The Role of Topical Antiseptic Agents Within Antimicrobial Stewardship Strategies for Prevention and Treatment of Surgical Site and Chronic Open Wound Infection

Efficiency of an algorithm for the prevention of sternal infection after cardiac surgery in children under 1 year of age: A single-center retrospective study

Background

Sternal infection is one of the most challenging complications to manage after heart surgery. The aim of our study is to evaluate the effectiveness of a developed algorithm for preventing sternal infection in pediatric patients after surgery for congenital heart disease (CHD).

Methods

We conducted a single-center study examining the treatment of 478 children with CHD. Patients were divided into 2 groups, taking into account the application of a developed management algorithm. A multivariate logistic regression analysis was used to identify the factors influencing the development of sternal infection following heart surgery using median sternotomy.

Results

A developed algorithm was applied in 308 children. In total, there were 16 cases of sternal infection (3.34 %) across both groups. Deep wound infection developed in 6 patients (1.26 %). Sternal infection developed in 2 children (0.65 %) in the first group (in which the algorithm was applied) and 14 children (8.2 %) in the second group. Deep sternal infection developed in 1 patient in the first group (0.33 %) and in 5 patients in the second group (2.94 %). As a result, perioperative risk factors as postoperative resternotomy (OR 23.315; p < 0.001), delayed sternal closure (OR 9.087; p = 0.003), development of acute renal failure (OR 5.322; p = 0.018) were associated with increased risk of infection and application of the developed algorithm resulted in a significant reduction in risk (OR 0.032; p < 0.001).

Conclusion

The suggested method for the prevention of sternal infection has significantly reduced the incidence of sternal infection after cardiac surgery in children less than 1 year of age. In patients with moderate to high risk for surgical site infection, surgeons can enhance wound healing and prevent wound infections with simple, inexpensive, and readily available tools and techniques. Surgical aspects, topical use of antibiotics, prevention of peripheral vasoconstriction, maintenance of normal oxygen delivery rates, and an individual approach to intensive care are essential.

Enhancing the mechanical strength of 3D printed GelMA for soft tissue engineering applications

Gelatin methacrylate (GelMA) hydrogels have gained significant traction in diverse tissue engineering applications through the utilization of 3D printing technology. As an artificial hydrogel possessing remarkable processability, GelMA has emerged as a pioneering material in the advancement of tissue engineering due to its exceptional biocompatibility and degradability. The integration of 3D printing technology facilitates the precise arrangement of cells and hydrogel materials, thereby enabling the creation of in vitro models that simulate artificial tissues suitable for transplantation. Consequently, the potential applications of GelMA in tissue engineering are further expanded. In tissue engineering applications, the mechanical properties of GelMA are often modified to overcome the hydrogel material's inherent mechanical strength limitations. This review provides a comprehensive overview of recent advancements in enhancing the mechanical properties of GelMA at the monomer, micron, and nano scales. Additionally, the diverse applications of GelMA in soft tissue engineering via 3D printing are emphasized. Furthermore, the potential opportunities and obstacles that GelMA may encounter in the field of tissue engineering are discussed. It is our contention that through ongoing technological progress, GelMA hydrogels with enhanced mechanical strength can be successfully fabricated, leading to the production of superior biological scaffolds with increased efficacy for tissue engineering purposes.

In Vitro Effect of Eucalyptus Essential Oils and Antiseptics (Chlorhexidine Gluconate and Povidone-Iodine) against Bacterial Isolates from Equine Wounds

Considering the increasing antibiotics resistance, there has been a propensity to replace them with antiseptics when it comes to wound management and treatment. Nevertheless, in recent years, there have been reports regarding resistance to antiseptics by some bacterial strains. There is also concern about the environmental impact of these substances. The aim of this study was to compare the antimicrobial efficacy of antiseptics and eucalyptus essential oils on bacterial strains from horse's wounds. We used twelve Escherichia coli, eight Staphylococcus aureus, two Staphylococcus pseudintermedius, one Staphylococcus vitulinus and one Staphylococcus saprophyticus strains from equine wounds. The effect of Eucalyptus radiata essential oil, Eucalyptus globulus essential oil, povidone-iodine and chlorhexidine gluconate against the isolated strains was evaluated applying the Kirby-Baüer method. Regarding the Escherichia coli strains, E. radiata and the mixture of E. radiata and E. globulus had a better inhibitory effect than antiseptics. E. globulus had a better effect against most Staphylococcus spp. compared to E. radiata. For both Gram-negative and Gram-positive strains tested, chlorhexidine gluconate had a better inhibitory effect than povidone-iodine. The antibacterial efficacy of essential oils highlights their potential to substitute or complement the use of antiseptics and so reduce resistance to antiseptics.

Antibiotic stewardship in Indian palliative care: a single-center retrospective study

Objective

Characterize antibiotic prescribing behaviors at an Indian palliative care center after the initiation of the Antibiotic Order Form (AOF): an antibiotic stewardship program involving a paper form to track antibiotic use and to provide prescription guidelines.

Design

Retrospective chart review.

Setting

Trivandrum Institute of Palliative Sciences (TIPS) is a palliative care organization in Kerala, India.

Methods

Antibiotic prescription data and patient data were collected for adult patients treated at TIPS between January 1, 2017, and October 31, 2019. Descriptive statistics and a Zero-Inflated Poisson regression model were used to analyze antibiotic prescriptions. AOF completion and prescription concordance with institutional guidelines were also evaluated.

