Topical antimicrobial toxicity

Bacterial removal using liposomes and an anionic adsorber

Extracorporeal blood purification techniques using magnetic beads, which physically remove bacteria, fungi, viruses, and cytokines (disease agents) from the blood causing sepsis, have been studied. However, magnetic bead influx, which causes hemolysis and cytotoxicity, is an important issue. This study proposed a novel method for removing Escherichia coli from the blood using liposomes with high biocompatibility. To realize this method, a pegylated cationic liposome conjugated with antibodies (PCLA) that can simultaneously adsorb disease agents with the conjugated liposome antibodies and adhere to electrostatic absorbers was developed. E. coli was successfully adsorbed by PCLA in phosphate-buffered saline and electrostatically removed with a high removal efficiency of the antigen-antibody reaction (approximately 100 %). The removal efficiency of the antigen-antibody reaction in filtered bovine blood was approximately 50 %, demonstrating E. coli removal in the blood using the same method. Results suggested that this method can remove various disease agents from the blood by changing the antibody type.

Effectiveness of a super-oxidized solution for decontaminating ACL grafts: a prospective study

BACKGROUND

Accidental contamination of anterior cruciate ligament (ACL) grafts during surgery is a relatively unexplored issue. This study aims to evaluate bacterial contamination in ACL grafts and the effectiveness of Microdacyn® in reducing contamination. The species of bacteria present on contaminated grafts and their antibiotic susceptibility were also analyzed.

METHODS

A total of 70 patients undergoing ACL reconstruction between 2019 and 2022 were included. Patients with prior knee surgery or immunodeficiency were excluded. Grafts were divided into three groups: (1) control (kept sterile), (2) contaminated (dropped on the operating room floor), and (3) rinsed (dropped and then decontaminated in Microdacyn®). Bacteriological examination and drug sensitivity tests were performed on all grafts. Statistical analysis was conducted using chi-square tests.

RESULTS

Grafts dropped on the floor showed a 74.3% (52 out of 70) contamination rate, with Staphylococcus epidermidis being the most commonly observed bacteria. After decontamination with Microdacyn®, 65.7% (46 out of 70) of the grafts were found sterile. The most sensitive antibiotics were trimethoprim + sulfamethoxazole, aztreonam and ceftazidime (97% effectiveness), while vancomycin, gentamicin, and meropenem were 95-96% effective.

CONCLUSIONS

While Microdacyn® reduced bacterial contamination, a significant portion of grafts remained contaminated, indicating that it is not fully effective. However, the bacteria found on the grafts showed high susceptibility to simple and inexpensive antibiotics, which did not contribute to increased resistance. Further studies exploring alternative decontamination methods are recommended to reduce the risk of complications from graft contamination during ACL reconstruction.

LEVEL OF EVIDENCE

II.

The efficacy and safety of acids as topical antimicrobial agents: a review

OBJECTIVE

Infected wounds, refractory to conventional therapy, are a major burden on the healthcare system. Available data show that many commonly used antiseptic agents may be toxic to the cells involved in the healing process and may affect the normal tissue repair. The topical use of different acids to control wound infections effectively and promote healing is well known. The present review aims to summarise the safety and efficacy of various acids as topical agents for treating wound infections.

METHOD

A literature search was performed in PubMed and manually from other sources (cross references and journal sites).

RESULTS

We reviewed 116 articles, from which data from 86 relevant articles were analysed. The studies showed that various organic acids were clinically effective in treating wound infections.

CONCLUSION

This study found that various organic acids can act as a substitute for antiseptics to control wound infections refractory to conventional antibiotic therapy and local wound care. Various organic acids differ in efficacy, safety and limitations as topical agents to control wound infections and promote healing. Some acids deliver better results than others, particularly in those cases in which antibiotics and routine antiseptic agents yield little lasting success, especially in controlling hospital strains with multiple antibiotic resistance. Among topically used acids, citric acid and acetic acid are associated with better results.

Safety Assessment of Hydrogen Peroxide as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of Hydrogen Peroxide for use in cosmetics. This ingredient is reported to function in cosmetics as an antimicrobial agent, cosmetic biocide, oral health care agent, and oxidizing agent. The Panel reviewed the data relevant to the safety of this ingredient and concluded that Hydrogen Peroxide is safe in cosmetics in the present practices of use and concentration described in this safety assessment.

Efficacy of sucrose and povidone-iodine mixtures in peritoneal dialysis catheter exit-site care

BACKGROUND

Exit-site infection (ESI) is a common recurring complication in patients undergoing peritoneal dialysis (PD). Sucrose and povidone-iodine (SPI) mixtures, antimicrobial ointments that promote wound healing, have been used for the treatment of ulcers and burns, but their efficacy in exit-site care is still unclear.

METHODS

This single-center retrospective observational study included patients who underwent PD between May 2010 and June 2022 and presented with episodes of ESI. Patients were divided into SPI and non-SPI groups and followed up from initial ESI onset until PD cessation, death, transfer to another facility, or June 2023.

RESULTS

Among the 82 patients (mean age 62, [54-72] years), 23 were treated with SPI. The median follow-up duration was 39 months (range, 14-64), with an overall ESI incidence of 0.70 episodes per patient-year. Additionally, 43.1% of second and 25.6% of third ESI were caused by the same pathogen as the first. The log-rank test demonstrated significantly better second and third ESI-free survival in the SPI group than that in the non-SPI group (p < 0.01 and p < 0.01, respectively). In a Cox regression analysis, adjusting for potential confounders, SPI use was a significant predictor of decreased second and third ESI episodes (hazard ratio [HR], 0.22; 95% confidence interval [CI], 0.10-0.52 and HR, 0.22; 95%CI, 0.07-0.73, respectively).

CONCLUSIONS

Our results showed that the use of SPI may be a promising option for preventing the incidence of ESI in patients with PD.

TRIAL REGISTRATION

This study was approved by the Keio University School of Medicine Ethics Committee (approval number 20231078) on August 28, 2023. Retrospectively registered.

Wound care practices following in-office cutaneous surgery among family physicians in Canada

OBJECTIVE

Family physicians (FPs) in Canada routinely perform in-office cutaneous surgery. There is strong evidence to support a moist wound healing environment, resulting in faster healing times and improved cosmesis. However, the wound care practices of FPs have not been previously studied. We aimed to examine the postoperative wound care practices of FPs after in-office cutaneous surgery.

METHOD

An online survey was distributed to Canadian FPs to determine post-surgical wound care practices. The survey examined moist versus dry wound healing and the reasons for these recommendations were explored. Additional wound care practices were also studied. Appropriate statistical analyses were undertaken.

RESULTS

A total of 573 (91.5%) FPs completed the survey. Just under half (49.2%) of FPs recommended moist wound healing to their patients, while the remaining respondents (50.8%) recommended dry wound healing. The most endorsed reason for both moist and dry wound care recommendations was prior training (63.1% and 65.3%, respectively). Most physicians (57.2%) recommended the use of a cream or ointment postoperatively. While there appeared to be consensus on recommending sun avoidance after cutaneous surgery (77.7%), additional wound care practices varied, including: the use of dressings; cleansing practices; smoking cessation; reduction in physical activity; photoprotection; water exposure; and scar treatment/cosmetic use.

CONCLUSION

Almost half of FPs in Canada responding to the survey did not recommend moist wound healing despite strong evidence to support this practice. We also noted a diverse range of postoperative wound care practices after in-office cutaneous surgery. Therefore, these results highlight a critical need for consistent wound care recommendations following cutaneous surgery for FPs in Canada.

Preparation and evaluation of blend polymer films for wound dressing using vancomycin-loaded polycaprolactone and carboxymethyl cellulose via crosslinking methods: Effect of mechanical strength, antibacterial activity, and cytotoxicity

Polycaprolactone (PCL) and carboxymethyl cellulose (CMC) are two materials with beneficial properties for wound healing applications. Here, the simple preparation of PCL/CMC polymer films via the crosslinking method was demonstrated for the first time. The polymer films represented the suitable properties of liquid absorption and tensile strength to be used as a wound dressing. The blend polymer films can also load the vancomycin, which prolongs the drug release for effectiveness against S. aureus. The trifluoroethanol showed less toxicity in comparison with other crosslinking agents. This process can also be applied further in other medical devices and wound healing applications.

Antiseptic, Hemostatic, and Wound Activity of Poly(vinylpyrrolidone)-Iodine Gel with Trimethyl Chitosan

Wound management practices have made significant advancements, yet the search for improved antiseptics persists. In our pursuit of solutions that not only prevent infections but also address broader aspects of wound care, we investigated the impact of integrating trimethyl chitosan (TMC) into a widely used poly(vinylpyrrolidone)-iodine gel (PVP-I gel). Our study assessed the antimicrobial efficacy of the PVP gel with TMC against Escherichia coli, Staphylococcus aureus, multidrug-resistant S. aureus MRSA, and Candida albicans. Additionally, we compared hemostatic effects using a liver puncture bleeding model and evaluated wound healing through histological sections from full-thickness dermal wounds in rats. The results indicate that incorporating TMC into the commercially available PVP-I gel did not compromise its antimicrobial activity. The incorporation of TMC into the PVP-I gel markedly improves its hemostatic activity. The regular application of the PVP-I gel with TMC resulted in an increased blood vessel count in the wound bed and facilitated the development of thicker fibrous tissue with a regenerated epidermal layer. These findings suggest that TMC contributes not only to antimicrobial activity but also to the intricate processes of tissue regeneration. In conclusion, incorporating TMC proves beneficial, making it a valuable additive to commercially available antiseptic agents.

Research methods assessing sodium hypochlorite cytotoxicity: A scoping review

Sodium hypochlorite (NaOCl) cytotoxicity has been assessed using different methodologies, which has led to arbitrary interpretations. This scoping review aimed to discuss the different methodological protocols for assessing NaOCl cytotoxicity. A literature review performed in the PubMed and Embase databases up to July 2023 identified manuscripts reporting NaOCl cytotoxicity. The dataset identified 546 publications, further screened by 2 reviewers. Ninety studies were identified and mined methodologically to collect information on cell type, cytotoxicity assay, NaOCl dilution solutions, presence of fetal bovine serum (FBS), and NaOCl exposure time. The culture medium used in cytotoxicity assays contains buffering substances that neutralize the pH of NaOCl, thus reducing its cytotoxicity, an approach that may lead to bias when solutions with different pH are compared. For short exposure periods, as in simulations to evaluate the contact between irrigant and periapical tissue cells during chemo-mechanical preparation, NaOCl dilution should be performed with saline, which does not buffer the irrigant. For long exposure periods, as in simulations of irrigant extrusions, NaOCl should be diluted in the culture medium, to reproduce the expected buffering effect occurring in extrusions. The presence of FBS in culture medium can decrease NaOCl toxicity. There is no standardization of NaOCl cytotoxicity methodologies. This poses the risk of arriving at incorrect results and, therefore, pertinent tests must be refined.

Amino acid buffered hypochlorite facilitates debridement of porcine infected burn wounds

INTRODUCTION

Removal of necrotic tissue is a vital step in the treatment of full-thickness burn wounds, with surgical debridement being the most effective method. Since minor burn wounds are typically treated on an outpatient basis where surgical capabilities can be limited there is a need for alternative treatment options. In this study we aim to evaluate the use of amino acid buffered hypochlorite (AABH) as a chemical enhancement for wound debridement in a porcine infected burn wound model.

METHOD

A total of 60 full-thickness burn wounds, 3 cm in diameter, were created on four pigs using a standardized burn device. The wounds were inoculated with 107 colony-forming units (CFU) of S. aureus. The experimental groups included wounds debrided with a plastic curette, wounds debrided after pretreatment with AABH, and control wounds wiped with gauze. Wounds were treated twice per week for three weeks. Debridement, healing, and infection parameters were evaluated over time.

