Antibiotic resistance in nosocomial pulmonary pathogens

Nosocomial pneumonia is the second most common hospital-acquired infection and are associated with antibiotic-resistant microrganisms. In nosocomial pneumonia, both the diagnosis of the disease and the identification of the pathogen agent are controversial. The lack of standard diagnostic criteria can lead to the inappropriate use of broad-spectrum antibiotic therapy and the emergence of multiresistant bacteria. Moreover, empirical antibiotic treatment must be prescribed after bacteriological sample but before culture results because the majority of nosocomial pneumonias require an urgent antibiotic therapy. Most nosocomial pneumonias are of an endogenous origin, particularly in mechanically ventilated patients, and this is associated with a higher rate of multiresistant methicillin-resistant Staphylococcus aureus, Acinetobacter baumanii, Klebsiella pneumoniae with extended spectrum b-lactamases, and Pseudomonadaceae. Multiple factors influence the frequency of pathogens associated with antibiotic resistance, such as duration of hospital stay, time of onset, prior antibiotic therapy, and local microbial ecology.