Biochemical and molecular changes of the zosteric acid-treated Escherichia coli biofilm on a mineral surface

Federica Villa,Cristina Cattò,Francesco Secundo,Fabio Forlani,Francesca Cappitelli

doi:10.1186/s13213-020-01617-1

Federica Villa, Cristina Cattò + Show 3 more

Open Access

https://doi.org/10.1186/s13213-020-01617-1

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Abstract

PurposeThe main goal of the present work was to assess the effectiveness of zosteric acid (ZA) in hindering Escherichia coli biofilm formation on a mineral surface.MethodsAttenuated total reflectance-Fourier transform infrared (ATR-FTIR) flow system was used to probe in situ the biochemical changes induced by ZA on E. coli sessile cells growing on the zinc selenide ATR plate. Comparative proteome analysis was conducted on the sessile cells to better understand the principal molecular changes that occur on ZA-treated biofilms.ResultsThe ZA treatment modified the kinetics of the biofilm development. After the ZA exposure, dramatic changes in the carbohydrates, proteins, and DNA profiles were observed over time in the ATR-FTIR spectra. These results were translated into the physiological effects such as the reduction of both the biomass and the EPS contents, the inhibition of the biofilm growth, and the promotion of the detachment. In E. coli sessile cells, the comparative proteome analysis revealed that, while the stress responses were upregulated, the pathways belonging to the DNA replication and repair were downregulated in the ZA-treated biofilms.ConclusionsThe ZA reduced the binding capability of E. coli cells onto the ZnSe crystal, hindering the firm adhesion and the subsequent biofilm development on a mineral surface. The variation of the protein patterns indicated that the ZA acted as a stress factor on the sessile cells that seemed to discourage biomass proliferation, consequently decreasing the surface colonization.

Highlights

The zosteric acid (ZA) treatment modified the kinetics of the biofilm development
No detectable changes in the wavenumber and the shape of the amide I and amide II bands were observed, suggesting that the ZA treatment did not induce changes in the protein’s secondary structure. All these findings—the dramatic changes in carbohydrates, proteins, and DNA profiles over time in the ZAtreated samples—are consistent with the previous results that showed the ability of ZA in hindering cell attachment and in slowing down the biofilm formation on polymeric surfaces (Dell'Orto et al 2017; Cattò et al 2018a, 2018b)
The effects of the antibiofilm compound on sessile cells were investigated by observing the response of E. coli to ZA at the protein level, using a comparative twodimensional gel electrophoresis approach

Summary

Introduction

The ZA treatment modified the kinetics of the biofilm development. After the ZA exposure, dramatic changes in the carbohydrates, proteins, and DNA profiles were observed over time in the ATR-FTIR spectra. The cell adhesion and the biofilm development on the ATR crystal were analyzed by monitoring the variation of the characteristic absorbance profiles of the bacterial functional groups in the 1800–900 cm-1 spectral range. The peak area of the amide II band (1546 cm-1) was used as a marker of biomass to monitor E. coli attachment and biofilm growth onto the ZnSe surface (Yunda et al 2020).

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