramatic scarcities of both therapeutic options and infection control measures. Although correct implementation of such measures is presumably cumbersome and expensive, the huge clinical and public health problems related to CPGN transmission, alongside the current scarcity of therapeutic options, seem to fully justify this choice.