Pseudomonas aeruginosa and Klebs ielia pneumoniae were the main pathogenic bacteria for infection and 48.2%of th e cases were combined with fungus infection.

• 2.；铜绿假单孢菌及克雷伯氏杆菌属是本院下呼吸道感染的主要致病菌，且合并真菌感染率高(48