| Abstract: | This research was aimed to investigate the effect of rosemarinic acid combined with antibacterial agents against bacterial carrying gene fosA3 in vitro.Resistance gene types were determined by identification of bacteria isolated in clinics.Antibacterial activity and fungicidal activity of rosemarinic acid were tested by oxford cup method and spread-plate method.The minimal inhibiton concertration (MIC) of rosemarinic acid and antibacterial agents were tested through twice micro-dilution method,fractional inhibitory concentration index (FICI) of rosemarinic acid combined with antibacterial agents were determined by microdilution checkerboard techniques.Escheriohia coli carrying multidrug resistance gene fosA3 was isolated.The MIC of rosemarinic acid was 640 μg/mL,when application of rosemarinic acid combined with ciprofloxacin,levofloxacin,coly-mycin,gatifloxacin,amikacin,ceftazidime,ceftiofur sodium,FICI≤0.5,showed an additive effect;With ceftriaxone sodium,norfloxacin,mequindox,0.5fosA3 Escheriohia coli.Antibacterial activities of antibacterial agents against the fosfomycin resistance gene fosA3 Escherichia coli were enhanced significantly by rosemarinic acid. |
