Copy Number of an Integron-Encoded Antibiotic Resistance Locus Regulates a Virulence and Opacity Switch in Acinetobacter baumannii AB5075.

ABSTRACT: We describe a novel genetic mechanism in which tandem amplification of a plasmid-borne integron regulates virulence, opacity variation, and global gene expression by altering levels of a putative small RNA (sRNA) in Acinetobacter baumannii AB5075. Copy number of this amplified locus correlated with the rate of switching between virulent opaque (VIR-O) and avirulent translucent (AV-T) cells. We found that prototypical VIR-O colonies, which exhibit high levels of switching and visible sectoring with AV-T cells by 24 h of growth, harbor two copies of this locus. However, a subset of opaque colonies that did not form AV-T sectors within 24 h were found to harbor only one copy. The colonies with decreased sectoring to AV-T were designated low-switching opaque (LSO) variants and were foun

SUBMITTER: Anderson SE 

PROVIDER: S-EPMC7542366 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature