Molecular and cellular characterisation of Staphylococcus aureus in chronic wounds

Chronic skin wounds (CW) represent a significant world health problem including reservoirs of multi-drug resistant bacterial biofilms. The precise role of bacteria in the aetiology of chronic inflammation and non-healing remains unclear. This study characterised MRSA from human CW and investigated how they inhibit wound healing, modulate immunological responses and resist treatment in comparison to control MRSA from asymptomatic nasal carriers (NC). Routine cultural analysis of 150 chronic wounds revealed 50% were colonised with <italic>S. aureus</italic>, of which 22.6% were MRSA. Multi-locus sequence typing identified two new sequence types and demonstrated that wound MRSA represented two clonal complexes (22 and 30) with almost 90% identified as hospital-acquired EMRSA-15. MRSA isolated from CW and NC were characterised for virulence factor (VF) expression and modulation of the innate immune system. Presence and expression of MRSA VFs indicated an association with sequence type. Greater expression of colonisation- (cna) and degradation- associated (hysA) VFs was evident in the wound MRSA, suggesting that modulation of virulence is important for non-healing. The ability of conventional biocides (iodine, silver, and potassium permanganate) to treat chronic wound bacteria, using the carrier-test method, revealed iodine as the only effective biocide. In vitro stimulation of the ability of the MRSA to induce innate immunity showed that CW-MRSA exhibited decreased TLR, cytokine and complement responses compared with NC-MRSA (IL-8, TNFa, complement activation PO.05). Moreover, biofilm- induced reductions in immunogenicity were observed compared with planktonic growth in monocyte and complement assays (PO.05). Scratch wound assays indicated that MRSA failed to inhibit keratinocyte migration (P>0.05), although bacterial growth conditions (biofilm vs. planktonic) significantly affected the observed cellular migration (PO.05). Virulence factor production and ability to modulate/evade the host innate immune response are important potential mechanisms by which MRSA are able to colonise chronic wounds. These studies provide important new insights into the role of MRSA in delayed dermal healing.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Molecular and cellular characterisation of Staphylococcus aureus in chronic wounds

Chronic skin wounds (CW) represent a significant world health problem including reservoirs of multi-drug resistant bacterial biofilms. The precise role of bacteria in the aetiology of chronic inflammation and non-healing remains unclear. This study characterised MRSA from human CW and investigated how they inhibit wound healing, modulate immunological responses and resist treatment in comparison to control MRSA from asymptomatic nasal carriers (NC). Routine cultural analysis of 150 chronic wounds revealed 50% were colonised with S. aureus, of which 22.6% were MRSA. Multi-locus sequence typing identified two new sequence types and demonstrated that wound MRSA represented two clonal complexes (22 and 30) with almost 90% identified as hospital-acquired EMRSA-15. MRSA isolated from CW and NC were characterised for virulence factor (VF) expression and modulation of the innate immune system. Presence and expression of MRSA VFs indicated an association with sequence type. Greater expression of colonisation- (cna) and degradation- associated (hysA) VFs was evident in the wound MRSA, suggesting that modulation of virulence is important for non-healing. The ability of conventional biocides (iodine, silver, and potassium permanganate) to treat chronic wound bacteria, using the carrier-test method, revealed iodine as the only effective biocide. In vitro stimulation of the ability of the MRSA to induce innate immunity showed that CW-MRSA exhibited decreased TLR, cytokine and complement responses compared with NC-MRSA (IL-8, TNFa, complement activation PO.05). Moreover, biofilm- induced reductions in immunogenicity were observed compared with planktonic growth in monocyte and complement assays (PO.05). Scratch wound assays indicated that MRSA failed to inhibit keratinocyte migration (P>0.05), although bacterial growth conditions (biofilm vs. planktonic) significantly affected the observed cellular migration (PO.05). Virulence factor production and ability to modulate/evade the host innate immune response are important potential mechanisms by which MRSA are able to colonise chronic wounds. These studies provide important new insights into the role of MRSA in delayed dermal healing.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Molecular and cellular characterisation of Staphylococcus aureus in chronic wounds

