Therapeutic index for local infections score (TILI): a new diagnostic tool.

Objective: Local wound infections are a major challenge for patients and health professionals. Various diagnostic and therapeutic options are available. However, a generally accepted standard is still lacking in Europe.

Antimicrobial stewardship in wound care.

Strategies to tackle the global crisis of antimicrobial resistance include implementing antimicrobial stewardship across the healthcare and agricultural sectors. Many clinical specialities have developed policies to advise practitioners on how to prescribe antibiotics more effectively, but there is still a lack of data on the impact of this change. Overuse and misuse of antibiotics have been commonplace since their introduction 70 years ago, and have contributed to the development of the resistance seen today.

Antimicrobial assessment of a chitosan microfibre dressing: a natural antimicrobial.

Objective: Chitosan is a natural biopolymer and is the main structural component of the cuticles of crustaceans, insects and molluscs and the cell walls of certain fungi. It is abundant in nature and is naturally antimicrobial. A natural fibre has been created with chitosan and is being used as a wound dressing, namely Kytocel.

Antimicrobial activity, cytotoxicity and chemical analysis of lemongrass essential oil (Cymbopogon flexuosus) and pure citral.

The aim of this study was to determine the antimicrobial effects of lemongrass essential oil (C. flexuosus) and to determine cytotoxic effects of both test compounds on human dermal fibroblasts. Antimicrobial susceptibility screening was carried out using the disk diffusion method.

Laboratory evaluation of Drawtex Hydroconductive dressing with LevaFiber technology.

Objective: The aim of this study was to assess absorption, sequestration and retention of microorganisms by Drawtex Hydroconductive dressing with LevaFiberTM technology.

Method: The absorption over time and the ability to sequester and retain bacteria were assessed in the laboratory using an in vitro model where known amounts of fluid and microorganisms were allowed to absorb and sequester over a 24 hour period. The reduction in numbers of microorganisms following sequestration was determined using standard plate counting methods.

Gastrostomy site infections: dealing with a common problem.

The most popular method of providing appropriate nutrition for large numbers of patients with swallowing difficulties is enteral feeding. However this treatment is not without complications, one of which is localized gastrostomy site infection. This is prevented initially by decolonisation of the oropharyngeal tract with antibiotic prophylaxis prior to insertion, and systemic antibiotics post insertion.

Investigation of food and environmental exposures relating to the epidemiology of Campylobacter coli in humans in Northwest England.

This study uses multilocus sequence typing (MLST) to investigate the epidemiology of Campylobacter coli in a continuous study of a population in Northwest England. All cases of Campylobacter identified in four Local Authorities (government administrative boundaries) between 2003 and 2006 were identified to species level and then typed, using MLST. Epidemiological information was collected for each of these cases, including food and recreational exposure variables, and the epidemiologies of C.

The benefits of silver in hygiene, personal care and healthcare.

Silver has been used for centuries as an antimicrobial agent to reduce bioburden and prevent infection. Its usage diminished when antibiotics were introduced but remained one of the most popular agents for wound infections, especially in burned patients. Incorporation of silver into a range of hygiene and healthcare applications has increased, and this has raised concerns over the development of silver resistance, toxicity, methods of testing products and evidence of efficacy.

Hydrodebridement of wounds: effectiveness in reducing wound bacterial contamination and potential for air bacterial contamination.

Background: The purpose of this study was to assess the level of air contamination with bacteria after surgical hydrodebridement and to determine the effectiveness of hydro surgery on bacterial reduction of a simulated infected wound.

Methods: Four porcine samples were scored then infected with a broth culture containing a variety of organisms and incubated at 37 degrees C for 24 hours. The infected samples were then debrided with the hydro surgery tool (Versajet, Smith and Nephew, Largo, Florida, USA).

Vapour-phase activities of essential oils against antibiotic sensitive and resistant bacteria including MRSA.

Aims: To determine whether essential oil (EO) vapours could reduce surface and airborne levels of bacteria including methicillin-resistant Staphylococcus aureus (MRSA).

