Poster abstracts

Poster number 41 submitted by Nicholas Frecker

Regulation of the putative ykkCD riboswitch by tetracycline and related antibiotics in Bacillus subtilis

Nicholas L. Frecker (Ball State University), Steve Trick (Ball State University), Delores James (Ball State University), Philip Belcher (Ball State University), Dr. Timea Gerczei (Ball State University)

Abstract:
Multi-drug resistance among bacterial pathogens can be mediated by a number of mechanisms, including efflux pumps. One such pump in Bacillus spp. is ykkCD, a heterodimer of the small multidrug resistance (SMR) family consisting of C and D subunits. Previous studies suggest that the expression of the gene is controlled by a putative riboswitch and that the antibiotic tetracycline binds to the riboswitch in vitro. Additional studies have shown that two derivatives of tetracycline also bind to the putative riboswitch. These findings now need to be confirmed in vivo. This study will explore the effects that tetracycline and its commercially available derivatives—doxycycline, anhydrotetracycline, oxytetracycline, and minocycline—have on the expression levels of the ykkCD gene in Bacillus subtilis. The level of ykkCD gene expression will be quantified using two different methods: (1) cellular ykkCD mRNA levels will be determined by quantitative RT-PCR and (2) ykkCD protein levels will be estimated using a ykkCD RNA-beta-galactosidase reporter gene construct. Together these results will shed light on the antibiotic specificity of the ykkCD RNA in vivo.

Keywords: Multi-drug resistance, Riboswitch, qRT-PCR