Results

Out of 7,450 unique patients, 675 (9%) were prescribed 1,448 antibiotics. Age was the strongest factor in determining the number of antibiotic courses with each additional year of age decreasing the expected antibiotic prescription count by 2% per year. The most common antibiotics prescribed were topical metronidazole (44%) and penicillins (29%). Among patients who died, 5% were prescribed antibiotics within the final month of life. In total, 32% of antibiotic prescriptions were documented in AOFs, and 18% were concordant with all institutional antibiotic prescribing guidelines.

Conclusions

This study is the first to analyze an antibiotic stewardship intervention in a palliative care setting within a low- and middle-income country. This retrospective study provides a benchmark of antibiotic use within Indian palliative care and highlights areas for future stewardship research including topical metronidazole use within palliative care and higher rates of antibiotic use among younger palliative care patients.

Efficacy of Polyhexamethylene Biguanide in Reducing Post-Operative Infections: A Systematic Review and Meta-Analysis

Background: Post-operative infections are a substantial cause of morbidity and mortality worldwide. Polyhexamethylene biguanide (PHMB) is an antimicrobial agent that has been used in various surgical settings to prevent infections. However, the literature on its efficacy in reducing post-operative infections remains unclear. Materials and Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of PHMB in reducing post-operative infections. The risk of bias and methodologic quality of the included studies were also assessed. Results: The systematic review included nine RCTs, and eight were included in the meta-analysis that showed that the use of PHMB was associated with a reduction in the rate of post-operative infections. The overall effect size was statistically significant, with moderate heterogeneity across the included studies (log Peto's odds ratio [OR], -0.890; 95% confidence interval [CI], -1.411 to -0.369; I2 = 41.89%). However, the diversity in the application of PHMB and the potential influence of other factors, such as adherence to infection prevention protocols and organizational-level variables, underscore the need for further primary studies. Conclusions: Polyhexamethylene biguanide appears to be a promising intervention for reducing post-operative infections. However, more high-quality, well-designed RCTs are needed to confirm these findings and to explore the most effective ways to use PHMB within specific infection prevention bundles. Future research should also aim to control for potential confounding factors to provide a more comprehensive understanding of the efficacy of PHMB in reducing post-operative infections.

Polyhexamethylene biguanide and its antimicrobial role in wound healing: a narrative review

A wound offers an ideal environment for the growth and proliferation of a variety of microorganisms which, in some cases, may lead to localised or even systemic infections that can be catastrophic for the patient; the development of biofilms exacerbates these infections. Over the past few decades, there has been a progressive development of antimicrobial resistance (AMR) in microorganisms across the board in healthcare sectors. Such resistant microorganisms have arisen primarily due to the misuse and overuse of antimicrobial treatments, and the subsequent ability of microorganisms to rapidly change and mutate as a defence mechanism against treatment (e.g., antibiotics). These resistant microorganisms are now at such a level that they are of grave concern to the World Health Organization (WHO), and are one of the leading causes of illness and mortality in the 21st century. Treatment of such infections becomes imperative but presents a significant challenge for the clinician in that treatment must be effective but not add to the development of new microbes with AMR. The strategy of antimicrobial stewardship (AMS) has stemmed from the need to counteract these resistant microorganisms and requires that current antimicrobial treatments be used wisely to prevent amplification of AMR. It also requires new, improved or alternative methods of treatment that will not worsen the situation. Thus, any antimicrobial treatment should be effective while not causing further development of resistance. Some antiseptics fall into this category and, in particular, polyhexamethylene hydrochloride biguanide (PHMB) has certain characteristics that make it an ideal solution to this problem of AMR, specifically within wound care applications. PHMB is a broad-spectrum antimicrobial that kills bacteria, fungi, parasites and certain viruses with a high therapeutic index, and is widely used in clinics, homes and industry. It has been used for many years and has not been shown to cause development of resistance; it is safe (non-cytotoxic), not causing damage to newly growing wound tissue. Importantly there is substantial evidence for its effective use in wound care applications, providing a sound basis for evidence-based practice. This review presents the evidence for the use of PHMB treatments in wound care and its alignment with AMS for the prevention and treatment of wound infection.

Infections in Burn Patients: A Retrospective View over Seven Years

Backgroundand objectives: Burn patients represent a challenging cohort because the injuries entail a vulnerability to colonisation by microorganisms. The ensuing infections can lead to serious complications and, in many cases, to the death of the burn patient. Surgical intervention and wound dressings, as well as antibiotic treatment, are crucial for optimising the treatment of the patient. Materialand Methods: In this retrospective analysis, we analysed the treatment course, antibiotic therapy, and general complications of 252 burn patients with second- or third-degree burns over a time span of 7 years. Results: Patients who developed infections tended to have, on average, a higher total body surface area (TBSA), higher abbreviated burn severity index (ABSI) scores, and longer hospital stays. Patients who were admitted to the burn unit after 2006 had significantly shorter stays in the burn unit. TBSA and ABSI scores were lower in the patient cohort admitted after 2006. Patients exhibiting a TBSA greater than 30% had significantly longer hospital stays and antibiotic treatment periods. TBSA and ABSI scores were significantly higher in patients who died. The results of binary logistic regression indicate that a higher ABSI score increases the odds ratio of developing an infection. Bacteria number had no significant effect on the odds of patient death but positively influenced the odds ratio of developing an infection. TBSA was negatively associated with the risk of developing an infection and was an insignificant predictor of mortality. Conclusions: To gauge the optimal treatment for a burn patient, it is crucial for practitioners to correctly select, dose, and time antibiotics for the patient. Monitoring bacterial colonisation is vital to nip rising infection in the bud and ensure the correct antibiotic selection. This will help prevent the development of multi-resistant bacteria.

