To characterize class 1 integrons in multi-drug resistant (MDR) P. aeruginosa in an intensive care unit of a teaching hospital. 23 strain of MDR P. aeruginosa recovered from patients in intensive care unit (ICU) were collected during 2008. The gene cassettes and antibiotic susceptibility of the isolates were characterized. All isolates were also subjected to pulsedfield gel electrophoresis (PFGE). Class 1 integrons were detected in 14 isolates (60.9%). Three types of gene cassettes were identified among these strains

including one that has not been reported previously. The vast majority of the cassettes encoded aminoglycoside resistance gene

including aacA4

aadA2

aadB

aac6Ⅱ.Most of isolates were classified into five PFGE patterns

type A (n=6); type B (n=6); type C (n=4); type D (n=2) and type E (n=2).The present study illustrates that integrons appear to be a common feature among MDR P. aeruginosa in Guangzhou of China

and associated with a high prevalence of antibiotic resistance. Our data also suggested that crossinfection of MDR P. aeruginosa was a challenging work in ICU.