ABSTRACT Identification of new genes involved in biofilm formation is needed to understand the molecular basis strain variation and pathogenic mechanisms implicated chronic staphylococcal infections. A biofilm-producing Staphylococcus aureus isolate was used generate biofilm-negative transposon (Tn917) insertion mutants. Two mutants were found with a significant decrease attachment inert surfaces (early adherence), intercellular adhesion, formation. The inserted at same locus both This ( bap...

ABSTRACT The enterococcal surface protein, Esp, is a high-molecular-weight protein of unknown function whose frequency significantly increased among infection-derived Enterococcus faecalis isolates. In this work, global structural similarity was found between Bap, biofilm-associated Staphylococcus aureus , and Esp. Analysis the relationship presence Esp-encoding gene ( esp ) biofilm formation capacity in E. demonstrated that highly associated P < 0.0001) with to form on polystyrene...

Summary We report here a new screening method based on the fluorescence of colonies calcofluor agar plates to identify transposon insertion mutants Salmonella enteritidis that are defective in biofilm development. The results not only confirmed requirement genes already described for modulation multicellular behaviour typhimurium and other species, but also revealed aspects formation process, such as two genetic elements, named bcs ABZC EFG operons, required synthesis an exopolysaccharide,...

Summary The formation of biofilm results in a major lifestyle switch that is thought to affect the expression multiple genes and operons. We used DNA arrays study global effect on gene mature Escherichia coli K‐12 biofilm. show that, when compared with exponential growth phase, 1.9% showed consistent up‐ or downregulation by factor greater than two, 10% E. genome significantly differentially expressed. functions induced these conditions correspond stress response as well energy production,...

Summary Staphylococcus aureus biofilm formation is associated with the production of polysaccharide intercellular adhesin (PIA/PNAG), product ica operon. The staphylococcal accessory regulator, SarA, a central regulatory element that controls S. virulence factors. By screening library Tn917 insertions in clinical strain, we identified SarA as being essential for development. Non‐polar mutations sar A four genetically unrelated strains decreased PIA/PNAG and completely impaired development,...

The capacity of Staphylococcus aureus to form biofilms on host tissues and implanted medical devices is one the major virulence traits underlying persistent chronic infections. matrix in which S. cells are encased a biofilm often consists polysaccharide intercellular adhesin (PIA) or poly-N-acetyl glucosamine (PNAG). However, surface proteins capable promoting development absence PIA/PNAG exopolysaccharide have been described. Here, we used two-dimensional nano-liquid chromatography mass...

RNA deep sequencing technologies are revealing unexpected levels of complexity in bacterial transcriptomes with the discovery abundant noncoding RNAs, antisense long 5′ and 3′ untranslated regions, alternative operon structures. Here, by applying to both short fractions (<50 nucleotides) obtained from major human pathogen Staphylococcus aureus , we have detected a collection RNAs that is generated genome-wide through digestion overlapping sense/antisense transcripts RNase III...

Abstract Age-related neurodegenerative diseases involving amyloid aggregation remain one of the biggest challenges modern medicine. Alterations in gastrointestinal microbiome play an active role aetiology neurological disorders. Here, we dissect amyloidogenic properties biofilm-associated proteins (BAPs) gut microbiota and their implications for synucleinopathies. We demonstrate that BAPs are naturally assembled as amyloid-like fibrils insoluble fractions isolated from human microbiota. show...

The development of surface-attached biofilm bacterial communities is considered an important source nosocomial infections. Recently, interference via signaling molecules and surface active compounds was shown to antagonize formation, suggesting that nonantibiotic produced during competitive interactions between bacteria could be used for reduction. Hence, a better understanding commensal/pathogen within community lead improved control exogenous pathogens. To reveal adhesion or growth-related...

ABSTRACT Escherichia coli is the primary cause of urinary tract infection (UTI) in developed world. The major factors associated with virulence uropathogenic E. (UPEC) are fimbrial adhesins, which mediate specific attachment to host receptors and trigger innate responses. Another group adhesins represented by autotransporter subgroup proteins. best characterized these proteins, antigen 43 (Ag43), a self-recognizing adhesin that cell aggregation biofilm formation K-12. sequenced genome...

Staphylococcus aureus can establish chronic infections on implanted medical devices due to its capacity form biofilms. Analysis of the factors that assemble cells into a biofilm has revealed occurrence strains produce either polysaccharide intercellular adhesin/poly-N-acetylglucosamine (PIA/PNAG) exopolysaccharide- or protein-dependent biofilm. Examination influence matrix nature capacities embedded bacteria remained elusive, because natural strain readily converts between polysaccharide-...

Two-component systems (TCSs) are key regulatory pathways allowing bacteria to adapt their genetic expression environmental changes. Bacitracin, a cyclic dodecylpeptide antibiotic, binds undecaprenyl pyrophosphate, the lipid carrier for cell wall precursors, effectively inhibiting peptidoglycan biosynthesis. We have identified novel and previously uncharacterized TCS in major human pathogen Staphylococcus aureus that we show be essential bacitracin nisin resistance: BraS/BraR system...

