Reproducible switching between a walled and cell wall-deficient lifestyle of actinomycetes using gradient agar plates.

The cell wall is a shape-defining structure that envelopes almost all bacteria, protecting them from biotic and abiotic stresses. Paradoxically, some filamentous actinomycetes have a natural ability to shed their cell wall under influence of hyperosmotic stress. These wall-deficient cells can revert to their walled state when transferred to a medium without osmoprotection but often lyse due to their fragile nature. Here, we designed plates with an osmolyte gradient to reduce cell lysis and thereby facilitating the transition between a walled and wall-deficient state. These gradient plates allow determining of the osmolyte concentration where switching takes place, thereby enabling careful and reproducible comparison between mutants affected by switching. Exploring these transitions could give valuable insights into the ecology of actinomycetes and their biotechnological applications.

The haustorium as a driving force for speciation in thallus-forming Laboulbeniomycetes.

Laboulbeniomycetes is a class of fungi that have obligate associations with arthropod hosts, either for dispersal (order Pyxidiophorales) or as biotrophic parasites (orders Herpomycetales and Laboulbeniales). Here, we focus on Herpomycetales and Laboulbeniales, which include fungi that form thalli, 3-dimensional, multicellular units of 1000 s of cells. Based on recently published data regarding patterns of speciation, we present the One-Host-One-Parasite model (1H1P) for haustorial thallus-forming Laboulbeniomycetes. We hypothesize that taxa with haustoria, rhizoidal structures that make contact with the host's body cavity, have very strict host specificity. For taxa without haustoria, the microhabitat-as selected by the host-governs host shifting, presence or absence of the fungus, abundance, effective host range, and geographic distribution. We make suggestions for future research including fluorescent labeling of waxy lipids and mass spectrometry. These techniques have the potential to generate the data necessary to evaluate the here proposed 1H1P hypothesis for Herpomycetales and Laboulbeniales.

Hyperbaric oxygen therapy: solution for difficult to heal acute wounds? Systematic review.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) is used to treat various wound types. However, the possible beneficial and harmful effects of HBOT for acute wounds are unclear. METHODS: We undertook a systematic review to evaluate the effectiveness of HBOT compared to other interventions on wound healing and adverse effects in patients with acute wounds. To detect all available randomized controlled trials (RCTs) we searched five relevant databases up to March 2010. Trial selection, quality assessment, data extraction, and data synthesis were conducted by two of the authors independently. RESULTS: We included five trials, totaling 360 patients. These trials, with some methodologic flaws, included different kinds of wound and focused on different outcome parameters, which prohibited meta-analysis. A French trial (n = 36 patients) reported that significantly more crush wounds healed with HBOT than with sham HBOT [relative risk (RR) 1.70, 95% confidence interval (CI) 1.11-2.61]. Moreover, there were significantly fewer additional surgical procedures required with HBOT (RR 1.60, 95% CI 1.03-2.50), and there was significantly less tissue necrosis (RR 1.70, 95% CI 1.11-2.61). In one of two American trials (n = 141) burn wounds healed significantly quicker with HBOT (P < 0.005) than with routine burn care. A British trial (n = 48) compared HBOT with usual care. HBOT resulted in a significantly higher percentage of healthy graft area in split skin grafts (RR 3.50, 95% CI 1.35-9.11). In a Chinese trial (n = 145) HBOT did not significantly improve flap survival in patients with limb skin defects. CONCLUSIONS: HBOT, if readily available, appears effective for the management of acute, difficult to heal wounds.

