Bacterial Adhesion Research Articles

Comparison of Bacterial Adherence on Different Archwires after Clinical Use

ABSTRACT Background: An essential component of orthodontic therapy, orthodontic archwires may operate as surfaces for bacterial adhesion, which might result in issues with oral health. Materials and Methods: This study assessed the bacterial adhesion to three different kinds of orthodontic archwires: beta-titanium (TMA), nickel-titanium (NiTi), and stainless steel (SS). At the conclusion of the clinical usage period, samples of each kind of archwire were gathered and submitted to microbiological investigation in order to determine the quantity of adhering bacterial colonies. Using scanning electron microscopy (SEM), the surface properties of the archwires were evaluated after usage. Results: The three kinds of archwires had significantly different rates of bacterial adhesion, according to the findings. With an average of 1500 ± 50 CFU/mm2, SS archwires showed the highest level of bacterial adhesion, followed by NiTi archwires at 1100 ± 45 CFU/mm2. The least amount of bacteria adhered to TMA archwires, with an average of 800 ± 30 CFU/mm2. According to SEM pictures, the degree of bacterial adhesion was associated with the archwires’ surface roughness, with smoother surfaces showing less bacterial colonization. Conclusion: In comparison with SS and NiTi archwires, the research finds that TMA archwires are linked to the least amount of bacterial adhesion.

Bacterial-host adhesion dominated by collagen subtypes remodelled by osmotic pressure.

Environmental osmolarity plays a crucial role in regulating the functions and behaviors of both host cells and pathogens. However, it remains unclear whether and how environmental osmotic stimuli modulate bacterial‒host interfacial adhesion. Using single-cell force spectroscopy, we revealed that the interfacial adhesion force depended nonlinearly on the osmotic prestimulation of host cells but not bacteria. Quantitatively, the adhesion force increased dramatically from 25.98 nN under isotonic conditions to 112.45 or 93.10 nN after the host cells were treated with the hypotonic or hypertonic solution. There was a strong correlation between the adhesion force and the number of host cells harboring adherent/internalized bacteria. We further revealed that enhanced overexpression levels of collagen XV and II were responsible for the increases in interfacial adhesion under hypotonic and hypertonic conditions, respectively. This work provides new opportunities for developing host-directed antibacterial strategies related to interfacial adhesion from a mechanobiological perspective.

Antimicrobial Surfaces: Stainless Steel Functionalized with the Essential Oil Component Vanillin

Pathogenic microorganisms can adhere to solid surfaces, leading to the formation of biofilms, thus building a physical barrier hindering the penetration and diffusion of antimicrobial compounds. In this context, the use of natural antimicrobial compounds, such as essential oil components, as substitutes for common synthetic antimicrobials in the fight to prevent antimicrobial resistance is explored. As stainless steel is one of the most widely used surfaces in different industries, we have developed an innovative antimicrobial treatment for stainless steel surfaces based on a multi-step functionalization process, in which the stainless steel surface is coated with a silica layer to which a vanillin derivative is covalently attached. The surface was analyzed by microscopy studies, indicating the correct immobilization on the surfaces. Antimicrobial studies (viability and bacterial adhesion assays) were performed against the bacteria Staphylococcus epidermidis, which is one of the most frequent causes of nosocomial infections. The results of the microbiological studies showed that vanillin-functionalized stainless steel surfaces reduce the bacteria viability by 100% and the biofilm formation on the stainless steel surface by 75% compared with non-functionalized surfaces, highlighting the contact-killing and adhesion resistance properties of the developed surface. Additional cycles using the functionalized surfaces showed good maintenance of the antimicrobial coating efficacy. Moreover, the surfaces coated with an intermediate silica layer demonstrated much greater antimicrobial activity than surfaces in which the active molecule was directly functionalized on the stainless steel surface.

Identification of Veillonella parvula and Streptococcus gordonii adhesins mediating co-aggregation and its impact on physiology and mixed biofilm structure.

