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1.
Front Cell Infect Microbiol ; 14: 1379206, 2024.
Article in English | MEDLINE | ID: mdl-38938878

ABSTRACT

Enteroaggregative E. coli (EAEC) is a major cause of diarrhea worldwide. EAEC are highly adherent to cultured epithelial cells and make biofilms. Both adherence and biofilm formation rely on the presence of aggregative adherence fimbriae (AAF). We compared biofilm formation from two EAEC strains of each of the five AAF types. We found that AAF type did not correlate with the level of biofilm produced. Because the composition of the EAEC biofilm has not been fully described, we stained EAEC biofilms to determine if they contained protein, carbohydrate glycoproteins, and/or eDNA and found that EAEC biofilms contained all three extracellular components. Next, we assessed the changes to the growing or mature EAEC biofilm mediated by treatment with proteinase K, DNase, or a carbohydrate cleavage agent to target the different components of the matrix. Growing biofilms treated with proteinase K had decreased biofilm staining for more than half of the strains tested. In contrast, although sodium metaperiodate only altered the biofilm in a quantitative way for two strains, images of biofilms treated with sodium metaperiodate showed that the EAEC were more spread out. Overall, we found variability in the response of the EAEC strains to the treatments, with no one treatment producing a biofilm change for all strains. Finally, once formed, mature EAEC biofilms were more resistant to treatment than biofilms grown in the presence of those same treatments.


Subject(s)
Biofilms , Deoxyribonucleases , Endopeptidase K , Escherichia coli , Biofilms/drug effects , Biofilms/growth & development , Endopeptidase K/pharmacology , Endopeptidase K/metabolism , Escherichia coli/drug effects , Escherichia coli/genetics , Deoxyribonucleases/metabolism , Deoxyribonucleases/pharmacology , Fimbriae, Bacterial/metabolism , Bacterial Adhesion/drug effects , Humans , Periodic Acid/pharmacology
2.
J Appl Microbiol ; 135(6)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38877639

ABSTRACT

AIM: Coaggregation, a highly specific cell-cell interaction mechanism, plays a pivotal role in multispecies biofilm formation. While it has been mostly studied in oral environments, its occurrence in aquatic systems is also acknowledged. Considering biofilm formation's economic and health-related implications in engineered water systems, it is crucial to understand its mechanisms. Here, we hypothesized that traceable differences at the proteome level might determine coaggregation ability. METHODS AND RESULTS: Two strains of Delftia acidovorans, isolated from drinking water were studied. First, in vitro motility assays indicated more swarming and twitching motility for the coaggregating strain (C+) than non-coaggregating strain (C-). By transmission electronic microscopy, we confirmed the presence of flagella for both strains. By proteomics, we detected a significantly higher expression of type IV pilus twitching motility proteins in C+, in line with the motility assays. Moreover, flagellum ring proteins were more abundant in C+, while those involved in the formation of the flagellar hook (FlE and FilG) were only detected in C-. All the results combined suggested structural and conformational differences between stains in their cell appendages. CONCLUSION: This study presents an alternative approach for identifying protein biomarkers to detect coaggregation abilities in uncharacterized strains.


Subject(s)
Biofilms , Drinking Water , Flagella , Proteomics , Biofilms/growth & development , Drinking Water/microbiology , Flagella/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Adhesion , Fimbriae, Bacterial/metabolism , Water Microbiology , Proteome
3.
Sci Rep ; 14(1): 13632, 2024 06 13.
Article in English | MEDLINE | ID: mdl-38871850

ABSTRACT

Helicobacter pylori is a prominent gastrointestinal pathogen associated with various gastrointestinal illnesses. It presents substantial health risks due to its antibiotic resistance. Therefore, it is crucial to identify alternative treatments for H. pylori infections. Limosilactobacillus spp exhibit probiotic properties with beneficial effects in humans; however, the mechanisms by which it counteracts H. pylori infection are unknown. This study aimed to evaluate the potential of Limosilactobacillus fermentum T0701 lyophilized cell-free supernatants (LCFS) against H. pylori. The LCFS has varying antimicrobial activities, with inhibition zones of up to 10.67 mm. The minimum inhibitory concentration and minimum bacterial concentration of LCFS are 6.25-25.00 mg/mL and 6.25 mg/mL to > 50.00 mg/mL, respectively, indicating its capability to inhibit H. pylori. There is morphological damage observed in H. pylori treated with LCFS. Additionally, H. pylori adhesion to AGS cells (human gastric adenocarcinoma epithelial cells) reduces by 74.23%, highlighting the LCFS role in preventing bacterial colonization. Moreover, LCFS exhibits no cytotoxicity or morphological changes in AGS cells, and with no detected virulence or antimicrobial resistance genes, further supporting its safety profile. L. fermentum T0701 LCFS shows promise as a safe and effective non-toxic agent against H. pylori, with the potential to prevent gastric colonization.


