Date of Award

Spring 5-2013

Degree Type

Honors College Thesis


Biological Sciences

First Advisor

Mohamed O. Elasri

Advisor Department

Biological Sciences


Staphylococcus aureus is an important human pathogen that causes a wide variety of diseases. Many S. aureus strains have emerged which are resistant to the penicillin class of antibiotics. Of primary importance is methicillin-resistant S. aureus (MRSA), which has cause frequent hospitalizations due to infections. In the past, MRSA was typically confined to hospital settings, but recently, community-associated MRSA (CA-MRSA) have been reported. CA-MRSA poses a major public health threat because of increased virulence and success in infecting otherwise healthy individuals. Previously we discovered a gene, msa, which plays a critical role in biofilm formation and regulation of the disease process. Recent studies indicate that msa is part of a three open reading frame operon and that the upstream neighboring genes may play a role in the regulation of the msa operon. In this study, we investigated the possibility that genes 1294-1298 regulate virulence factors of S. aureus. We constructed a 1294-1298 mutant in CA-MRSA USA300 strain LAC using the allelic replacement vector pKOR1 and found that it produced a weaker biofilm in addition to increased autolysis, protease production, pigmentation production, hemolysin production and lipase production-all indicators that genes 1294-1298 play a role in the virulence of S. aureus. We hope to explore the possibility of exploring the regulatory network of the msa operon and its neighboring genes and exploit them as a target for therapy for recalcitrant staph infections.

Included in

Life Sciences Commons