Hyperbaric oxygen therapy for treating acute surgical and traumatic wounds.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) is used as a treatment for acute wounds (such as those arising from surgery and trauma) however the effects of HBOT on wound healing are unclear.  OBJECTIVES: To determine the effects of HBOT on the healing of acute surgical and traumatic wounds. SEARCH STRATEGY: We searched the Cochrane Wounds Group Specialised Register (25 August 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3), Ovid MEDLINE (1950 to August Week 2 2010 ), Ovid MEDLINE (In-Process & Other Non-Indexed Citations August 24, 2010), Ovid EMBASE (1980 to 2010, Week 33) and EBSCO CINAHL (1982 to 20 August 2010). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing HBOT with other interventions or comparisons between alternative HBOT regimens. DATA COLLECTION AND ANALYSIS: Two review authors conducted selection of trials, risk of bias assessment, data extraction and data synthesis independently. Any disagreements were referred to a third review author.  MAIN RESULTS: Three trials involving 219 participants were included. The studies were clinically heterogeneous, therefore a meta-analysis was inappropriate.One trial (48 participants with burn wounds undergoing split skin grafts) compared HBOT with usual care and reported a significantly higher complete graft survival associated with HBOT (95% healthy graft area risk ratio (RR) 3.50; 95% confidence interval (CI) 1.35 to 9.11). A second trial (36 participants with crush injuries) reported significantly more wounds healed with HBOT than with sham HBOT (RR 1.70; 95% CI 1.11 to 2.61) and fewer additional surgical procedures required with HBOT: RR 0.25; 95% CI 0.06 to 1.02 and significantly less tissue necrosis: RR 0.13; 95% CI 0.02 to 0.90). A third trial (135 people undergoing flap grafting) reported no significant differences in complete graft survival with HBOT compared with dexamethasone (RR 1.14; 95% CI 0.95 to 1.38) or heparin (RR 1.21; 95% CI 0.99 to 1.49).Many of the predefined secondary outcomes of the review, including mortality, pain scores, quality of life, patient satisfaction, activities daily living, increase in transcutaneous oxygen pressure (TcpO(2)), amputation, length of hospital stay and costs, were not reported. All three trials were at unclear or high risk of bias. AUTHORS' CONCLUSIONS: There is a lack of high quality, valid research evidence regarding the effects of HBOT on wound healing. Whilst two small trials suggested that HBOT may improve the outcomes of skin grafting and trauma these trials were at risk of bias. Further evaluation by means of high quality RCTs is needed.

[Antiseptics to prevent or treat wound infections; myths and evidence]. / Antiseptica ter preventie of behandeling van wondinfecties: mythes en evidence.

Antiseptics are commonly applied to prevent or treat wound infections. Many common opinions about antiseptics appear not to be supported by convincing evidence. The aim of this review is to compare such traditional beliefs with currently available evidence. While antiseptics obviously reduce the number of pathogens, their value as a supplement to or as replacement of wound cleansing remains unclear.Some antiseptics encourage wound healing, others may even delay it. Many of the adverse effects ascribed to antiseptics are not supported by evidence; nevertheless this has resulted in a reduction of their use.If used as part of a multifaceted approach to wound care, antiseptics are to be preferred over locally applied antibiotics as they are safer, have a broader spectrum of activity (particularly against antibiotic-resistant bacteria), and rarely lead to resistance.

Dilemmas in measuring and using pressure ulcer prevalence and incidence: an international consensus.

Pressure ulcer prevalence and incidence data are increasingly being used as indicators of quality of care and the efficacy of pressure ulcer prevention protocols. In some health care systems, the occurrence of pressure ulcers is also being linked to reimbursement. The wider use of these epidemiological analyses necessitates that all those involved in pressure ulcer care and prevention have a clear understanding of the definitions and implications of prevalence and incidence rates. In addition, an appreciation of the potential difficulties in conducting prevalence and incidence studies and the possible explanations for differences between studies are important. An international group of experts has worked to produce a consensus document that aims to delineate and discuss the important issues involved, and to provide guidance on approaches to conducting and interpreting pressure ulcer prevalence and incidence studies. The group's main findings are summarised in this paper.

Occlusive vs gauze dressings for local wound care in surgical patients: a randomized clinical trial.

