Changing trend of antimicrobial resistance among pathogens isolated from lower respiratory tract at a university-affiliated hospital of China, 2006-2010

Objective: To investigate the distribution and the antimicrobial resistance of pathogens in lower respiratory tract infection from 2006 to 2010.

Methods: The sputum specimens from inpatients with lower respiratory tract infection in the First Affiliated Hospital of Nanjing Medical University during the past five years were cultured and identified; the antimicrobial resistance was analyzed by the software WHONET 5.4.

Results: A total of 12,191 isolates were characterized in sputum samples: 73.5% were Gram-negative bacteria, 13.7% were Gram-positive bacteria, and 12.8% were fungi. The isolation rate of Acinetobacter was significantly increasing from 12.8% in 2006 to 26.4% in 2010. The Gram-negative bacterial resistance rate to the second and third generation cephalosporin increased year by year. Decreasing trend, 78.7% in 2006 decreased to 63.5% in 2010 (R²=0.93 and P<0.01), in resistance to clindamycin against Staphylococcus aureus was observed. Worth noting is the drug resistance of Acinetobacter and Klebsiella pneumoniae to carbapenem significantly increased (R²>0.3 and P≤0.05).

Conclusions: The antimicrobial resistance of pathogens in lower respiratory tract infection increased in recent years. The hospitals and government departments should strengthen management of the use of some antibiotics, such as the second/third generation cephalosporin and carbapenem, in order to enhance the effectiveness of medication.