Transcriptional analysis of D, D-carboxypeptidase genes as secondary cephalosporin resistance reporters in Escherichia coli harbouring blaCTX-M.
Upregulation of dacB and dacD genes in Escherichia coli indicates their potential as reporters for cephalosporin resistance, with 15 resistant isolates showing increased expression.
- Why it matters: Detecting antimicrobial resistance is challenging due to emerging plasmid-encoded variants, necessitating alternative markers like endogenous resistance genes that respond to antibiotic stress.
- What they did: The study analyzed transcriptional responses of D,D-carboxypeptidase genes and bolA in 30 clinical E. coli isolates under cephalosporin stress, using qRT-PCR, network analysis, and gene transformation techniques.
- The result: Findings demonstrate that dacB and dacD are consistently upregulated during antibiotic exposure, suggesting their use as diagnostic markers and providing insights into host-specific adaptive resistance mechanisms.