Pharmacokinetic control on the release of antimicrobial drugs from pH-responsive electrospun wound dressings

The acidic pH of healthy skin changes during wound healing due to the exposure of the inner dermal and subcutaneous tissue and due to the potential colonization of pathogenic bacteria. In chronic non-healing wounds, the pH values vary in a wide pH range but the appearance of an alkaline shift is common. After a wound is incurred, neutral pH in the wound bed is characteristic of the activation of the cascade of regenerative and remodeling processes. In order to adjust drug release to the specific pH of the wound, herein, drug-loaded wound dressings having pH-responsiveness containing antiseptics and antibiotics and exerting different release kinetics in order to have a perfect match between the drug release kinetics, and the pH conditions of each wound type, were developed. We have fabricated drug-loaded electrospun nanofibers loaded with the antiseptic chlorhexidine, with the broad-spectrum antibiotic rifampicin, and with the antimicrobial of natural origin thymol, using the pH-dependent methacrylic acid copolymer Eudragit® L100-55, which dissolves at pH > 5.5; those drugs were loaded within Eudragit® S100, which dissolves at pH > 7 and, finally, within the methacrylic ester copolymer Eudragit® RS100 which is pH independent and slowly erodes and releases its contained cargo. The antibacterial action of those advanced wound dressings has been evaluated against methicillin-sensitive S. aureus Newman strain expressing the coral green fluorescent protein (cGFP), as a model of a Gram-positive bacteria, and against E. coli S17 strain as a model of a Gram-negative bacteria. It was demonstrated that those combinational products integrate in one device the required characteristics for a wound dressing with the therapeutic action of a contained active principle and can be selected depending on the wound acidic or alkaline status for its appropriated management.

Cytotoxicity and Wound Closure Evaluation in Skin Cell Lines after Treatment with Common Antiseptics for Clinical Use

In recent years, new therapies, such as skin cell lines injections, have emerged to promote re-epithelialization of damaged areas such as chronic ulcers or to treat patients with severe burns. Antiseptics are commonly used during wound clinical management to avoid serious infections, but they may delay the healing process due to their apparent cytotoxicity to skin cells. The cytotoxicity of ethanol, chlorhexidine digluconate, sodium hypochlorite, povidone iodine and polyhexanide was evaluated in this in vitro study on human fibroblasts and keratinocytes. Treatments were applied to each cell type culture every 48 h for 14 days. To determine the cytotoxic of antiseptics, cell viability (Live/Dead^®) and cell proliferation (AlamarBlue™) assays were performed on cell monolayers. Cell migration capacity was evaluated with a wound closure assay. Results showed how chlorhexidine digluconate and ethanol significantly reduced the viability of keratinocytes and inhibited cell migration. Povidone iodine followed by chlorhexidine digluconate significantly reduced fibroblast cell viability. Povidone iodine also inhibited cell migration. Sodium hypochlorite was the least detrimental to both cell types. If epithelial integrity is affected, the wound healing process may be altered, so the information gathered in this study may be useful in selecting the least aggressive antiseptic after treatment with new emerging therapies.

Assessing the inflammatory response to in vitro polymicrobial wound biofilms in a skin epidermis model

Wounds can commonly become infected with polymicrobial biofilms containing bacterial and fungal microorganisms. Microbial colonization of the wound can interfere with sufficient healing and repair, leading to high rates of chronicity in certain individuals, which can have a huge socioeconomic burden worldwide. One route for alleviating biofilm formation in chronic wounds is sufficient treatment of the infected area with topical wound washes and ointments. Thus, the primary aim here was to create a complex in vitro biofilm model containing a range of microorganisms commonly isolated from the infected wound milieu. These polymicrobial biofilms were treated with three conventional anti-biofilm wound washes, chlorhexidine (CHX), povidone-iodine (PVP-I), and hydrogen peroxide (H₂O₂), and efficacy against the microorganisms assessed using live/dead qPCR. All treatments reduced the viability of the biofilms, although H₂O₂ was found to be the most effective treatment modality. These biofilms were then co-cultured with 3D skin epidermis to assess the inflammatory profile within the tissue. A detailed transcriptional and proteomic profile of the epidermis was gathered following biofilm stimulation. At the transcriptional level, all treatments reduced the expression of inflammatory markers back to baseline (untreated tissue controls). Olink technology revealed a unique proteomic response in the tissue following stimulation with untreated and CHX-treated biofilms. This highlights treatment choice for clinicians could be dictated by how the tissue responds to such biofilm treatment, and not merely how effective the treatment is in killing the biofilm.

The Benefits and Harms of Cleansing for Acute Traumatic Wounds: A Narrative Review

ABSTRACT

Acute traumatic wound cleansing is currently a controversial issue demonstrated by the variability in solutions and techniques used to clean wounds in clinical practice. Although there is evidence of improved infection outcomes in wounds cleansed with antiseptics, these observations are often undermined by concurrent use of antibiotics in addition to poor study design. Cleansing techniques including pressurized irrigation have also been investigated indicating potential harms such as edema and inconsistencies in irrigation pressures. The purpose of this article is to provide a narrative review on the contemporary evidence indicating the potential harms and benefits of wound cleansing in the context of acute traumatic wounds.This literature review reveals that acute wound cleansing in clinical practice remains heavily dependent on tradition rather than robust clinical evidence. The evidence base remains limited because of methodological and pragmatic issues in obtaining definitive data on the efficacy of specific agents and techniques. Future studies should focus on establishing the relative benefits of different cleansing solutions and techniques. Establishing the most effective use of antiseptic cleansing solutions may also help reduce further antimicrobial resistance as observed in recent studies. Clinicians responsible for cleansing wounds must consider patient preference when deciding which solution and techniques are used. In addition, a risk assessment considering the potential harms and benefits of different solutions and techniques must be performed.