RESULTS

After one week, but not after two and three weeks, the curette and AABH groups had higher debrided weights compared to control (p < 0.05). Percentage of wound area adequately cleared from necrotic tissue was higher in the AABH-group compared to the curette-group and control, after one week. The earliest healing was measured in the AABH group after two weeks (5 % of wounds), which also had the most healed wounds after three weeks (55 %). In both the AABH and the curette groups, bacterial load had fallen below 105 CFU/g after two weeks. No CFU were detectable in the AABH group after three weeks. The AABH-group was also the easiest to debride.

CONCLUSION

Our results indicate that AABH facilitates wound debridement and could be a helpful addition to an effective treatment modality for removal of necrotic tissue in full-thickness burns.

Fracture-related infection

Musculoskeletal trauma leading to broken and damaged bones and soft tissues can be a life-threating event. Modern orthopaedic trauma surgery, combined with innovation in medical devices, allows many severe injuries to be rapidly repaired and to eventually heal. Unfortunately, one of the persisting complications is fracture-related infection (FRI). In these cases, pathogenic bacteria enter the wound and divert the host responses from a bone-healing course to an inflammatory and antibacterial course that can prevent the bone from healing. FRI can lead to permanent disability, or long courses of therapy lasting from months to years. In the past 5 years, international consensus on a definition of these infections has focused greater attention on FRI, and new guidelines are available for prevention, diagnosis and treatment. Further improvements in understanding the role of perioperative antibiotic prophylaxis and the optimal treatment approach would be transformative for the field. Basic science and engineering innovations will be required to reduce infection rates, with interventions such as more efficient delivery of antibiotics, new antimicrobials, and optimizing host defences among the most likely to improve the care of patients with FRI.

Using engineered water nanostructures (EWNS) for wound disinfection: Case study of Acinetobacter baumannii inactivation on skin and the inhibition of biofilm formation

Engineered water nanostructures (EWNS) were utilized to deliver a cocktail of nature derived antimicrobials, to assess their efficacy as a solution to the problem of wound infections. The wound related microorganism Acinetobacter baumannii was inoculated on stainless steel and porcine skin and treated with EWNS. EWNS were able to reduce A. baumannii on stainless steel by 4.79 logs in 15 min, and 2 logs in 30 min on porcine skin. The EWNS were able to reduce the strength of A. baumannii biofilm on stainless steel by 87.31% as measured with the XTT assay (P < .001) and 86.27% in cellular counts (P < .001), after two EWNS interventions of 30 min each. Total antimicrobial dose delivered to the surface was 1.42 ng. SEM of biofilms after EWNS treatment showed reduced biomass. These results indicate that the EWNS technology has potential for application in field of wound disinfection and healing.

Teachers: 2021 Upchurch Lecture

ABSTRACT

Examples of influential teachings are drawn from the 6 decades of a single surgeon's education.

Lugol's solution and Gentian violet eradicate methicillin-resistant Staphylococcus aureus biofilm in skin wound infections

The study aimed to evaluate the antibacterial efficacy of Lugol's solution 5% and Gentian violet 1% against methicillin-resistant Staphylococcus aureus (MRSA) biofilm in vivo. The bactericidal efficacy for treatment of MRSA-biofilm skin wound infection was tested in a murine model. Luciferase-tagged S. aureus Xen31, a MRSA-strain derived from S. aureus ATCC-3359130, was used for infection. Wounds were made in the skin of mice and infected with MRSA. The mice were treated with Lugol's solution and Gentian violet. Application of the antimicrobial agents started 24 hours post infection and was repeated daily for five-days. The antimicrobial effect on the biofilm bacteria was evaluated by measuring bioluminescence from MRSA daily for seven-days. Lugol's solution and Gentian violet showed a significant reduction in luminescent signals from the first assessment day to all subsequent days (P < .001). Lugol's solution and Gentian violet effectively eradicated MRSA in biofilm in vivo and could be alternatives or in addition to topical antibiotics when MRSA-biofilm wound infection is suspected.

Comparison Benefit between Hydrogen Peroxide and Adrenaline in Tonsillectomy: A Randomized Controlled Study

This study aimed to further evaluate the benefit of topical hemostasis agents in tonsillectomy. We compared the clinical effects of topical application between hydrogen peroxide and adrenaline in tonsillectomy. Overall, 60 patients (120 tonsils) were prospectively enrolled for tonsillectomy between February 2018 and December 2020. The patients were randomly assigned to either the hydrogen peroxide or adrenaline group. Then, tonsillectomy was performed using hydrogen peroxide as a hemostatic agent on the assigned side, while adrenaline was applied to the other side. All procedures were performed by a surgeon who was blinded to the randomization. The outcome measurements of operation time, intraoperative blood loss, postoperative pain, and hemorrhage events were analyzed. The intraoperative blood loss was significantly lower in the hydrogen peroxide group than in the adrenaline group (9.99 ± 4.51 mL vs. 13.87 ± 6.32 mL; p = 0.0). The median operation time was also significantly lower in the hydrogen peroxide group (8.02 ± 3.59 min vs. 9.22 ± 3.88 min; p = 0.019). Meanwhile, the visual analogue scale (VAS) scores were significantly higher in the hydrogen peroxide group (4.98 ± 1.94 vs. 4.27 ± 1.97; p = 0.001). The topical application of hydrogen peroxide as a hemostatic agent effectively decreases the operation time and intraoperative blood loss. Thus, hydrogen peroxide can be used as a routine hemostatic agent for bleeding control in tonsillectomy.

Acetic Acid Use in Chronic Wound Healing: A Multiple Case Series

BACKGROUND

Acetic acid is bacteriostatic or bactericidal to many gram-negative and gram-positive microorganisms, especially Pseudomonas. Nevertheless, it has also been found to possess cytotoxic effects in concentrations as low as 0.25% inhibiting the epithelialization process during wound healing.

CASES

In this multiple case series, we present 2 cases of chronic traumatic leg wounds treated with gauze moistened with acetic acid (0.25%), which were covered with a securing dressing and compression stockinet. Both patients were told to apply gauze moistened with acetic acid (0.25%) twice daily. In both cases, the wound progressed to blue-green drainage and wet yellow slough tissue to near-complete beefy granulation tissue. At this point, acetic acid was replaced with collagen or petrolatum dressing until complete wound closure was achieved. The treatment of these wounds illustrated successful use of acetic acid for chronic wound care.