OBJECTIVE: To compare effectiveness and costs of gauze-based vs occlusive, moist-environment dressing principles. DESIGN: Randomized clinical trial. SETTING: Academic Medical Center, Amsterdam, the Netherlands. PATIENTS: Two hundred eighty-five hospitalized surgical patients with open wounds. INTERVENTION: Patients received occlusive (ie, foams, alginates, hydrogels, hydrocolloids, hydrofibers, or films) or gauze-based dressings until their wounds were completely healed. MAIN OUTCOME MEASURES: Primary end points were complete wound healing, pain during dressing changes, and costs. Secondary end point was length of hospital stay. RESULTS: Time to complete wound healing did not differ significantly between occlusive (median, 66 days; interquartile range [IQR], 29-133 days) and gauze-based dressing groups (median, 45 days; IQR, 26-106 days; log-rank P = .31). Postoperative wounds (62% of the wounds included) healed significantly (P = .02) quicker using gauze dressings (median, 45 days; IQR, 22-93 days vs median, 72 days; IQR, 36-132 days). Median pain scores were low and similar in the occlusive (0.90; IQR, 0.29-2.34) and the gauze (0.64; IQR, 0.22-1.95) groups (P = .32). Daily costs of occlusive materials were significantly higher (occlusive, euro6.34 [US $9.95] vs gauze, euro1.85 [US $2.90]; P < .001), but nursing time costs per day were significantly higher when gauze was used (occlusive, euro1.28 [US $2.01] vs gauze, euro2.41 [US $3.78]; P < .001). Total cost for local wound care per patient per day during hospitalization was euro7.48 (US $11.74) in the occlusive group and euro3.98 (US $6.25) in the gauze-based group (P = .002). CONCLUSIONS: The occlusive, moist-environment dressing principle in the clinical surgical setting does not lead to quicker wound healing or less pain than gauze dressings. The lower costs of less frequent dressing changes do not balance the higher costs of occlusive materials. Trial Registration trialregister.nl Identifier: 56264738.

Inter- and intra-observer (dis)agreement among nurses and doctors to classify colour and exudation of open surgical wounds according to the Red-Yellow-Black scheme.

AIM AND OBJECTIVES: Primary: to study the level of agreement among nurses and doctors in classifying the colour and exudation of open wounds according to the Red-Yellow-Black scheme. Secondary: to check their agreement with an international expert panel on whether their classification was correct. BACKGROUND: Nurses and doctors classify open wounds to assess systemic and local treatment options. Nowadays, several classification schemes are being used. The Red-Yellow-Black-scheme is commonly used for classifying open wounds or is part of other, more intricate, wound classification models. METHODS: Eighteen representative photographs of red, yellow and black wounds were presented to 63 nurses and 79 doctors from the Department of Surgery. They classified these open wounds for colour and amount of exudation. Group kappa's (kappa) were calculated to assess inter- and intra-observer agreement and their agreement with an expert panel. RESULTS: Agreement among the 63 nurses on wound colour (kappa = 0.61; 95% CI: 0.49-0.74) and exudation (kappa = 0.49; 95% CI: 0.29-0.68) was moderate to good. Agreement among the 79 doctors was similar: kappa = 0.61; 95% CI 0.49-0.73 for wound colour and kappa = 0.48; 95% CI: 0.36-0.61 for exudation. Nurses' and doctors' agreement with the expert panel was also moderate to good: kappa-values ranged between 0.48 and 0.77. CONCLUSION: Based on the good to moderate inter-observer agreement as found in this study, the Red-Yellow-Black -scheme appears to be a reliable and accurate classification scheme to assess open (surgical) wounds. Such a scheme may enable nurses and doctors to select the appropriate treatment modalities and evaluate the progress of the healing process. RELEVANCE TO CLINICAL PRACTICE: The Red-Yellow-Black scheme is a helpful tool to classify all kinds of wounds and can be used as stand-alone classification method or as part of wound management concepts.