Citrobacter pneumonia

Citrobacter pneumonia is an uncommon lower respiratory tract infection caused by Gram-negative bacilli of the genus *Citrobacter*, most frequently *Citrobacter freundii* or *Citrobacter koseri* It primarily occurs as an opportunistic, nosocomial infection in hospitalized patients, mechanically ventilated individuals, neonates, elderly populations, and immunocompromised hosts with significant comorbidities

Citrobacter pneumonia is an uncommon lower respiratory tract infection caused by Gram-negative bacilli of the genus *Citrobacter*, most frequently *Citrobacter freundii* or *Citrobacter koseri* It primarily occurs as an opportunistic, nosocomial infection in hospitalized patients, mechanically ventilated individuals, neonates, elderly populations, and immunocompromised hosts with significant comorbidities Pathophysiologically, colonization and subsequent invasion of the pulmonary parenchyma trig...

It primarily occurs as an opportunistic, nosocomial infection in hospitalized patients, mechanically ventilated individuals, neonates, elderly populations, and immunocompromised hosts with significant comorbidities

Pathophysiologically, colonization and subsequent invasion of the pulmonary parenchyma trigger alveolar inflammation and tissue damage, often presenting with fever, dyspnea, hypoxemia, purulent sputum production, and radiologic evidence of pulmonary infiltrates or consolidation

Because *Citrobacter* species frequently possess chromosomal AmpC beta-lactamases or other multi-drug resistance mechanisms, the infection can follow an aggressive clinical course and is often complicated by lung cavitation, empyema, bacteremia, and septic shock

Because *Citrobacter* species frequently possess chromosomal AmpC beta-lactamases or other multi-drug resistance mechanisms, the infection can follow an aggressive clinical course and is often complicated by lung cavitation, empyema, bacteremia, and septic shock