A preliminary study on outer membrane permeation of multiple-antibiotic-resistant Proteus mirabilis
- VernacularTitle:多重耐药奇异变形杆菌外膜通透性改变的初步研究
- Author:
Bei JIA
;
Yuanshu QIAN
- Publication Type:Journal Article
- Keywords:
Proteus mirabilis;
Outer membrane protein;
Drug resistance;
Drug uptake;
Ultrastructure
- From:
Chinese Journal of Infectious Diseases
2000;18(3):155-158
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the alterations of outer membrane permeation of multiple-antibiotic-resistant Proteus mirabilis.Methods Laboratory-derived cefotaxime-resistant mutants were induced by serial passages of clinical isolated susceptible Proteus mirabilis on cefotaxime-containing agar.Thereafter,the outer membrane proteins(OMP)of the parental strains and mutants were analyzed by sodium dodeeyl sulfate-polyacrylamide gradient gel electrophresis(SDS-PAGE)and the uptake of ciprofloxacin (CPLX)was determined with high pressure liquid chromatography(HPLC).Lastly,morphological analysis was performed by scanning and transmission electron microscopy.Results Compared with the parental strains.the mutants wete resistant to quinolones,cephalosporins and penicillins;the content of OMP with relative molecular weight 40 000 was reduced and that of 37 000 0MP was increased.The uptake of CPLX was reduced and the ratios of peak concentration were decreased to 1:1.74,1:1.53 compared with that of suseeptible strains.CPLX concentration absorbed was lower than the break point 1 mg/L of resistance and the difference of CPLX intracellular concentration between resistant and susceptible strains was less than 2 times.which resulted in much more increase of minimum inhibitory concentrations(MICs).Meanwhile,it was observed under electronic microscopy that resistant strains lost the rodlike shape and had more distinctive membrane fold,wider periplasmic space and les8 nucleiods.Conclusion The multiple-antibiotic-resistant Proteus mirabilis shows decrease of drug uptake and changes of ultrastructure,which may be related to alterations of outer membrane permeation.
