Meropenem-colistin combo slows carbapenem resistance in lab isolates

This laboratory study examined how ertapenem-mono-resistant Enterobacterales isolates evolve further carbapenem resistance under subinhibitory antibiotic exposure. Using serial passage and whole-genome sequencing, the study reported that subinhibitory meropenem exposure rapidly selected for porin-associated resistance mutations in E. coli (ompC) and K. pneumoniae (ompK36), while E. cloacae developed resistance through a non-porin mechanism; co-exposure to meropenem plus colistin significantly delayed resistance development and reduced MIC increases compared to meropenem alone (P<0.05). Sequencing of 26 clinical carbapenem-resistant K. pneumoniae isolates found similar disruptive ompK36 mutations, including one identified experimentally, supporting a shared resistance pathway.

Most relevant for: Relevant to management of infections caused by non-carbapenemase-producing Enterobacterales with isolated ertapenem resistance, particularly E. coli and K. pneumoniae.

Summary written by an AI model from the source text and dated by the source's publication date. Check the original before acting on it. How MedFollow selects and summarizes updates.

Informational only. Not medical advice. Not a substitute for clinical judgment. Always consult current guidelines and your own clinical judgment.