A Case of Infective Endocarditis Caused by Citrobacter koseri: Unraveling a Rare Pathogen and Dire Outcome.

Citrobacter koseri (formerly classified as Citrobacter diversus) is a gram-negative bacillus (GNB) that occurs as an opportunistic pathogen in neonates and immunocompromised patients. Citrobacter species have been implicated in nosocomial settings leading to infections involving the urinary tract, respiratory tract, liver, biliary tract, meninges, and even in rarer conditions-blood stream infection and infective endocarditis (IE). Gram-negative bacilli are responsible for 3% to 4% of all IE cases and have been traditionally associated with intravenous drug users. Patients with non-HACEK (species other than Haemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, or Kinglella species) GNB IE have poor clinical outcomes with higher rates of in-hospital mortality and complications. The American Heart Association (AHA) and Infectious Diseases Society of America (IDSA) both recommend the use of combination antibiotic therapy with a beta-lactam (penicillins, cephalosporins, or carbapenems) and either an aminoglycoside or fluoroquinolones for 6 weeks (about 1 and a half months) to treat IE due to non-HACEK GNB. Citrobacter koseri is becoming more recognized due to its inherent resistance to ampicillin and emerging drug resistance to beta lactams and aminoglycosides requiring carbapenem therapy. Our case is of a 75-year-old male with no previously reported history of primary or secondary immunodeficiency disorders who developed C koseri blood stream infection. His infectious work-up revealed mitral valve IE and septic cerebral emboli resulting in ischemic infarcts. This case illustrates the importance of recognizing GNB organisms as rising human pathogens in IE cases even without active injection drug use or nosocomial exposure.

An evaluation of Rezafungin: the latest treatment option for adults with candidemia and invasive candidiasis.

INTRODUCTION: Invasive fungal infections, especially candidemia and invasive candidiasis, continue to cause substantial morbidity and mortality. In addition, the emergence of drug-resistant Candida species, notably C. glabrata and C. auris, along with limitations in available treatments, highlights the urgent need for novel, effective antifungal agents. AREAS COVERED: This review discusses the results of in vitro studies evaluating the spectrum and highlights the pharmacokinetic/pharmacodynamic properties. It also includes discussions on two key clinical studies that assess safety, tolerability, and efficacy. EXPERT OPINION: Rezafungin has demonstrated comparable efficacy to other echinocandins in two clinical studies and exhibits in vitro activity against a broad range of Candida species and Aspergillus spp. It has a favorable safety profile with minimal side effects, and no drug interactions or effects on QT intervals. In contrast to other echinocandins, it demonstrates dose-dependent killing, a prolonged half-life, and low clearance make it suitable for once-weekly dosing, which is supported by clinical trials confirming its efficacy. Rezafungin offers a promising option for the outpatient management of difficult to treat fungal infections. It has become a valuable addition to the antifungal arsenal, with the potential to reduce hospital length of stay and hospitalization costs and combat drug-resistant Candida species.

Evaluation of Short Versus Long Courses of Antibiotics in Critically Ill Patients With Gram-Negative Bloodstream Infections.

BACKGROUND: Short courses of antibiotics (7-10 days) are effective for uncomplicated gram-negative bloodstream infections (GN-BSI). However, prior studies have been limited to small cohorts of critically ill patients. OBJECTIVE: The objective of this study was to evaluate the safety and efficacy of short courses of therapy compared with longer courses in patients admitted to the intensive care unit (ICU) with GN-BSI. METHODS: Propensity-matched, retrospective cohort study of critically ill patients with GN-BSI. The primary outcome was a composite of 30-day mortality or 60-day relapse. Secondary endpoints were components of the composite, 30-day relapse, cure with or without adverse drug events (ADE), and ADEs. Regression analysis was performed to identify factors predictive of the composite outcome. RESULTS: 225 patients were included in the propensity analysis, 145 in the long cohort and 80 in the short cohort. The primary outcome occurred in 3.8% of patients in the short group and 9.0% of patients in the long group (P = 0.24). There was no difference in 30-day mortality (3.8% vs 5.5%, P = 0.79), 60-day relapse (0% vs 3.4%, P = 0.23), or 30-day readmission (20% vs 22.8%, P = 0.76). ADEs were more common in the long group (47.2% vs 34.1%, OR 1.7, 95% CI 1.04-2.9), primarily attributable to diarrhea. CONCLUSION AND RELEVANCE: In critically ill patients with GN-BSI, there were no efficacy outcome differences in patients treated with a short course of antibiotics compared with longer. However, patients in the short group were less likely to experience ADE. These findings suggest that short courses of antibiotics are effective for GN-BSI in critically ill patients.