Comparison of Two Transmission Electron Microscopy Methods to Visualize Drug-Induced Alterations of Gram-Negative Bacterial Morphology.
Hang Thi Nguyen, Lisa A O'Donovan, Henrietta Venter, Cecilia C Russell, Adam McCluskey, Stephen W Page, Darren J Trott, Abiodun D Ogunniyi
Author Information
Hang Thi Nguyen: Australia Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, SA 5371, Australia.
Lisa A O'Donovan: ARC Centre of Excellence in Plant Energy Biology, School of Agriculture Food & Wine, Waite Campus, The University of Adelaide, Urrbrae, SA 5064, Australia. ORCID
Henrietta Venter: Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia. ORCID
Cecilia C Russell: Chemistry School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.
Adam McCluskey: Chemistry School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia. ORCID
Stephen W Page: Neoculi Pty Ltd., Burwood, VIC 3125, Australia.
Darren J Trott: Australia Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, SA 5371, Australia.
Abiodun D Ogunniyi: Australia Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, Roseworthy Campus, The University of Adelaide, Roseworthy, SA 5371, Australia. ORCID
In this study, we optimized and compared different transmission electron microscopy (TEM) methods to visualize changes to Gram-negative bacterial morphology induced by treatment with a robenidine analogue (NCL195) and colistin combination. Aldehyde-fixed bacterial cells (untreated, treated with colistin or NCL195 + colistin) were prepared using conventional TEM methods and compared with ultrathin Tokuyasu cryo-sections. The results of this study indicate superiority of ultrathin cryo-sections in visualizing the membrane ultrastructure of and , with a clear delineation of the outer and inner membrane as well as the peptidoglycan layer. We suggest that the use of ultrathin cryo-sectioning can be used to better visualize and understand drug interaction mechanisms on the bacterial cell membrane.
