A rapid antimicrobial susceptibility test based on single-cell morphological analysis

A rapid antibiotic susceptibility test (AST) is desperately needed in clinical settings for fast and appropriate antibiotic administration. Traditional ASTs, which rely on cell culture, are not suitable for urgent cases of bacterial infection and antibiotic resistance owing to their relatively long test times. We describe a novel AST called single-cell morphological analysis (SCMA) that can determine antimicrobial susceptibility by automatically analyzing and categorizing morphological changes in single bacterial cells under various antimicrobial conditions. The SCMA was tested with four Clinical and Laboratory Standards Institute standard bacterial strains and 189 clinical samples, including extended-spectrum b-lactamase–positive Escherichia coli and Klebsiella pneumoniae, imipenem-resistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococci from hospitals. The results were compared with the gold standard broth microdilution test. The SCMA results were obtained in less than 4 hours, with 91.5% categorical agreement and 6.51% minor, 2.56% major, and 1.49% very major discrepancies. Thus, SCMA provides rapid and accurate antimicrobial susceptibility data that satisfy the recommended performance of the U.S. Food and Drug Administration.

http://stm.sciencemag.org/content/6/267/267ra174

Another good one from ASCB: Two component systems in Caulobacter

Fiebig 2014 - A Cell Cycle and Nutritional Checkpoint Controlling Bacterial Surface Adhesion

Went to a sweet talk by Petra Schwille at ASCB the other day and made a reading list about self-organization of the Min and Fts proteins.  Enjoy.


Loose 2008 - Spatial Regulators for Bacterial Cell Division Self-Organize into Surface Waves in Vitro

Zieske 2012 - Reconstitution of Pole-to-Pole Oscillations of Min Proteins in Microengineered Polydimethylsiloxane Compartments

Arumugam 2012 - Surface Topology Engineering of Membranes for the Mechanical Investigation of the Tubulin Homologue FtsZ

Loose 2013 - The bacterial cell division proteins FtsA and FtsZ self-organize into dynamic cytoskeletal patterns

Zieske 2014 - Surface topology assisted alignment of Min protein waves

Zieske 2014 - Reconstitution of self-organizing protein gradients as spatial cues in cell-free systems

Arumugam 2014 - MinCDE exploits the dynamic nature of FtsZ filaments for its spatial regulation

Oldies but goodies

These are courtesy of Tristan and Ethan:

1) Everyone likes star-shaped bacteria, but not everyone has read the original paper!

Prosthecomicrobium and Ancalomicrobiutm: New Prosthecate Freshwater Bacteria

2) Amazing EM images of the type VI secretion system, from 1967:

A "MICROTUBULE" IN A BACTERIUM 

Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB

 

Kathrin Schirner, Ye-Jin Eun, Mike Dion, Yun Luo, John D Helmann, Ethan C Garner &
Suzanne Walker

Abstract:
The bacterial actin homolog MreB, which is crucial for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of lipid-linked peptidoglycan precursors. When precursors are depleted, MreB filaments disassemble into the cytoplasm, and peptidoglycan synthesis becomes disorganized. In cells that lack wall teichoic acids but continue to make peptidoglycan, dynamic MreB filaments are observed, although their presence is not sufficient to establish a rod shape. We propose that the cell regulates MreB filament association with the membrane, allowing rapid and reversible inactivation of cell wall enzyme complexes in response to the inhibition of cell wall synthesis.

http://www.nature.com/nchembio/journal/vaop/ncurrent/full/nchembio.1689.html

Mercier 2014 - Excess membrane synthesis drives a primitive mode of cell proliferation

L-form propagation in B. subtilis.

Imagination in Science, Jacobus Henricus van 't Hoff

http://www.ias.ac.in/resonance/Volumes/12/05/0088-0100.pdf

Ultrastructural Assessment of Wolbachia Endosymbiont – Filarial Nematode Host Interaction

High Pressure Freezing/Freeze Substitution Fixation Improves the Ultrastructural Assessment of Wolbachia Endosymbiont – Filarial Nematode Host Interaction

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0086383