The Analysis of Expression and Antibiotic Susceptibilities of CTX-M-38 Type Extended-Spectrum-Lactamase / 天津医药

ABSTRACT

Objective: To express CTX-M-38 type extended-spectrum-lactamase, and detect its distribution and antibiotic susceptibilities. Methods: Total of 46 strains producing ESBL E.coli was collected from the first affiliated hospital of Zheng zhou University. The CTX-M-38 ESBL gene was selected by PCR using gene recombination technique to construct pET28a-CTX-M-38. The expression of CTX-M-38 in BL21 E.coli and its antibiotic susceptibilities were carried out by liquid dilution test. Testing the enzyme activities of culture supernatant and bacteria sonicate to reflect its distribution. Results: The size of amplified gene product was about 900 bp. The DNA sequence was matched with the information of gene bank. The enzyme activities from bacteria sonicate were stronger than the culture supernatant .The transformant was resistance to penicillins, the first, second and third generations of cephalosporins. It was sensitive to imipenem. The transformant was also sensitive to ceftazidime and aztreonam in vitro, and resistance to antibiotics including beta-lactamase inhibitors except piperacillin/tazobactam. The transformant was also resistance to gentamicin,minocycline, ciprofloxacin and levofloxacin. Conclusion: The CTX-M-38 type ESBL is successfully expressed at designed experimental condition in this study. The product mainly lies inside the bacteria. The transformant shows wide resistance to antibiotics.