Low-Temperature Gas Plasma Combined with Antibiotics for the Reduction of Methicillin-Resistant Staphylococcus aureus Biofilm Both In Vitro and In Vivo

Biofilm infections in wounds seriously delay the healing process, and methicillin-resistant Staphylococcus aureus is a major cause of wound infections. In addition to inactivating micro-organisms, low-temperature gas plasma can restore the sensitivity of pathogenic microbes to antibiotics. However, the combined treatment has not been applied to infectious diseases. In this study, low-temperature gas plasma treatment promoted the effects of different antibiotics on the reduction of S. aureus biofilms in vitro. Low-temperature gas plasma combined with rifampicin also effectively reduced the S. aureus cells in biofilms in the murine wound infection model. The blood and histochemical analysis demonstrated the biosafety of the combined treatment. Our findings demonstrated that low-temperature gas plasma combined with antibiotics is a promising therapeutic strategy for wound infections.

Estrategias de protección antimicrobiana en el cuidado de heridas: evidencia para el uso de apósitos recubiertos con DACC

BACKGROUND

Antimicrobial resistance (AMR) is one of the most serious health threats globally. The development of new antimicrobials is not keeping pace with the evolution of resistant microorganisms, and novel ways of tackling this problem are required. One of such initiatives has been the development of antimicrobial stewardship programmes (AMS). The use of wound dressings that employ a physical sequestration and retention approach to reduce bacterial burden offers a novel approach to support AMS. Bacterial-binding by dressings and their physical removal can minimise their damage and prevent the release of harmful endotoxins.

OBJECTIVE

To highlight AMS to promote the correct use of antimicrobials and to investigate how dialkylcarbamyl chloride (DACC)-coated dressings can support AMS.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify articles relating to AMS, and the use of wound dressings in the prevention and treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent wound infection in a way that does not kill or damage the microorganisms were reviewed.

RESULTS

The evidence demonstrated that using bacterial-binding wound dressings that act in a physical manner (eg, DACC-coated dressings) to preventing infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical sequestration and removal of intact microorganisms from the wound bed (eg, a wound dressing that uses DACC technology to prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Health care-associated infections: Controlled delivery of cationic antiseptics from polymeric excipients

Nowadays, the treatment of health care-associated infections represents a serious issue, due to the increasing number of bacterial strains resistant to traditional antibiotics. The use of antiseptics like quaternary ammonium salts and biguanides is a viable alternative to face these life-threatening infections. However, their inherent toxicity as well as the necessity of providing a sustained release to avoid the formation of pathogen biofilms are compelling obstacles towards their assessment in the hospitals. Within this framework, the role of polymeric drug delivery systems is fundamental to overcome the aforementioned problems. Biocompatibility, biodegradability and excipient-drug interactions are crucial properties determining the efficacy of the formulation. In this work, we provide an in-depth analysis of the polymer drug delivery systems that have been developed or are under development for the sustained release of positively charged antiseptics, highlighting the crucial characteristics that allowed to achieve the most relevant therapeutic effects. We reported and compared natural occurring polymers and synthetic carriers to show their pros and cons and applicability in the treatment of health care-associated infections. Then, the discussion is focused on a particularly relevant class of materials adopted for the scope, represented by polyesters, which gave rise, due to their biodegradability, to the field of resorbable drug delivery devices. Finally, a specific analysis on the effect of the polymer functionalization over the formulation performances for the different types of polymeric carriers is presented.

Challenges in the management of chronic wound infections

OBJECTIVES

Chronic wound infections may delay the healing process and are responsible for a significant burden on healthcare systems. Since inappropriate management may commonly occur in the care of these patients, this review aims to provide a practical guide underlining actions to avoid in the management of chronic wound infections.

METHODS

We performed a systematic review of the literature available in PubMed in the last 10 years, identifying studies regarding the management of patients with chronic wound infections. A panel of experts discussed the potential malpractices in this area. A list of 'Don'ts', including the main actions to be avoided, was drawn up using the 'Choosing Wisely' methodology.

RESULTS

In this review, we proposed a list of actions to avoid for optimal management of patients with chronic wound infections. Adequate wound bed preparation and wound antisepsis should be combined, as the absence of one of them leads to delayed healing and a higher risk of wound complications. Moreover, avoiding inappropriate use of systemic antibiotics is an important point because of the risk of selection of multidrug-resistant organisms as well as antibiotic-related adverse events.

CONCLUSION

A multidisciplinary team of experts in different fields (surgeon, infectious disease expert, microbiologist, pharmacologist, geriatrician) is required for the optimal management of chronic wound infections. Implementation of this approach may be useful to improve the management of patients with chronic wound infections.

