Construction On E.coli OmpF Gene Deletion Strains And Its Analysis Of Drug Resistance In Yunnan Saba Pigs

Out membrane protein F（OmpF）is one of the major outer membrane proteins ofEscherichia coli, the diameter is1nm. Many nutrients and most of the β-lactam antibioticsdiffuse to thallus by this channel. The target molecules of β-lactam antibiotics are penicillinbinding proteins (PBPs) that located on the cell membrane of bacteria. The drug resistanceof gram negative bacteria is connecting to the production of β-lactamase and the existenceof outer membrane. The depress or lose of bacterial membrane pore protein expression willcause antibiotic resistance of the bacteria to β-lactam antibiotics.While gene knockouttechnology is an important means to study gene function.To study the effect of gene OmpFin the E. coli’s drug resistance to β-lactams, in this study, by the technology of λ phageRED recombination system, we constructed the E. coli OmpF gene deletion strains using E.coli strains that our laboratory saved.To study the relationship bettween OmpF andβ-lactams, drug sensitivity assay and MIC experiment were used to compare E.coli geneOmpF and missing strains’ resistance to beta-lactam antibiotics.The result shows that weconstruct the OmpF gene deletion strains successfully. The drug sensitivity assays test ofantibiotic resistance to E.coli gene OmpF and missing strains showed that the parentalstrain is sensitive to CZ，CFP，AMP，MPN，IPM，CRO，CAZ and VI in the β-lactamantibiotic, and the OmpF gene deletion strains is medium sensitive to CZ，MPN，AMP，CAZ，with drug resistance to CFP，CRO and VI..OmpF gene deletion strains is sensitiveto IPM，but the inhibition zone is reduced.The MIC test of antibiotic resistance to E.coli gene OmpF and missing strains showed that the parental strain is sensitive to CZ，CFP，AMP，CRO，CAZ and CTX，and the OmpF gene deletion strains is medium sensitive to CZand CAZ，with drug resistance to CFP，AMP，CRO and CTX.The drug sensitivity of CROparental strain is more than64times than deletion strains.The result indicates that thecompars on of OmpF gene deletion and parental strains in E.coli, the OmpF gene deletionstrains have a various extent in the resistant to β-lactam antibiotics.