CONCLUSION

Our experience with these cases suggests that appearance of blue-green wound drainage and wet yellow slough tissue is a reasonable indication for the use of gauze moistened with acetic acid (0.25%). Further research is needed to test the efficacy of these principles in guiding acetic acid use in wound care.

Prevention and treatment of burn wound infections: the role of topical antimicrobials

INTRODUCTION

Infections related to the skin are the principal drivers of morbidity and mortality following severe burn, therefore a diverse armamentarium of topical antimicrobial agents were developed over the history of burn care. The last 30 years witnessed dramatic changes in the application of surgical intervention and utilization of topical therapies.

AREAS COVERED

We explore well-known topical antimicrobial products used in burn care. First, we investigate how fundamental changes in the practice of burn surgery influenced the choice of topical therapies used. Then, we examine antimicrobial creams and ointments commonly recognized due to their long record of use in burn care. Next, we dive into antimicrobial solutions commonly used as adjuncts to surgical intervention. Finally, we explore representative antimicrobial dressings, an ever-advancing roster of products opening the door to the next era in burn care. We also describe how these new agents relate to already established tools in present-day burn care.

EXPERT OPINION

In the current day, though the wisdom of early excision and wound closure remains valid, we continue to strive to minimize aggressive wound excision and disfiguring donor tissue collection while securing rapid wound closure. To this end, antimicrobial therapies are titrated to optimize operative outcomes and provide non-operative wound care when appropriate. Antimicrobial agents bridge the gap with the next generation of skin substitute and skin replacement therapies.

What Is the Optimal Irrigation Solution in the Management of Periprosthetic Hip and Knee Joint Infections?

BACKGROUND

Thorough irrigation and debridement using an irrigation solution is a well-established treatment for both acute and chronic periprosthetic joint infections (PJIs). In the absence of concrete data, identifying the optimal irrigation agent and protocol remains challenging.

METHODS

A thorough review of the current literature on the various forms of irrigations and their additives was performed to evaluate the efficacy and limitations of each solution as pertaining to pathogen eradication in the treatment of PJI. As there is an overall paucity of high-quality literature comparing irrigation additives to each other and to any control, no meta-analyses could be performed. The literature was therefore summarized in this review article to give readers concise information on current irrigation options and their known risks and benefits.

RESULTS

Antiseptic solutions include povidone-iodine, chlorhexidine gluconate, acetic acid, hydrogen peroxide, sodium hypochlorite, hypochlorous acid, and preformulated commercially available combination solutions. The current literature suggests that intraoperative use of antiseptic irrigants may play a role in treating PJI, but definitive clinical studies comparing antiseptic to no antiseptic irrigation are lacking. Furthermore, no clinical head-to-head comparisons of different antiseptic irrigants have identified an optimal irrigation solution.

CONCLUSION

Further high-quality studies on the optimal irrigation additive and protocol for the management of PJI are warranted to guide future evidence-based decisions.

Role of an acidic environment in the treatment of diabetic foot infections: A review

Management of diabetic foot ulcers is the biggest challenge to the clinician, as conventional antibiotic therapies and local wound care have their own limitations. They are not effective for control of infections and promotion of healing because of cytotoxic effects. In view of cytotoxicity of routinely used topical antiseptic agents, this article focuses on the search of an ideal topical antiseptic agent that is safe and effective in controlling infectious agents and also in promoting the healing process. This review focuses on the use of various acids such as citric, acetic, hyaluronic, and hypochlorous acids as topical agents in diabetic foot infections. This article also focuses on the different roles of acids in the treatment of diabetic foot infections.

Acetic acid and the skin: a review of vinegar in dermatology

Vinegar is commonly used as a home remedy for many skin problems. It is important for dermatologists to understand the evidence supporting its use in skin disease, as well as potential adverse effects, so they can properly counsel patients on the safe use of this widely available treatment. Vinegar possesses antimicrobial and antioxidant properties that provide utility in wound care as well as bacterial and fungal infections. There is also evidence to support its use in pruritus, head lice removal, and treatment of striae gravidarum. While generally safe, inappropriate use can result in damage to the skin. In this review, we discuss the evidence supporting vinegar as a treatment for skin disease, as well as adverse events reported from misuse, to provide dermatologists the knowledge to counsel patients on the safe and appropriate use of vinegar.

Pursuit of the ideal antiseptic irrigation solution in the management of periprosthetic joint infections

Irrigation and debridement in the treatment of periprosthetic joint infection (PJI) serve an integral role in the eradication of bacterial burden and subsequent re-infection rates. Identifying the optimal irrigation agent, however, remains challenging, as there is limited data on superiority. Direct comparison of different irrigation solutions remains difficult because of variability in treatment protocols. While basic science studies assist in the selection of irrigation fluids, in vitro results do not directly translate into clinical significance once implemented in vivo. Dilute povidone iodine, hydrogen peroxide, chlorhexidine gluconate, acetic acid, sodium hypochlorite, hypochlorous acid, and preformed combination solutions all have potential against a broad spectrum of PJI pathogens with their own unique advantages and disadvantages. Future clinical studies are needed to identify ideal irrigation solutions with optimal bactericidal properties and low cytotoxicity for PJI treatment.