Antimicrobial stewardship strategies in wound care: evidence to support the use of dialkylcarbamoyl chloride (DACC)- coated wound dressings

BACKGROUND

Traditionally, infections are treated with antimicrobials (for example, antibiotics, antiseptics, etc), but antimicrobial resistance (AMR) has become one of the most serious health threats of the 21st century (before the emergence of COVID-19). Wounds can be a source of infection by allowing unconstrained entry of microorganisms into the body, including antimicrobial-resistant bacteria. The development of new antimicrobials (particularly antibiotics) is not keeping pace with the evolution of resistant microorganisms and novel ways of addressing this problem are urgently required. One such initiative has been the development of antimicrobial stewardship (AMS) programmes, which educate healthcare workers, and control the prescribing and targeting of antimicrobials to reduce the likelihood of AMR. Of great importance has been the European Wound Management Association (EWMA) in supporting AMS by providing practical recommendations for optimising antimicrobial therapy for the treatment of wound infection. The use of wound dressings that use a physical sequestration and retention approach rather than antimicrobial agents to reduce bacterial burden offers a novel approach that supports AMS. Bacterial-binding by dressings and their physical removal, rather than active killing, minimises their damage and hence prevents the release of damaging endotoxins.

AIM

Our objective is to highlight AMS for the promotion of the judicious use of antimicrobials and to investigate how dialkylcarbamoyl chloride (DACC)-coated dressings can support AMS goals.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify published articles describing data relating to AMS, and the use of a variety of wound dressings in the prevention and/or treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent and/or treat wound infection in a manner that does not kill or damage the microorganisms (for example, by actively binding and removing intact microorganisms from wounds) were then narratively reviewed.

RESULTS

The evidence reviewed here demonstrates that using bacterial-binding wound dressings that act in a physical manner (for example, DACC-coated dressings) as an alternative approach to preventing and/or treating infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical uptake, sequestration and removal of intact microorganisms from the wound bed (for example, a wound dressing that uses DACC technology to successfully prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS (for example, reducing the use of antimicrobials in wound treatment regimens) by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Comparative in vitro evaluation of the antimicrobial activities of povidone-iodine and other commercially available antiseptics against clinically relevant pathogens

Aims: Antiseptics, such as povidone-iodine (PVP-I), play an important role in infection control across a wide range of clinical settings. This study aimed to evaluate the comparative in vitro efficacy and rate of onset of action of a range of formulations of PVP-I and other commonly used antiseptics. Methods: The antimicrobial efficacy of a range of antiseptics and antimicrobial agents used for skin, wound, vagina and oral antisepsis was evaluated according to the EU Standards DIN EN1276 and EN14476. The panel of organisms tested included bacterial and fungal pathogens and two enteroviruses (Coxsackievirus A16 [CA16] and Enterovirus 71 [EV71]). Results: All PVP-I products tested were highly efficacious in vitro (>99.99% kill rate) against a range of clinically relevant bacterial and fungal pathogens with rapid onset of action (30-60 seconds), at both high and low concentrations. By comparison, the efficacy of other antiseptics tested was generally reduced upon dilution. PVP-I products used in wound and oral care were found to be more effective in vitro against CA16 and EV71, and had a faster onset of action than most other agents tested. Conclusion: This study provides valuable insights into the in vitro efficacy of a range of commonly used antiseptics and may help inform the selection of appropriate antiseptics by healthcare professionals.

Polyvinyl alcohol/chitosan wound dressings loaded with antiseptics

Wound care remains a challenge in healthcare. This work aimed to develop a new polyvinyl alcohol (PVA)/chitosan (Ch) based wound dressing able to ensure protection, hydration and a controlled release of antiseptics, as alternative to actual treatments. Two distinct formulations (1:1 and 3:1, w/w) were prepared, sterilized by autoclaving and characterized concerning surface morphology, degradation over the time, mechanical properties and hydrophilicity. Both dressings revealed adequate properties for the intended purpose. The dressings were loaded with chlorhexidine (CHX) and polyhexanide (PHMB) and the drug release profiles were determined using Franz diffusion cells. The release of PHMB was more sustained than CHX, lasting for 2 days. As the amounts of drugs released by PVA/Ch 1:1 were greater, the biological tests were done only with this formulation. The drug loaded dressings revealed antibacterial activity against S. aureus and S. epidermidis, but only the ones loaded with PHMB showed adequate properties in terms of cytotoxicity and irritability. The application of this elastic dressing in the treatment of wounds in a dog led to faster recovery than conventional treatment, suggesting that the material can be a promising alternative in wound care.

Novel Bis-Ammonium Salts of Pyridoxine: Synthesis and Antimicrobial Properties

A series of 108 novel quaternary bis-ammonium pyridoxine derivatives carrying various substituents at the quaternary nitrogen’s and acetal carbon was synthesized. Thirteen compounds exhibited antibacterial and antifungal activity (minimum inhibitory concentration (MIC) 0.25–16 µg/mL) comparable or superior than miramistin, benzalkonium chloride, and chlorhexidine. A strong correlation between the lipophilicity and antibacterial activity was found. The most active compounds had logP values in the range of 1–3, while compounds with logP > 6 and logP < 0 were almost inactive. All active compounds demonstrated cytotoxicity comparable with miramistin and chlorhexidine on HEK-293 cells and were three-fold less toxic when compared to benzalkonium chloride. The antibacterial activity of leading compound 5c₁₂ on biofilm-embedded Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli or Pseudomonas aeruginosa was comparable or even higher than that of the benzalkonium chloride. In vivo 5c₁₂ was considerably less toxic (LD₅₀ 1705 mg/kg) than benzalkonium chloride, miramistine, and chlorhexidine at oral administration on CD-1 mice. An aqueous solution of 5c₁₂ (0.2%) was shown to be comparable to reference drugs efficiency on the rat’s skin model. The molecular target of 5c₁₂ seems to be a cellular membrane as other quaternary ammonium salts. The obtained results make the described quaternary bis-ammonium pyridoxine derivatives promising and lead molecules in the development of the new antiseptics with a broad spectrum of antimicrobial activity.

