Carriage of disinfectant resistance genes in clinically isolated Escherichia coli and minimal inhibitory concentration of five disinfectants / 中国感染控制杂志

ABSTRACT

Objective To understand the disinfectant resistance of clinically isolated Escherichia coli (E.coli)and carriage of disinfectant resistance genes.Methods Disinfectant resistance gene sugE (c ),sugE (p ),qacEΔ1 ,and qacE of 82 isolates of E.coli were detected with polymerase chain reaction (PCR),minimal inhibitory concentra-tions (MICs)were measured with agar dilution methods.Results Among 82 E.coli isolates,positive rates of dis-infectant resistance gene sugE (c ),sugE (p ),qacEΔ1 ,qacE,sugE (c )+qacEΔ1 ,and qacE+qacEΔ1 +sugE (c ) were 84.15% (n=69),1 .22% (n=1),76.83% (n=63),73.17 % (n=60),68.29% (n=56),and 59.76% (n=49)respectively.There was no significant differences in carriage status of four disinfectant resistance genes be-tween extended-spectrumβ-lactamases (ESBLs)-producing and non-ESBLs-producing strains,as well as cefepime sensitive and resistant strains (all P >0.05);MIC values of benzalkonium chloride,cetylpyridinium chloride,am-monium bromide,and triclosan for 82 isolates of E.coli were all > standard stain;MIC values of chlorhexidine for 32 isolates of E.coli were all > standard stain,for 50 other E.coli strains were all ≤ standard strain.There were no significant difference in MIC values of benzalkonium chloride,cetylpyridinium chloride,ammonium bromide,and triclosan between ESBLs-and non-ESBLs-producing strains,as well as cefepime sensitive and resistant strains(all P >0.05);while MIC values of chlorhexidine showed a significant difference (both P <0.05).Conclusion Detection rates of disinfectant resistance gene qacE,qacEΔ1 ,and sugE(c)in E.coli from clinical specimens are high,MICs of disinfectants such as benzalkonium chloride for E.coli are generally higher than standard strain.