Degree Name

PhD (Doctor of Philosophy)


Biomedical Sciences

Date of Award


Committee Chair or Co-Chairs

W. Scott Champney

Committee Members

Bert C. Lampson, J. Russell Hayman, Douglas P. Thewke, Mitchell E. Robinson


Antibiotics have been commonly used in medical practice for over 40 years. However, the misuse and overuse of current antibiotics is thought to be the primary cause for the increase in antibiotic resistance.

Many current antibiotics target the bacterial ribosome. Antibiotics such as aminoglycosides and macrolides specifically target the 30S or 50S subunits to inhibit bacterial growth. During the assembly of the bacterial ribosome, ribosomal RNA of the 30S and 50S ribosomal subunits is processed by bacterial ribonucleases (RNases). RNases are also involved in the degradation and turnover of this RNA during times of stress, such as the presence of an antibiotic. This makes ribonucleases a potential target for novel antibiotics.

It was shown that Escherichia coli mutants that were deficient for RNase III, RNase E, RNase R, RNase G, or RNase PH had an increase in ribosomal subunit assembly defects. These mutant bacterial cells also displayed an increased sensitivity to neomycin and paromomycin antibiotics. My research has also shown that an inhibitor of RNases, vanadyl ribonucleoside complex, potentiated the effects of an aminoglycoside and a macrolide antibiotic in wild type Escherichia coli, methicillin sensitive Staphylococcus aureus, and methicillin resistant Staphylococcus aureus.

RNases are essential enzymes in both rRNA maturation and degradation. Based on this and previous work, the inhibition of specific RNases leads to an increased sensitivity to antibiotics. This work demonstrates that the inhibition of RNases might be a new target to combat antibiotic resistance.

Document Type

Dissertation - unrestricted


Copyright by the authors.

Included in

Bacteriology Commons