Abstract: Objective: To discover the extended spectrum beta-lactamases (ESBLs) gene types and the characteristics of Acinetinbacter lwoffi strains which were highly resistant to most kinds of antibiotics and to compare the differentiation in nucleotide and amino acid sequences to show the possible influence in laboratory. Methods: Three strains of A.lwoffi with ESBLs phenomenon were isolated from patients′ sputum suffering from respiratory infection. The genes of blaTEM, SHV, OXA, IMP and CTX-M were determined by PCR. Nucleotide sequences were detected by ABI automated sequencer and analyzed by the DNA star software to compare the differentiation in nucleotide and amino acid sequences. Results: The bla-TEM gene type was determined in two strains, but the blaTEM, SHV, OXA, IMP and CTX-M genes were not determined in another strain. Amplified nucleotide sequences of TEM genes were 1012bp and 1007bp, respectively. The identical rate was 98.2%. There were 17 pairs different in them. The blaTEM gene, 832bp, coded for 277 amino acids. Among them, 8 amino acids were different, which mainly happened on Asp, Gly and Ser, substituted by His, Arg/Ala and Cys. They had pI value of 5.479 and 5.083, respectively. Conclusion: The blaTEM gene presented in A.lwoffi highly resistant strains in Shandong province. However, they produce some differentiations in nucleotide and amino acid sequences. These differentiations influence some conditions of laboratory method to pick up the resistant strains.

Key words: Acinetobacter lwoffi, extended spectrum beta-lactamases, nucleotide, amino acid, differentiation