Subject(s)
Anti-Bacterial Agents , Helicobacter pylori , Limosilactobacillus fermentum , Microbial Sensitivity Tests , Helicobacter pylori/drug effects , Limosilactobacillus fermentum/physiology , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Freeze Drying , Probiotics/pharmacology , Bacterial Adhesion/drug effects , Helicobacter Infections/microbiology , Helicobacter Infections/drug therapy , Cell Line, Tumor
4.
Nat Commun ; 15(1): 4912, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38851738

ABSTRACT

Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual trimer arrangement with a positively charged external surface and negatively charged solvent exposed internal cavity. Through molecular dynamics simulations, we show how the glycosaminoglycan chondroitin-4-sulphate associates with the Lcl-CTD surface via distinct binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate-binding mechanism.


Subject(s)
Bacterial Proteins , Collagen , Glycosaminoglycans , Legionella pneumophila , Molecular Dynamics Simulation , Protein Binding , Glycosaminoglycans/metabolism , Glycosaminoglycans/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/chemistry , Legionella pneumophila/metabolism , Collagen/metabolism , Collagen/chemistry , Crystallography, X-Ray , Chondroitin Sulfates/metabolism , Chondroitin Sulfates/chemistry , Bacterial Adhesion , Protein Domains , Legionnaires' Disease/microbiology , Legionnaires' Disease/metabolism , Humans , Amino Acid Sequence
5.
Sci Total Environ ; 944: 173889, 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-38876335

ABSTRACT

The transport and retention of bacteria in porous media, such as aquifer, are governed by the solid-liquid interface characteristics and bacterial mobility. The secretion of extracellular polymeric substance (EPS) by bacteria modifies their surface property, and thereby has effects on their adhesion to surface. The role of EPS in bacterial mobility within saturated quartz sand media is uncertain, as both promoting and inhibitory effects have been reported, and underlying mechanisms remain unclear. In this study, the effects of EPS on bacterial transport behavior and possible underlying mechanism were investigated at 4 concentrations (0 mg L-1, 50 mg L-1, 200 mg L-1 and 1000 mg L-1) using laboratory simulation experiments in conjunction with Extend Derjaguin-Landau-Verweu-Overbeek (XDLVO) modeling. The results showed that EPS facilitated bacterial mobility at all tested concentrations. It could be partially explained by the increased energy barrier between bacterial cells and quartz sand surface in the presence of EPS. The XDLVO sphere-plate model predicted that EPS induced a higher electrostatic double layer (EDL) repulsive force, Lewis acid-base (AB) and steric stabilization (ST), as well as a lower Lifshitz-van der Waals (LW) attractive force. However, at the highest EPS concentration (1000 mg L-1), the promotion of EPS on bacterial mobility weakened as a result of lower repulsive interactions between cells, which was supported by observed enhanced bacterial aggregation. Consequently, the increased aggregation led to greater bio-colloidal straining and ripening in the sand column, weakening the positive impact of EPS on bacterial transport. These findings suggested that EPS exhibited concentration-dependent effects on bacterial surface properties and transport behavior and revealed non-intuitive dual effects of EPS on those processes.


Subject(s)
Bacteria , Extracellular Polymeric Substance Matrix , Porosity , Bacteria/metabolism , Surface Properties , Groundwater/chemistry , Bacterial Adhesion
6.
BMC Microbiol ; 24(1): 221, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38909237

