Proteomic and transcriptomic analyses of Cutibacterium acnes biofilms and planktonic cultures in presence of epinephrine.

Transcriptomic and proteomic analysis were performed on 72 h biofilms of the acneic strain Cutibacterium acnes and planktonic cultures in the presence of epinephrine. Epinephrine predominantly downregulated genes associated with various transporter proteins. No correlation was found between proteomic and transcriptomic profiles. In control samples, the expression of 51 proteins differed between planktonic cultures and biofilms. Addition of 5 nM epinephrine reduced this number, and in the presence of 5 µM epinephrine, the difference in proteomic profiles between planktonic cultures and biofilms disappeared. According to the proteomic profiling, epinephrine itself was more effective in the case of C. acnes biofilms and potentially affected the tricarboxylic acid cycle (as well as alpha-ketoglutarate decarboxylase Kgd), biotin synthesis, cell division, and transport of different compounds in C. acnes cells. These findings are consistent with recent research on Micrococcus luteus, suggesting that the effects of epinephrine on actinobacteria may be universal.

Epinephrine affects gene expression levels and has a complex effect on biofilm formation in M icrococcus luteus strain C01 isolated from human skin.

In this study, the effect of epinephrine on the biofilm formation of Micrococcus luteus C01 isolated from human skin was investigated in depth for the first time. This hormone has a complex effect on biofilms in various systems. In a system with polytetrafluoroethylene (PTFE) cubes, treatment with epinephrine at a physiological concentration of 4.9 × 10-9 M increased the total amount of 72-h biofilm biomass stained with crystal violet and increased the metabolic activity of biofilms, but at higher and lower concentrations, the treatment had no significant effect. On glass fiber filters, treatment with the hormone decreased the number of colony forming units (CFUs) and changed the aggregation but did not affect the metabolic activity of biofilm cells. In glass bottom plates examined by confocal microscopy, epinephrine notably inhibited the growth of biofilms. RNA-seq analysis and RT-PCR demonstrated reproducible upregulation of genes encoding Fe-S cluster assembly factors and cyanide detoxification sulfurtransferase, whereas genes encoding the co-chaperone GroES, the LysE superfamily of lysine exporters, short-chain alcohol dehydrogenase and the potential c-di-GMP phosphotransferase were downregulated. Our results suggest that epinephrine may stimulate matrix synthesis in M. luteus biofilms, thereby increasing the activity of NAD(H) oxidoreductases. Potential c-di-GMP pathway proteins are essential in these processes.

[Regulation of Biofilm Formation by Pseudomonas chlororaphis in an vitro System].

The mutants of Pseudomonas chlororaphis 449 with completely or partially suppressed accumulation of N-acyl homoserine lactones exhibited the absence or a pronounced decrease of their capacity for stimulation of biofilm growth in the presence of azithromycin. Biofilms of the wild type strain preformed in the presence of the stimulatory azithromycin concentrations exhibited more intense staining with a polysaccharide-specific dye 1,9-dimethyl methylene blue (DMMB) and were more resistant to heat shock. These findings indicate accumulation of the structural matrix polysaccharides, which play a protective role under the conditions of thermal shock. Extremely low azithromycin concentrations (0.001-0.01 µg/mL) inhibit biofilm formation by P. chlororaphis 449 and P. chlororaphis 66 with suppression of the synthesis of DMMB-staining polysaccharides.