Risk and clinical impact of bacterial resistance/susceptibility to silver-based wound dressings: a systematic review

Objective:

To perform a systematic review of the literature on bacterial resistance, tolerance and susceptibility of silver within the context of wound therapy using silver-based dressings.

Methods:

A literature search was carried out using PubMed, Embase and Cochrane Library databases, the focus was whether results from microbiological experimental in vitro tests with reference strains and clinical wound isolates are reflected in clinical practice with regards to their ‘resistance’ profiles, comparable with those observed for antibiotics. The search results were allocated to six categories: resistance and resistance mechanism, in vitro tests with standard strains and wound isolates, prevalence and incidence, impact on clinical practice and impact on antibiotic therapy as well as reviews, expert opinions and consensus.

Results:

Based on all findings of the literature, it cannot be confirmed that a related clinical resistance to silver-ions in silver-based dressings has clinical impact, although endogenous and exogenous genetic resistance patterns have been described and intensively investigated. A translation of these genetic resistance-expression structures to phenotypic appearances, similar to those known for antibiotics, has not been demonstrated for silver in the literature.

Conclusion:

It can be concluded that there is no definitive evidence available and further studies should be conducted.

Clinical impact of an anti-biofilm Hydrofiber dressing in hard-to-heal wounds previously managed with traditional antimicrobial products and systemic antibiotics

Background

Hard-to-heal wounds are often compromised by the presence of biofilm. This presents an infection risk, yet traditional antimicrobial wound care products and systemic antibiotics are often used despite the uncertainty of therapeutic success and wound progression. The aim of this study was to investigate the clinical impact of a next-generation anti-biofilm Hydrofiber wound dressing (AQUACEL Ag+ Extra[AQAg+ E]) in hard-to-heal wounds that had previously been treated unsuccessfully with traditional silver-, iodine- or polyhexamethylene biguanide (PHMB)-containing dressings and products and/or systemic antibiotics.

Methods

Clinical case study evaluations of the anti-biofilm dressing were conducted, where deteriorating or stagnant wounds were selected by clinicians and primary dressings were replaced by the anti-biofilm dressing for up to 4 weeks, or as deemed clinically appropriate, with monitoring via case report forms. The data was stratified for cases where traditional silver-, iodine- or PHMB-containing products, or systemic antibiotics, had been used prior to the introduction of the anti-biofilm dressing.

Results

Sixty-five cases were identified for inclusion, wounds ranging in duration from 1 week to 20 years (median: 12 months). In 47 (72%) cases the wounds were stagnant, while 15 (23%) were deteriorating; 3 wounds were not recorded. After an average of 4.2 weeks of management with the anti-biofilm dressing (range: 1-11 weeks), in 11 (17%) cases the wounds had healed (i.e. complete wound closure), 40 (62%) wounds improved, 9 (14%) wounds remained the same and 5 (8%) wounds deteriorated.

Conclusions

The introduction of this anti-biofilm dressing into protocols of care that had previously involved wound management with traditional antimicrobial products and/or antibiotics was shown to facilitate improvements in the healing status of most of these hard-to-heal wounds. Dressings containing proven anti-biofilm technology, in combination with antimicrobial silver and exudate management technology, appear to be an effective alternative to traditional antimicrobial products and antibiotics in the cases presented here. The use of antimicrobial wound dressings that contain anti-biofilm technology may have a key role to play in more effective wound management and antibiotic stewardship.

Non-antibiotic antimicrobial interventions and antimicrobial stewardship in wound care

Control of wound infection today relies largely on antibiotics, but the continual emergence of antibiotic-resistant microorganisms threatens a return to the pre-antibiotic era when physicians used antiseptics to prevent and manage infection. Some of those antiseptics are still used today, and others have become available. A diverse variety of non-antibiotic antimicrobial interventions are found on modern formularies. Unlike the mode of action of antibiotics, which affect specific cellular target sites of pathogens, many non-antibiotic antimicrobials affect multiple cellular target sites in a non-specific way. Although this reduces the likelihood of selecting for resistant strains of microorganisms, some have emerged and cross-resistance between antibiotics and antiseptics has been detected. With the prospect of a post-antibiotic era looming, ways to maintain and extend our antimicrobial armamentarium must be found. In this narrative review, current and emerging non-antibiotic antimicrobial strategies will be considered and the need for antimicrobial stewardship in wound care will be explained.

Bacterial-binding dressings in the management of wound healing and infection prevention: a narrative review

The aim of this review was to present the clinical data on the use of the family of bacterial-binding dressings (Sorbact; dialkylcarbamoyl chloride-coated) in the treatment of a variety of acute and chronic wounds. The findings are discussed in terms of the effectiveness of the bacterial-binding dressings on bacterial bioburden reduction, infection prevention, initiation/progression of wound healing and cost-effectiveness. The evidence in support of the bacterial-binding dressings is strongest in the area of infection prevention in surgical wounds, with several controlled trials showing the prophylactic benefit of the dressing in these wounds. Wound bioburden management in chronic wounds is supported by a number of clinical studies. In total, 29 published clinical studies (with a total of 4044 patients) were included in this review.