ABSTRACT

BACKGROUND: Group B Streptococcus (GBS) is a commensal of healthy adults and an important pathogen in newborns, the elderly and immunocompromised individuals. GBS displays several virulence factors that promote colonisation and host infection, including the ST-17 strain-specific adhesin Srr2, previously characterised for its binding to fibrinogen. Another common target for bacterial adhesins and for host colonization is fibronectin, a multi-domain glycoprotein found ubiquitously in body fluids, in the extracellular matrix and on the surface of cells. RESULTS: In this study, fibronectin was identified as a novel ligand for the Srr2 adhesin of GBS. A derivative of the ST-17 strain BM110 overexpressing the srr2 gene showed an increased ability to bind fibrinogen and fibronectin, compared to the isogenic wild-type strain. Conversely, the deletion of srr2 impaired bacterial adhesion to both ligands. ELISA assays and surface plasmon resonance studies using the recombinant binding region (BR) form of Srr2 confirmed a direct interaction with fibronectin with an estimated Kd of 92 nM. Srr2-BR variants defective in fibrinogen binding also exhibited no interaction with fibronectin, suggesting that Srr2 binds this ligand through the dock-lock-latch mechanism, previously described for fibrinogen binding. The fibronectin site responsible for recombinant Srr2-BR binding was identified and localised in the central cell-binding domain of the protein. Finally, in the presence of fibronectin, the ability of a Δsrr2 mutant to adhere to human cervico-vaginal epithelial cells was significantly lower than that of the wild-type strain. CONCLUSION: By combining genetic and biochemical approaches, we demonstrate a new role for Srr2, namely interacting with fibronectin. We characterised the molecular mechanism of this interaction and demonstrated that it plays a role in promoting the adhesion of GBS to human cervico-vaginal epithelial cells, further substantiating the role of Srr2 as a factor responsible for the hypervirulence of GBS ST-17 strains. The discovery of the previously undescribed interaction between Srr2 and fibronectin establishes this adhesin as a key factor for GBS colonisation of host tissues.


Subject(s)
Adhesins, Bacterial , Bacterial Adhesion , Fibronectins , Protein Binding , Streptococcus agalactiae , Streptococcus agalactiae/genetics , Streptococcus agalactiae/metabolism , Streptococcus agalactiae/pathogenicity , Fibronectins/metabolism , Humans , Adhesins, Bacterial/metabolism , Adhesins, Bacterial/genetics , Fibrinogen/metabolism , Fibrinogen/genetics , Epithelial Cells/microbiology , Female , Streptococcal Infections/microbiology , Virulence Factors/metabolism , Virulence Factors/genetics
7.
Sci Rep ; 14(1): 14426, 2024 06 23.
Article in English | MEDLINE | ID: mdl-38910172

ABSTRACT

Vaginitis, a prevalent gynecological condition in women, is mainly caused by an imbalance in the vaginal micro-ecology. The two most common types of vaginitis are vaginal bacteriosis and vulvovaginal candidiasis, triggered by the virulent Gardnerella vaginalis and Candida albicans, respectively. In this study, a strain capable of inhibiting G. vaginalis and C. albicans was screened from vaginal secretions and identified as Lactobacillus gasseri based on 16S rRNA sequences. The strain, named L. gasseri VHProbi E09, could inhibit the growth of G. vaginalis and C. albicans under co-culture conditions by 99.07% ± 0.26% and 99.95% ± 0.01%, respectively. In addition, it could significantly inhibit the adhesion of these pathogens to vaginal epithelial cells. The strain further showed the ability to inhibit the enteropathogenic bacteria Escherichia coli and Salmonella enteritidis, to tolerate artificial gastric and intestinal fluids and to adhere to intestinal Caco-2 cells. These results suggest that L. gasseri VHProbi E09 holds promise for clinical trials and animal studies whether administered orally or directly into the vagina. Whole-genome analysis also revealed a genome consisting of 1752 genes for L. gasseri VHProbi E09, with subsequent analyses identifying seven genes related to adhesion and three genes related to bacteriocins. These adhesion- and bacteriocin-related genes provide a theoretical basis for understanding the mechanism of bacterial inhibition of the strain. The research conducted in this study suggests that L. gasseri VHProbi E09 may be considered as a potential probiotic, and further research can delve deeper into its efficacy as an agent which can restore a healthy vaginal ecosystem.


Subject(s)
Candida albicans , Gardnerella vaginalis , Lactobacillus gasseri , Probiotics , Vagina , Female , Humans , Lactobacillus gasseri/genetics , Caco-2 Cells , Gardnerella vaginalis/genetics , Vagina/microbiology , Bacterial Adhesion , Vaginitis/microbiology , RNA, Ribosomal, 16S/genetics
8.
J Appl Microbiol ; 135(6)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38857885

