Study On The Characteristics Of Extended Spectrum β-Lactamases From Enterobacter Cloacae And The Inhibitory Effects Of Deoxyribozyme On β-Lactamase Gene Expression

OBJECTIVE:To study the characteristics of extended spectrumβ-lactamase from Enterobacter cloacae and the inhibitory effects of deoxyribozyme(10-23 DRz) onβ-lactamase gene expression.METHODS:59 clinical isolates of Enterobacter cloacae were identified by the API20-E system. MIC was determined with the standard agar dilution technique, Theβ-lactamases of clinical isolates were screened by Nitrocefin. A modified three-dimensional test was used to detect isolates which produced AmpCβ-lactamases and ESBLs.Conjungation experiment was performed between clinical isolates and E.coli JM109, the plasmid was extracted by alkaline lysis method. blaSHV, blaCTX-M and blaTEM genes were amplified by PCR and sequenced. The gene ofβ- lactamase was cloned into pBK-CMV vector and expressed in E. coli JM109. The...