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3 results on '"Mona Johannessen"'

1. Single-cell phenotypic profiling and backtracing exposes and predicts clinically relevant subpopulations in isogenic Staphylococcus aureus communities

Author

Jonathan Hira, Bhupender Singh, Tirthankar Halder, Anel Mahmutovic, Clement Ajayi, Arif Ahmed Sekh, Kristin Hegstad, Mona Johannessen, and Christian S. Lentz

Subjects
Biology (General), QH301-705.5
Abstract

Abstract Isogenic bacterial cell populations are phenotypically heterogenous and may include subpopulations of antibiotic tolerant or heteroresistant cells. The reversibility of these phenotypes and lack of biomarkers to differentiate functionally different, but morphologically identical cells is a challenge for research and clinical detection. To overcome this, we present ´Cellular Phenotypic Profiling and backTracing (CPPT)´, a fluorescence-activated cell sorting platform that uses fluorescent probes to visualize and quantify cellular traits and connects this phenotypic profile with a cell´s experimentally determined fate in single cell-derived growth and antibiotic susceptibility analysis. By applying CPPT on Staphylococcus aureus we phenotypically characterized dormant cells, exposed bimodal growth patterns in colony-derived cells and revealed different culturability of single cells on solid compared to liquid media. We demonstrate that a fluorescent vancomycin conjugate marks cellular subpopulations of vancomycin-intermediate S. aureus with increased likelihood to survive antibiotic exposure, showcasing the value of CPPT for discovery of clinically relevant biomarkers.

Published
2024
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2. Flagella-mediated secretion of a novel Vibrio cholerae cytotoxin affecting both vertebrate and invertebrate hosts

Author

Fatemeh Askarian, Simon Tuck, Karina Persson, Per Larsson, Sun Nyunt Wai, Mitesh Dongre, Regina R. Miftakhova, Bernt Eric Uhlin, Jonas von Hofsten, Kyaw Min Aung, Marc Erhardt, Mona Johannessen, Jenny L. Persson, and Bhupender Singh

Subjects
0301 basic medicine, 030106 microbiology, Cellular microbiology, Medicine (miscellaneous), Flagellum, medicine.disease_cause, General Biochemistry, Genetics and Molecular Biology, Virulence factor, Microbiology, Microbiology in the medical area, 03 medical and health sciences, medicine, Bacteriology, Mikrobiologi inom det medicinska området, Secretion, lcsh:QH301-705.5, Caenorhabditis elegans, biology, Toxin, VDP::Medisinske Fag: 700::Basale medisinske, odontologiske og veterinærmedisinske fag: 710, biology.organism_classification, bacterial infections and mycoses, VDP::Medical disciplines: 700::Basic medical, dental and veterinary science disciplines: 710, 030104 developmental biology, lcsh:Biology (General), Vibrio cholerae, General Agricultural and Biological Sciences
Abstract

Using Caenorhabditis elegans as an infection host model for Vibrio cholerae predator interactions, we discovered a bacterial cytotoxin, MakA, whose function as a virulence factor relies on secretion via the flagellum channel in a proton motive force-dependent manner. The MakA protein is expressed from the polycistronic makDCBA (motility-associated killing factor) operon. Bacteria expressing makDCBA induced dramatic changes in intestinal morphology leading to a defecation defect, starvation and death in C. elegans. The Mak proteins also promoted V. cholerae colonization of the zebrafish gut causing lethal infection. A structural model of purified MakA at 1.9 Å resolution indicated similarities to members of a superfamily of bacterial toxins with unknown biological roles. Our findings reveal an unrecognized role for V. cholerae flagella in cytotoxin export that may contribute both to environmental spread of the bacteria by promoting survival and proliferation in encounters with predators, and to pathophysiological effects during infections.

Published
2018
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3. Flagella-mediated secretion of a novel

Author

Mitesh, Dongre, Bhupender, Singh, Kyaw Min, Aung, Per, Larsson, Regina, Miftakhova, Karina, Persson, Fatemeh, Askarian, Mona, Johannessen, Jonas, von Hofsten, Jenny L, Persson, Marc, Erhardt, Simon, Tuck, Bernt Eric, Uhlin, and Sun Nyunt, Wai

Abstract

Using

Published
2018

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