ABSTRACT

AIMS: Klebsiella pneumoniae, an important opportunistic pathogen of nosocomial inflection, is known for its ability to form biofilm. The purpose of the current study is to assess how co- or mono-cultured probiotics affect K. pneumoniae's ability to produce biofilms and investigate the potential mechanisms by using a polyester nonwoven chemostat and a Caco-2 cell line. METHODS AND RESULTS: Compared with pure cultures of Lactobacillus rhamnosus and Lactobacillus sake, the formation of K. pneumoniae biofilm was remarkably inhibited by the mixture of L. rhamnosus, L. sake, and Bacillus subtilis at a ratio of 5:5:1 by means of qPCR and FISH assays. In addition, Lactobacillus in combination with B. subtilis could considerably reduce the adherence of K. pneumoniae to Caco-2 cells by using inhibition, competition, and displacement assays. According to the RT-PCR assay, the adsorption of K. pneumoniae to Caco-2 cells was effectively inhibited by the co-cultured probiotics, leading to significant reduction in the expression of proinflammatory cytokines induced by K. pneumoniae. Furthermore, the HPLC and RT-PCR analyses showed that the co-cultured probiotics were able to successfully prevent the expression of the biofilm-related genes of K. pneumoniae by secreting plenty of organic acids as well as the second signal molecule (c-di-GMP), resulting in inhibition on biofilm formation. CONCLUSION: Co-culture of L. sake, L. rhamnosus, and B. subtilis at a ratio of 5:5:1 could exert an antagonistic effect on the colonization of pathogenic K. pneumoniae by down-regulating the expression of biofilm-related genes. At the same time, the co-cultured probiotics could effectively inhibit the adhesion of K. pneumoniae to Caco-2 cells and block the expression of proinflammatory cytokines induced by K. pneumoniae.


Subject(s)
Biofilms , Coculture Techniques , Klebsiella pneumoniae , Probiotics , Biofilms/growth & development , Klebsiella pneumoniae/physiology , Humans , Probiotics/pharmacology , Caco-2 Cells , Bacillus subtilis/physiology , Bacillus subtilis/genetics , Lacticaseibacillus rhamnosus/physiology , Bacterial Adhesion , Lactobacillus/physiology , Cytokines/metabolism
9.
Int J Mol Sci ; 25(11)2024 May 24.
Article in English | MEDLINE | ID: mdl-38891904

ABSTRACT

Tooth loss during the lifetime of an individual is common. A strategy to treat partial or complete edentulous patients is the placement of dental implants. However, dental implants are subject to bacterial colonization and biofilm formation, which cause an infection named peri-implantitis. The existing long-term treatments for peri-implantitis are generally inefficient. Thus, an electrical circuit was produced with zirconia (Zr) samples using a hot-pressing technique to impregnate silver (Ag) through channels and holes to create a path by LASER texturing. The obtained specimens were characterized according to vitro cytotoxicity, to ensure ZrAg non-toxicity. Furthermore, samples were inoculated with Staphylococcus aureus using 6.5 mA of alternating current (AC). The current was delivered using a potentiostat and the influence on the bacterial concentration was assessed. Using AC, the specimens displayed no bacterial adhesion (Log 7 reduction). The in vitro results presented in this study suggest that this kind of treatment can be an alternative and promising strategy to treat and overcome bacterial adhesion around dental implants that can evolve to biofilm.


Subject(s)
Bacterial Adhesion , Biofilms , Dental Implants , Staphylococcus aureus , Zirconium , Dental Implants/microbiology , Zirconium/chemistry , Biofilms/growth & development , Biofilms/drug effects , Humans , Electric Stimulation/methods , Surface Properties , Peri-Implantitis/microbiology , Peri-Implantitis/therapy , Silver/chemistry , Silver/pharmacology
10.
Int J Biol Macromol ; 271(Pt 1): 132698, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38824104

ABSTRACT

Ecofriendly fabrics with antibacterial and anti-adhesion properties have been attracted an increasing attention in recent years. Herein, natural menthol modified polyacrylate (PMCA) antibacterial adhesion agent was synthesized by esterification and polymerisation while natural pterostilbene-grafted-chitosan (PGC) antibacterial agent was prepared through Mannich reaction. The antibacterial and anti-adhesion cotton fabric was fabricated through durable PMCA dip finishing and then layer-by-layer self-assembly of PGC. The results showed that the antibacterial adhesion rates and antibacterial rates of the dual-function cotton fabric against Staphylococcus aureus and Escherichia coli reached up to 99.9 %. Its antibacterial adhesion rates improved by 36.1 % and 40.1 % in comparison with those of cotton fabric treated by menthol alone. Meanwhile against S. aureus, the dual-function cotton fabrics improved the antibacterial rates by 56.7 % and 36.4 %, respectively, from those of chitosan- and pterostilbene-treated fabrics. Against E. coli, the improvements were 89.4 % and 24.8 %, respectively. After 20 household washings, the dual-function cotton fabric maintained >80 % of its original anti-adhesion and antibacterial rates against both species. The dual-function cotton fabric also possessed safe and excellent wearability.


