A flat embedding method for transmission electron microscopy reveals an unknown mechanism of tetracycline

Michaela Wenzel, Marien P. Dekker, Biwen Wang, Maroeska J. Burggraaf, Wilbert Bitter, Jan R. T. van Weering, Leendert W. Hamoen

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Transmission electron microscopy of cell sample sections is a popular technique in microbiology. Currently, ultrathin sectioning is done on resin-embedded cell pellets, which consumes milli- to deciliters of culture and results in sections of randomly orientated cells. This is problematic for rod-shaped bacteria and often precludes large-scale quantification of morphological phenotypes due to the lack of sufficient numbers of longitudinally cut cells. Here we report a flat embedding method that enables observation of thousands of longitudinally cut cells per single section and only requires microliter culture volumes. We successfully applied this technique to Bacillus subtilis, Escherichia coli, Mycobacterium bovis, and Acholeplasma laidlawii. To assess the potential of the technique to quantify morphological phenotypes, we monitored antibiotic-induced changes in B. subtilis cells. Surprisingly, we found that the ribosome inhibitor tetracycline causes membrane deformations. Further investigations showed that tetracycline disturbs membrane organization and localization of the peripheral membrane proteins MinD, MinC, and MreB. These observations are not the result of ribosome inhibition but constitute a secondary antibacterial activity of tetracycline that so far has defied discovery.
Original languageEnglish
Pages (from-to)306
Number of pages1
JournalCommunications Biology
Volume4
Issue number1
DOIs
Publication statusPublished - 8 Mar 2021

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