Dataset Information

Monoclonal Antibodies Specific to the Extracellular Domain of Histidine Kinase YycG of Staphylococcus epidermidis Inhibit Biofilm Formation.

ABSTRACT: Staphylococcus epidermidis is frequently associated with biofilm-related infections. Biofilms drastically reduce the efficacy of conventional antibiotics and the host immune system. In S. epidermidis biofilm formation, a major role is played by the YycG/YycF two-component system, and previous findings have indicated that inhibitors targeting the cytoplasmic HATPase_c domain of YycG kinase in S. epidermidis exhibit bactericidal and biofilm-killing activities. Therefore, we hypothesized that monoclonal antibodies (mAbs) against YycG extracellular (YycG_ex) domain would block the signal transduction and influence the biofilm formation of S. epidermidis. In this study, we screened out two YycG_ex-specific mAbs showing the highest affinity for the target, mAbs 2F3 and 1H1. These mAbs inhibited S. epidermidis biofilm formation in a dose-dependent manner, and at a concentration of 160 μg/mL, mAbs 2F3 and 1H1 caused 78.3 and 93.1% biofilm reduction, respectively, relative to normal mouse IgG control. When co-cultivated with YycG_ex mAbs, S. epidermidis cells showed diminished initial-adherence capacity, and the antibody treatment further led to a marked decrease in the synthesis of polysaccharide intercellular adhesin and in the transcriptional level of genes encoding proteins involved in biofilm formation. Lastly, we determined that the epitopes recognized by the two YycG_ex mAbs are located within aa 59-70 of the YycG_ex domain. It indicates that the YycG_ex domain may be a potential candidate as a vaccine for the prevention of S. epidermidis biofilm infections.

SUBMITTER: Lyu Z

PROVIDER: S-EPMC7426370 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundPolymicrobial infections are responsible for significant mortality and morbidity in adults and children. Staphylococcus epidermidis and Candida albicans are the most frequent combination of organisms isolated from polymicrobial infections. Vascular indwelling catheters are sites for mixed species biofilm formation and pose a significant risk for polymicrobial infections. We hypothesized that enhancement of biofilms in a mixed species environment increases patient mortality and morbidity.ResultsMixed species biofilms of S. epidermidis and C. albicans were evaluated in vitro and in a subcutaneous catheter infection model in vivo. Mixed species biofilms were enhanced compared to single species biofilms of either S. epidermidis or C. albicans. A mixed species environment increased catheter infection and increased dissemination of S. epidermidis in mice. Microarrays were used to explore differential gene expression of S. epidermidis in the mixed species biofilms. In mixed species biofilms, compared to single species S. epidermidis biofilms, 2.7% of S. epidermidis genes were upregulated and 6% were down regulated. Staphylococcal autolysis repressors lrgA and lrgB were down regulated 36-fold and 27-fold respectively. The role of biofilm extracellular DNA was investigated by quantitation and by evaluating the effects of DNAse in a concentration and time dependent manner. S. epidermidis specific eDNA was increased in mixed species biofilms and further confirmed by degradation with DNAse.ConclusionsMixed-species biofilms are enhanced and associated with increased S. epidermidis-specific eDNA in vitro and greater systemic dissemination of S. epidermidis in vivo. Down regulation of the lrg operon, a repressor of autolysis, associated with increased eDNA suggests a possible role for bacterial autolysis in mixed species biofilms. Enhancement and systemic dissemination of S. epidermidis may explain adverse outcomes after clinical polymicrobial infections of S. epidermidis and C. albicans.

Project description:RsaE is a conserved small regulatory RNA (sRNA) which was previously reported to represent a riboregulator of central carbon flow and other metabolic pathways in Staphylococcus aureus and Bacillus subtilis. Here we show that RsaE contributes to extracellular (e)DNA release and biofilm-matrix switching towards polysaccharide intercellular adhesin (PIA) production in a hypervariable Staphylococcus epidermidis isolate. Transcriptome analysis through differential RNA sequencing (dRNA-seq) in combination with confocal laser scanning microscopy (CLSM) and reporter gene fusions demonstrate that S. epidermidis protein- and PIA-biofilm matrix producers differ with respect to RsaE and metabolic gene expression. RsaE is spatiotemporally expressed within S. epidermidis PIA-mediated biofilms, and its overexpression triggers a PIA biofilm phenotype as well as eDNA release in an S. epidermidis protein biofilm matrix-producing strain background. dRNA-seq and Northern blot analyses revealed RsaE to exist as a major full-length 100-nt transcript and a minor processed species lacking approximately 20 nucleotides at the 5'-end. RsaE processing results in expansion of the mRNA target spectrum. Thus, full-length RsaE interacts with S. epidermidis antiholin-encoding lrgA mRNA, facilitating bacterial lysis and eDNA release. Processed RsaE, however, interacts with the 5'-UTR of icaR and sucCD mRNAs, encoding the icaADBC biofilm operon repressor IcaR and succinyl-CoA synthetase of the tricarboxylic acid (TCA) cycle, respectively. RsaE augments PIA-mediated biofilm matrix production, most likely through activation of icaADBC operon expression via repression of icaR as well as by TCA cycle inhibition and re-programming of staphylococcal central carbon metabolism towards PIA precursor synthesis. Additionally, RsaE supports biofilm formation by mediating the release of eDNA as stabilizing biofilm matrix component. As RsaE itself is heterogeneously expressed within biofilms, we consider this sRNA to function as a factor favoring phenotypic heterogeneity and supporting division of labor in S. epidermidis biofilm communities.

Dataset Information

Monoclonal Antibodies Specific to the Extracellular Domain of Histidine Kinase YycG of Staphylococcus epidermidis Inhibit Biofilm Formation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets