Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances

Abstract

Extracellular polymeric substances (EPS) constitutes crucial elements within bacterial biofilms, facilitating accelerated antimicrobial resistance and conferring defense against the host's immune cells. Developing precise and effective antibiofilm approaches and strategies, tailored to the specific characteristics of EPS composition, can offer valuable insights for the creation of novel antimicrobial drugs. This, in turn, holds the potential to mitigate the alarming issue of bacterial drug resistance. Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias, which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds. Considering the pivotal role of EPS in biofilm functionality, it is imperative for EPS research to delve deeper into the analysis of intricate compositions, moving beyond the current focus on polymeric materials. This necessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches. In this study, we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions. Additionally, novel strategies aimed at targeting EPS to enhance biofilm penetration were explored, with a specific focus on highlighting the limitations associated with colorimetric methods. Furthermore, we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges. This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS, thereby inhibiting biofilm formation. This insight opens up a new avenue for exploration within this research domain.

Keywords: Analytic strategies and approaches; Composition characterization; Extracellular polymeric substances (EPS); Promoting biofilm penetration.

Graphical abstract

Fig. 1

The working principle of (A) Raman spectroscopy and (B) Fourier transform infrared (FTIR) spectroscopy.

Fig. 2

Current analytical approaches for extracellular polymeric substances (EPS) composition. eDNA: extracellular DNA; HPAEC-PAD: high-performance anion exchange chromatography-pulsed amperometric detector; RM: Raman microscopy; SERS: surface-enhanced Raman scattering; FTIR: Fourier transform infrared spectroscopy; CLSM: confocal laser scanning microscopy; ConA: concanavalin A; SDS: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; 2D gel: two-dimensional gel electrophoresis; MS: mass spectrometry.

Fig. 3

Possible cross-interferences of components present in extracellular polymeric substances (EPS) with colorimetric methods. BSA: bovine serum albumin; BCA: bicinchoninic acid.

Fig. 4

A flow chat of proposed research scheme of polysaccharide identification.

Fig. 5

Extracellular polymeric substances (EPS) targeting strategies using (A) nanoparticles (NPs) and (B) microneedles (MNs).

Fig. 6

Extracellular polymeric substances (EPS) targeting strategies using (A) clustered regularly interspaced short palindromic repeats (CRISPR) arrays, (B) enzymatic methods, and (C) phage therapy.