Crystal N. Johnson

Biography

Dr. Crystal N. Johnson is currently working as a Associate Professor in the Department of Department of Environmental Sciences, Louisiana State University , USA. Her research interests includes nvironmental cues, including sea surface temperature, salinity, chlorophyll, turbidity, suspended particulate matter, and dissolved organic carbon.. she is serving as an editorial member and reviewer of several international reputed journals. Dr. Crystal N. Johnson is the member of many international affiliations. She has successfully completed his Administrative responsibilities. she has authored of many research articles/books related to nvironmental cues, including sea surface temperature, salinity, chlorophyll, turbidity, suspended particulate matter, and dissolved organic carbon..

Research Interest

I am currently examining how Vibrio spp. (V. parahaemolyticus, V. vulnificus, and V. cholerae) respond to environmental cues, including sea surface temperature, salinity, chlorophyll, turbidity, suspended particulate matter, and dissolved organic carbon. It is well-established that temperature affects the levels of these naturally occurring marine bacteria (i.e., their levels are higher in warmer months and lower in cooler months), but it remains unclear what combinations of other environmental factors contribute to the variations in vibrio levels. I am also examining the genetic relationships among pathogenic vibrios. The vast majority of the naturally occurring vibrios are non-pathogenic, but almost all of the vibrios isolated from human illnesses contain some pathogenicity factor (such as a hemolysin or a urease). Little is known about the small subpopulation of environmental vibrios that contain these pathogenicity factors. Thus, I am using phylogenetic typing [Rep-PCR, multilocus sequence typing (MLST)] to identify the relationships among the potential pathogens found in water, oysters, and sediment, and also their relationship to those pathogens that turn up in humans. I am interested in a more recently described pathogenicity factor in vibrios called the Type III Secretion System (TTSS). TTSSs work by injecting effector proteins into eukaryotic cells that interfere with host cell signaling cascades and their ability to mount an immune response to fight off vibrio infections. I have also recently developed an interest in avian microbiology and currently seek collaborations in this area. I also have a strong commitment to outreach. As a component of my current NSF funding, I established the Summer Research Internship (SumRI), in which two high school students spend 6-8 weeks in my lab each summer doing hands-on research using vibrios that the students themselves isolate and characterize. I also enjoy speaking to the public about science, including how and why I became a scientist, general microbiology, and what my research in particular means for the general public.