Dataset Information

Inhibition of staphylococcal biofilm formation by nitrite.

ABSTRACT: Several environmental stresses have been demonstrated to increase polysaccharide intercellular adhesin (PIA) synthesis and biofilm formation by the human pathogens Staphylococcus aureus and Staphylococcus epidermidis. In this study we characterized an adaptive response of S. aureus SA113 to nitrite-induced stress and show that it involves concomitant impairment of PIA synthesis and biofilm formation. Transcriptional analysis provided evidence that nitrite, either as the endogenous product of respiratory nitrate reduction or after external addition, causes repression of the icaADBC gene cluster, mediated likely by IcaR. Comparative microarray analysis revealed a global change in gene expression during growth in the presence of 5 mM sodium nitrite and indicated a response to oxidative and nitrosative stress. Many nitrite-induced genes are involved in DNA repair, detoxification of reactive oxygen and nitrogen species, and iron homeostasis. Moreover, preformed biofilms could be eradicated by the addition of nitrite, likely the result of the formation of toxic acidified nitrite derivatives. Nitrite-mediated inhibition of S. aureus biofilm formation was abrogated by the addition of nitric oxide (NO) scavengers, suggesting that NO is directly or indirectly involved. Nitrite also repressed biofilm formation of S. epidermidis RP62A.

SUBMITTER: Schlag S

PROVIDER: S-EPMC2168742 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Inhibition of staphylococcal biofilm formation by nitrite.

Schlag Steffen S Nerz Christiane C Birkenstock Timo A TA Altenberend Florian F Götz Friedrich F

Journal of bacteriology 20070824 21

Several environmental stresses have been demonstrated to increase polysaccharide intercellular adhesin (PIA) synthesis and biofilm formation by the human pathogens Staphylococcus aureus and Staphylococcus epidermidis. In this study we characterized an adaptive response of S. aureus SA113 to nitrite-induced stress and show that it involves concomitant impairment of PIA synthesis and biofilm formation. Transcriptional analysis provided evidence that nitrite, either as the endogenous product of res ...[more]

PMID: 17720780

Similar Datasets

Project description:Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and non-proteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation without interfering with bacterial cell viability. Due to absence of cell toxicity, the extract might represent a good starting material to develop a future remedy to block staphylococcal biofilm formation on contact lenses and thereby to prevent intractable contact lens-mediated ocular infections.

Project description:Staphylococcus epidermidis, the common inhabitant of human skin and mucosal surfaces has emerged as an important pathogen in patients receiving surgical implants and medical devices. Entering the body via surgical sites and colonizing the medical devices through formation of multi-layered biofilms it leads to refractory and persistent device-related infections (DRIs). Staphylococcal proportions within biofilms are more tolerant to antibiotics and immune responses, and thus are hard-to-treat. The consequent morbidity and mortality, and economic losses in health care systems has strongly necessitated the need for development of new anti-bacterial and anti-biofilm based therapeutics. In this study, we describe the biological activity of a marine sponge-derived Streptomyces sp. SBT348 extract in restraining staphylococcal growth and biofilm formation on polystyrene, glass, medically relevant titan metal and silicone surfaces. A bio-assay guided fractionation was performed to isolate the active compound (C3) from the crude SBT348 extract. Our results demonstrated that C3 effectively inhibits the growth (MIC: 31.25 µg/ml) and biofilm formation (sub-MIC range: 1.95-<31.25 µg/ml) of S. epidermidis RP62A in vitro. Chemical characterization of C3 by heat and enzyme treatments, and High-Resolution Fourier Transform Mass Spectrometry (HRMS) revealed its heat-stable and non-proteinaceous nature, and high molecular weight (1258. 3257 Da). Cytotoxicity profiling of C3 in vitro on mouse fibroblast (NIH/3T3) and macrophage (J774.1) cell lines, and in vivo on the greater wax moth larvae Galleria melonella revealed its non-toxic nature at the effective dose. Transcriptome analysis of C3 treated-S. epidermidis RP62A has further unmasked the negative effect of C3 on central metabolism (carbon, amino acid and protein, lipids, nucleotide and energy) suggesting its mode of action. Taken together, these findings suggest that C3 could be possibly used as antibacterial and antibiofilm coatings on medically-relevant surfaces and prevent the relapsing staphylococcal DRIs.

Dataset Information

Inhibition of staphylococcal biofilm formation by nitrite.

Publications

Inhibition of staphylococcal biofilm formation by nitrite.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets