A bacteriocin expression platform for targeting pathogenic bacterial species.

Bacteriocins are antimicrobial peptides that are naturally produced by many bacteria. They hold great potential in the fight against antibiotic resistant bacteria, including ESKAPE pathogens. Engineered live biotherapeutic products (eLBPs) that secrete bacteriocins can be created to deliver targeted bacteriocin production.

The Development and Characterisation of a P(3HB--4HB)-Bioactive Glass-Graphene Hydrogel as a Potential Formulation for Biomedical and Therapeutical Translation.

The clinical management of wounds is known to be a significant challenge: not only does the dressing need to ensure and provide the appropriate barrier and healing characteristics, but consideration of patient compliance concerning comfort, functionality, and practicality also needs to be included. The poly(3-hydroxybutyrate--4-hydroxubutyrate) (P(3HB--4HB)) copolymer, isolated from USM1020 ( USM1020), was produced in the presence of excess carbon sources (1,4-butanediol and 1,6-hexanediol) using either a shake flask cultivation process or a bioreactor fermentation system. P(3HB--4HB) is widely known to be biodegradable and highly biocompatible and contains a tuneable 4HB monomer molar fraction, which is known to affect the final physicochemical properties of the intracellular copolymer.

Zn and N Codoped TiO Thin Films: Photocatalytic and Bactericidal Activity.

We explore a series of Zn and N codoped TiO thin films grown using chemical vapor deposition. Films were prepared with various concentrations of Zn (0.4-2.

Crystal Violet-Impregnated Slippery Surface to Prevent Bacterial Contamination of Surfaces.

Biofilms which are self-organized communities can contaminate various infrastructural systems. Preventing bacterial adhesion on surfaces is more desirable than cleaning or disinfection of bacteria-contaminated surfaces. In this study, a 24 h bacterial adhesion test showed that "slippery surfaces" had increased resistance to bacterial contamination compared to polydimethylsiloxane and superhydrophobic surfaces.

Enhanced Photocatalytic and Antibacterial Ability of Cu-Doped Anatase TiO Thin Films: Theory and Experiment.

Multifunctional thin films which can display both photocatalytic and antibacterial activity are of great interest industrially. Here, for the first time, we have used aerosol-assisted chemical vapor deposition to deposit highly photoactive thin films of Cu-doped anatase TiO on glass substrates. The films displayed much enhanced photocatalytic activity relative to pure anatase and showed excellent antibacterial (vs and ) ability.

Adhesion of Methicillin-Resistant Staphylococcus aureus and Candida albicans to Parylene-C-Coated Polymethyl Methacrylate.

Purpose: To determine whether coating polymethyl methacrylate (PMMA) discs with Parylene-C would reduce Staphylococcus aureus and Candida albicans biofilm formation.

Materials And Methods: MRSA and Candida albicans single and dual biofilms were grown for 48 hours in artificial saliva on parylene-C-coated or uncoated PMMA, and the viable biofilm colony-forming units were counted.

Results: There was no significant difference in the count of viable methicillin-resistant Staphylococcus aureus or Candida albicans recovered from single- or dual-species biofilms between coated and uncoated PMMA discs.

Photobactericidal Activity of Dual Dyes Encapsulated in Silicone Enhanced by Silver Nanoparticles.

Crystal violet (CV) and methylene blue (MB) dyes with silver (Ag) nanoparticles (NPs) were encapsulated into silicone to produce light-activated antimicrobial surfaces. Optical microscopy and X-ray photoelectron spectroscopy showed that CV and MB were diffused throughout the silicone samples and that Ag NPs were successfully encapsulated by the swell-encapsulation-shrink process. Antimicrobial tests on and showed that CV/MB-encapsulated silicone samples have stronger photobactericidal activity than CV or MB samples and the addition of Ag NPs significantly enhanced the antimicrobial activity under white light.

Antimicrobial Properties of Copper-Doped ZnO Coatings under Darkness and White Light Illumination.

We report the first antimicrobial study of transparent and robust Cu-doped ZnO coatings that displayed potent antimicrobial activity that resulted in bacterial () reduction below detection limits within 6 h of illumination via a white light source that is found in hospital environments. The same bacterial reduction rate was observed even under darkness for 4.0 atom % Cu-doped ZnO films thus providing an efficient 24 h disinfection.

The Anti-Biofouling Properties of Superhydrophobic Surfaces are Short-Lived.

Superhydrophobic surfaces are present in nature on the leaves of many plant species. Water rolls on these surfaces, and the rolling motion picks up particles including bacteria and viruses. Man-made superhydrophobic surfaces have been made in an effort to reduce biofouling.

Bicarbonate induces high-level resistance to the human antimicrobial peptide LL-37 in Staphylococcus aureus small colony variants.

Objectives: Staphylococcus aureus small colony variants (SCVs) cause persistent infections and are resistant to cationic antibiotics. Antimicrobial peptides (AMPs) have been suggested as promising alternatives for treating antibiotic-resistant bacteria. We investigated the capacity of the human cationic AMP LL-37 to kill SCVs in the presence of physiological concentrations of bicarbonate, which are reported to alter bacterial membrane permeability and change resistance of bacteria to AMPs.

Superhydrophobic and White Light-Activated Bactericidal Surface through a Simple Coating.

Bacterial adhesion and proliferation on surfaces are a challenge in medical and industrial fields. Here, a simple one-step technique is reported to fabricate self-cleaning and bactericidal surfaces. White, blue, and violet paints were produced using titanium dioxide nanoparticles, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, crystal violet, toluidine Blue O, and ethanol solution.