Role of hydrogen peroxide in intra-operative wound preparation based on an in vitro fibrin clot degradation model

Three per cent hydrogen peroxide (H₂O₂) is widely used to irrigate acute and chronic wounds in the surgical setting and clinical experience tells us that it is more effective at removing dried-on blood than normal saline alone. We hypothesise that this is due to the effect of H₂O₂ on fibrin clot architecture via fibrinolysis. We investigate the mechanisms and discuss the clinical implications using an in vitro model. Coagulation assays with normal saline (NaCl), 1% and 3% concentrations of H₂O₂ were performed to determine the effect on fibrin clot formation. These effects were confirmed by spectrophotometry. The effects of 1%, 3% and 10% H₂O₂ on the macroscopic and microscopic features of fibrin clots were assessed at set time intervals and compared to a NaCl control. Quantitative analysis of fibrin networks was undertaken to determine the fibre length, diameter, branch point density and pore size. Fibrin clots immersed in 1%, 3% and 10% H₂O₂ demonstrated volume losses of 0.09-0.25mm³/min, whereas those immersed in the normal saline gained in volume by 0.02±0.13 mm³/min. Quantitative analysis showed that H₂O₂ affects the structure of the fibrin clot in a concentration-dependent manner, with the increase in fibre length, diameter and consequently pore sizes. Our results support our hypothesis that the efficacy of H₂O₂ in cleaning blood from wounds is enhanced by its effects on fibrin clot architecture in a concentration- and time-dependent manner. The observed changes in fibre size and branch point density suggest that H₂O₂ is acting on the quaternary structure of the fibrin clot, most likely via its effect on cross-linking of the fibrin monomers and may therefore be of benefit for the removal of other fibrin-dependent structures such as wound slough.

Cytotoxic effect of sodium hypochlorite (Lavanox 0.08%) and chlorhexidine gluconate (Irrisept 0.05%) on human osteoblasts

Purpose

Soft tissue, bone and joint infections are severe complications in orthopedic and traumatological surgery. Lavanox (0.08% NaOCl) and Irrisept (0.05% chlorhexidine gluconate, CHG) are industrially produced antiseptic solutions commonly used in infection treatment. Regarding this clinical indication, the microbicidal effect is often investigated, but toxicity to osteoblasts has rarely been examined. This is important to decide whether these solutions should be used in septic situations in which bone healing must take place. The hypothesis of the present study is that NaOCl and CHG are cytotoxic to osteoblasts even after a short exposure time.

Methods

Human osteoblasts were isolated from donors with osteoarthritis during total knee and hip arthroplasty. Cells were cultivated and treated with both antiseptic solutions for 2, 5 and 10 min in different dilutions. Toxicity was quantified by counting cells, lactate dehydrogenase (LDH) expression, spectrophotometric quantification via XTT assay and FDA/PI fluorescence microscopy.

Results

Analyzing viable cells after treatment with both antiseptics showed a significant decrease in viable cells through LDH expression test, XTT assay, fluorescence microscopy and light microscopy, depending on concentration. The time dependence showed a trend to more cell death at longer exposure times, without significance.

Conclusion

Toxic effects on osteoblasts were shown after treatment with 0.08% NaOCl and 0.05% CHG after an exposure time of 2 min which also was concentration dependent. There was no difference in cytotoxicity between both antiseptics. In conclusion, these antiseptic solutions may be used with caution in situations requiring bone healing.

Trial registration number

Local ethics committee registration number: 5176–07/16

Supplementary Information

The online version contains supplementary material available at 10.1007/s00590-021-02907-3.

Antimicrobial stewardship of antiseptics that are pertinent to wounds: the need for a united approach

Long before the nature of infection was recognized, or the significance of biofilms in delayed healing was understood, antimicrobial agents were being used in wound care. In the last 70 years, antibiotics have provided an effective means to control wound infection, but the continued emergence of antibiotic-resistant strains and the documented antibiotic tolerance of biofilms has reduced their effectiveness. A range of wound dressings containing an antimicrobial (antibiotic or non-antibiotic compound) has been developed. Whereas standardized methods for determining the efficacy of non-antibiotic antimicrobials in bacterial suspension tests were developed in the early twentieth century, standardized ways of evaluating the efficacy of antimicrobial dressings against microbial suspensions and biofilms are not available. Resistance to non-antibiotic antimicrobials and cross-resistance with antibiotics has been reported, but consensus on breakpoints is absent and surveillance is impossible. Antimicrobial stewardship is therefore in jeopardy. This review highlights these difficulties and in particular the efficacy of current non-antibiotic antimicrobials used in dressings, their efficacy, and the challenges of translating in vitro efficacy data to the efficacy of dressings in patients. This review calls for a unified approach to developing standardized methods of evaluating antimicrobial dressings that will provide an improved basis for practitioners to make informed choices in wound care.

Antibiofilm and antipersister activity of acetic acid against extensively drug resistant Pseudomonas aeruginosa PAW1

Pseudomonas aeruginosa is an ESKAPE pathogen associated with difficult-to-treat burn wound and surgical-site infections. This study aimed to characterise an extensively drug resistant (XDR) P. aeruginosa isolate (designated PAW1) and to investigate the antibiofilm and antipersister effect of acetic acid on PAW1. PAW1 was identified using biotypic (VITEK) and genotypic (16S rDNA) analysis. Minimum inhibitory concentration (MIC) and disc susceptibility testing showed high level resistance against all antibiotics from classes including beta lactams, cephems, carbapenems and fluoroquinolones. It was therefore identified as extensively drug resistant (XDR), showing resistance to all antibiotics except for, aminoglycoside (gentamicin and netilmicin) and lipopeptides (polymyxin B). Time kill assays showed antibiotic tolerant, persister cell formation in presence of 100X MICs of gentamicin and polymyxin B. Other virulence traits such as ability to produce lipase, protease, haemolysin, and siderophores and to form biofilms were additional factors which may contribute to its pathogenicity. PAW1 showed promising susceptibility against acetic acid with MIC and minimum biofilm inhibitory concentration of 0.156% (v/v). Percent viability of PAW1 was dependent on dose and treatment time of acetic acid. 0.625% acetic acid treatment of 5 minutes was effective in killing >90% planktonic cells showing lesser toxicity to L929 cells (IC₅₀ = 0.625%). Biofilm disruption caused due to acetic acid was also dose dependent, showing 40.57% disruption after treatment with 0.625% acetic acid for 5 minutes. FESEM imaging and live dead staining of planktonic and biofilm forms of PAW1 confirmed that acetic acid treatment caused 19.04% of cell shrinkage and disruption of extracellular matrix resulting in killing of cells. Antipersister activity of acetic acid was demonstrated by showing complete killing of PAW1 at 4X MIC. Overall, this study characterised an XDR isolate P. aeruginosa showing resistance and tolerance to various antibiotics. Antipersister and antibiofilm effect of acetic acid demonstrates the importance of forgotten topical agents as an effective strategy to treat XDR pathogens.

