In situ probing the interior of single bacterial cells at nanometer scale

Liu, Boyin, Uddin, Md. Hemayet, Wah Ng Tuck, Paterson, David L., Velkov, Tony, Li, Jian and Fu, Jing (2014) In situ probing the interior of single bacterial cells at nanometer scale. Nanotechnology, 25 41: . doi:10.1088/0957-4484/25/41/415101

Author Liu, Boyin
Uddin, Md. Hemayet
Wah Ng Tuck
Paterson, David L.
Velkov, Tony
Li, Jian
Fu, Jing
Title In situ probing the interior of single bacterial cells at nanometer scale
Journal name Nanotechnology   Check publisher's open access policy
ISSN 0957-4484
Publication date 2014-10-17
Year available 2014
Sub-type Article (original research)
DOI 10.1088/0957-4484/25/41/415101
Open Access Status
Volume 25
Issue 41
Total pages 13
Place of publication Bristol, United Kingdom
Publisher Institute of Physics Publishing
Collection year 2015
Language eng
Formatted abstract
We report a novel approach to probe the interior of single bacterial cells at nanometre resolution by combining focused ion beam (FIB) and atomic force microscopy (AFM). After removing layers of pre-defined thickness in the order of 100 nm on the target bacterial cells with FIB milling, AFM of different modes can be employed to probe the cellular interior under both
ambient and aqueous environments. Our initial investigations focused on the surface topology induced by FIB milling and the hydration effects on AFM measurements, followed by assessment of the sample protocols. With fine-tuning of the process parameters, in situ AFM probing beneath the bacterial cell wall was achieved for the first time. We further demonstrate the proposed method by performing a spatial mapping of intracellular elasticity and chemistry of the multi-drug resistant strain Klebsiella pneumoniae cells prior to and after it was exposed to the ‘last-line’ antibiotic polymyxin B. Our results revealed increased stiffness occurring in both surface and interior regions of the treated cells, suggesting loss of integrity of the outer membrane from polymyxin treatments. In addition, the hydrophobicity measurement using a functionalized AFM tip was able to highlight the evident hydrophobic portion of the cell such as the regions containing cell membrane. We expect that the proposed FIB–AFM platform will help in gaining deeper insights of bacteria–drug interactions to develop potential strategies for combating multi-drug resistance.
Keyword Antibiotic resistance
Atomic force microscopy
Elastic modulus
Focused ion beam
Single cell analysis
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 2 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 2 times in Scopus Article | Citations
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