Objective:To study the risk factors of nosocomial respiratpory tract infections caused by Stenotrophomonas Maltophilia(SM)and to guide the treatment of SM infections by drugs sensitivity tests.

• 目的：探讨嗜麦芽窄食单胞菌(SM)院内呼吸道感染的危险因素及其药敏结果，指导治疗。