Critical Role of 3'-Downstream Region of pmrB in Polymyxin Resistance in Escherichia coli BL21(DE3).

ABSTRACT: Polymyxins, such as colistin and polymyxin B, are the drugs used as a last resort to treat multidrug-resistant Gram-negative bacterial infections in humans. Increasing colistin resistance has posed a serious threat to human health, warranting in-depth mechanistic research. In this study, using a functional cloning approach, we examined the molecular basis of colistin resistance in Escherichia coli BL21(DE3). Five transformants with inserts ranging from 3.8 to 10.7 kb displayed significantly increased colistin resistance, three of which containing pmrB locus and two containing pmrD locus. Stepwise subcloning indicated that both the pmrB with a single G361A mutation and at least a 103 bp downstream region of pmrB are essential for conferring colistin resistance. Analysis of the mRNA level an

SUBMITTER: Xu F 

PROVIDER: S-EPMC8004244 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature