A5038535303- Force Microscopy Techniques and Applications
- Bacteriophages and microbial interactions
- Bacterial Genetics and Biotechnology
- Mycobacterium research and diagnosis
- Bacterial biofilms and quorum sensing
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- Sirtuins and Resveratrol in Medicine
- Mechanical and Optical Resonators
- SARS-CoV-2 and COVID-19 Research
- Lipid Membrane Structure and Behavior
- SARS-CoV-2 detection and testing
- Tuberculosis Research and Epidemiology
- Herpesvirus Infections and Treatments
- Autophagy in Disease and Therapy
- Microbial Fuel Cells and Bioremediation
- thermodynamics and calorimetric analyses
- COVID-19 Clinical Research Studies
- Yersinia bacterium, plague, ectoparasites research
- Microfluidic and Bio-sensing Technologies
- RNA regulation and disease
- Antibiotic Resistance in Bacteria
- Advanced Electron Microscopy Techniques and Applications
- Protein Structure and Dynamics
- Cellular Mechanics and Interactions
University of California, San Francisco
2020-2024
Lawrence Berkeley National Laboratory
2022-2024
Harvard University
2024
École Polytechnique Fédérale de Lausanne
2017-2020
Institut Pasteur
2013
Département Génétique Animale
2013
Inserm
2013
New York University
2009-2010
University of Richmond
2008
Bacterial Subversion Tactics Intracellular bacterial pathogens such as Listeria monocytogenes can change host cell transcription programs to promote infection. Eskandarian et al. ( 1238858 ) found that during infection, the effector protein InlB promoted movement of a deacetylase, SIRT2, from its normal location in cytosol nucleus. In nucleus, SIRT2 helped repress number genes by deacetylating one their associated histones. mice, reduced levels impaired
ABSTRACT Background Serological tests are crucial tools for assessments of SARS-CoV-2 exposure, infection and potential immunity. Their appropriate use interpretation require accurate assay performance data. Method We conducted an evaluation 10 lateral flow assays (LFAs) two ELISAs to detect anti-SARS-CoV-2 antibodies. The specimen set comprised 128 plasma or serum samples from 79 symptomatic RT-PCR-positive individuals; 108 pre-COVID-19 negative controls; 52 recent individuals who underwent...
In most well-studied rod-shaped bacteria, peptidoglycan is primarily crosslinked by penicillin-binding proteins (PBPs). However, in mycobacteria, crosslinks formed L,D-transpeptidases (LDTs) are highly abundant. To elucidate the role of these unusual crosslinks, we characterized Mycobacterium smegmatis cells lacking all LDTs. We find that generate LDTs required for rod shape maintenance specifically at sites aging cell wall, a byproduct polar elongation. Asymmetric growth leads to...
Endospores formed by Bacillus subtilis are encased in a tough protein shell known as the coat, which consists of at least 70 different proteins. We investigated process spore coat morphogenesis using library 40 proteins fused to green fluorescent and demonstrate that two successive steps can be distinguished assembly. The first step, initial localization surface, is dependent on morphogenetic SpoIVA SpoVM. second encasement, requires third protein, SpoVID. show spoVID mutant cells, most...
Abstract Mycobacteria grow by inserting new cell wall material in discrete zones at the poles. This pattern implies that polar growth must be assembled de novo each division, but mechanisms control initiation of pole are unknown. Here, we combine time-lapse optical and atomic force microscopy to measure single-cell mycobacteria with nanometer-scale precision. We show is biphasic due a lag phase variable duration before transitions from slow fast growth. transition division independent...
The rod shaped Mycobacterium smegmatis displays complex cell surface morphology, characterized by wave-form features and driven asymmetric growth dynamics. To systematically analyze these morphological variations, we developed a comprehensive computational pipeline for automated processing of Long-Term Time-Lapse Atomic Force Microscopy (LTTL-AFM) images M. cells cultured in axenic conditions stress. Upon running the to produce large enough datasets single height profiles, identify...
Invading microbes face a myriad of cidal mechanisms phagocytes that inflict physical damage to microbial structures. How intracellular bacterial pathogens adapt these stresses is not fully understood. Here, we report the discovery virulence mechanism by which changes mechanical stiffness mycobacterial cell surface confer refraction killing during infection. Long-term time-lapse atomic force microscopy was used reveal process “mechanical morphotype switching” in mycobacteria exposed host...
Shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called Suf and Isc. S. flexneri strains containing deletion mutations in the entire suf operon (UR011) or iscSUA genes (UR022) were constructed. Both mutants defective surviving exposure to oxidative stress. The mutant showed growth that was comparable parental strain both iron-replete iron-limiting media; however, isc reduced growth, relative strain, media. Although...
Imaging living cells by atomic force microscopy (AFM) promises not only high-resolution topographical data, but additionally, mechanical contrast, both of which are obtainable with other techniques. Such imaging is however challenging, as need to be measured low interaction forces prevent either deformation or detachment from the surface. Off-resonance modes periodically probe surface have been shown advantageous, they provide excellent control combined large amplitudes, help reduce lateral...
Similar to other prokaryotes, mycobacteria decorate their major cell envelope glycans with minor covalent substituents whose biological significance remains largely unknown. We report on the discovery of a mycobacterial enzyme, named here SucT, that adds succinyl groups arabinan domains both arabinogalactan (AG) and lipoarabinomannan (LAM). Disruption SucT-encoding gene in Mycobacterium smegmatis abolished AG LAM succinylation altered hydrophobicity rigidity bacilli without significantly...
Summary The major facilitator superfamily transporter Rv1410 and the lipoprotein LprG (Rv1411) are encoded by a conserved two‐gene operon contribute to virulence in Mycobacterium tuberculosis . was originally postulated function as drug efflux pump, but recent studies suggested that work concert insert triacylglycerides lipoarabinomannans into outer membrane. Here, we conducted microscopic analyses of smegmatis lacking observed cell separation defect, while surface rigidity measured atomic...
Abstract In most well studied rod-shaped bacteria, peptidoglycan is primarily crosslinked by penicillin binding proteins (PBPs). However, in mycobacteria, L,D-transpeptidase (LDT)-mediated crosslinks are highly abundant. To elucidate the role of these unusual crosslinks, we characterized mycobacterial cells lacking all LDTs. We find that LDT-mediated required for rod shape maintenance specifically at sites aging cell wall, a byproduct polar elongation. Asymmetric growth leads to non-uniform...
Imaging living cells by atomic force microscopy (AFM) promises not only high-resolution topographical data, but additionally, mechanical contrast, which are obtainable with other techniques. Such imaging is however challenging, as need to be measured low interaction forces prevent either deformation or detachment from the surface. Off-resonance modes periodically probe surface have been shown advantageous, they provide excellent control combined large amplitudes, help reduce lateral...