Chloramphenicol stress triggers oxidative adaptation in Acinetobacter baumannii ATCC19606 devoid of RND efflux pumps AdeAB or AdeIJ.

Deletion of craA significantly reduces chloramphenicol resistance in Acinetobacter baumannii ATCC19606, highlighting its dominant role among efflux pumps.

• Why it matters: Understanding efflux pumps' broader physiological roles is crucial for combating multidrug resistance and bacterial resilience, which are major clinical challenges.
• What they did: Researchers analyzed transcriptomic and phenotypic responses of mutants lacking efflux pumps AdeAB, AdeIJ, or CraA under chloramphenicol stress, focusing on stress adaptation mechanisms.
• The result: Findings show CraA is essential for chloramphenicol resistance, while AdeIJ and AdeAB are linked to oxidative and metal stress responses, revealing efflux pumps' roles beyond drug expulsion.