Investigating Extracellular DNA Release in Staphylococcus xylosus Biofilm In Vitro.
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ABSTRACT:
SUBMITTER: Leroy S
PROVIDER: S-EPMC8617998 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in Staphylococcus aureus V329 and has been predicted as important for other species as well. Although Bap orthologs are also present in most S. xylosus strains, their contribution to biofilm formation has not yet been demonstrated. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in S. xylosus and the motif structure of two biofilm-forming S. xylosus strains TMW 2.1023 and TMW 2.1523 was compared to Bap of S. aureus V329. We found that despite an identical structural arrangement into four regions, Bap from S. xylosus differs in key factors to Bap of S. aureus, i.e., isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of bap had no effect on aggregation behavior of selected S. xylosus strains and biofilm formation was unaffected (TMW 2.1023) or at best slightly reduced under neutral conditions (TMW 2.1523). Further, we could not observe any typical characteristics of a S. aureus Bap-positive phenotype such as functional impairment by calcium addition and rough colony morphology on congo red agar (CRA). A dominating role of Bap in cell aggregation and biofilm formation as reported mainly for S. aureus V329 was not observed. In contrast, this work demonstrates that functions of S. aureus Bap cannot easily be extrapolated to S. xylosus Bap, which appears as non-essential for biofilm formation in this species. We therefore suggest that biofilm formation in S. xylosus follows different and multifactorial mechanisms.
| S-EPMC8708073 | biostudies-literature
Project description:Staphylococcus xylosus, a coagulase-negative, non-pathogenic bacterium, responsible for opportunistic infections in humans and bovine mastitis, has the ability to form biofilms, which are responsible for persistent infections and antibiotic resistance. In our study, azithromycin significantly inhibited biofilm formation by altering protein expression. Of the 1764 proteins measured by the isobaric Tag for Relative and Absolute Quantification (iTRAQ) technique, only 148 proteins showed significantly different expression between the azithromycin-treated and untreated cells. Most ribosomal proteins were markedly up-regulated, and the expression of the proteins involved in histidine biosynthesis, which, in turn, influence biofilm formation, was down-regulated, particularly imidazole glycerophosphate dehydratase (IGPD). Previously, we had observed that IGPD plays an important role in biofilm formation by S. xylosus. Therefore, hisB expression was studied by real-time PCR, and the interactions between azithromycin and IGPD were predicted by molecular docking analysis. hisB was found to be significantly down-regulated, and six bond interactions were observed between azithromycin and IGPD. Many active atoms of azithromycin did not interact with the biologically active site of IGPD. Surface plasmon resonance analysis used to further study the relationship between IGPD and azithromycin showed minimum interaction between them. Histidine content in the azithromycin-treated and untreated groups was determined. We noted a slight difference, which was not consistent with the expression of the proteins involved in histidine biosynthesis. Therefore, histidine degradation into glutamate was also studied, and we found that all proteins were down-regulated. This could be the reason why histidine content showed little change between the treated and untreated groups. In summary, we found that azithromycin is a potential inhibitor of S. xylosus biofilm formation, and the underlying mechanism was preliminarily elucidated in this study.
| S-EPMC6048454 | biostudies-literature
Project description:Staphylococcus (S.) xylosus is a coagulase-negative Staphylococcus species naturally present in food of animal origin with a previously described potential for biofilm formation. In this study we characterized biofilm formation of five selected strains isolated from raw fermented dry sausages, upon different growth conditions. Four strains exhibited a biofilm positive phenotype with strain-dependent intensities. Biofilm formation of S. xylosus was influenced by the addition of glucose, sodium chloride and lactate to the growth medium, respectively. It was further dependent on strain-specific cell surface properties. Three strains exhibited hydrophobic and two hydrophilic cell surface properties. The biofilm positive hydrophilic strain TMW 2.1523 adhered significantly better to hydrophilic than to hydrophobic supports, whereas the differences in adherence to hydrophobic versus hydrophilic supports were not as distinct for the hydrophobic strains TMW 2.1023, TMW 2.1323, and TMW 2.1521. Comparative genomics enabled prediction of functional biofilm-related genes and link these to phenotypic variations. While a wide range of biofilm associated factors/genes previously described for S. aureus and S. epidermidis were absent in the genomes of the five strains analyzed, they all possess the gene encoding biofilm associated protein Bap. The only biofilm negative strain TMW 2.1602 showed a mutation in the bap sequence. This study demonstrates that Bap and surface hydrophobicity are important factors in S. xylosus biofilm formation with potential impact on the assertiveness of a starter strain against autochthonous staphylococci by competitive exclusion during raw sausage fermentation.
| S-EPMC6603148 | biostudies-literature
Project description:The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in Staphylococcus aureus V329 and other species. Although Bap orthologs are also present in most S. xylosus strains, their contribution to biofilm formation has not yet been determined. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in S. xylosus and the motif structure of two biofilm-forming S. xylosus strains TMW 2.1023 and TMW 2.1523 was compared to Bap of S. aureus V329. We found that despite an identical structural arrangement into four regions, Bap from S. xylosus differs in key factors to Bap of S. aureus i.e. isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of bap had no effect on aggregation behavior of selected S. xylosus strains and a significant reduction in biofilm was only observed for one strain (TMW 2.1523) under neutral conditions. Further we could not observe any typical characteristics of a S. aureus Bap positive phenotype such as functional impairment by calcium addition and rough colony morphology on CRA. A predominant role of Bap in cell aggregation and biofilm formation as reported for S. aureus V329 was not observed. We therefore suggest that biofilm formation follows different, multifactorial mechanisms, and cannot be referred to as the primary function of Bap in S. xylosus.