Bacteria and Antibiotics in Wound Healing

This review of the literature concerning bacteria, antibiotics and tissue repair shows there are extensive data supporting microbial interference with wound healing once bacterial burden exceeds 104 CFU per unit of measure, The mechanism of bacterial interference lies largely in prolonging the inflammatory phase of tissue repair. Reducing the microbial bioburden allows tissue repair to continue. Systemic and topical antimicrobials appear critical to reducing the bioburden and facilitating repair. The current controversy over the use of antimicrobials in patients with chronically infected wounds, in particular, revolves around the definition of infection. The reliance on classic clinical signs of inflammation to support antimicrobial use in these patients is tenuous due to the lack of correlation of these signs with the microbial burden known to impair tissue repair.

Skin cleansing and topical product use in patients with epidermolysis bullosa: Results from a multicenter database

BACKGROUND/OBJECTIVES

Epidermolysis bullosa (EB) comprises a group of inherited skin blistering diseases. There is currently no cure, and management includes skin protection and prevention of infection. To date, there has been no systematic investigation of home skin care practices among EB patients on a multicenter scale.

METHODS

This cross-sectional, observational study included data collected from patients with EB enrolled in the Epidermolysis Bullosa Characterization and Clinical Outcomes Database (EBCCOD) who provided answers to a patient-directed questionnaire between January 1, 2017, and December 31, 2017.

RESULTS

Of 202 respondents, 130 (64.4%) had dystrophic EB, 51 (25.2%) had EB simplex, 21 (7.4%) had junctional EB, 3 (1.5%) had Kindler syndrome, and 3 (1.5%) had an unspecified subtype. Seventy-eight patients reported cleansing in plain water only (39%). Of those who used an additive in their cleansing water, 75 (57%) added salt, 71 (54%) added bleach, 36 (27%) added vinegar, and 34 (26%) endorsed the use of an "other" additive (multiple additives possible). Reported concentrations of additives ranged widely from 0.002% sodium hypochlorite and 0.002% acetic acid solutions, which are thought to have negligible effects on microbes, to 0.09% sodium hypochlorite and 0.156% acetic acid, concentrations shown to be cytotoxic. One hundred eighty-eight patients answered questions regarding topical product use (93%). Of those, 131 reported topical antimicrobial use (70%). Mupirocin and bacitracin were the most commonly reported topical antibiotics (59, 58 [31.4%, 30.9%], respectively).

CONCLUSIONS

These findings highlight the variety of skin care routines and frequent use of topical antimicrobials among EB patients and have potential implications for antibiotic resistance. The reported range of bleach and vinegar additives to cleansing water, including cytotoxic concentrations, emphasizes the need for clear and optimized skin cleansing recommendations.

Use of Cleansing Agents at the Peritoneal Catheter Exit Site

Heavy bacterial colonization results in exit-site infection. Antiseptic and non antiseptic agents have both been used for exit-site cleansing. An ideal cleansing agent should not only reduce the number of microorganisms, but should also be harmless to the body's defenses and should not interfere with wound healing. In vitro studies using animal cells have demonstrated that some antiseptic agents have adverse effects on wound healing. Strong cytotoxic antiseptics should be discouraged in exit-site cleansing.

In choosing an appropriate cleansing agent for exit-site care, the phase of wound healing, the condition of the exit site, and the goal of cleansing should be taken into consideration. Antimicrobial soap is recommended for cleansing a healed exit site, but biocompatible solution is preferred for the postoperative, infected, or traumatized exit site. In vivo studies on the effectiveness of some cleansing agents are still lacking, and clinical study of exit-site cleansing is needed to determine the most effective agents for the task.

Peritoneal Catheters and Exit-Site Practices toward Optimum Peritoneal Access: 1998 Update

The peritoneal catheter is the PD patient's lifeline. Advances in catheter knowledge have made it possible to obtain access to the peritoneal cavity safely and to maintain access over an extended period of time. Catheter-related infections remain a major problem, solutions for which are being actively researched. Nevertheless, the successful outcome of a catheter is very much dependent on meticulous care and attention to detail. Adherence to the principles of catheter insertion and subsequent management and care remain the cornerstone of successful PD access. The guidelines provided in this publication represent a consensus view based on studies from the literature and opinions of experts in this field; it is hoped that implementation of these guidelines will improve catheter-related outcomes and, therefore, enhance patient care.

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.

Acetic acid dressings: Finding the Holy Grail for infected wound management

Background

Wounds have since long, contributed majorly to the health-care burden. Infected long-standing non-healing wounds place many demands on the treating surgeon and are devastating for the patients physically, nutritionally, vocationally, financially, psychologically and socially. Acetic acid has long been included among agents used in the treatment of infected wounds. In this study, we have evaluated the use of acetic acid for topical application in the treatment of infected wounds.

Materials and Methods

A total of 100 patients with infected wounds were treated with topical application of 1% acetic acid as dressing material after appropriate cleaning. A specimen of wound swab was collected before first application and further on days 3, 7, 10 and 14. Daily dressings of wounds were done similarly. Minimum inhibitory concentration (MIC) of acetic acid against various organisms isolated was determined.

Results

The patients treated ranged between 9 and 60 years, with the mean age 33 years. Nearly 70% of patients were male. Aetiologies of wounds: infective 35, diabetic 25, trauma 20, burns 10, venous ulcers 5 and infected graft donor site 5. Various microorganisms isolated include Pseudomonas aeruginosa (40%), Staphylococcus aureus (2%), Acinetobacter (12%), Escherichia Coli (5%), Proteus mirabilis (3%), Klebsiella (18%), methicillin-resistant S. aureus (10%), Streptococcus (2%) and Enterococcus (1%), Citrobacter (1%). Few wounds (6%) also isolated fungi. About 28%, 64% and 8% of patients isolated no growth on culture after 7, 14 and 21 days, respectively. MIC of all isolated organisms was ≤0.5%.

