Super‐resolution microscopy reveals cell wall dynamics and peptidoglycan architecture in ovococcal bacteria

Wheeler, Richard; Mesnage, Stéphane; Boneca, Ivo G.; Hobbs, Jamie K.; Foster, Simon J.

doi:10.1111/j.1365-2958.2011.07871.x

Cited by 109 publications

(129 citation statements)

References 40 publications

(72 reference statements)

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“…This model (Fig. 7) is consistent with the old measurements of cell wall dimensions (37) and the most recent data about the localization of the synthetic machineries and their activities (12,14,38). Upon mild piperacillin challenge, the transpeptidase activity of PBP2x is mostly inhibited, but septal material could still be assembled by class A PBPs, although with a lower degree of cross-linking.…”

Section: Discussionsupporting

confidence: 78%

Mechanism of β-Lactam Action in Streptococcus pneumoniae: the Piperacillin Paradox

Philippe

Gallet

Morlot

et al. 2015

Antimicrob Agents Chemother

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fThe human pathogen Streptococcus pneumoniae has been treated for decades with ␤-lactam antibiotics. Its resistance is now widespread, mediated by the expression of mosaic variants of the target enzymes, the penicillin-binding proteins (PBPs). Understanding the mode of action of ␤-lactams, not only in molecular detail but also in their physiological consequences, will be crucial to improving these drugs and any counterresistances. In this work, we investigate the piperacillin paradox, by which this ␤-lactam selects primarily variants of PBP2b, whereas its most reactive target is PBP2x. These PBPs are both essential monofunctional transpeptidases involved in peptidoglycan assembly. PBP2x participates in septal synthesis, while PBP2b functions in peripheral elongation. The formation of the "lemon"-shaped cells induced by piperacillin treatment is consistent with the inhibition of PBP2x. Following the examination of treated and untreated cells by electron microscopy, the localization of the PBPs by epifluorescence microscopy, and the determination of the inhibition time course of the different PBPs, we propose a model of peptidoglycan assembly that accounts for the piperacillin paradox.

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Section: Discussionsupporting

confidence: 78%

Mechanism of β-Lactam Action in Streptococcus pneumoniae: the Piperacillin Paradox

Philippe

Gallet

Morlot

et al. 2015

Antimicrob Agents Chemother

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“…33 Structured illumination super-resolution microscopy on cells treated with fluorescent vancomycin, which labels the PG precursor and nascent unmatured PG, allowed measurement of the dimensions of PG insertion sites throughout the cell cycle. Briefly, as in E. hirae, S. pneumoniae shows overlapping rounds of cell wall synthesis, with the insertion of new wall material at the equators of daughter cells that are not separated yet, whereas E. faecalis and L. lactis show discrete rounds of division.…”

Section: The Two Morphogenetic Machineries Modelmentioning

confidence: 99%

The Elongation of Ovococci

Philippe

Vernet

Zapun

2014

Microbial Drug Resistance

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“…The cell wall provides a point of (non)covalent attachment of important extracellular enzymes and external structures, such as pili and flagella (359). It also participates in processes of adhesion, cell aggregation, and cell division (360). Most importantly for this review, the cell envelope acts as a diffusion barrier between the cell and its surroundings.…”

Section: Protecting the Cell Envelopementioning

confidence: 99%

Stress Physiology of Lactic Acid Bacteria

Papadimitriou

Alegría

Bron

et al. 2016

Microbiol Mol Biol Rev

480

404

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SUMMARYLactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g.,Lactococcus lactis), probiotic (e.g., severalLactobacillusspp.), and pathogenic (e.g.,EnterococcusandStreptococcusspp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.

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Super‐resolution microscopy reveals cell wall dynamics and peptidoglycan architecture in ovococcal bacteria

Cited by 109 publications

References 40 publications

Mechanism of β-Lactam Action in Streptococcus pneumoniae: the Piperacillin Paradox

Mechanism of β-Lactam Action in Streptococcus pneumoniae: the Piperacillin Paradox

The Elongation of Ovococci

Stress Physiology of Lactic Acid Bacteria

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