W. Michael McShan, Ph.D.
My research interests focus on the genetics and genomics of group A streptococci (Streptococcus pyogenes), one of the most common bacterial pathogens of humans. Group A streptococcal infections are a leading cause of morbidity worldwide and are responsible for over $3 billion in annual treatment costs in the USA alone.
One project involves the novel control of DNA mismatch repair in S. pyogenes by a temperate bacteriophage (bacterial virus). This mechanism of control has never been observed before in any species and may represent an important system for the rapid acquisition of favorable mutations to allow the organism to escape host defenses or antimicrobial therapy. Genome analysis reveals that other streptococcal genes may be under bacteriophage control, and thus these studies may lead to an increased understanding of the control of many genes that may influence the ability of this bacterium to initiate infections and avoid host defenses.
A second line of investigation looks at the influence of a novel membrane protein on the expression of the extracellular bacterial toxins in S. pyogenes. Much of the damage that results from group A streptococcal infections is caused by the release of these toxin, and understanding the mechanisms controlling their production could lead to improved patient management.
Education & Experience
Baylor University 1976
Ph.D. in Microbiology and Immunology
Baylor College of Medicine, 1988
Publications & Presentations
- Rahman M, Nguyen S V, McCullor K A, King C J, Jorgensen J H, McShan M. Comparative Genome Analysis of the Daptomycin Resistant Streptococcus anginosus strain J4206 associated with Breakthrough Bacteremia. Genome Biol Evol. 2016
- Bao Y J, Liang Z, Mayfield J A, McShan M, Lee S W, Ploplis V A, Castellino F J. Novel genomic rearrangements mediated by multiple genetic elements in Streptococcus pyogenes M23ND confer potential for evolutionary persistence. Microbiology. 2016; 162 : 1346-59
- Hendrickson C, Euler C W, Nguyen S V, Rahman M, McCullor K A, King C J, Fischetti V A, McShan M. Elimination of chromosomal island SpyCIM1 from Streptococcus pyogenes strain SF370 reverses the mutator phenotype and alters global transcription. PLoS One. 2015; 10 : 23