Karla Satchell | |
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Born | Karla Fullner August 9, 1975 Wooster, Ohio, U.S. |
Education | Pacific Lutheran University (BA) University of Washington (PhD) |
Awards | Investigator in Pathogenesis of Infectious Disease, Burroughs Wellcome Fund (2006) Driskill Graduate Program Dean's Outstanding Teacher Award, Northwestern Feinberg School of Medicine (2016) |
Scientific career | |
Fields | Bacteriology Structural biology immunology |
Institutions | University of Pittsburgh Harvard Medical School Northwestern University, Feinberg School of Medicine |
Karla Satchell, (born Karla Fullner on August 9, 1975), is an American microbiologist who is currently a professor at Northwestern University Feinberg School of Medicine [1] and an elected fellow of the American Association for the Advancement of Science. [2]
She earned her Ph.D at University of Washington in 1996 and conducted postdoctoral training with John Mekalanos at Harvard Medical School. [1]
Her interests are bacteriology, structural biology, and immunology, [3] cytoskeleton, cellular microbiology, bacteria and diseases [4] and pathogenesis. [1] She is especially known for defining how the MARTX toxin in Vibrio cholerae is a modular protein that delivers its constituent effectors to host cells. [5]
Satchell is head of the Center for Structural Genomics of Infectious Diseases at Northwestern. The Center, established in 2007, provides an established consortium of laboratories in North America for rapid response research related to infectious disease outbreaks. It maps and examines the genomes of disease causing agents such as viruses to establish effective treatments. [6] [7]
Cholera is an infection of the small intestine by some strains of the bacterium Vibrio cholerae. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea lasting a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish. Symptoms start two hours to five days after exposure.
Vibrio cholerae is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimp, and other shellfish. Some strains of V. cholerae are pathogenic to humans and cause a deadly disease called cholera, which can be derived from the consumption of undercooked or raw marine life species or drinking contaminated water.
Vibrio is a genus of Gram-negative bacteria, possessing a curved-rod (comma) shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Being highly salt tolerant and unable to survive in fresh water, Vibrio spp. are commonly found in various salt water environments. Vibrio spp. are facultative anaerobes that test positive for oxidase and do not form spores. All members of the genus are motile. They are able to have polar or lateral flagellum with or without sheaths. Vibrio species typically possess two chromosomes, which is unusual for bacteria. Each chromosome has a distinct and independent origin of replication, and are conserved together over time in the genus. Recent phylogenies have been constructed based on a suite of genes.
Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical mechanism of cell secretion is via secretory portals at the plasma membrane called porosomes. Porosomes are permanent cup-shaped lipoprotein structures embedded in the cell membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell.
Vibrio vulnificus is a species of Gram-negative, motile, curved rod-shaped (vibrio), pathogenic bacteria of the genus Vibrio. Present in marine environments such as estuaries, brackish ponds, or coastal areas, V. vulnificus is related to V. cholerae, the causative agent of cholera. At least one strain of V. vulnificus is bioluminescent. Increasing seasonal ocean temperatures and low-salt marine environments like estuaries favor a greater concentration of Vibrio within filter-feeding shellfish; V. vulnificus infections in the Eastern United States have increased eightfold from 1988–2018.
An enterotoxin is a protein exotoxin released by a microorganism that targets the intestines. They can be chromosomally or plasmid encoded. They are heat labile (>60⁰), of low molecular weight and water-soluble. Enterotoxins are frequently cytotoxic and kill cells by altering the apical membrane permeability of the mucosal (epithelial) cells of the intestinal wall. They are mostly pore-forming toxins, secreted by bacteria, that assemble to form pores in cell membranes. This causes the cells to die.
Gopinath Balakrish Nair is an Indian microbiologist known for his work on cholera. At present, he is the Ag. Regional Adviser, Research Policy and Cooperation Unit, Department of Communicable Diseases, World Health Organization. Before joining WHO, he was the executive director of Translational Health Science and Technology Institute (THSTI), Faridabad, NCR, India. Before joining THSTI, he was working in NICED as the director. He has also served as the director of Laboratory Sciences Division at the International Center for Diarrhoeal Diseases Research,, Dhaka, Bangladesh.