Conclusion

pH of the wound environment plays a pivotal role in wound healing. Acetic acid with concentration of 1% has shown to be efficacious against wide range of bacteria as well as fungi, simultaneously accelerating wound healing. Acetic acid is non-toxic, inexpensive, easily available and efficient topical agent for effective elimination of wound infections caused due to multi-drug resistant, large variety of bacteria and fungus.

Hydrogen peroxide and cutaneous biology: Translational applications, benefits, and risks

Hydrogen peroxide (H₂O₂) is an endogenous reactive oxygen species that contributes to oxidative stress directly as a molecular oxidant and indirectly through free radical generation. Topically applied 1% to 45% H₂O₂ can be used for a range of clinical purposes, which will be reviewed here in addition to its safety. In concentrations from 1% to 6%, H₂O₂ has antimicrobial properties and can act as a debriding agent through its effervescence, making low-concentration H₂O₂ useful for wound care. H₂O₂ has also been shown to promote venous insufficiency ulcer healing, but studies in other wound types are needed. In 1% formulations, H₂O₂ is used outside the United States to treat acne and has shown efficacy similar to or greater than benzoyl peroxide, with reduced side effects. In a concentration of 40%, H₂O₂ is US Food and Drug Administration-approved to treat seborrheic keratoses and may cause fewer pigmentary changes than cryotherapy, although elimination often requires 2 to 4 treatments. However, H₂O₂ should be used with caution, as exposure can cause adverse effects through its oxidant capabilities. Low H₂O₂ concentrations cause only transient symptoms (blanching and blistering), but exposure to 9% to 45% H₂O₂ can cause more severe skin damage, including epidermal necrosis leading to erythema and bullae. Overall, H₂O₂ has numerous therapeutic uses, and novel indications, such as treating actinic keratoses and skin cancers, continue to be explored.

Dakin's Solution: "One of the most important and far-reaching contributions to the armamentarium of the surgeons"

Henry Drysdale Dakin is a notable person in the history of surgery, wound care, military medicine and infectious disease control. Dakin is an exemplar scientist who in the midst of war forged an international collaboration with scientists in multiple fields to create and universalize an antiseptic utopia, which saved thousands lives during World War I, remarkably diminished functional disabilities from wounds and continues to be a "far-reaching armamentarium" of the surgeons and wound care specialists around the globe. Dakin investigated over 200 different antiseptic substances to finally conclude that a 0.5% buffered sodium hypochlorite solution satisfies his criteria for an ideal antiseptic. The only potential limitation was that the germicidal property of the solution was short lived, which meant the solution had to be used continuously or repeatedly delivered into wounds. Dakin's solution, still in use by modern wound care specialists around the globe, has laid the foundation for wound care management as we know it today. Nevertheless, Dakin contributed more to science than just his solution. In this article, Dakin's life story, his unique scientific career and his contributions to surgical literature are explored. The article also illustrates how a wartime necessity resulted in a medical discovery that is still in use to date.

Topical adjuvants incompletely remove adherent Staphylococcus aureus from implant materials

Adjuvant treatments including Betadine, Dakin's solution (sodium hypochlorite), or hydrogen peroxide (H₂ O₂ ) have been attempted to eradicate prosthetic joint infection caused by biofilm or intracellular bacteria. The purpose of this study was to evaluate the in vitro abilities of chemical adjuvants to decrease Staphylococcus aureus (S. aureus) biofilm presence on orthopaedic implant grade materials, including titanium, stainless steel, and cobalt chrome. S. aureus biofilms were grown for 48 h and evaluated for baseline colony forming units/centimeter squared (CFU/cm² ) and compared to treatments with Betadine, Dakin's solution, H₂ O₂ , or 1% chlorine dioxide (ClO₂ ). Control discs (n = 18) across all metals had an average of 4.2 × 10⁷ CFU/cm² . All treatments had statistically significant reductions in CFU/cm² when compared to respective control discs (p < 0.05). For all metals combined, the most efficacious treatments were Betadine and H₂ O₂ , with an average 98% and 97% CFU/cm² reduction, respectively. There were no significant differences between reductions seen with Betadine and H₂ O₂ , but both groups had statistically greater reductions than Dakin's solution and ClO₂ . There was no change in antibiotic resistance patterns after treatment. Analysis of S. aureus biofilms demonstrated a statistically significant reduction in biofilm after a five-minute treatment with the modalities, with an average two log reduction in CFU/cm² . Statement of clinical significance: While statistically significant reductions in CFU/cm² were accomplished with chemical adjuvant treatments, the overall concentration of bacteria never fell below 10⁵ CFU/cm² , leading to questionable clinical significance. Further techniques to eradicate biofilm should be investigated. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1599-1604, 2018.

Antimicrobial peptide delivery: an emerging therapeutic for the treatment of burn and wounds

The management of wounds and burns is becoming difficult using conventional therapeutics available due to resistance development by microbes. Therefore, there is an utmost need to develop therapeutic alternatives to these agents. Antimicrobial peptides have emerged as a novel class of agents for the effective management of wounds and burns due to their potent nature along with minimal chances of resistance development against them. This article focuses on highlighting the importance of these antimicrobial peptides among the various therapeutic alternatives for burns and wounds. Further, effective delivery strategies for these agents that are being employed and investigated are reported along with an overview of the importance of these agents in the coming years.

In vitro comparative cytotoxicity study of a novel biocidal iodo-thiocyanate complex

Novel biocides, which avoid the induction of cross-resistance to antibiotics, are an urgent societal requirement. Here, we compared the cytotoxic and bactericidal effects of a new antimicrobial agent, the iodo-thiocyanate complex (ITC), with those of the common antiseptics, hydrogen peroxide (H₂O₂), povidone iodine (PVP-I) and Lugol's iodine (Lugol). The antimicrobials were co-incubated for 10 min with HeLa and Escherichia coli cells in the presence and absence of organic matter (Dulbecco's modified Eagle's medium, supplemented with 10% fetal bovine serum). The cytotoxic concentrations of ITC were equivalent to its bactericidal concentrations (7.8 μg ml^-1). By contrast, cytotoxic effects of H₂O₂, PVP-I and Lugol were apparent at concentrations lower than their bactericidal concentrations (250, 250 and 125 μg ml^-1, respectively). The cellular effects of ITC were not quenched by organic matter, unlike the other antiseptics. ITC, PVP-I and Lugol had hemolytic effect on horse erythrocytes at high concentrations, while H₂O₂ showed no hemolysis. ITC, at 30 or 300 μg ml^-1, did not cause DNA breakage in HeLa cells as assessed by an in vitro comet assay in the absence of S9 metabolic activation, whereas H₂O₂ caused extensive single-strand DNA breaks. The pronounced antimicrobial potency of ITC and its favorable cytotoxicity profile suggests that ITC should be considered for antiseptic applications.

