The isolation rate of Gram negative bacteria was 25.5 for Escherichia coli with 13 isolates, 19.6 for Pseudomonas aeruginosa with 10 isolates, and 13.7 for Klebsiella pneumoniae with 7 isolates, most of which were isolated from grade III fractures. The isolation rate of P. aeruginosa was 60 6 isolates from grade IIIA and 71.4 5 isolates from grade IIIB for K. pneumoniae, while for E. coli it was 69.2 9 isolates from grade IIIC. ...