Cholera toxin is an AB5 multimeric protein complex secreted by the bacterium Vibrio cholerae. CTX is responsible for the massive, watery diarrhea characteristic of cholera infection. It is a member of the heat-labile enterotoxin family.
Sambhunath De ; was an Indian medical scientist and researcher, who discovered the cholera toxin, the animal model of cholera, and successfully demonstrated the method of transmission of cholera pathogen Vibrio cholerae.
Microbial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or lipooligosaccharide (LOS) that are in the outer plasma membrane of Gram-negative bacteria. The botulinum toxin, which is primarily produced by Clostridium botulinum and less frequently by other Clostridium species, is the most toxic substance known in the world. However, microbial toxins also have important uses in medical science and research. Currently, new methods of detecting bacterial toxins are being developed to better isolate and understand these toxins. Potential applications of toxin research include combating microbial virulence, the development of novel anticancer drugs and other medicines, and the use of toxins as tools in neurobiology and cellular biology.
The RTX toxin superfamily is a group of cytolysins and cytotoxins produced by bacteria. There are over 1000 known members with a variety of functions. The RTX family is defined by two common features: characteristic repeats in the toxin protein sequences, and extracellular secretion by the type I secretion systems (T1SS). The name RTX refers to the glycine and aspartate-rich repeats located at the C-terminus of the toxin proteins, which facilitate export by a dedicated T1SS encoded within the rtx operon.
The CTXφ bacteriophage is a filamentous bacteriophage. It is a positive-strand DNA virus with single-stranded DNA (ssDNA).
Jorge Enrique Galán is an Argentinian-American microbiologist who specializes in infectious disease, bacterial pathogenesis including Salmonella.
The type VI secretion system (T6SS) is molecular machine used by a wide range of Gram-negative bacterial species to transport effectors from the interior of a bacterial cell across the cellular envelope into an adjacent target cell. While often reported that the T6SS was discovered in 2006 by researchers studying the causative agent of cholera, Vibrio cholerae, the first study demonstrating that T6SS genes encode a protein export apparatus was actually published in 2004, in a study of protein secretion by the fish pathogen Edwardsiella tarda.
John Mekalanos is a microbiologist who is primarily known for leading one of the first teams that reported the discovery of the type VI secretion system as well as his work on the pathogenicity of the bacterial species Vibrio cholerae, its toxin, and its secretion systems. Since 1998, he has been a member of the National Academy of Sciences.
Liise-anne Pirofski is a Professor of Medicine, Microbiology and Immunology at Albert Einstein College of Medicine and Montefiore Medical Center. She is a Member of the Association of American Physicians, and a Fellow of the American Association for the Advancement of Science, American Academy of Microbiology, American College of Physicians and the Infectious Diseases Society of America.
Melanie Blokesch is a German microbiologist. Her research focuses on Vibrio cholerae, the bacterium causing cholera. She is a professor of life sciences at École Polytechnique Fédérale de Lausanne (EPFL), where she heads the Laboratory of Molecular Microbiology.
Barney S. Graham is an American immunologist, virologist, and clinical trials physician.
Gemma Reguera is a Spanish-American microbiologist and professor at Michigan State University. She is the editor-in-chief of the journal Applied and Environmental Microbiology and was elected fellow of the American Academy of Microbiology in 2019. She is the recipient of the 2022 Alice C. Evans Award for Advancement of Women from the American Society for Microbiology. Her lab's research is focused on electrical properties of metal-reducing microorganisms.
Virginia L. Miller is a microbiologist known for her work on studying the factors leading to disease caused by bacteria. Miller is an elected fellow of the American Academy of Microbiology (2003) and a former Pew Charitable Trust Biomedical Scholar (1989).