Our research explores the mechanisms of bacterial adhesion within the dental plaque, focusing on Veillonella parvula, a key player in the oral microbiome. Dependent on lactate from streptococci, V. parvula plays a crucial bridging role in the formation of dental biofilms by co-aggregating with other bacteria. Despite its importance, the understanding of the underlying mechanisms of co-aggregation remains limited. Our study shows that V. parvula uses different trimeric autotransporters to adhere to oral Streptococci and Actinomyces. We additionally identify a novel adhesin from S. gordonii, VisA (SGO_2004) facilitating this interaction. We found that although co-aggregation does not affect cell-cell communication, it is critical for biofilm structure and species distribution. This research opens up new avenues for exploring microbial interactions in dental health and diseases.

Colibactin-driven colon cancer requires adhesin-mediated epithelial binding.

Various bacteria are suggested to contribute to colorectal cancer (CRC) development1-5, including pks+ Escherichia coli, which produces the genotoxin colibactin that induces characteristic mutational signatures in host epithelial cells6. However, it remains unclear how the highly unstable colibactin molecule is able to access host epithelial cells to cause harm. Here, using the microbiota-dependent ZEB2-transgenic mouse model of invasive CRC7, we demonstrate that the oncogenic potential of pks+ E. coli critically depends on bacterial adhesion to host epithelial cells, mediated by the type 1 pilus adhesin FimH and the F9 pilus adhesin FmlH. Blocking bacterial adhesion using a pharmacological FimH inhibitor attenuates colibactin-mediated genotoxicity and CRC exacerbation. We also show that allelic switching of FimH strongly influences the genotoxic potential of pks+ E. coli and can induce a genotoxic gain-of-function in the probiotic strain Nissle 1917. Adhesin-mediated epithelial binding subsequently allows the production of the genotoxin colibactin in close proximity to host epithelial cells, which promotes DNA damage and drives CRC development. These findings present promising therapeutic routes for the development of anti-adhesive therapies aimed at mitigating colibactin-induced DNA damage and inhibiting the initiation and progression of CRC, particularly in individuals at risk for developing CRC.

A peptide targeting outer membrane protein A of Acinetobacter baumannii exhibits antibacterial activity by reducing bacterial pathogenicity.

The World Health Organization has classified multidrug-resistant (MDR) Acinetobacter baumannii as a significant threat to human health, necessitating the urgent discovery of new antibacterial drugs to combat bacterial resistance. Outer membrane protein A of A. baumannii (AbOmpA) is an outer membrane-anchored β-barrel-shaped pore protein that plays a critical role in bacterial adhesion, invasion, and biofilm formation. Therefore, AbOmpA is considered a key virulence factor of A. baumannii. Herein, we screened three phage display peptide libraries targeting AbOmpA and identified several peptides. Among them, P92 (amino acid sequence: QMGFMTSPKHSV) exhibited the highest binding affinity with AbOmpA, with a KD value of 7.84 nM. In vitro studies demonstrated that although P92 did not directly inhibit bacterial growth, it significantly reduced the invasion and adhesion capabilities of multiple clinical isolates of MDR A. baumannii and concentration-dependently inhibited biofilm formation by acting on OmpA. Furthermore, the polymerase chain reaction results confirmed a significant positive correlation between the antibacterial effect of P92 and OmpA expression levels. Encouragingly, P92 also displayed remarkable therapeutic efficacy against A. baumannii infection in various models, including an in vitro cell infection model, a mouse skin infection model, and a mouse sepsis model. These results highlight P92 as a novel and highly effective antimicrobial molecule specifically targeting the virulence factor AbOmpA.

Development of protective egg yolk immunoglobulins (IgY) targeting CfaB, LTB, and EtpA recombinant proteins of Enterotoxigenic Escherichia coli (ETEC) for inhibiting toxin activity and bacterial adherence.

