Abstract: OBJECTIVE To investigate the distribution and drug resistance of pathogens causing pulmonary infections in patients with Alzheimer 's disease and analyze the related risk factors so as to provide guidance for prognosis of the patients with Alzheimer 's disease.METHODS A total of 66 Alzheimer 's disease patients complicated with pulmonary infections who were treated in the hospital from Jul 2010 to Feb 2016 were enrolled in the study.The bacterial culture and drug susceptibility testing were carried out for the patients, the distribution and drug resistance of the pathogens isolated from the patients with infections were observed, and the related risk factors for the infections were analyzed.RESULTS Totally 106 strains of pathogens were isolated from the 66 patients, of which 82 (77.36%) were gram-negative bacteria, 18 (16.98%) were gram-positive bacteria, and 6 (5.66%) were fungi; Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa were dominant among the gram-negative bacteria, accounting for 38.68%, 11.32%, and 11.32%, respectively; Staphylococcus aureus and Staphylococcus warneri were the predominant species of the gram-positive bacteria, accounting for 6.60% and 4.72%, respectively.The drug resistance rates of the gram-negative bacteria to imipenem and meropenem were less than 9.00%, and the drug resistance rates of the gram-positive bacteria to vancomycin was 0.The results of univariate analysis and multivariate analysis indicated that the risk factors for the pulmonary infections in the patients with Alzheimer 's disease included the more than 70 years of age, complication with diabetic mellitus, long bedridden time, length of hospital stay more than 1 month, long disease course, and smoking history.CONCLUSIONThe complication with pulmonary infections may reduce the lung function of the patients with Alzheimer 's disease and result in chronic brain hypoxia diseases, cerebral cortical vascular damage, and decline of brain's ability to regulate the breathing as well, which is also the leading cause of the bacteria not to be easily removed from the lungs.It is of great clinical significance for the prognosis of patients with Alzheimer 's disease to investigate the distribution and drug resistance of the pathogens causing the pulmonary infection and analyze the risk factors.