Subject(s)
Anti-Bacterial Agents , Chitosan , Cotton Fiber , Escherichia coli , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Escherichia coli/drug effects , Staphylococcus aureus/drug effects , Chitosan/chemistry , Chitosan/pharmacology , Bacterial Adhesion/drug effects , Stilbenes/pharmacology , Stilbenes/chemistry , Textiles , Microbial Sensitivity Tests , Acrylic Resins/chemistry
11.
Arch Microbiol ; 206(7): 322, 2024 Jun 22.
Article in English | MEDLINE | ID: mdl-38907754

ABSTRACT

Limosilactobacillus reuteri DSM17938 is one of the most pivotal probiotics, whose general beneficial effects on the intestinal microbiota are well recognized. Enhancing their growth and metabolic activity can effectively regulate the equilibrium of intestinal microbiota, leading to improved physical health. A common method to promote the growth of Lactobacillus is the addition of prebiotics. Current research suggests that proteins and their hydrolysates from different sources with potential prebiotic activity can also promote the growth of probiotics. In this study, soybean proteins and peptides were effective in promoting the growth, organic acid secretion, and adhesive properties of Limosilactobacillus reuteri DSM17938 to Caco-2 cells. These results illustrate the feasibility of soybean proteins and peptides as prebiotics, providing theoretical and practical advantages for their application.


Subject(s)
Bacterial Adhesion , Limosilactobacillus reuteri , Peptides , Probiotics , Soybean Proteins , Limosilactobacillus reuteri/growth & development , Limosilactobacillus reuteri/metabolism , Soybean Proteins/pharmacology , Soybean Proteins/metabolism , Soybean Proteins/chemistry , Humans , Caco-2 Cells , Bacterial Adhesion/drug effects , Peptides/pharmacology , Prebiotics , Gastrointestinal Microbiome/drug effects , Glycine max/microbiology
12.
Microbiology (Reading) ; 170(6)2024 Jun.
Article in English | MEDLINE | ID: mdl-38916198

ABSTRACT

Bacterial infection is a dynamic process resulting in a heterogenous population of infected and uninfected cells. These cells respond differently based on their bacterial load and duration of infection. In the case of infection of macrophages with Crohn's disease (CD) associated adherent-invasive Escherichia coli (AIEC), understanding the drivers of pathogen success may allow targeting of cells where AIEC replicate to high levels. Here we show that stratifying immune cells based on their bacterial load identifies novel pathways and therapeutic targets not previously associated with AIEC when using a traditional homogeneous infected population approach. Using flow cytometry-based cell sorting we stratified cells into those with low or high intracellular pathogen loads, or those which were bystanders to infection. Immune cells transcriptomics revealed a diverse response to the varying levels of infection while pathway analysis identified novel intervention targets that were directly related to increasing intracellular AIEC numbers. Chemical inhibition of identified targets reduced AIEC intracellular replication or inhibited secretion of tumour necrosis factor alpha (TNFα), a key cytokine associated with AIEC infection. Our results have identified new avenues of intervention in AIEC infection that may also be applicable to CD through the repurposing of already available inhibitors. Additionally, they highlight the applicability of immune cell stratification post-infection as an effective approach for the study of microbial pathogens.


Subject(s)
Crohn Disease , Escherichia coli Infections , Escherichia coli , Macrophages , Tumor Necrosis Factor-alpha , Crohn Disease/microbiology , Crohn Disease/immunology , Macrophages/microbiology , Macrophages/immunology , Humans , Escherichia coli Infections/microbiology , Escherichia coli Infections/immunology , Escherichia coli/genetics , Tumor Necrosis Factor-alpha/metabolism , Bacterial Load , Bacterial Adhesion , Host-Pathogen Interactions
13.
Med Sci Monit ; 30: e944255, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38843112

ABSTRACT

Orthodontic treatments, while essential for achieving optimal oral health, present challenges in infection control due to the propensity for bacterial adhesion and biofilm formation on orthodontic appliances. Silver-coated orthodontic materials have emerged as a promising solution, leveraging the potent antimicrobial properties of silver nanoparticles (AgNPs). Antibacterial coatings are used in orthodontics to prevent the formation of bacterial biofilms. This systematic review evaluated the literature on antimicrobial silver coatings on fixed orthodontic appliances, including archwires, brackets, and microimplants. Two evaluators, working independently, rigorously conducted a comprehensive search of various databases, including PubMed, PubMed Central, Embase, Scopus and Web of Science. This systematic review comprehensively examined in vitro studies investigating the antimicrobial efficacy of silver-coated orthodontic archwires, brackets, and microimplants. The review registered in PROSPERO CRD42024509189 synthesized findings from 18 diverse studies, revealing consistent and significant reductions in bacterial adhesion, biofilm formation, and colony counts with the incorporation of AgNPs. Key studies demonstrated the effectiveness of silver-coated archwires and brackets against common oral bacteria, such as Streptococcus mutans and Staphylococcus aureus. Microimplants coated with AgNPs also exhibited notable antimicrobial activity against a range of microorganisms. The systematic review revealed potential mechanisms underlying these antimicrobial effects, highlighted implications for infection prevention in orthodontic practice, and suggested future research avenues. Despite some study heterogeneity and limitations, the collective evidence supports the potential of silver-coated orthodontic materials in mitigating bacterial complications, emphasizing their relevance in advancing infection control measures in orthodontics.


