Microbiology and Immunology | Biological Sciences

Microbiology and Immunology

Faculty research interests in the area of microbiology and immunology include fungal pathogenesis (Park Lab), innate mucosal immunity (Porter Lab), microbial ecology (Ramirez Lab), environmental microbiology (Salmassi Lab), applied microbiology and biotechnology (Xu Lab), and Molecular Microbiology (Cohen Lab). An asterisk following a name in a publication citation indicates a student coauthor.

Fungal Pathogenesis

		Contact:  Hyunsook Park, Ph.D. Office:  ASCL 353, ext: 3-2060 Laboratory:  ASCL 348, ext: 3-2035 E-mail:  [email protected] Web:  /faculty/hyunsook-park
		Confocal microscopy of the yeast C. albicans grown with oral epithelial cell. Germ tube (on the right) penetrates into the mammalian cell.

Research Summary
Our research program focuses on host-pathogen interactions in infectious disease. In particular, we have focused on the pathogenic mechanisms of the fungus Candida albicans during the initiation of oropharyngeal candidiasis. We are identifying key virulence factors governing the early stage of oral candidiasis using a transcriptional profiling analysis and gene disruption approach.

Innate Mucosal Immunity

		Contact:  Edith Porter, M.D. Office:  ASCL 355, ext: 3-6353 Laboratory:  ASCL 333, ext: 3-2079 E-mail:  [email protected] Web:  http://instructional1.calstatela.edu/eporter/porterlab
		Transmission electron microscopy, 10,000-fold magnification, of Pseudomonas aeruginosa showing ultrastructural changes of the cell wall after treatment with the free fatty acid docosahexaenoic acid and the antimicrobial polypeptide lysozyme.

Research Summary
Our research focuses on mucosal innate immunity, specifically, antimicrobial effector molecules that directly act on and kill bacterial pathogens. A great deal of our work has targeted the activity and regulation of the antimicrobial peptide human defensin 5 in the intestinal and genital tract and the response of Paneth cells, specialized defense cells in the small intestine, to infection with Salmonella. Recently, we have begun to explore role of host-derived antimicrobial lipids, in particular cholesteryl esters, in the mucosal defense of the respiratory and genital tract.

Microbial Ecology

		Contact:  Gustavo Ramirez, Ph.D. Office:  ASCL 218, ext: 3-7480 Laboratory:  ASCR 347 , ext: 3-XXXX E-mail:  [email protected] Web:  https://www.ramirezlaboratory.com
		Microbial colonization experiment deployed at a deep-sea octopus nursery located ~3km depth in the Costa Rican Pacific, El Dorado Outcrop, summer of 2023.

Research Summary
We are engaged in interdisciplinary investigations that integrate ecology and genomics to study the diversity, distribution, and functioning of microbial communities in nature. This involves high-throughput molecular sequencing merged with environmental metadata analyzed using high-performance computing. Our work is at the nexus of basic science and applications in conservation biology, environmental monitoring, and biotechnology. Microbes and their activities are agnostic to environments; thus, on-going projects in our group include exploring the ecology of marine, animal GI, and desert soil related microbiomes. 

Environmental Microbiology

		Contact:  Tina Salmassi, Ph.D. Office:  ASCL 315, ext: 3-2065 Laboratory:  ASCL 327, ext: 3-2083 E-mail:  [email protected] Web:  http://instructional1.calstatela.edu/tsalmas
		Arsenite oxidizing bacterium (Agrobacterium albertimagni strain AOL15) isolated from the surface of aquatic plants at Hot Creek, California.

Research Summary
Our laboratory is interested in the interactions between microbes and the environment. We use classical microbiology and molecular biology techniques to study the diversity of bacteria in a variety of environments such as soils, natural waters, plant surfaces, and the hindgut of termites. By observing bacteria both in their natural niches and under controlled laboratory conditions, we hope to better understand the chemistry carried out by these microscopic organisms and their role in the biogeochemical cycling of the elements.

Applied Microbiology and Biotechnology

		Contact:  Howard Xu, Ph.D. Office:  ASCL 356, ext: 3-2188 Laboratory:  ASCL 337, ext: 3-2040 E-mail:  [email protected] Web:  /research/hxu3

Research Summary
Our long-term objective is to contribute in the fight against bacterial pathogens through the discovery of novel antibiotic therapeutics, the development of rapid pathogen detection technologies, and molecular characterization of bacterial pathogens. This objective will be achieved by employing several modern, novel and complimentary approaches: bacterial functional genomics, microbial physiology, biochemistry, molecular biology, novel assay development, high-throughput screening, and clinical microbiology. Critical to the success of various research projects are the ongoing collaborations with our colleagues on campus, from UCLA, Los Angeles County USC Medical Center, Indiana University, University of Michigan, National Laboratories, and Canada's National Research Council.

Molecular Microbiology

		Contact:  Susan Cohen, Ph.D. Office:  ASCL 354, ext: 3-2091 Laboratory:  ASCL 331 E-mail:  [email protected]  Web:  http://cohenlabcsula.weebly.com/
		Fluorescence micrographs of cyanobacterial strain Synechococcus elongatus PCC 7942 (red) expressing a YFP-KaiC fusion, showing that circadian clock protein KaiC is localized diffusely throughout the cell during the day and localized to the cell pole at night.

Research Summary

Circadian rhythms, driven by an internal biological or circadian clock, are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Cyanobacteria are the simplest organisms and only prokaryotes known to have a rigorously tested and robust circadian clock. We use the genetically tractable Synechococcus elongatus PCC 7942 as a premier model organism for studying the molecular details and regulation of the clock. We use a combination of cell biology, genetics, biochemistry and molecular biology to understand how the Kai oscillator functions in the context of the three-dimensional cell.

Note: ASCL = Wallis Annenberg Integrated Science Complex-Wing A (La Kretz Hall). When calling from off-campus, the area code and prefix for all telephone extensions is (323) 34X-XXXX.