Enterotoxigenic Escherichia coli (ETEC) stands as a prevalent bacterial cause of global diarrheal incidents. ETEC's primary virulence factors encompass the B subunit of the Heat Labile Enterotoxin, along with the adhesion factors CfaB and EtpA. In this study, we isolated IgY antibodies against the three virulence factors individually, in pairs, and as triple cocktails. The in vitro efficacy of these IgY antibodies was examined, focusing on inhibiting heat-labile enterotoxin (LT) toxin cytotoxicity and impeding ETEC adherence to HT29 cells. Assessing the impact of IgY-treated bacteria on intestinal epithelial cells utilized the standard ileal loop method. Results demonstrated that the anti-LTB IgY antibody at 125µg/ml and IgY antibodies from double and tertiary cocktails at 200µg/ml effectively inhibited LT toxin attachment to the Y1 cell line. Pre-incubation of HT29 intestinal cells with specific IgYs reduced bacterial attachment by 59.7%. In the ileal loop test, toxin neutralization with specific IgYs curtailed the toxin's function in the intestine, leading to a 74.8% reduction in fluid accumulation compared to control loops. These findings suggest that egg yolk immunoglobulins against recombinant proteins LTB, CfaB, and EtpA, either individually or in combination, hold promise as prophylactic antibodies to impede the functioning of ETEC bacteria.

PVDF‐based nanocomposite coatings with superhydrophobic and antibacterial properties on stainless steel surfaces

AbstractIn this study, using a spray‐coating technique, stainless steel surfaces were coated with polyvinylidene fluoride (PVDF) and carbon soot nanoparticles. We imparted various surface properties onto the coatings' surfaces by varying the nanoparticle content and the preparation method. The main aim was to develop antibacterial surfaces by inducing superhydrophobic properties in stainless steel surfaces. In a one‐step preparation method, 5% and 10% of nanoparticles were insufficient to achieve superhydrophobicity, whereas 20% significantly increased the water contact angle to 153°. Morphological evaluations revealed the formation of a nano‐scale structure, which also led to a staggering antibacterial rate of 99.5% against Listeria monocytogenes. Using a two‐step preparation, soot nanoparticles were localized at the coating's top layer, which led to superhydrophobicity at a lower nanoparticle content (10%). However, the bacterial adhesion study showed a lower antibacterial rate (~93%). The difference in bacterial adhesion results was explained by various roughness structures according to the atomic force microscopy results. The developed system has a promising potential to be used as self‐cleaning and antibacterial coatings in the medical and food industries.Highlights Stainless steel surfaces were coated with PVDF and carbon soot nanoparticles Imparted various surface properties onto the coatings' surfaces Developed antibacterial surfaces by inducing superhydrophobic properties Using a two‐step, soot nanoparticles were localized at the coating's top layer Bacterial adhesion study showed a lower antibacterial rate (~93%).

Architectural dissection of adhesive bacterial cell surface appendages from a "molecular machines" viewpoint.

The ability of bacteria to interact with and respond to their environment is crucial to their lifestyle and survival. Bacterial cells routinely need to engage with extracellular target molecules, in locations spatially separated from their cell surface. Engagement with distant targets allows bacteria to adhere to abiotic surfaces and host cells, sense harmful or friendly molecules in their vicinity, as well as establish symbiotic interactions with neighboring cells in multicellular communities such as biofilms. Binding to extracellular molecules also facilitates transmission of information back to the originating cell, allowing the cell to respond appropriately to external stimuli, which is critical throughout the bacterial life cycle. This requirement of bacteria to bind to spatially separated targets is fulfilled by a myriad of specialized cell surface molecules, which often have an extended, filamentous arrangement. In this review, we compare and contrast such molecules from diverse bacteria, which fulfil a range of binding functions critical for the cell. Our comparison shows that even though these extended molecules have vastly different sequence, biochemical and functional characteristics, they share common architectural principles that underpin bacterial adhesion in a variety of contexts. In this light, we can consider different bacterial adhesins under one umbrella, specifically from the point of view of a modular molecular machine, with each part fulfilling a distinct architectural role. Such a treatise provides an opportunity to discover fundamental molecular principles governing surface sensing, bacterial adhesion, and biofilm formation.

