A 4-year surveillance of antimicrobial resistance patterns of Acinetobacter baumanni in a university-affiliated hospital in China

摘要

Objectives: To investigate the changes in resistance of Acinetobacter baumanni ( A. baumannii ) to different antimicrobial agents and the association of resistance rates with several independent factors: specimen origin, hospital wards, patients’ gender and age, from 2008 to 2011. Methods: Bacterial isolates were isolated from January 2008 to December 2011 in the First Affiliated Hospital of Nanjing Medical University. Antimicrobial susceptibility testing was determined by the Kirby-Bauer Disk Diffusion Agar method as recommended by CLSI. Data were managed by the software WHONET 5.4 and analyzed by SPSS 17.0 software. Results: The proportion of A. baumannii in our hospital increased from 7.0% in 2008 to 18.8% in 2011, becoming the most frequent pathogen in gram-negative isolates. 79.9% of A. baumannii were cultured from respiratory tract and geriatrics showed the highest isolation rate of A. baumannii during 4 years. The resistance rates to 12 antibiotics significantly increased from 2008 to 2011, from 14.8% to 90.8% to imipenem, and from 23.3% to 91.1% to meropenem. Statistical analysis demonstrated that the specimen origin, hospital wards, patients' gender and age were associated with resistance rate in varying degrees. Conclusions: The 4-year surveillance of antimicrobial susceptibility demonstrated the rapid increase of drug-resistant strains of A. baumannii , and revealed several factors related with resistance rate. Knowing the antimicrobial resistance patterns will help guide the empirical therapy and strengthen interventional infection control measures in China.