ABSTRACT Staphylococcus epidermidis biofilm formation is associated with the production of polysaccharide intercellular adhesin (PIA)--poly- N -acetylglucosamine (PNAG) by products icaADBC operon. Recent evidence indicates that SarA, a central regulatory element controls aureus virulence factors, essential for synthesis PIA/PNAG and ensuing development in this species. Based on presence sarA homolog, we hypothesized SarA could also be involved regulation process S. . To investigate this,...

Biofilms are communities of bacteria that grow encased in an extracellular matrix often contains proteins. The spatial organization and the molecular interactions between scaffold proteins remain most cases largely unknown. Here, we report Bap protein Staphylococcus aureus self-assembles into functional amyloid aggregates to build biofilm response environmental conditions. Specifically, is processed fragments containing at least N-terminus become aggregation-prone self-assemble amyloid-like...

The ability of Escherichia coli to colonize both intestinal and extraintestinal sites is driven by the presence specific virulence factors, among which are autotransporter (AT) proteins. Members trimeric AT adhesin family important factors for several gram-negative pathogens mediate adherence eukaryotic cells extracellular matrix (ECM) In this study, we characterized a new (UpaG) from uropathogenic E. (UPEC). Molecular analysis UpaG revealed that it translocated cell surface adopts...

Acinetobacter baumannii has emerged as a dangerous opportunistic pathogen, with many strains able to form biofilms and thus cause persistent infections. The aim of the present study was use high-throughput sequencing techniques establish complete transcriptome profiles planktonic (free-living) sessile (biofilm) forms A. ATCC 17978 thereby identify differences in their gene expression patterns. Collections mRNA from (both exponential stationary phase cultures) cells were sequenced. Six...

Biofilm formation is one of the main causes for persistence Acinetobacter baumannii, a pathogen associated with severe infections and outbreaks in hospitals. Here, we performed comparative proteomic analyses (2D-DIGE MALDI-TOF/TOF iTRAQ/SCX-LC–MS/MS) cells at three different conditions: exponential, late stationary phase, biofilms. These results were compared alterations proteome resulting from exposure to biofilm inhibitory compound (salicylate). Using this multiple-approach strategy,...

Cyclic di-GMP (c-di-GMP) is a secondary messenger that controls variety of cellular processes, including the switch between biofilm and planktonic bacterial lifestyle. This nucleotide binds to effectors in order exert its regulatory functions. In Salmonella, two proteins, BcsA YcgR, both them containing c-di-GMP binding PilZ domain, are only known receptors. BcsA, upon binding, synthesizes cellulose, main exopolysaccharide matrix. YcgR dedicated c-di-GMP-dependent inhibition motility through...

Abstract Bacteria use two-component systems (TCSs) to sense and respond environmental changes. The core genome of the major human pathogen Staphylococcus aureus encodes 16 TCSs, one which (WalRK) is essential. Here we show that S. can be deprived its complete sensorial TCS network still survive under growth arrest conditions similarly wild-type bacteria. Under replicating conditions, however, WalRK system necessary sufficient maintain bacterial growth, indicating sensing through TCSs mostly...

Modification of the biomaterial surface topography is a promising strategy to prevent bacterial adhesion and biofilm formation. In this study, we use direct laser interference patterning (DLIP) modify polystyrene at sub-micrometer scale. The results revealed that three-dimensional micrometer structures have profound impact on adhesion. Thus, line- pillar-like patterns enhanced S. aureus adhesion, whereas complex lamella microtopography reduced in static continuous flow culture conditions....

The biofilm matrix, composed of exopolysaccharides, proteins, nucleic acids and lipids, plays a well-known role as defence structure, protecting bacteria from the host immune system antimicrobial therapy. However, little is known about its responsibility in interaction cells with tissues. Staphylococcus aureus, leading cause biofilm-associated chronic infections, able to develop built on proteinaceous Bap-mediated matrix. Here, we used Bap protein model investigate that components matrix...

The presence of regulatory sequences in the 3′ untranslated region (3′-UTR) eukaryotic mRNAs controlling RNA stability and translation efficiency is widely recognized. In contrast, relevance 3′-UTRs bacterial mRNA functionality has been disregarded. Here, we report evidences showing that around one-third mapped major human pathogen Staphylococcus aureus carry longer than 100-nt thus, potential functions. We selected long 3′-UTR icaR, which codes for repressor main exopolysaccharidic compound...

Bacteria have developed an exclusive signal transduction system involving multiple diguanylate cyclase and phosphodiesterase domain-containing proteins (GGDEF EAL/HD-GYP, respectively) that modulate the levels of same diffusible molecule, 3'-5'-cyclic diguanylic acid (c-di-GMP), to transmit signals obtain specific cellular responses. Current knowledge about c-di-GMP signaling has been inferred mainly from analysis recombinant bacteria either lack or overproduce individual members pathway,...

ABSTRACT Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infection (UTI) in developed world. The major factors associated with virulence UPEC are fimbrial adhesins, which mediate specific attachment to host receptors and trigger innate responses. Another group adhesins represented by autotransporter (AT) subgroup proteins. genome-sequenced prototype strain CFT073 contains 11 putative AT-encoding genes. In this study, we have performed a detailed molecular...