“Janus” PEEK implant with sandwich Mg-containing coating for infected tissue repair

Having good antibacterial properties and promoting soft and hard tissue repair are the keys to successful implantation of intraosseous transcutaneous. Polyether ether ketone (PEEK) is a class of FDA-approved polymer implants. However, the surface of PEEK is bioinert, which is easy to cause postoperative infection and poor tissue integration. In this study, polypyrrole (Ppy) was polymerized on sulfonated PEEK, Mg3(PO4)2 nanosheets were grown in situ on one side, and polycaprolactone (PCL) was then spun on the surface to form a Janus-like surface on PEEK. The Ppy/Mg3(PO4)2/PCL composite coating could inhibit bacterial adhesion, and the excellent photothermal properties of Ppy/Mg3(PO4)2/PCL and Ppy coatings further promote the removal of bacteria due to the accumulated heat. After the infection was eliminated, the Janus-like surface of modified PEEK switched macrophages to anti-proinflammatory response and promoted both soft and hard tissue repair. The Ppy modified sulfonated PEEK could promote collagen secretion in the soft tissue, while the PCL films on Ppy/Mg3(PO4)2/PCL was densified by temperature response under near-infrared light treatment to close the exposed interface of Mg3(PO4)2 nanosheets that was more conducive to bone repair. In summary, PEEK with Janus-like surface consisting of Ppy/Mg3(PO4)2/PCL and Ppy has multiple biological functions of sequential antibacterial and soft and hard tissue repair, and is a promising candidate material for intraosseous transcutaneous implants.

Deletion of glycosyltransferase galE impairs the InlB anchoring and pathogenicity of Listeria monocytogenes

ABSTRACT Listeria monocytogenes (L. monocytogenes) is a foodborne intracellular pathogen that causes serious disease in both humans and animals. InlB is the major internalin protein of L. monocytogenes, which anchors to the bacterial surface and mediates its invasion into various host cells. Recent studies have shown that galactosylation of the cell wall polymer wall teichoic acid (WTA) is essential for InlB anchoring on the cell surface of L. monocytogenes serotype 4b strains. Galactosylation of WTA is exerted by the coordinated action of several glycosyltransferases, including GalU, GalE, GtcA, GttA, and GttB. Among these glycosyltransferases, GttA and GttB are specific to serotype 4b strains, whereas GalE, GalU, and GtcA are conserved across all serotypes. The role of GalE in InlB anchoring and L. monocytogenes pathogenicity remains unclear. In this study, we deleted the galE gene, which is involved in galactosylation, from L. monocytogenes strain ScottA. We found that galE deletion reduced InlB anchoring, weakened bacterial adhesion and invasion of Caco-2 cells (human colorectal adenocarcinoma cells) and MGC803 cells (human gastric carcinoma cells), increased phagocytosis but decreased proliferation in RAW264.7 cells (mouse mononuclear macrophage leukaemia cells), and decreased bacteria load, mortality, and tissue damage in infected mice. Taken together, galE deletion significantly reduced the anchoring of InlB and weakened the pathogenicity of L. monocytogenes. This finding provides new insights into the correlation between cell wall modification and pathogenicity of L. monocytogenes.

Osteoblast Growth in Quaternized Silicon Carbon Nitride Coatings for Dental Implants.

The demand for dental implants has increased, establishing them as the standard of care for replacing missing teeth. Several factors contribute to the success or failure of an implant post-placement. Modifications to implant surfaces can enhance the biological interactions between bone cells and the implant, promoting better outcomes. Surface coatings have been developed to electrochemically alter implant surfaces, aiming to reduce healing time, enhance bone growth, and prevent bacterial adhesion. Quaternized silicon carbon nitride (QSiCN) is a novel material with unique electrochemical and biological properties. This study aimed to assess the influence of QSiCN, silicon carbide nitride (SiCN), and silicon carbide (SiC) coatings on the viability of osteoblast cells on nanostructured titanium surfaces. The experiment utilized thirty-two titanium sheets with anodized TiO2 nanotubes featuring nanotube diameters of 50 nm and 150 nm. These sheets were divided into eight groups (n = 4): QSiCN-coated 50 nm, QSiCN-coated 150 nm, SiCN-coated 50 nm, SiCN-coated 150 nm, SiC-coated 50 nm, SiC-coated 150 nm, non-coated 50 nm, and non-coated 150 nm. Preosteoblast MC3T3-E1 Subclone 4 cells (ATCC, USA) were used to evaluate osteoblast viability. After three days of cell growth, samples were assessed using scanning electron microscopy (SEM). The results indicated that QSiCN coatings significantly increased osteoblast proliferation (p < 0.005) compared to other groups. The enhanced cell adhesion observed with QSiCN coatings is likely due to the positive surface charge imparted by N+.