Subject(s)
Biofilms , Metal Nanoparticles , Orthodontic Brackets , Silver , Silver/pharmacology , Humans , Biofilms/drug effects , Orthodontic Brackets/microbiology , Orthodontic Wires/microbiology , Orthodontic Appliances, Fixed , Anti-Infective Agents/pharmacology , Coated Materials, Biocompatible/pharmacology , Anti-Bacterial Agents/pharmacology , Streptococcus mutans/drug effects , Bacterial Adhesion/drug effects , Staphylococcus aureus/drug effects
14.
Vet Res ; 55(1): 70, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38822378

ABSTRACT

Adaptation of avian pathogenic E. coli (APEC) to changing host environments including virulence factors expression is vital for disease progression. FdeC is an autotransporter adhesin that plays a role in uropathogenic Escherichia coli (UPEC) adhesion to epithelial cells. Expression of fdeC is known to be regulated by environmental conditions in UPEC and Shiga toxin-producing E. coli (STEC). The observation in a previous study that an APEC strain IMT5155 in which the fdeC gene was disrupted by a transposon insertion resulted in elevated adhesion to chicken intestinal cells prompted us to further explore the role of fdeC in infection. We found that the fdeC gene prevalence and FdeC variant prevalence differed between APEC and nonpathogenic E. coli genomes. Expression of the fdeC gene was induced at host body temperature, an infection relevant condition. Disruption of fdeC resulted in greater adhesion to CHIC-8E11 cells and increased motility at 42 °C compared to wild type (WT) and higher expression of multiple transporter proteins that increased inorganic ion export. Increased motility may be related to increased inorganic ion export since this resulted in downregulation of YbjN, a protein known to supress motility. Inactivation of fdeC in APEC strain IMT5155 resulted in a weaker immune response in chickens compared to WT in experimental infections. Our findings suggest that FdeC is upregulated in the host and contributes to interactions with the host by down-modulating motility during colonization. A thorough understanding of the regulation and function of FdeC could provide novel insights into E. coli pathogenesis.


Subject(s)
Adhesins, Escherichia coli , Bacterial Adhesion , Chickens , Escherichia coli Infections , Poultry Diseases , Poultry Diseases/microbiology , Escherichia coli Infections/veterinary , Escherichia coli Infections/microbiology , Animals , Adhesins, Escherichia coli/genetics , Adhesins, Escherichia coli/metabolism , Gene Expression Regulation, Bacterial , Escherichia coli/physiology , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism
15.
Appl Microbiol Biotechnol ; 108(1): 360, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38836914

ABSTRACT

In the fight against hospital-acquired infections, the challenge posed by methicillin-resistant Staphylococcus aureus (MRSA) necessitates the development of novel treatment methods. This study focused on undermining the virulence of S. aureus, especially by targeting surface proteins crucial for bacterial adherence and evasion of the immune system. A primary aspect of our approach involves inhibiting sortase A (SrtA), a vital enzyme for attaching microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) to the bacterial cell wall, thereby reducing the pathogenicity of S. aureus. Verbascoside, a phenylethanoid glycoside, was found to be an effective SrtA inhibitor in our research. Advanced fluorescence quenching and molecular docking studies revealed a specific interaction between verbascoside and SrtA, pinpointing the critical active sites involved in this interaction. This molecular interaction significantly impedes the SrtA-mediated attachment of MSCRAMMs, resulting in a substantial reduction in bacterial adhesion, invasion, and biofilm formation. The effectiveness of verbascoside has also been demonstrated in vivo, as shown by its considerable protective effects on pneumonia and Galleria mellonella (wax moth) infection models. These findings underscore the potential of verbascoside as a promising component in new antivirulence therapies for S. aureus infections. By targeting crucial virulence factors such as SrtA, agents such as verbascoside constitute a strategic and potent approach for tackling antibiotic resistance worldwide. KEY POINTS: • Verbascoside inhibits SrtA, reducing S. aureus adhesion and biofilm formation. • In vivo studies demonstrated the efficacy of verbascoside against S. aureus infections. • Targeting virulence factors such as SrtA offers new avenues against antibiotic resistance.


