Construction of ompW knock-out mutants of Escherichia coli to increase sensitivity to neomycinsulphate and ampicillin
大肠杆菌外膜蛋白ompW基因敲除菌的构建及其对两种抗生素的敏感性

Objective]To investigate the contribution of an outer membrane protein OmpW to tolerance neomycinsulphate and ampicillin of Escherichia coli K12.Methods] The ompW knock-out mutant(ΔompW) of E.coli K12 was generated using λ-Red recombination system.Then the minimal inhibitory concentration(MIC) and the survival rates under 1/2 MIC of neomycinsulphate or ampicillin of ΔompW and E.coli K12 were determined respectively.Results] The ΔompW was successfully obtained through confirmation of PCR analysis at the gene level and Western blot analysis at the protein level.The MIC of neomycinsulphate of ΔompW is 1.7 μg/mL.The value is much lower than that of E.coli K12,which is 8.0 μg/mL.Difference of survival rates under 1/2 MIC of neomycinsulphate of ΔompW and E.coli K12 was also observed,and their survival rates are 39% and 98%,respectively.The MIC of ampicillin of ΔompW is 3.3 μg/mL.The value is also lower than that of E.coli K12(16.0 μg/mL).The survival rates under 1/2 MIC ampicillin of ΔompW and E.coli K12 are 30.3% and 70.38%,respectively.Conclusion] The ΔompW is much more sensitive to neomycinsulphate and ampicillin than its parent strain.The result indicated that OmpW played crucial role in bacteria resistance of drug.