A Comprehensive Review of Antimicrobial Agents Against Clinically Important Bacterial Pathogens: Prospects for Phytochemicals.

Antimicrobial resistance (AMR) hinders the effective treatment of a range of bacterial infections, posing a serious threat to public health globally, as it challenges the currently available antimicrobial drugs. Among the various modes of antimicrobial action, antimicrobial agents that act on membranes have the most promising efficacy. However, there are no consolidated reports on the shortcomings of these drugs, existing challenges, or the potential applications of phytochemicals that act on membranes. Therefore, in this review, we have addressed the challenges and focused on various phytochemicals as antimicrobial agents acting on the membranes of clinically important bacterial pathogens. Antibacterial phytochemicals comprise diverse group of agents found in a wide range of plants. These compounds have been found to disrupt cell membranes, inhibit enzymes, interfere with protein synthesis, generate reactive oxygen species, modulate quorum sensing, and inhibit bacterial adhesion, making them promising candidates for the development of novel antibacterial therapies. Recently, polyphenolic compounds have been reported to have proven efficacy against nosocomial multidrug-resistant pathogens. However, more high-quality studies, improved standards, and the adoption of rules and regulations are required to firmly confirm the clinical efficacy of phytochemicals derived from plants. Identifying potential challenges, thrust areas of research, and considering viable approaches is essential for the successful clinical translation of these compounds.

Immune Suppression and Rapid Invasion of Nile Tilapia Gills Following an Acute Challenge by Flavobacterium davisii

Flavobacterium davisii is one of the causative agents of columnaris disease, significantly impacting Nile tilapia aquaculture. This study examines the invasion and immune evasion mechanisms of a highly virulent F. davisii strain through transcriptomic profiling of tilapia gills following acute immersion. We identified 8192 differentially expressed genes (DEGs) at 2 h, 6 h, and 12 h post-infection. They are enriched in pathways related to oxidative stress, immune suppression, tissue necrosis, and bacterial infection. Notably, early overexpression of rhamnose-binding lectin and mucin genes facilitated bacterial adhesion. Key immune genes, including those encoding major histocompatibility complex (MHC), immunoglobulins (Ig), Toll-like receptors (TLRs), and chemokines, were downregulated, indicating immune suppression. Conversely, immune evasion genes such as Fc receptor-like (FcRL) and programmed death-ligand 1 (PDL1) were upregulated, along with genes associated with reactive oxygen species (ROS) production, leading to increased tissue damage. Additionally, the upregulation of fibroblast growth factor and collagen genes suggested active tissue repair. In conclusion, F. davisii rapidly invades its host by enhancing adhesion to gill tissues, suppressing immune function, and inducing tissue damage. These findings enhance our understanding of F. davisii infection mechanisms and support the future breeding of disease-resistant tilapia and the development of sustainable control strategies.

Green Synthesis of silver nanoparticles from clematis gouriana leaf extract: Physicochemical characterization and antibacterial activity determination for treatment of blood stream infections

