Acidothermophilic bacteria of the genus Alicyclobacillus are frequent contaminants of fruit-based products. This study is the first attempt to characterize the physico-chemical surface properties of two Alicyclobacillus sp. and quantify their adhesion disposition to model materials [diethylaminoethyl (DEAE), carboxyl- and octyl-modified magnetic beads] representing materials with different surface properties used in the food industry. An insight into the mechanism of adhesion was gained through comparison of experimental adhesion intensities with predictions of a colloidal interaction model (XDLVO). Experimental data (contact angles, zeta potentials, size) on interacting surfaces (cells and materials) were used as inputs into the XDLVO model. The results revealed that the most significant adhesion occurred at pH 3. Adhesion of both vegetative cells and spores of two Alicyclobacillus sp. to all materials studied was the most pronounced under acidic conditions, and adhesion was influenced mostly by electrostatic attractions. The most intensive adhesion of vegetative cells and spores at pH 3 was observed for DEAE followed by hydrophobic octyl and hydrophilic carboxyl surfaces. Overall, the lowest rate of adhesion between cells and model materials was observed at an alkaline pH. Consequently, prevention of adhesion should be based on the use of alkaline sanitizers and/or alkaline rinse water.

• Klíčová slova
• Alicyclobacillus sp., Cell adhesion, Model materials, Surface interaction, XDLVO model,
• MeSH
• Alicyclobacillus chemie   fyziologie   MeSH
• bakteriální adheze * MeSH
• koncentrace vodíkových iontů MeSH
• povrchové vlastnosti MeSH
• spory bakteriální chemie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH

Biofilms are complex microbial communities that tend to attach to either biotic or abiotic surface. Enclosed in a self-produced extracellular polymeric substance (EPS) matrix, the biofilms often cause persistent infections. The objective of this study was to investigate the antibiofilm activity of dimethyl sulfoxide (DMSO) and afatinib against Gram-negative pathogens. Test microorganisms used in this study were Escherichia coli ATCC 1299, Pseudomonas aeruginosa ATCC 10145, and Salmonella typhimurium ATCC 14028. Biofilms were developed in 96-well microplate at 37°C for 24 h. Following removal of non-adherent cells, analysis of biofilm viability, biofilm biomass, and extracellular polymeric substances (EPS) matrix were performed using resazurin assay, crystal violet assay, and attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy, respectively. Bradford protein assay was conducted to determine the total amount of EPS proteins. The results demonstrated that both 32% DMSO alone and its combination with 3.2 μg/mL afatinib were effective in killing biofilm cells and reducing biofilm biomass. IR spectral variations of EPS matrix of biofilms in the range between 1700 and 900 cm-1 were also observed. Reduction in EPS proteins verified the chemical modifications of EPS matrix. In conclusion, 32% DMSO alone and its combination with 3.2 μg/mL afatinib showed remarkable antibiofilm activities against Gram-negative pathogens. It was suggested that the biofilm inhibition was mediated by the chemical modification of EPS matrix.

• Klíčová slova
• Afatinib, Antibiofilm, Dimethyl sulfoxide, Gram-negative pathogen,
• MeSH
• afatinib MeSH
• antibakteriální látky farmakologie   MeSH
• biofilmy účinky léků   MeSH
• chinazoliny farmakologie   MeSH
• dimethylsulfoxid farmakologie   MeSH
• Escherichia coli účinky léků   fyziologie   MeSH
• Pseudomonas aeruginosa účinky léků   fyziologie   MeSH
• Salmonella typhimurium účinky léků   fyziologie   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• synergismus léků MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• afatinib MeSH
• antibakteriální látky MeSH
• chinazoliny MeSH
• dimethylsulfoxid MeSH