![women in lab examining sample jar, one woman points at the sample](https://medschool.umich.edu/sites/default/files/styles/large_16_9/public/2023-05/M_I-girlsInSnitkinLab.jpg?h=9672153d&itok=NZ-VflP7)
There are many different bacteria that cause many diseases. At the University of Michigan Medical School Department of Microbiology & Immunology, we study a wide variety of gram-positive and gram-negative pathogens.
A common method to classify bacteria is Gram staining which distinguishes between gram-positive (the bacteria turns blue) and gram-negative bacteria (which do not retain the stain and are red or pink). The term “Gram” refers to a specimen staining method developed by Hans Christian Gram in 1884. It involves staining an organism with crystal violet or methylene blue dye and then observing the organism under a microscope.
Some of the pathogens include:
- Mucosal pathogens: Campylobacter jejuni, E. coli, Helicobacter pylori, Proteus mirabilis, Vibrio cholerae
- Intracellular pathogens: Legionella pneumophila, Listeria monocytogenes)
- Select agents: Bacillus anthracis, Brucella spp., Yersiniapestis, Mycobacteria tuberculosis).
- Toxin secretion (cholera toxin) and antimicrobial and therapeutic agent: Actinomycetes, Cyanobacteria, Myxobacteria spp.
Other aspects of study include vaccine development and mathematical modeling of infection.
![headshot of Michael Bachman](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-02/Bachman-Michael-2023.jpeg?itok=LSzhDQx4)
Clinical Associate Professor of Microbiology and Immunology
Medical Director, Clinical Microbiology Laboratory
Program Director, Clinical Research
Clinical Pathology Division
![Suzy Dawid](https://medschool.umich.edu/sites/default/files/styles/wide/public/2023-10/dawid_suzanne4x5.jpg?itok=PAngQqsH)
Associate Professor of Pediatrics
Associate Professor of Microbiology and Immunology
![Philip C. Hanna](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-04/phil_hanna.jpg?itok=YKlXL-kf)
MS Program Director
Microbiology and Immunology
![KirschnerDenise22-large-853x1280 copy.jpeg](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/KirschnerDenise22-large-853x1280%20copy.jpeg?itok=1JaJYsv5)
Microbiology and Immunology Mentoring Program and Professor of Microbiology and Immunology
![labcoat](https://medschool.umich.edu/modules/custom/outline_design_system/assets/images/labcoat_default.jpg)
![headshot of Harry Mobley](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/Mobley-Harry-2023.png?itok=Q8009kQQ)
Frederick Novy Collegiate Professor and Professor of Microbiology and Immunology
![headshot of Mary ORiordan](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/ORiordan-Mary.png?itok=lIqfbfZq)
Professor of Microbiology and Immunology
PhD Program Director & Graduate Studies Chair
Microbiology & Immunology
![Maria Sandkvist M&I-1200x1500.jpeg](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/Maria%20Sandkvist%20M%26I-1200x1500.jpeg?itok=Z9ymQdu2)
Program Director, Microbiology and Immunology
![headshot of Pat Schloss](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/Schloss-Pat-2023.png?itok=rwrfVgtw)
Frederick G Novy Collegiate Professor of Microbiome Research and Professor of Microbiology and Immunology
![labcoat](https://medschool.umich.edu/modules/custom/outline_design_system/assets/images/labcoat_default.jpg)
Professor of Medicinal Chemistry, College of Pharmacy
Professor of Microbiology and Immunology
Professor of Chemistry, College of Literature, Science, and the Arts
Research Professor, Life Sciences Institute
![Snitkin-Evan-2024](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-07/Snitkin-Evan-2024.jpg?itok=lmh26KAo)
Associate Professor of Internal Medicine
![swanson-michele](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/SwansonMichele-1200x1500.jpeg?itok=2HVDT607)
Director of Postdoctoral Studies
![young-vince](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/YoungVince-1200x1500.jpg?itok=KZACmf-f)
Professor of Internal Medicine
Professor of Microbiology and Immunology
![shenoy-anukul](https://medschool.umich.edu/sites/default/files/styles/wide/public/2024-01/ShenoyAnukul-1200x1500.jpeg?itok=1NBIixkI)