Chronic skin wounds (CW) represent a significant world health problem including reservoirs of multi-drug resistant bacterial biofilms. The precise role of bacteria in the aetiology of chronic inflammation and non-healing remains unclear. This study characterised MRSA from human CW and investigated how they inhibit wound healing, modulate immunological responses and resist treatment in comparison to control MRSA from asymptomatic nasal carriers (NC). Routine cultural analysis of 150 chronic wounds revealed 50% were colonised with S. aureus, of which 22.6% were MRSA. Multi-locus sequence typing identified two new sequence types and demonstrated that wound MRSA represented two clonal complexes (22 and 30) with almost 90% identified as hospital-acquired EMRSA-15. MRSA isolated from CW and NC were characterised for virulence factor (VF) expression and modulation of the innate immune system. Presence and expression of MRSA VFs indicated an association with sequence type. Greater expression of colonisation- (cna) and degradation- associated (hysA) VFs was evident in the wound MRSA, suggesting that modulation of virulence is important for non-healing. The ability of conventional biocides (iodine, silver, and potassium permanganate) to treat chronic wound bacteria, using the carrier-test method, revealed iodine as the only effective biocide. In vitro stimulation of the ability of the MRSA to induce innate immunity showed that CW-MRSA exhibited decreased TLR, cytokine and complement responses compared with NC-MRSA (IL-8, TNFa, complement activation PO.05). Moreover, biofilm- induced reductions in immunogenicity were observed compared with planktonic growth in monocyte and complement assays (PO.05). Scratch wound assays indicated that MRSA failed to inhibit keratinocyte migration (P>0.05), although bacterial growth conditions (biofilm vs. planktonic) significantly affected the observed cellular migration (PO.05). Virulence factor production and ability to modulate/evade the host innate immune response are important potential mechanisms by which MRSA are able to colonise chronic wounds. These studies provide important new insights into the role of MRSA in delayed dermal healing

Oral surgery referrals at a UK dental hospital in the context of a managed vlinical network: a mixed-methods study

Background and aims: To inform the first Welsh OS Managed Clinical Network (MCN), a mixed-methods study investigated existing patterns, quality, suitability and reasons for referral to secondary care at the University Dental Hospital in Wales. Materials and methods: A random sample of 298 OS referrals were studied over a six-month period. Data recording proforma included details on referral practitioner, patient and referral diagnosis. Referrals were categorised by Levels of complexity (Levels 1, 2 and 3) and face-to-face, semi-structured and audio-recorded interviews were conducted with five frequent referrers. Results: The age range of patients was between 1 and 92 years, with over 58% (n=174) female. Majority of referrals (80%) were from GDPs. Top six practices accounted for a fifth (21%) of referrals, with three of these practices were corporate dental chains. Approximately, a third of referrals were categorised as Level 1 (37%), Level 2 (33%) and Level 3 (30%) complexity. 16% provided no medical history, and only 13% included supporting radiographs. Five themes emerged as reasons for oral surgery referrals: contract limitations, perception that new graduates lack OS practical skills, communication, practice resources and risk. Conclusions: Priorities for the Wales OS MCN are to reduce inappropriate referrals to secondary care and to ensure quality referrals. Introduction of the pan-Wales electronic Referral Management System in May 2019 is welcome in this context. The newly formed Health Education and Improvement Wales, with lead roles in education, training and shaping the healthcare workforce, will form a vital part in tackling barriers for safe OS in primary care

Comparison of foam swabs and toothbrushes as oral hygiene interventions in mechanically ventilated patients: a randomised split mouth study