Aggregatibacter actinomycetemcomitans serotype prevalence and antibiotic resistance in a UK population with periodontitis.

Objectives: Aggregatibacter actinomycetemcomitans is a recognised pathogen involved in aggressive periodontitis. Seven serotypes of A. actinomycetemcomitans exist with a range of virulence and distribution dependent on ethnicity and geography.

An Ochre Mutation Results in a Small Colony Variant That Can Undergo Phenotypic Switching via Two Alternative Mechanisms.

can undergo phenotypic switching between a normal colony phenotype (NCP) and a small colony variant (SCV). The SCV phenotype confers increased antibiotic resistance and the capacity to persist within human tissues and cells, and because these cells can revert back to the NCP they cause chronic and/or recurrent infections that are very difficult to treat. A complete picture of the genetic events that can lead to phenotypic switching in is currently lacking.

Light activated antimicrobial agents can inactivate oral malodour causing bacteria.

Oral malodour is a common condition which affects a large proportion of the population, resulting in social, emotional and psychological stress. Certain oral bacteria form a coating called a biofilm on the tongue dorsum and degrade organic compounds releasing volatile sulfur compounds that are malodourous. Current chemical treatments for oral malodour such as mouthwashes containing chlorhexidine or essential oils, are not sufficiently effective at reducing the bacterial load on the tongue.

Photodynamic inactivation of Candida albicans by hematoporphyrin monomethyl ether.

Aim: To evaluate the capacity of hematoporphyrin monomethyl ether (HMME) in the presence of light to cause photodynamic inactivation (PDI) of Candida albicans.

Materials & Methods: HMME photoactivity was evaluated against azole-susceptible and -resistant C. albicans.

Photodynamic inactivation of Klebsiella pneumoniae biofilms and planktonic cells by 5-aminolevulinic acid and 5-aminolevulinic acid methyl ester.

The treatment of Klebsiella pneumoniae, particularly extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae, is currently a great challenge. Photodynamic antimicrobial chemotherapy is a promising approach for killing antibiotic-resistant bacteria.

Antibacterial properties of Cu-ZrO thin films prepared via aerosol assisted chemical vapour deposition.

The antibacterial properties of a Cu-ZrO film grown via aerosol assisted chemical vapour deposition are presented. The composite film showed high activity against E. coli (Gram-negative) and S.

Oxacillin sensitization of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius by antisense peptide nucleic acids in vitro.

Background: Antibiotic resistance genes can be targeted by antisense agents, which can reduce their expression and thus restore cellular susceptibility to existing antibiotics. Antisense inhibitors can be gene and pathogen specific, or designed to inhibit a group of bacteria having conserved sequences within resistance genes. Here, we aimed to develop antisense peptide nucleic acids (PNAs) that could be used to effectively restore susceptibility to β-lactams in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP).

Pancreatic amylase is an environmental signal for regulation of biofilm formation and host interaction in Campylobacter jejuni.

Campylobacter jejuni is a commensal bacterium in the intestines of animals and birds and a major cause of food-borne gastroenteritis in humans worldwide. Here we show that exposure to pancreatic amylase leads to secretion of an α-dextran by C. jejuni and that a secreted protease, Cj0511, is required.

Identification of an antibacterial protein by functional screening of a human oral metagenomic library.

Screening of a bacterial artificial chromosome (BAC) library containing metagenomic DNA from human plaque and saliva allowed the isolation of four clones producing antimicrobial activity. Three of these were pigmented and encoded homologues of glutamyl-tRNA reductase (GluTR), an enzyme involved in the C5 pathway leading to tetrapyrole synthesis, and one clone had antibacterial activity with no pigmentation. The latter contained a BAC with an insert of 15.

Antimicrobial activity of copper and copper(i) oxide thin films deposited via aerosol-assisted CVD.

Hospital acquired infections are prevalent in many hospitals and contaminated touch surfaces are a route of transmission. To find a solution for this, copper and copper oxide thin films were deposited via aerosol assisted chemical vapour deposition using copper nitrate as the precursor and the films were characterised by a range of techniques including powder X-ray diffraction and scanning electron microscopy. The antimicrobial activity of the deposited copper and copper oxide films were investigated against Staphylococcus aureus (S.

Staphylococcus aureus small colony variants are susceptible to light activated antimicrobial agents.

Background: Antibiotic therapy can select for small colony variants of Staphylococcus aureus that are more resistant to antibiotics and can result in persistent infections, necessitating the development of more effective antimicrobial strategies to combat small colony variant infections. Photodynamic therapy is an alternative treatment approach which utilises light in combination with a light-activated antimicrobial agent to kill bacteria via a non-specific mechanism of action. In this study, we investigated whether the combination of 665 nm laser light and the light-activated antimicrobial agent methylene blue was able to successfully kill S.

The lipoprotein components of the Isd and Hts transport systems are dispensable for acquisition of heme by Staphylococcus aureus.

Heme is a key molecule for Staphylococcus aureus and is involved in many aspects of oxidative metabolism. Crucially, heme is required for the activity of cytochromes of the electron transport chain. Staphylococcus aureus is able to obtain heme either through biosynthesis or through acquisition from the host.

Interaction of staphylococci with bone.

Staphylococci, in particular Staphylococcus aureus, are the predominant cause of bone infections worldwide. These infections are painful, debilitating and with the rise in antibiotic-resistant forms, increasingly difficult to treat. The growth in the number of prosthetic joint replacement procedures also provides new opportunities for these infections to take hold.