ABSTRACT
The aim of this work was to monitor the potential antibiofilm properties of biosurfactants (BS) isolated from Bacillus amyloliquefaciens 3/22 against biofilm formation of the indicator strain Staphylococcus aureus CCM 4223. In this work, the effect of BS 3/22 on biofilm growth during co-incubation, inhibition of biofilm-forming cell adhesion and biofilm dispersion was studied. BS 3/22 inhibited biofilm formation, with its formation decreasing significantly (p < 0.05; p < 0.01; p < 0.001) with increasing BS 3/22 concentration. BS 3/22 also showed antiadhesive activity, which correlated with the concentration used. The dispersing effect of isolated BS 3/22 on a 24-hour biofilm was also detected. BS 3/22 were effective in biofilm dispersion even at lower concentrations compared to antiadhesive activity and inhibition of biofilm formation.
Subject(s)
Bacillus amyloliquefaciens , Anti-Bacterial Agents/pharmacology , Biofilms , Staphylococcus aureusABSTRACT
Biosurfactants (BSs) are surface-active compounds produced by diverse microorganisms, including the genus Bacillus. These bioactive compounds possess biological activities such as antiadhesive, antimicrobial and antibiofilm effects that can lead to important applications in combating many infections. Based on these findings, we decided to investigate the antibiofilm activity of BSs from the marine Bacillus amyloliquefaciens against Staphylococcus aureus CCM 4223. Expression of biofilm-related genes was also evaluated using qRT-PCR. Isolated and partially purified BSs were identified and characterized by molecular tools and by UHPLC-DAD and MALDI-TOF/MS. Bacillus amyloliquefaciens 3/22, that exhibited surfactant activity evaluated by oil spreading assay, was characterized using the 16S rRNA sequencing method. Screening by PCR detected the presence of the sfp, srfAA, fenD and ituD genes, suggesting production of the lipopeptides (LPs) surfactin, fengycin and iturin. The above findings were further supported by the results of UHPLC-DAD and MALDI-TOF/MS. As quantified by the crystal violet method, the LPs significantly (p < 0.001) reduced biofilm formation of S. aureus in a dose-dependent manner and decreased expression of biofilm-related genes fnbA, fnbB, sortaseA and icaADBC operon. Data from our investigation indicate a promising therapeutic application for LPs isolated from B. amyloliquefaciens toward prevention of S. aureus biofilm infections.
ABSTRACT
The aim of this work was to monitor the potential antibiofilm properties of biosurfactants (BS) isolated from Bacillus amyloliquefaciens 3/22 against biofilm formation of the indicator strain Staphylococcus aureus CCM 4223. In this work, the effect of BS 3/22 on biofilm growth during co-incubation, inhibition of biofilm-forming cell adhesion and biofilm dispersion was studied. BS 3/22 inhibited biofilm formation, with its formation decreasing significantly (p < 0.05; p < 0.01; p < 0.001) with increasing BS 3/22 concentration. BS 3/22 also showed antiadhesive activity, which correlated with the concentration used. The dispersing effect of isolated BS 3/22 on a 24-hour biofilm was also detected. BS 3/22 were effective in biofilm dispersion even at lower concentrations compared to antiadhesive activity and inhibition of biofilm formation.
Subject(s)
Bacillus amyloliquefaciens , Anti-Bacterial Agents/pharmacology , Biofilms , Staphylococcus aureusABSTRACT
Resistance of pathogenic bacteria is currently one of the major medical problems. Most microbial infections are based on the formation of biofilms, which are a significant reservoir of pathogens. The aim of this study is to determine the antibiofilm and antimicrobial activity of biosurfactants isolated from intestinal lactobacilli and marine bacteria. Biosurfactants (BS) isolated from the strains L. fermentum 2I3, L. fermentum B2/6, L. reuteri SL16, L. reuteri B6/1, S. luteola 3/22, Brevibacillus sp. 4/9, Brevibacillus sp. 2/30 and B. amyloliquefaciens 1/6K significantly (p < 0.001) inhibited the biofilm formation of S. aureus CCM 3953 and P. mirabilis CCM 7188, with higher inhibition detected in BS of marine bacteria when compared to BS isolated from lactobacilli. The results suggest that the mechanism of the antibiofilm effect of BS isolated from lactobacilli against both the reference strains is the same and it is not the result of their antimicrobial action. In contrast, the mechanism of the antibiotic effect of BS isolated from marine bacteria probably depends on the properties of the indicator strain. Key words: biosurfactants biofilm pathogens inhibition.
