Effect of Copperleaf Water Extractions Combined with Antibacterial Agents on Escherichia coli Containing Fosfomycin Resistance Gene FosA3

YAO Xiaoyun;SONG Jianwu;XIA Juan;QIN Yan;HUANG Liyun;LI Haiyan;HUANG Kai;SI Hongbin;College of Animal Science and Technology,Guangxi University;

Copperleaf;;antibiotics;;fosA3 gene;;combined induction;;minimal inhibitory concentration;;FICI

This research was aimed to investigate the effect of Copperleaf water extracts combined with antibiotics against bacteria carrying multidrug resistance gene fos A3 in vitro. Resistance gene types were determined by identification of bacteria isolated in clinics. The minimal inhibiton concertration( MIC) of water extracts of Copperleaf and antibacterial agents were tested through twice micro-dilution method. Escherichia coli containing Fos A3 were induced and subcultured by the 1 /2 MIC of water extracts of Copperleaf combined with antibacterial agents. Fractional inhibitory concentration indexes( FICI) of extracts combined with antibacterial agents were determined by microdilution checkerboard techniques. The results showed that Escheriohia coli carrying multidrug resistance gene fos A3 was isolated. The MIC of water extracts from Copperleaf was 0. 5 g / m L,the MIC of antimicrobial significantly decreased and all fell below1. 562 5 after 3 times of passages by 0. 25 g / m L extracts combined with 14 antimicrobial. When Copperleaf water extracts were applied with ceftriaxone sodium,fosfomycin,colymycin,sulfamonomethoxine,ceftazidime and ceftiofur sodium,the FICI were less than or equal to 0. 5. Andwith amoxicillin,ciprofloxacin,norfloxacin,levofloxacin,mequindox,clinafloxacin,amikacin,and florfenicol,the FICI were more than0. 5 and less than 1. The antibacterial activities of antibacterial agents against the Fos A3 from Escherichia coli were enhanced significantly by water extracts of Copperleaf,and showed additive effect or synergistic activity correlation.