Abstract:Objective To study the classification of pathogenic strains and drug sensitivity of hospital acquired pneumonia in ICU. Methods 350 cases of pathogenic bacteria isolated from clinical sputum samples of hospital acquired pneumonia from January to December 2018 in target department were collected, and systematic retrospective investigation was carried out to analyze the classification of pathogenic bacteria strains and the results of drug sensitivity. Results Gram-negative bacilli(58.3%) were isolated from clinical sputum, among which Acinetobacter baumannii(28.4%)was the most, followed by Klebsiella pneumonia(25.5%), Pseudomonas aeruginosa(20.6%), Escherichia coli1(18.1%), and some strains produced ESBLs and resistant to carbapenem. Gram-positive bacteria were mainly Staphylococcus aureus(45.9%), followed by Staphylococcus haemolyticus(21.4%), Enterococcus faecium(15.3%). Fungi include Candida albicans(39.6%), smooth Candida(16.7%), nearly smooth Candida(12.5%). The study found that old age, indwelling artificial airway and hypoproteinemia were the risk factors of MDR, and the difference was statistically significant(p＜0.05). Conclusion Gram-negative bacteria were the main pathogens of hospital acquired pneumonia in ICU. However, the emergence of multidrug resistant pathogens increased the difficulty of clinical anti-infection treatment, and the rational use of antibiotics should be advocated in clinic.To control the emergence and delay the spread of drug-resistant bacteria, it needed to strengthen drug resistance monitoring and drug use, pay attention to hand hygiene, reduce invasive operation, strictly carry out disinfection and isolation measures.