Sub-Lethal levels of Gentamicin impacts gonococcal gene expression

The continued emergence of Neisseria gonorrhoeae (Ng) isolates resistant to first-line antibiotics has focused efforts on understanding how alternative therapies such as expanded use of gentamicin (Gen) might counteract this global public health problem. Focusing on Gen as a possible alternative antibiotic for treatment of gonorrheal infections, we used RNA-Seq to determine if sub-lethal levels of Gen might impact gonococci on a transcriptional level. We found that sub-lethal Gen altered expression of a finite number of genes in gonococcal strain FA19. Many of the differentially regulated genes were associated with known stress responses elaborated by Ng under different harmful conditions. Within the Gen regulon, we found that the hicAB operon, which encodes the putative HicAB toxin-antitoxin system, was transcriptionally activated in response to Gen. To determine the Gen induced regulon in GC, an RNA-Seq analysis was performed using total RNA samples collected from wild-type (WT) strain FA19 grown in the presence or absence of sub-lethal Gen (2 µ g/mL, 0.25X MIC) for 4 hours in GC broth