Abstract Introduction During critical illness, dental plaque may serve as a reservoir of respiratory pathogens. This study compared the effectiveness of toothbrushing with a small-headed toothbrush or a foam-headed swab in mechanically ventilated patients. Methods This was a randomised, assessor-blinded, split-mouth trial, performed at a single critical care unit. Adult, orally intubated patients with >20 teeth, where >24 hours of mechanical ventilation was expected were included. Teeth were cleaned 12-hourly using a foam swab or toothbrush (each randomly assigned to one side of the mouth). Cleaning efficacy was based on plaque scores, gingival index and microbial plaque counts. Results High initial plaque (mean=2.1 (SD 0.45)) and gingival (mean=2.0 (SD 0.54)) scores were recorded for 21 patients. A significant reduction compared with initial plaque index occurred using both toothbrushes (mean change=−1.26, 95% CI −1.57 to −0.95; p<0.001) and foam swabs (mean change=−1.28, 95% CI −1.54 to −1.01; p<0.001). There was significant reduction in gingival index over time using toothbrushes (mean change=−0.92; 95% CI −1.19 to −0.64; p<0.001) and foam swabs (mean change=−0.85; 95% CI −1.10 to −0.61; p<0.001). Differences between cleaning methods were not statistically significant (p=0.12 for change in gingival index; p=0.24 for change in plaque index). There was no significant change in bacterial dental plaque counts between toothbrushing (mean change 3.7×104 colony-forming units (CFUs); minimum to maximum (−2.5×1010 CFUs, 8.7×107 CFUs)) and foam swabs (mean change 9×104 CFUs; minimum to maximum (−3.1×1010 CFUs, 3.0×107 CFUs)). Conclusions Patients admitted to adult intensive care had poor oral health, which improved after brushing with a toothbrush or foam swab. Both interventions were equally effective at removing plaque and reducing gingival inflammation. Trial registration number NCT01154257; Pre-results

Alginate Oligosaccharides Inhibit Fungal Cell Growth and Potentiate the Activity of Antifungals against Candida and Aspergillus spp.

The oligosaccharide OligoG, an alginate derived from seaweed, has been shown to have anti-bacterial and anti-biofilm properties and potentiates the activity of selected antibiotics against multi-drug resistant bacteria. The ability of OligoG to perturb fungal growth and potentiate conventional antifungal agents was evaluated using a range of pathogenic fungal strains. Candida (n = 11) and Aspergillus (n = 3) spp. were tested using germ tube assays, LIVE/DEAD staining, scanning electron microscopy (SEM), atomic force microscopy (AFM) and high-throughput minimum inhibition concentration assays (MICs). In general, the strains tested showed a significant dose-dependent reduction in cell growth at ≥6% OligoG as measured by optical density (OD600; P&#60;0.05). OligoG (&#62;0.5%) also showed a significant inhibitory effect on hyphal growth in germ tube assays, although strain-dependent variations in efficacy were observed (P&#60;0.05). SEM and AFM both showed that OligoG (≥2%) markedly disrupted fungal biofilm formation, both alone, and in combination with fluconazole. Cell surface roughness was also significantly increased by the combination treatment (P&#60;0.001). High-throughput robotic MIC screening demonstrated the potentiating effects of OligoG (2, 6, 10%) with nystatin, amphotericin B, fluconazole, miconazole, voriconazole or terbinafine with the test strains. Potentiating effects were observed for the Aspergillus strains with all six antifungal agents, with an up to 16-fold (nystatin) reduction in MIC. Similarly, all the Candida spp. showed potentiation with nystatin (up to 16-fold) and fluconazole (up to 8-fold). These findings demonstrate the antifungal properties of OligoG and suggest a potential role in the management of fungal infections and possible reduction of antifungal toxicity

Meta-analysis of (single-cell method) benchmarks reveals the need for extensibility and interoperability

Computational methods represent the lifeblood of modern molecular biology. Benchmarking is important for all methods, but with a focus here on computational methods, benchmarking is critical to dissect important steps of analysis pipelines, formally assess performance across common situations as well as edge cases, and ultimately guide users on what tools to use. Benchmarking can also be important for community building and advancing methods in a principled way. We conducted a meta-analysis of recent single-cell benchmarks to summarize the scope, extensibility, and neutrality, as well as technical features and whether best practices in open data and reproducible research were followed. The results highlight that while benchmarks often make code available and are in principle reproducible, they remain difficult to extend, for example, as new methods and new ways to assess methods emerge. In addition, embracing containerization and workflow systems would enhance reusability of intermediate benchmarking results, thus also driving wider adoption

ACR guidance document on MR safe practices: 2013

Because there are many potential risks in the MR environment and reports of adverse incidents involving patients, equipment and personnel, the need for a guidance document on MR safe practices emerged. Initially published in 2002, the ACR MR Safe Practices Guidelines established de facto industry standards for safe and responsible practices in clinical and research MR environments. As the MR industry changes the document is reviewed, modified and updated. The most recent version will reflect these changes. J. Magn. Reson. Imaging 2013;37:501–530. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96674/1/24011_ftp.pd