BackgroundThe global incidence of bloodstream infections (BSIs) is rising, necessitating the development of effective therapeutic strategies to achieve complete eradication. This study focuses on the synthesis of silver nanoparticles (AgNPs) functionalized with Clematis gouriana extract (CG) (CG-AgNPs) as a potential alternative to conventional treatments for combating BSIs caused by bacterial pathogens. MethodsAgNPs were synthesized by reducing silver nitrate (AgNO₃) using CG extract. The formation of CG-AgNPs was confirmed through UV-Vis spectroscopy, while their characterization included the determination of mean particle size and zeta potential. Elemental composition was analyzed using energy-dispersive X-ray (EDX) spectroscopy. The in vitro antibacterial efficacy of CG-AgNPs was assessed through multiple assays, including a time-kill assay, a film bioadhesion assay, and measurement of reactive oxygen species (ROS) generation. ResultsSPR (surface plasmon resonance) has been employed to validate the development of AgNPs by observing a colour shift to dark brown. The mean particle size and zeta potential of the CG-AgNPs were found to be 38 ± 2nm (PDI 0.104 ± 0.03) and -31.2 ± 1.4mV, respectively. Additionally, E-XRD results show that the prepared AgNPs comply with the silver presence. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the CG-AgNPs against Staphylococcus aureus (S. aureus) were observed to be 6.25 ± 0.8µg/mL and 13.5 ± 2.4µg/mL, respectively.Similarly, the MIC and MBC of CG-AgNPs against Escherichia coli (E. coli) were found to be 13.5 ± 1.5μg/mL and 26 ± 2.8μg/mL, respectively. CG-AgNPs also prevented biofilm formation and bacterial adhesion in a dose-dependent manner; 100% inhibition was achieved in 48h at MBC. In addition, CG-AgNPs remarkably escalated the ROS level within cells, indicating their mechanism of antimicarobial activity. ConclusionsThe findings of this study demonstrate that CG-AgNPs synthesized via green synthesis exhibit significant antibacterial activity, highlighting their potential as an effective alternative for the treatment of BSIs. However, further in vivo studies are required to optimize a suitable dosage form and validate their therapeutic efficacy against bacterial infections in clinical settings.

Dual layer-coating of PDMS to prevent calcification and bacterial infection for the potential use of urinary tract biomaterials

Polydimethylsiloxane (PDMS) is widely used in medical devices because of its exceptional properties. However, challenges, such as biofouling and bacterial infections, arise from their hydrophobic nature, especially in devices intended for the urinary tract. To address these issues, this study pioneered a surface modification strategy aimed at enriching PDMS with both hydrophilicity and antifouling attributes, making it ideal for urinary tract device applications. We introduced a novel dual-layer coating process, initially grafting a hydrogel-like poly(acrylic acid) (PAA) layer onto PDMS through benzophenone-mediated photoinitiated polymerization to enhance surface hydrophilicity. Subsequently, polyethyleneimine (PEI) was covalently bonded to the PAA layer, ensuring the formation of a stable antifouling surface that prevented bacterial adhesion and calcium deposition. This method guarantees a robust coating that performs consistently across various environmental conditions, including the fluctuating pH levels typical of the urinary tract. Comprehensive surface characterization validated the substantial improvements in hydrophilicity along with significant reductions in bacterial adhesion and calcium deposition. The innovative PAA/PEI dual-layer coating demonstrated marked superiority over conventional uncoated and single-layer-coated PDMS samples, offering a promising solution for enhancing the safety and efficacy of PDMS-based urinary tract devices. The implications of this study extend beyond immediate applications and provide valuable insights into the domains of biomaterials and medical device engineering.

Comparative evaluation of surface changes and bond strength of microabrasion bleached enamel before and after remineralization with nano-hydroxyapatite paste: In vitro study

Objectives: Comparative evaluation of surface changes and bond strength of Microabrasion Bleached enamel before and after Remineralization with Nano-hydroxyapatite paste, an In vitro study. Methods: Enamel samples were divided into - Group I - Conventional bleaching (HB), Group II - Conventional bleaching with remineralization (HB+N-Hp), Group III - Microabrasion-assisted bleaching (M+HB), and Group IV - Microabrasion-assisted bleaching with remineralization (M+HB+N Hp). Surface roughness was measured using a profilometer. Samples were stored in artificial saliva for two weeks, then bonded with nanofilled composite resin and subjected to shear bond strength (SBS) analysis. Results: Group IV (M+HB+N-Hp) showed higher surface roughness than Groups I (HB) and II (HB+N-Hp), while Group II had significantly lower surface roughness compared to Groups III (M+HB) and IV. In terms of shear bond strength (SBS), Group III exhibited significantly higher SBS than Group I, whereas Group II showed significantly reduced SBS compared to Group I. All values were statistically significant. Conclusions: Remineralization with N-Hp reduces the surface roughness caused by bleaching and microabrasion, potentially decreasing bacterial biofilm adherence. Despite increased surface roughness correlating with better bond strength, microabrasion-assisted bleaching followed by remineralization and direct composite veneering after two weeks is a promising minimally invasive treatment for severe tooth discolorations. Further studies should explore varying frequencies and concentrations of N-Hp application.