Advanced drug delivery systems and artificial skin grafts for skin wound healing

Cutaneous injuries, especially chronic wounds, burns, and skin wound infection, require painstakingly long-term treatment with an immense financial burden to healthcare systems worldwide. However, clinical management of chronic wounds remains unsatisfactory in many cases. Various strategies including growth factor and gene delivery as well as cell therapy have been used to enhance the healing of non-healing wounds. Drug delivery systems across the nano, micro, and macroscales can extend half-life, improve bioavailability, optimize pharmacokinetics, and decrease dosing frequency of drugs and genes. Replacement of the damaged skin tissue with substitutes comprising cell-laden scaffold can also restore the barrier and regulatory functions of skin at the wound site. This review covers comprehensively the advanced treatment strategies to improve the quality of wound healing.

Therapeutic response and safety of the topical, sequential use of antiseptic, keratolytic, and pentamidine creams (3-PACK) on Leishmania (Viannia) braziliensis-infected mice

BACKGROUND

Topical treatment of New World cutaneous leishmaniasis can be affected by bacterial coinfection, hyperkeratosis, and transdermal drug delivery.

OBJECTIVE

The aim of this work was to evaluate the therapeutic response and safety of the topical, sequential use of antiseptic, keratolytic, and pentamidine isethionate (PMD) creams (3-PACK kit) on CL-infected BALB/c mice.

METHODS

A 0.5% chlorhexidine solution (CGH), 10% salicylic acid (SA), and 3% or 6% PMD were used as antiseptic, keratolytic, and antileishmanial drugs, respectively. During the first seven days, antiseptic, followed by 10% SA gel and PMD cream, were applied topically. Subsequently, treatment was performed only with the antiseptic and PMD creams. Skin irritation, reduction of lesion size (mm²), and parasitic load were observed until 30 days of treatment were completed.

FINDINGS

The 3-PACK treatment using 6% PMD induced a complete lesion reduction in 3/6 mice and a partial reduction in 1/6 mice, with no parasites observed. In contrast, CGH and SA alone, along with the vehicle, were not effective (p < 0.05). Moderate to severe erythema was observed at the application site.

MAIN CONCLUSION

The topical 3-PACK using 6% PMD was 67% effective in the treatment of CL by Leishmania (Viannia) braziliensis. Currently, work is ongoing to improve PMD isethionate formulation and to determine a dose-response.

Standardising intraoperative irrigation with 0.05% chlorhexidine gluconate in caesarean delivery to reduce surgical site infections: A single institution experience

Background

Surgical site infection is a significant cause of morbidity and mortality following caesarean delivery.

Objective

To determine whether standardising intraoperative irrigation with 0.05% chlorhexidine gluconate during caesarean delivery could decrease infection rates.

Methods

This was a process improvement project involving 742 women, 343 of whom received low-pressured 0.05% chlorhexidine gluconate irrigation during caesarean delivery over a one-year period. Infection rates were compared with a standard-of-care control group (399 women) undergoing caesarean delivery the preceding year.

Results

The treatment group infection rate met the study goal by achieving a lower infection rate than the control group, though this was not statistically significant. A significant interaction effect between irrigation with 0.05% chlorhexidine gluconate and antibiotic administration time existed, such that infection occurrence in the treatment group was not dependent on antibiotic timing, as opposed to the control group infection occurrence, which was dependent on antibiotic timing.

Conclusion

Intraoperative irrigation with 0.05% chlorhexidine gluconate during caesarean delivery did not statistically significantly reduce the rate of infections. It did render the impact of antibiotic administration timing irrelevant in prevention of surgical site infection. This suggests a role for 0.05% chlorhexidine gluconate irrigation in mitigating infection risk whether antibiotic prophylaxis timing is suboptimal or ideal.

In vitro cellular viability studies on a concentrated surfactant-based wound dressing

In this study, three cellular cytotoxic assays (direct contact assay, extraction assay, and cell insert assay) were applied to evaluate the effects of a concentrated surfactant gel preserved with antimicrobials and a concentrated surfactant gel with 1% silver sulfadiazine on both the mouse fibroblast cell line L929 and human dermal fibroblasts (HDFa). Also, the in vitro wound model was wounded by a 100 μL pipette tip and used to assess cell migration and wound closure after treatment with both gels. A needle-scratched membrane disruption model was used to preliminarily evaluate membrane stabilisation and the membrane-resealing effects of concentrated surfactant gels. It was demonstrated that the concentrated surfactant gel preserved with antimicrobials was not toxic to both L929 and HDFa. However, the concentrated surfactant gel with 1% silver sulfadiazine demonstrated a degree of cytotoxicity to both cell types. After treatment with a concentrated surfactant gel preserved with antimicrobials, cell movement to close the scratch gap was enhanced at 24 and 48 hours. The results also showed that cells treated with the concentrated surfactant gel preserved with antimicrobials decreased cell necrosis and improved cell resistance of the f-actin rearrangement after a needle scratch. The results demonstrated that a concentrated surfactant gel preserved with antimicrobials is non-cytotoxic and has ability to accelerate wound closure by enhancing cell mobility. Furthermore, the concentrated surfactant gel appeared to stabilise the plasma membrane and demonstrated a resealing ability and helped to retain the plasma membrane integrity and enhanced wound healing.