Methods And Results: The antibacterial activity of geranium and lemongrass EO individually and blended were evaluated over a range of concentrations by direct contact and vapour diffusion. The EO were tested in vitro against a selection of antibiotic-sensitive and -resistant bacteria, including MRSA, vancomycin-resistant Enterococci (VRE), Acinetobacter baumanii and Clostridium difficile.

Prevalence of toxin producing strains of Staphylococcus aureus in a pediatric burns unit.

The aims of the study were to determine the sites in a pediatric burns unit that were contaminated with Staphylococcus aureus. Samples from the environment in bedrooms and the common room were taken monthly for 6 months using blood agar for total counts and Baird-Parker agar for S. aureus.

Antimicrobial and barrier effects of silver against methicillin-resistant Staphylococcus aureus.

Objective: Two strains of methicillin-resistant Staphylococcus aureus (MRSA), termed epidemic strains (EMRSA-15 and EMRSA-16), were used to evaluate the antimicrobial and barrier effect of four silver dressings (two silver donating and two non-silver-donating) available in the UK at the time of the study.

Method: The moist surface of a blood agar plate was covered with 10(6) colony-forming units of the respective strain of MRSA, and dressings were applied to the surface and incubated at 37 degrees C for different time periods and the upper and lower surfaces subcultured for residual growth.

Results: The nanocrystalline dressings (silver donating) were effective as a barrier from one hour until the study end (72 hours): no penetration of EMRSA-15 and EMRSA-16 through the dressing occurred.

Multilocus sequence typing of Neisseria meningitidis directly from clinical samples and application of the method to the investigation of meningococcal disease case clusters.

Infections associated with Neisseria meningitidis are a major public health problem in England, Wales, and Northern Ireland. Currently, over 40% of cases are confirmed directly from clinical specimens using PCR-based methodologies without an organism being isolated. A nested/seminested multilocus sequence typing (MLST) system was developed at the Health Protection Agency Meningococcal Reference Unit to allow strain characterization beyond the serogroup for cases confirmed by PCR only.

Optimisation of intact cell MALDI method for fingerprinting of methicillin-resistant Staphylococcus aureus.

The use of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry on intact cell microorganisms, Intact Cell MALDI (ICM), has been shown by numerous workers to yield effective species level identification. Early work highlighted the significant effect that variation in culture media, incubation conditions and length of incubation had on the spectra produced. Therefore, in order to achieve reliable and reproducible species level identification and sub-typing of microorganisms from ICM fingerprints, it has been essential to develop standardised methods.

Antimicrobial resistance of invasive Streptococcus pneumoniae isolates in a British district general hospital: the international connection.

Between January 2000 and March 2001, Streptococcus pneumoniae were isolated from the blood of 56 patients admitted to a single district general hospital in the South-East of England. The serotype and antibiotic susceptibility were determined for all isolates and, for those resistant to erythromycin, the presence or absence of the mef(A) and erm(B) genes was determined by PCR. Multi-locus sequence typing, along with PFGE, was undertaken on all isolates resistant to penicillin or erythromycin and a group of antibiotic-susceptible isolates, to identify whether globally distributed pneumococcal clones, as described by the Pneumococcal Molecular Epidemiology Network (PMEN), were present in the study population.

The effect of essential oils on methicillin-resistant Staphylococcus aureus using a dressing model.

Patchouli, tea tree, geranium, lavender essential oils and Citricidal (grapefruit seed extract) were used singly and in combination to assess their anti-bacterial activity against three strains of Staphylococcus aureus: Oxford S. aureus NCTC 6571 (Oxford strain), Epidemic methicillin-resistant S. aureus (EMRSA 15) and MRSA (untypable).

The role of Acticoat with nanocrystalline silver in the management of burns.

Silver is an effective antimicrobial agent, but older silver-containing formulations are rapidly inactivated by the wound environment, requiring frequent replenishment. These older formulations may also be pro-inflammatory and may delay healing. Acticoat (Smith & Nephew, Hull, UK) is a relatively new form of silver antimicrobial barrier dressing which helps avoid the problems of earlier agents.

Detection of antibodies to Staphylococcus aureus Toxic Shock Syndrome Toxin-1 using a competitive agglutination inhibition assay.

