外排泵抑制剂CCCP对不同耐药机制介导的沙门菌黏菌素耐药性的逆转作用

Reversal Effect of Efflux Pump Inhibitor CCCP on Colistin Resistance of Salmonella Strains Mediated by Different Mechanisms

为了寻求逆转细菌黏菌素耐药性的方法,探讨外排泵抑制剂氰氯苯腙(Carbonyl cyanide m-chlorophenylhydrazine,CCCP)对不同耐药机制的沙门菌黏菌素耐药性的逆转作用,采用PCR技术和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对临床分离的沙门菌进行鉴定,采用微量肉汤稀释法测定黏菌素对沙门菌分离株的最小抑菌浓度(Minimal inhibit concentration,MIC),应用常规PCR技术和全基因组二代平台Illumina Hiseq X Ten测序技术对沙门菌黏菌素耐药机制进行分析,并分析了CCCP对不同耐药机制分离菌株黏菌素耐药性的逆转作用。结果表明,共分离鉴定出沙门菌32株,随机选择8株黏菌素耐药沙门菌为受试菌株,其中4株菌为mcr-1阳性菌株,4株为双组份信号转导系统PhoPQ和PmrAB相关基因突变菌株。8株沙门菌在加入CCCP后黏菌素MIC大幅度降低(MIC降低1/4096~1/256),CCCP对质粒介导和染色体双组份信号转导系统介导的沙门菌黏菌素耐药性均有逆转效果。

In order to find a way to reverse the colistin resistance of bacterial,we investigated the effects of efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazine(CCCP)on the colistin resistance of Salmonella isolates with different resistance mechanisms.PCR and matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF-MS)were used to identify the clinical isolates of Salmonella.The minimal inhibitory concentration(MIC)of colistin against Salmonella was determined by broth dilution method.The resistant mechanism of Salmonella isolates to colistin was analyzed by routine PCR and whole genome second-generation sequencing.The reverse effect of CCCP on the colistin resistance of Salmonella isolates with different drug resistant mechanisms was analyzed.The results showed that a total of 32 Salmonella strains were identified.Eight colistin-resistant Salmonella isolates were randomly selected as the test strains,four of which were mcr-1 positive,the other four strains were mutants of two-component signal transduction system PhoPQ and PmrAB related genes.After adding CCCP,the MICs of colistin against 8 Salmonella isolates decreased significantly(the MIC reduced by 1/4096~1/256).CCCP can reverse the resistance of Salmonella isolates mediated by plasmid and chromosome two-component signal transduction system.