The investigation of mutation of outer membrance oprD gene in clinical imipenem resistant Pseudomonas aeruginosa

Objective To study the mutations of outer-membrane porin gerte (oprD) in imipenem-resistant Pseudomonas aeruginosa.Methods The PCR was applied to detect the oprD gene from the 34 clinical imipenem-resistant Pseudomonas aeruginosa.DNA sequence was proceeded to analysis the nuclentide sequence of the oprD gene and the deduced amino acid sequence.To analysis the mutation and the function of the oprD domain,those mutations were compaired with the standard Pseudomonas aeruginosa ATCC27853 and 2 clinical imipenem-susceptibility isolates.Results oprD gene mutation was wide and diverse.The rate of the mutation was 92.3% (12/13),mutations were concluded dot mutation,deletion mutation and insert mutation,those result in the amino sequence change and frame shift in L2 and L3 loops of outer membrane protein D,hampering the combine of oprD and imipenem.Some new mutations were found.They were 1 079,1 114,1 196,1 206,1 288,1 300,1 301 bases and 115,127,154,158,185,189 aminos.All above mutations were not deteced in ATCC 27853 and 2 clinical imipenem-susoeptibility isolates.Conclusions The wide and diverse mutations in oprD gene result in amino acid change and/or frame shift L2 and L3 loops,hampering the binding of IMP and oprD.Those may result in resistance to imipenem in Pseudomonas aeruginosa. Key words: Pseudomonas aeruginosa; Proteins; lmipenem; Drug resistance,bacterial; Mutation