Mesomycoplasma (Mycoplasma) ovipneumoniae dihydrolipoamide dehydrogenase is an immunogenic plasminogen binding protein and a putative adhesin

The interaction of Mesomycoplasma (Mycoplasma) ovipneumoniae (M. ovipneumoniae) with host cells is a pivotal step in the infection process, underlining the necessity to develop vaccines and therapeutic approaches targeting the pathogen's key invasion mechanisms. The bacterium's capacity for adherence, invasion, and subsequent evasion of the host immune response underpins its pathogenicity, rendering adherence genes feasible vaccine targets. This study focuses on pyruvate dehydrogenase complex component E3 (PdhD), a membrane-anchored surface protein implicated in these pathogenic processes. Bioinformatics analysis reveals the conservation of PdhD sequence within M. ovipneumoniae. Membrane protein extraction, immunoblotting and ELISA assay have confirmed the presence of PdhD on the M. ovipneumoniae surface and cytoplasm, suggesting its multifunctionality. Our research employed antibody inhibition assays to characterize the bacterial adhesion suppression by anti-PdhD antibodies, complemented by bactericidal complement assays, supporting its candidacy as a putative vaccine target. The ELISA binding assay substantiated that PdhD binded to plasminogen (Plg) in a dose-dependent manner. Notably, PdhD is also involved in biofilm formation. The inhibitory effect of anti-PdhD sera on biofilm formation is congruent with novel therapeutic strategies targeting related mycoplasmas. This study reports the characterization of the first virulence-associated protein PdhD of M. ovipneumoniae and suggests its potential as a vaccine target to combat M. ovipneumoniae infection.

Effect of shear rate on early Shewanella oneidensis bacterial adhesion dynamics monitored by Deep Learning

Effect of shear rate on early Shewanella oneidensis bacterial adhesion dynamics monitored by Deep Learning

Antibacterial and anti-biofilm efficacy of selenium nanoparticles against Pseudomonas aeruginosa: Characterization and in vitro analysis

Pseudomonas aeruginosa (P. aeruginosa), a Gram-negative opportunistic pathogen, poses significant treatment challenges due to its antibiotic resistance and biofilm formation. This study investigates the anti-bacterial and anti-biofilm activities of chemically synthesized selenium nanoparticles (SeNPs) against P. aeruginosa. SeNPs were synthesized using ascorbic acid as a reducing agent and characterized. Biofilm formation was quantified using a modified microtiter plate method, and the anti-biofilm efficacy of SeNPs was evaluated using confocal microscopy and SEM. The P.aeruginosa isolates exhibited high resistance to piperacillin-tazobactam (60%) and ceftazidime (59%). SeNPs demonstrated a round shape with a diameter of 15-18 nm. UV-Vis spectra showed a peak at 275 nm, and XRD analysis revealed crystalline peaks corresponding to selenium. The FTIR spectra confirmed the presence of various functional groups. SeNPs significantly reduced biofilm formation in a dose-dependent manner, with MIC50 and MIC90 values of 60 μg/mL and 80 μg/mL, respectively. Confocal microscopy and SEM analysis showed a notable decrease in biofilm thickness and bacterial adherence post-SeNPs treatment. These findings suggest that SeNPs could be a promising alternative or adjunctive treatment option for combating antibiotic-resistant P. aeruginosa infections. Further research is warranted to explore the clinical applications of SeNPs in treating biofilm-associated infections.