Aims: To develop a competitive agglutination inhibition assay (CAIA) for the detection of anti-Toxic Shock Syndrome Toxin-1 (TSST-1) antibody in serum samples using a commercially available reverse passive agglutination assay (RPLA) kit.

Methods And Results: TSST-1 toxin and sera were incubated together, so that anti-toxin IgG would complex with the toxin. Latex particles sensitized with rabbit IgG anti-TSST-1 were added to test for un-complexed toxin.

What's new in burn microbiology? James Laing Memorial Prize Essay 2000.

A variety of factors contribute to the development of infection in burned patients. The role of wound management procedures, risk factors associated with infection, typical bacterial pathogens and associated exotoxins, current problems with antibiotic resistance, wound sampling and rare complications of infection are described. The use of new novel treatments that are currently being developed, such as cell signalling molecules and the increasing use of natural antimicrobial agents, for example honey, papaya fruit and tea-tree oil are discussed.

Development and evaluation of a 'real-time' RT-PCR for the detection of enterovirus and parechovirus RNA in CSF and throat swab samples.

A two-step reverse transcriptase TaqMantrade mark duplex PCR (RT-PCR) assay was developed using the ABI 7700 Sequence Detection System for the detection of enterovirus (EV) and parechovirus type 1 and 2 (PEV) RNA from samples of cerebrospinal fluid (CSF) and throat swabs. Using sequence-specific fluorescent dye labeled probes and continuous 'real-time' monitoring, PCR amplified product accumulation was measured. Based on limiting dilutions, the TaqMantrade mark enterovirus and parechovirus RT-PCR showed an increase of two orders of magnitude compared to cell culture with sensitivity of 100% (7/7) when assessed using enterovirus cell culture positive samples (CSF, TS).

Effects of silver sulphadiazine on the production of exoproteins by Staphylococcus aureus.

The effects of subinhibitory concentrations of silver sulphadiazine (AgSD) on exoprotein production in Staphylococcus aureus strains T1, T4, RN4282 and RN 4282agr were studied. AgSD markedly increased levels of toxic shock syndrome toxin (TSST)-1 in strains T4 and RN4282. This effect was independent of agr and AgSD restored TSST-1 production to the wild-type level in RN 4282agr.

Intact cell mass spectrometry (ICMS) used to type methicillin-resistant Staphylococcus aureus: media effects and inter-laboratory reproducibility.

Intact cell mass spectrometry (ICMS) rapidly analyses the surface composition of microorganisms providing rapid, discriminatory fingerprints for identification and subtyping of important nosocomial pathogens such as methicillin resistant Staphylocccus aureus (MRSA). In this study, ICMS using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI TOF/MS) was assessed for the identification and subtyping of MRSA. An intra- and inter-laboratory reproducibility study was carried out and the effects of culture media (an important source of variation for ICMS) were also studied.

Simultaneous detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in suspected cases of meningitis and septicemia using real-time PCR.

A single-tube 5' nuclease multiplex PCR assay was developed on the ABI 7700 Sequence Detection System (TaqMan) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae from clinical samples of cerebrospinal fluid (CSF), plasma, serum, and whole blood. Capsular transport (ctrA), capsulation (bexA), and pneumolysin (ply) gene targets specific for N. meningitidis, H.

Contamination and sensitivity issues with a real-time universal 16S rRNA PCR.

A set of universal oligonucleotide primers specific for the conserved regions of the eubacterial 16S rRNA gene was designed for use with the real-time PCR Applied Biosystems 7700 (TaqMan) system. During the development of this PCR, problems were noted with the use of this gene as an amplification target. Contamination of reagents with bacterial DNA was a major problem exacerbated by the highly sensitive nature of the real-time PCR chemistry.

A survey into toxic shock syndrome (TSS) in UK burns units.

Toxic shock syndrome (TSS) is a rare complication of a Staphylococcus aureus infection and is primarily seen in children with small burns. The true incidence of TSS in burns patients is not known and the number of presumptive cases rarely reported. This survey was undertaken to determine if the incidence of TSS in children with burns could be related to the type of dressing used to cover the wound.