Teaching Interests

BSC 476/576 Molecular Biology
BSC 478L/578L Molecular Biology Laboratory
BSC 481/581 Pathogenic Microbiology
 

Research Interests

In my laboratory, we are interested in molecular mechanisms of virulence and our research program focuses on various aspects of virulence in pathogenic bacteria. Specifically, we are interested in the Gram-positive opportunistic pathogen Staphylococcus aureus.

Staphlococcus aureus causes a variety of hospital- and community-acquired infections that range from superficial (i.e., impetigo, cellulitis) to severe (i.e. osteomyelitis, endocarditis). The emergence of strains resistant to vancomycin, an antibiotic of "last resort," coupled with the lack of an anti-staphylococcal vaccine have made this pathogen an increasingly serious health problem. The success of S. aureus as a pathogen is due to its extensive virulence factors that allow for invasion of virtually every organ system. There is an urgent need to develop novel therapeutic agents to control S. aureus infections. Included among the potential therapeutic targets are global regulatory systems of virulence factors. Two global regulators are central for coordinating the expression of most known virulence factors: the accessory gene regulator (agr) and the staphylococcal accessory regulator (sarA). agr is a quorum-sensing system that is responsible for up-regulating the production of exoproteins and repressing the cell-bound proteins at the transition from exponential to postexponential growth phases. This system is crucial in infection because it allows S. aureus to shift from colonization to invasion. The second global regulator, sarA, has been shown to activate agr and therefore regulates virulence factors indirectly. SarA protein has also been shown to directly repress transcription of the genes encoding several virulence factors including the collagen binding adhesin (cna) in an agr-independent fashion.

My laboratory currently focuses on finding and characterizing novel regulatory elements that modulate sarA function or control virulence in S. aureus. The ultimate goal of our research program is to identify new therapeutic targets to combat staphylococcal infections.

In collaborations with Dr. Lowe (Chemistry and Biochemistry), Dr. Mathias (Polymer Science) and Dr. Wicks (Polymer Science), we are also developing antimicrobial surfaces by synthesizing and testing polymers that may be used coating on medical devices to prevent nosocomial infections.

Current Graduate Students

Representative Publications

Sambanthamoorthy, Karthik, Mark S. Smeltzer and Mohamed O. Elasri. 2006. Identification and characterization of msa (SA1233), a gene involved in expression of SarA and several virulence factors in Staphylococcus aureus. Microbiology. 152: 2559-2572.


Nagarajan, Vijayaraj., Navodit Kaushik, Beddhu Murali, Chaoyang Zhang, Sanyogita Lakhera, Mohamed O. Elasri and Youping Deng. 2006. A Fourier Transformation based Method to Mine Peptide Space for Antimicrobial Activity. BMC Bioinformatics. 7 Suppl 2:S2.


Dizman, Bekir, Mohamed O. Elasri, Lon J. Mathias. 2006. Synthesis and Characterization of Antibacterial and Temperature Responsive Methacrylamide Polymers. Macromolecules. 39(17): 5738-5746.


Ward, Marty, Melissa Sanchez, Mohamed O. Elasri and Andrew B. Lowe. 2006. Antimicrobial Activity of Statistical Polymethacrylic Sulfobetaines Against Gram Positive and Gram Negative Bacteria. Journal of Applied Polymer Science. 101: 1036–1041.


Dizman, Bekir, Mohamed O. Elasri, Lon J. Mathias. 2005. Synthesis, Characterization, and Antibacterial Activities of Novel Methacrylate Polymers Containing Norfloxacin. Biomacromolecules. 6(1): 514-520.


Blevins, Jon S., Mohamed O. Elasri, Scott D. Allmendinger, Karen E. Beenken, Robert A. Skinner, J. Roby Thomas, and Mark S. Smeltzer. 2003. Role of sarA in the pathogenesis of Staphylococcus aureus musculoskeletal infection. Infection and Immunity 71: 516-523.


Elasri, Mohamed O., J. Roby Thomas, Robert A. Skinner, Jon S. Blevins, Karen E. Beenken, Carl L. Nelson, and Mark S. Smeltzer. 2002. The Staphylococcus aureus Collagen Adhesin Contributes to the Pathogenesis of Osteomyelitis. Bone 30:275-280.