In situ gelation of rhEGF-containing liquid crystalline precursor with good cargo stability and system mechanical properties: a novel delivery system for chronic wounds treatment

The objective of this study was to develop a novel delivery system for recombinant human epidermal growth factor (rhEGF) for chronic wound treatment. Such a delivery system should be of good cargo stability and system mechanical properties in order to guarantee a satisfactory wound-healing effect. rhEGF-containing lyotropic liquid crystalline precursors (rhEGF-LLCPs) with in situ gelation capability were considered as a promising candidate to achieve this aim. Various properties of the optimal formulations (rhEGF-LLCP1 and rhEGF-LLCP2) were characterized, including apparent viscosity, gelation time, in vitro release and phase behavior. The stability of rhEGF and system mechanical properties (i.e. mechanical rigidity and bioadhesive force) were verified. Interestingly, rhEGF-LLCP2 with a larger internal water channel diameter exhibited faster release rate in vitro and then better bioactivity in Balb/c 3T3 and HaCaT cell models. Moreover, rhEGF-LLCP2 showed distinct promotion effects on wound closure, inflammatory recovery and re-epithelization process in Sprague-Dawley rat models. In conclusion, rhEGF-LLCP emerged as a prospective candidate to preserve the stability and enhance the wound-healing effect of rhEGF, which might serve as a new delivery system for chronic wound therapies.

Appropriate use of dressings containing nanocrystalline silver to support antimicrobial stewardship in wounds

Antimicrobial resistance is an ever-increasing global concern, with the era of untreatable infection becoming a reality. Wound care is no exception, with increasing issues of antibiotic-resistant infections across different wound types and care settings. Antibiotic resistance and stewardship have been the priority for most strategic interventions so far; however, in wound care, alternative or supplementary strategies using antiseptics should be considered. Antiseptics such as silver can provide effective cidal activity across a broad range of wound pathogens, assuming they are used at the correct level for an appropriate duration. Evidence summarised in this manuscript suggests that effective antiseptics, such as nanocrystalline silver, have an increasing body of evidence in support of their use to minimise transmission of antibiotic-resistant organisms as part of institutional infection control procedures and, in addition, through appropriate early use and stewardship on local wound infections, in conjunction with local procedures, to minimise the need for systemic antibiotic therapy. Engagement, alignment, and collaboration between wound care professionals and wider related teams and governments on antimicrobial stewardship, and the potential role of antiseptics within this, will help to generate further evidence for such interventions in the fight against antimicrobial-resistant infections in wound care.

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. It is an absorbent fibre dressing that is claimed to be biodegradable and biocompatible. This study was undertaken to assess the antimicrobial properties of the microfibre wound dressing using a variety of methods commonly used to assess other antimicrobial dressings.

METHOD

The zone of inhibition (ZOI) assay, challenge test (log reduction), time-to-kill and an in vitro wound model were all used in this report. Representative Gram-positive and Gram-negative bacteria were used and one yeast, Candida albicans.

RESULTS

The ZoI test showed no observable zones around the dressing but killed the organisms underneath the dressing. There was a >3 log reduction of Staphylococcus aureus and Escherichia coli within two hours and >3 log reduction against Pseudomonas aeruginosa and Candida albicans between four and 24 hours in the challenge test. In the wound model, there was a 2 log reduction of Escherichia coli within the wound model and in the sponge and culture medium below the dressing.

CONCLUSION

The chitosan microfibre wound dressing gives wound care an additional dressing to use to help prevent and manage bioburden and wound infection.

Antiseptics for burns: a review of the evidence

The burn patient is easily subject to colonization by microorganisms and infection, due to reduced defence capabilities and immune dysfunction. Moreover, burn units and intensive care units are characterized by a selection of resistant bacterial strains. If the burn patient is not adequately cared for in terms of infection prevention and control, sepsis is inevitable. Nowadays, several different antiseptics and antiseptic dressings are used in the topical treatment of burns, each with positive and negative effects. Topical antiseptics allow control of bacterial load, but they can also cause cytotoxicity and reduce healing rate. Choosing the most effective antiseptic is crucial to preventing infection from compromising wound healing. The present study aims to review the available literature in order to highlight evidence on the use of topical antiseptics in burns.

A 2000 patient retrospective assessment of a new strategy for burn wound management in view of infection prevention and treatment

Infections in burn patients are still the principal cause of complications in burn injuries. The aim of this study is to assess a new strategy for burn wound management in view of infection prevention and treatment in the experience of the Burn Treatment Center in Siemianowice Śląskie. The applied methodology involved the analysis of patient records describing the hospital's epidemiological situation between 2014 and 2016. The analysis also included the use and cost of antibiotics, silver-containing dressings, and other antiseptics relative to the number of sepsis cases, including those caused by Pseudomonas aeruginosa, as well as the mortality ratio. The total costs of prevention and treatment of infections were reduced, while the use of silver-containing dressings and antiseptics increased. The number of patients with sepsis decreased, including cases caused by P. aeruginosa, and the mortality ratio was reduced. Introducing a strategy for burn wound-oriented infection prevention and treatment in burn patients provides a number of benefits. It is also cost-effective. Using locally applied active dressings and antiseptics can be a welcome choice for often-unnecessary antibiotic therapy of a suspected or existing burn wound infection.

Considering a new domain for antimicrobial stewardship: Topical antibiotics in the open surgical wound

The global push to combat the problem of antimicrobial resistance has led to the development of antimicrobial stewardship programs (ASPs), which were recently mandated by The Joint Commission and the Centers for Medicare and Medicaid Services. However, the use of topical antibiotics in the open surgical wound is often not monitored by these programs nor is it subject to any evidence-based standardization of care. Survey results indicate that the practice of using topical antibiotics intraoperatively, in both irrigation fluids and powders, is widespread. Given the risks inherent in their use and the lack of evidence supporting it, the practice should be monitored as a core part of ASPs, and alternative agents, such as antiseptics, should be considered.