Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

BMC Microbiology

Shixing Liu¹  Tieli Zhou¹  Na Huang¹  Lijiang Chen¹  Cui Zhou¹  Renchi Fang²  Ying Zhang³  Kaihang Yu³  Jianming Cao³ 

[1] Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, 325035, Wenzhou, China;Department of Laboratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, 310003, Hangzhou, China;School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, 325035, Wenzhou, China;

关键词: Enterobacter cloacae;    Carbapenem;    Colistin;    Co-resistance;   

DOI  :  10.1186/s12866-021-02250-x

来源: Springer

【 摘 要 】

BackgroundThe emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains.ResultsThis study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found.ConclusionsThis study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

【 授权许可】

CC BY