Appropriate initial antibiotic treatment based on early diagnosis of etiology will improve the outcome of sepsis. The incidence rates of multidrug-resistant (MDR) bacteria, which are different between countries, will affect the accuracy of etiological diagnoses according to the American Thoracic Society (ATS) guidelines. Therefore the investigators determined the accuracy of the ATS criteria in predicting infection or colonization related to MDR bacteria in China.

All data concerning patient characteristics at ICU admission and during ICU stay were prospectively collected.Screening for MDR bacteria (using nasal swabs, tracheal aspirates from intubated patients and specimens from the infection location) was performed at ICU admission and discharge. Risk factors for infection or colonization with MDR bacteria were recorded, and the accuracy of the ATS criteria in predicting infection or colonization with these bacteria at ICU admission was documented. All of the infected patients were treated by the attending physician, and the choice and adjustment of antibiotic were in accordance with the recommendations of the ATS guidelines.

Inclusion Criteria:

• All patients hospitalized in the ICU were eligible for this study

Critically ill patients admitted to icu