2022-01-20 | PXD029728 | Pride
Project description:Bacterial biofilms do serious harm to the diabetic foot ulcer (DFU) because they play a crucial role in infection invasion and spread. Staphylococcus aureus, the predominant Gram-positive bacteria in diabetic foot infection (DFI), is often associated with colonization and biofilm formation. Through biofilm formation tests in vitro, we observed that S. aureus bacteria isolated from DFU wounds were more prone to form biofilms than those from non-diabetic patients, while there was no difference in blood sugar between the biofilm (+) diabetics (DB+) and biofilm (-) diabetics (DB-). Furthermore, we found that advanced glycation end products (AGEs) promoted the biofilm formation of S. aureus in clinical isolates and laboratory strains in vitro, including a methicillin-resistant strain. Analysis of biofilm components demonstrated that the biofilms formed mainly by increasing extracellular DNA (eDNA) release; remarkably, the S. aureus global regulator sigB was upregulated, and its downstream factor lrgA was downregulated after AGE treatments. Mechanism studies using a sigB-deleted mutant (Newman-ΔsigB) confirmed that AGEs decreased expression of lrgA via induction of sigB, which is responsible for eDNA release and is a required component for S. aureus biofilm development. In conclusion, the present study suggests that AGEs promote S. aureus biofilm formation via an eDNA-dependent pathway by regulating sigB. The data generated by this study will provide experimental proof and theoretical support to improve DFU infection healing.
| S-EPMC7381169 | biostudies-literature
Project description:Staphylococcus xylosus is a commensal of the skin of humans and animals and a ubiquitous bacterium naturally present in food. It is one of the major starter cultures used for meat fermentation, but a few strains could potentially be hazardous and are related to animal opportunistic infections. To better understand the genetic diversity of S. xylosus intraspecies, suppressive and subtractive hybridization (SSH) was carried out with the S. xylosus C2a strain, a commensal of human skin, used as the driver for three tester strains, S04002 used as a starter culture, S04009 isolated from cow mastitis, and 00-1747, responsible for mouse dermatitis. SSH revealed 122 tester-specific fragments corresponding to 149 open reading frames (ORFs). A large proportion of these ORFs resembled genes involved in specific metabolisms. Analysis of the distribution of the tester-specific fragments in 20 S. xylosus strains of various origins showed that the S. xylosus species could be divided into two clusters with one composed only of potentially hazardous strains. The genetic content diversity of this species is colocalized in a region near the origin of replication of the chromosome. This region of speciation previously observed in the Staphylococcus genus corresponded in S. xylosus species to a strain-specific region potentially implicated in ecological fitness.
| S-EPMC2168225 | biostudies-literature
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.
| S-EPMC3833181 | biostudies-literature
Project description:Staphylococcus xylosus (S. xylosus) is an AT-rich and coagulase-negative Staphylococcus (CNS). It is normally regarded as non-pathogenic, however, recent studies have demonstrated that it is related to human opportunistic infections and bovine mastitis. In addition, S. xylosus strains have the ability to form biofilm. Biofilms are also involved in chronic infections and antibiotic resistance, there are only a few reports about cefquinome inhibiting S. xylosus biofilm formation and the protein targets of cefquinome. In our study, we found that sub-MICs of cefquinome were sufficient to inhibit biofilm formation. To investigate the potential protein targets of cefquinome, we used iTRAQ for the analyses of cells at two different conditions: 1/2-MIC (0.125 ?g/mL) cefquinome treatment and no treatment. Using iTRAQ technique and KEGG database analysis, we found that proteins differently expression in histidine metabolism pathway may play a role in the process by which 1/2-MIC (0.125 ?g/mL) cefquinome inhibits S. xylosus biofilm formation. Interestingly, we found a sharply down-regulated enzyme [A0A068E9J3 imidazoleglycerol-phosphate dehydratase (IGPD)] involved in histidine metabolism pathway in cefquinome-treated cells. We demonstrated the important role of IGPD in sub-MICs cefquinome inhibiting biofilm formation of S. xylosus by gene (hisB) knockout, IGPD enzyme activity and histidine content assays. Thus, our data sheds light on important role of histidine metabolism in S. xylosus biofilm formation; especially, IGPD involved in histidine metabolism might play a crucial role in sub-MICs cefquinome inhibition of biofilm formation of S. xylosus, and we propose IGPD as an attractive protein target of cefquinome.
| S-EPMC5896262 | biostudies-literature
Project description:Comparison of biofilm versus planktonic mode of growth in Staphylococcus aureus
2014-01-18 | E-MEXP-3924 | biostudies-arrayexpress
Project description:Staphylococcus xylosus (S. xylosus) has become an emerging opportunistic pathogen due to its strong biofilm formation ability. Simultaneously, the biofilm of bacteria plays an important role in antibiotic resistance and chronic infection. Here, we confirmed that rutin can effectively inhibit biofilm formation in S. xylosus, of which the inhibition mechanism involves its ability to interact with imidazole glycerol phosphate dehydratase (IGPD), a key enzyme in the process of biofilm formation. We designed experiments to target IGPD and inhibited its activities against S. xylosus. Our results indicated that the activity of IGPD and the amount of histidine decreased significantly under the condition of 0.8 mg/ml rutin. Moreover, the expression of IGPD mRNA (hisB) and IGPD protein was significantly down-regulated. Meanwhile, the results from molecular dynamic simulation and Bio-layer interferometry (BLI) technique showed that rutin could bind to IGPD strongly. Additionally, in vivo studies demonstrated that rutin treatment reduced inflammation and protect mice from acute mastitis caused by S. xylosus. In summary, our findings provide new insights into the treatment of biofilm mediated persistent infections and chronic bacterial infections. It could be helpful to design next generation antibiotics to against resistant bacteria.
| S-EPMC8385535 | biostudies-literature