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.

Esophageal Rupture Presenting with ST Segment Elevation and Junctional Rhythm Mimicking Acute Myocardial Infarction.

Esophageal rupture is a rare but potentially fatal cause of chest pain. The presentation is variable and can mimic other conditions such as aortic dissection, pulmonary embolism, and myocardial infarction (MI). A 71-year-old male with a history of coronary artery disease presented to the ED with complaints of acute chest pain and respiratory distress. Over the next 48 hours, the patient developed dynamic ST segment changes on surface electrocardiogram mimicking an inferolateral ST segment elevation MI accompanied by a junctional rhythm. Curiously, his cardiac enzymes remained negative during this time, but his clinical status continued to deteriorate. A subsequent CT scan demonstrated a lower esophageal rupture, and the patient underwent successful endoscopic stenting. While rare, prompt recognition of esophageal rupture is imperative to improving morbidity and mortality. While esophageal rupture has been noted to cause ST segment elevation before, this appears to be the first case associated with a junctional rhythm.