Subject(s)
Aminoacyltransferases , Anti-Bacterial Agents , Bacterial Adhesion , Bacterial Proteins , Biofilms , Cysteine Endopeptidases , Glucosides , Methicillin-Resistant Staphylococcus aureus , Molecular Docking Simulation , Phenols , Staphylococcal Infections , Bacterial Proteins/metabolism , Bacterial Proteins/antagonists & inhibitors , Aminoacyltransferases/antagonists & inhibitors , Aminoacyltransferases/metabolism , Cysteine Endopeptidases/metabolism , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Glucosides/pharmacology , Animals , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Phenols/pharmacology , Bacterial Adhesion/drug effects , Biofilms/drug effects , Anti-Bacterial Agents/pharmacology , Moths/microbiology , Virulence/drug effects , Disease Models, Animal , Virulence Factors/metabolism , Enzyme Inhibitors/pharmacology , Polyphenols
16.
Biofouling ; 40(5-6): 333-347, 2024.
Article in English | MEDLINE | ID: mdl-38836545

ABSTRACT

The corrosion behaviors of four pure metals (Fe, Ni, Mo and Cr) in the presence of sulfate reducing bacteria (SRB) were investigated in enriched artificial seawater (EASW) after 14-day incubation. Metal Fe and metal Ni experienced weight losses of 1.96 mg cm-2 and 1.26 mg cm-2, respectively. In contrast, metal Mo and metal Cr exhibited minimal weight losses, with values of only 0.05 mg cm-2 and 0.03 mg cm-2, respectively. In comparison to Mo (2.2 × 106 cells cm-2) or Cr (1.4 × 106 cells cm-2) surface, the sessile cell counts on Fe (4.0 × 107 cells cm-2) or Ni (3.1 × 107 cells cm-2) surface was higher.


Subject(s)
Bacterial Adhesion , Sulfates , Corrosion , Sulfates/chemistry , Metals/chemistry , Seawater/microbiology , Seawater/chemistry , Biofilms/drug effects , Biofilms/growth & development , Bacteria/drug effects , Biofouling/prevention & control
17.
Biosens Bioelectron ; 261: 116491, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38879900

ABSTRACT

As one class of molecular imprinted polymers (MIPs), surface imprinted polymer (SIP)-based biosensors show great potential in direct whole-bacteria detection. Micro-contact imprinting, that involves stamping the template bacteria immobilized on a substrate into a pre-polymerized polymer matrix, is the most straightforward and prominent method to obtain SIP-based biosensors. However, the major drawbacks of the method arise from the requirement for fresh template bacteria and often non-reproducible bacteria distribution on the stamp substrate. Herein, we developed a positive master stamp containing photolithographic mimics of the template bacteria (E. coli) enabling reproducible fabrication of biomimetic SIP-based biosensors without the need for the "real" bacteria cells. By using atomic force and scanning electron microscopy imaging techniques, respectively, the E. coli-capturing ability of the SIP samples was tested, and compared with non-imprinted polymer (NIP)-based samples and control SIP samples, in which the cavity geometry does not match with E. coli cells. It was revealed that the presence of the biomimetic E. coli imprints with a specifically designed geometry increases the sensor E. coli-capturing ability by an "imprinting factor" of about 3. These findings show the importance of geometry-guided physical recognition in bacterial detection using SIP-based biosensors. In addition, this imprinting strategy was employed to interdigitated electrodes and QCM (quartz crystal microbalance) chips. E. coli detection performance of the sensors was demonstrated with electrochemical impedance spectroscopy (EIS) and QCM measurements with dissipation monitoring technique (QCM-D).


