AUTHOR=Sonnleitner Elisabeth , Pusic Petra , Wolfinger Michael T. , Bläsi Udo 

TITLE=Distinctive Regulation of Carbapenem Susceptibility in Pseudomonas aeruginosa by Hfq

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01001

DOI=10.3389/fmicb.2020.01001

ISSN=1664-302X

ABSTRACT=<p>Carbapenems are often the antibiotics of choice to combat life threatening infections caused by the opportunistic human pathogen <italic>Pseudomonas aeruginosa</italic>. The outer membrane porins OprD and OpdP serve as entry ports for carbapenems. Here, we report that the RNA chaperone Hfq governs post-transcriptional regulation of the <italic>oprD</italic> and <italic>opdP</italic> genes in a distinctive manner. Hfq together with the recently described small regulatory RNAs (sRNAs) ErsA and Sr0161 is shown to mediate translational repression of <italic>oprD</italic>, whereas <italic>opdP</italic> appears not to be regulated by sRNAs. At variance, our data indicate that <italic>opdP</italic> is translationally repressed by a regulatory complex consisting of Hfq and the catabolite repression protein Crc, an assembly known to be key to carbon catabolite repression in <italic>P. aeruginosa</italic>. The regulatory RNA CrcZ, which is up-regulated during growth of <italic>P. aeruginosa</italic> on less preferred carbon sources, is known to sequester Hfq, which relieves Hfq-mediated translational repression of genes. The differential carbapenem susceptibility during growth on different carbon sources can thus be understood in light of Hfq-dependent <italic>oprD</italic>/<italic>opdP</italic> regulation and of the antagonizing function of the CrcZ RNA on Hfq regulatory complexes.</p>