Integration of transcriptomic and proteomic approaches unveils the molecular mechanism of membrane disintegration in Escherichia coli O157:H7 with ultrasonic treatment

Ultrasonic disinfection in wastewater treatment has been studied for years at the phenotypic level, while the un-derstanding of the molecular inactivation mechanism is still not clear. Here, the responses of Escherichia coli O157:H7 to ultrasound treatment were investigated using RNA sequencing (RNA-Seq) and tandem mass tags (TMT) based quantitative proteomics methods. The analyses revealed that 770 genes and 201 proteins were sig-nificantly changed upon ultrasound treatment. Moreover, the integrated transcriptomic and proteomic analyses uncovered a set of 59 genes or proteins were differentially expressed in ultrasound-treated cells, providing an overview of the cellular responses to ultrasonic field. According to the bioinformatic analyses, genes and proteins that may be involved in lipid asymmetry preservation and outer membrane homeostasis maintenance (including phospholipid metabolism, lipopolysaccharide biosynthesis and transport, and fatty acid metabolism) were spe-cifically up-regulated. Therefore, we proposed that the metabolism disorder of cellular membrane lipids (lipo-polysaccharide, phospholipid, and fatty acid included) was one of the main challenges for the bacteria upon ultrasonic stress. In this study, we initially proposed a novel mechanism regarding the ultrasound-induced mem-brane disintegration from a multi-omics perspective, which may present an important step toward deciphering the molecular inactivation mechanism of ultrasonic field and provide a theoretical foundation for the application of ultrasound technology for the control of waterborne pathogens. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study revealed significant changes in gene and protein expression of Escherichia coli O157:H7 upon ultrasound treatment, with genes and proteins related to lipid metabolism and membrane homeostasis being specifically up-regulated. This indicates that the disruption of cellular membrane lipid metabolism is a major challenge for bacteria under ultrasonic stress.