Subject(s)
Bacterial Adhesion , Biosensing Techniques , Escherichia coli , Polymers , Escherichia coli/isolation & purification , Polymers/chemistry , Molecular Imprinting/methods , Surface Properties , Molecularly Imprinted Polymers/chemistry , Escherichia coli Infections/microbiology , Biomimetic Materials/chemistry
18.
FEMS Microbiol Lett ; 3712024 Jan 09.
Article in English | MEDLINE | ID: mdl-38866708

ABSTRACT

This study aimed to investigating the possible interference caused by glass test tubes on the quantification of bacterial adhesion to hydrocarbons by the MATH test. The adhesion of four bacteria to hexadecane and to glass test tubes was evaluated employing different suspending polar phases. The role of the ionic strength of the polar phase regarding adhesion to glassware was investigated. Within the conditions studied, Gram-positive bacteria adhered to both the test tube and the hydrocarbon regardless of the polar phase employed; meanwhile, Escherichia coli ATCC 25922 did not attach to either one. The capacity of the studied microorganisms to adhere to glassware was associated with their electron-donor properties. The ionic strength of the suspending media altered the patterns of adhesion to glass in a strain-specific manner by defining the magnitude of electrostatic repulsion observed between bacteria and the glass surface. This research demonstrated that glass test tubes may interact with suspended bacterial cells during the MATH test under specific conditions, which may lead to overestimating the percentage of adhesion to hydrocarbons and, thus, to erroneous values of cell surface hydrophobicity.


Subject(s)
Bacterial Adhesion , Glass , Glass/chemistry , Escherichia coli , Alkanes/chemistry , Osmolar Concentration , Hydrophobic and Hydrophilic Interactions , Hydrocarbons/metabolism , Gram-Positive Bacteria/isolation & purification
19.
Cells ; 13(12)2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38920649

ABSTRACT

Mycobacterium tuberculosis causes 6.4 million cases of tuberculosis and claims 1.6 million lives annually. Mycobacterial adhesion, invasion of host cells, and subsequent intracellular survival are crucial for the infection and dissemination process, yet the cellular mechanisms underlying these phenomena remain poorly understood. This study created a Bacillus Calmette-Guérin (BCG) transposon library using a MycomarT7 phage carrying a Himar1 Mariner transposon to identify genes related to mycobacteria adhesion and invasion. Using adhesion and invasion model screening, we found that the mutant strain B2909 lacked adhesion and invasion abilities because of an inactive fadD18 gene, which encodes a fatty-acyl CoA ligase, although the specific function of this gene remains unclear. To investigate the role of FadD18, we constructed a complementary strain and observed that fadD18 expression enhanced the colony size and promoted the formation of a stronger cord-like structure; FadD18 expression also inhibited BCG growth and reduced BCG intracellular survival in macrophages. Furthermore, FadD18 expression elevated levels of the proinflammatory cytokines IL-6, IL-1ß, and TNF-α in infected macrophages by stimulating the NF-κB and MAPK signaling pathways. Overall, the FadD18 plays a key role in the adhesion and invasion abilities of mycobacteria while modulating the intracellular survival of BCG by influencing the production of proinflammatory cytokines.


Subject(s)
Cytokines , Mycobacterium tuberculosis , Cytokines/metabolism , Macrophages/microbiology , Macrophages/metabolism , Mycobacterium bovis , Mice , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Animals , Humans , NF-kappa B/metabolism , Microbial Viability , Bacterial Adhesion
20.
Sci Rep ; 14(1): 14964, 2024 06 28.
Article in English | MEDLINE | ID: mdl-38942800

ABSTRACT

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative agent of Johne's Disease, a chronic granulomatous enteritis of ruminants. MAP establishes an infection in the host via the small intestine. This requires the bacterium to adhere to, and be internalised by, cells of the intestinal tract. The effector molecules expressed by MAP for this purpose remain to be fully identified and understood. Mammalian cell entry (mce) proteins have been shown to enable other Mycobacterial species to attach to and invade host epithelial cells. Here, we have expressed Mce1A, Mce1D, Mce3C and Mce4A proteins derived from MAP on the surface of a non-invasive Escherichia coli to characterise their role in the initial interaction between MAP and the host. To this end, expression of mce1A was found to significantly increase the ability of the E. coli to attach and survive intracellularly in human monocyte-like THP-1 cells, whereas expression of mce1D was found to significantly increase attachment and invasion of E. coli to bovine epithelial cell-like MDBK cells, implying cell-type specificity. Furthermore, expression of Mce1A and Mce1D on the surface of a previously non-invasive E. coli enhanced the ability of the bacterium to infect 3D bovine basal-out enteroids. Together, our data contributes to our understanding of the effector molecules utilised by MAP in the initial interaction with the host, and may provide potential targets for therapeutic intervention.


Subject(s)
Bacterial Proteins , Mycobacterium avium subsp. paratuberculosis , Paratuberculosis , Mycobacterium avium subsp. paratuberculosis/metabolism , Paratuberculosis/microbiology , Animals , Humans , Cattle , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Adhesion , Epithelial Cells/microbiology , Epithelial Cells/metabolism , Escherichia coli/metabolism , Cell Line , THP-1 Cells
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