Surgical Site Irrigation in Plastic Surgery

BACKGROUND

The incidence of infection following breast implant reconstruction remains high at the level of 24%. Surgical site irrigation is commonly used for its prevention. However, the lack of evidence-based guidelines for antibiotic prophylaxis in breast implant surgery necessitates research for optimal irrigation technique.

OBJECTIVES

composition and exposure time of irrigation solution for surgical site infection (SSI) prophylaxis using an in vitro model of a surgical site.

METHODS

The study design was an in vitro model to assess antibiotic irrigation of a surgical site. Strains of Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Group A Streptococcus, and Pseudomonas aeruginosa were seeded on blood agar growth medium and irrigated with various antibiotic and antiseptic solutions under different exposure times. The presence and quantity of the colonies grown were estimated after 24-hour incubation. Repetition of the studies for 5 times with each investigated irrigation solution and microorganism was performed. Optimal irrigation agents were chosen based on the ability to achieve sterility with minimal tissue toxicity.

RESULTS

The optimal wound irrigation agents for SSI prophylaxis in our study were found to be 0.05% chlorhexidine or triple antibiotic antibiotic solutions. Adding of vancomycin to the irrigation solutions did not show an increase in their effectiveness. Prolonged irrigation exposure time was necessary to achieve sterility of the in vitro model of a surgical site.

CONCLUSIONS

We recommend 0.05% chlorhexidine or triple antibiotic solution for topical SSI prophylaxis in breast implant surgery. Sufficient time of irrigation can be achieved by maintaining some of the solution in the pocket and delaying drainage for at least 30 minutes.

LEVEL OF EVIDENCE 5

Consensus on Wound Antisepsis: Update 2018

Wound antisepsis has undergone a renaissance due to the introduction of highly effective wound-compatible antimicrobial agents and the spread of multidrug-resistant organisms (MDROs). However, a strict indication must be set for the application of these agents. An infected or critically colonized wound must be treated antiseptically. In addition, systemic antibiotic therapy is required in case the infection spreads. If applied preventively, the Wounds-at-Risk Score allows an assessment of the risk for infection and thus appropriateness of the indication. The content of this updated consensus recommendation still largely consists of discussing properties of octenidine dihydrochloride (OCT), polihexanide, and iodophores. The evaluations of hypochlorite, taurolidine, and silver ions have been updated. For critically colonized and infected chronic wounds as well as for burns, polihexanide is classified as the active agent of choice. The combination 0.1% OCT/phenoxyethanol (PE) solution is suitable for acute, contaminated, and traumatic wounds, including MRSA-colonized wounds due to its deep action. For chronic wounds, preparations with 0.05% OCT are preferable. For bite, stab/puncture, and gunshot wounds, polyvinylpyrrolidone (PVP)-iodine is the first choice, while polihexanide and hypochlorite are superior to PVP-iodine for the treatment of contaminated acute and chronic wounds. For the decolonization of wounds colonized or infected with MDROs, the combination of OCT/PE is preferred. For peritoneal rinsing or rinsing of other cavities with a lack of drainage potential as well as the risk of central nervous system exposure, hypochlorite is the superior active agent. Silver-sulfadiazine is classified as dispensable, while dyes, organic mercury compounds, and hydrogen peroxide alone are classified as obsolete. As promising prospects, acetic acid, the combination of negative pressure wound therapy with the instillation of antiseptics (NPWTi), and cold atmospheric plasma are also subjects of this assessment.

Lugol's solution eradicates Staphylococcus aureus biofilm in vitro

OBJECTIVES

The aim of the study was to evaluate the antibacterial efficacy of Lugol's solution, acetic acid, and boric acid against Staphylococcus aureus biofilm.

METHODS

The efficacy of Lugol's solution 1%, 0.1%, and 0.05%, acetic acid 5% or boric acid 4.7% for treatment of Staphylococcus aureus biofilm in vitro was tested using 30 clinical strains. Susceptibility in the planktonic state was assessed by disk diffusion test. Antiseptic effect on bacteria in biofilm was evaluated by using a Biofilm-oriented antiseptic test (BOAT) based on metabolic activity, a biofilm bactericidal test based on culturing of surviving bacteria and confocal laser scanning microscopy combined with LIVE/DEAD staining.

RESULTS

In the planktonic state, all tested S. aureus strains were susceptible to Lugol's solution and acetic acid, while 27 out of 30 tested strains were susceptible to boric acid. In biofilm the metabolic activity was significantly reduced following exposure to Lugol's solution and 5% acetic acid, while boric acid exposure led to no significant changes in metabolic activities. In biofilm, biocidal activity was observed for Lugol's solution 1% (30/30), 0.1% (30/30), and 0.05% (26/30). Acetic acid and boric acid showed no bactericidal activity in this test. Confocal laser scanning microscopy, assessed in 4/30 strains, revealed significantly fewer viable biofilm bacteria with Lugol's solution (1% p < 0.001, 0.1% p = 0.001 or 0.05% p = 0.001), acetic acid 5% for 10 min (p = 0.001) or 30 min (p = 0.015), but not for acetic acid for 1 min or boric acid.

CONCLUSION

Lugol's solution 1.0% and 0.1% effectively eradicated S. aureus in biofilm and could be an alternative to conventional topical antibiotics where S. aureus biofilm is suspected such as external otitis, pharyngitis and wounds.

History and Advancement of Burn Treatments

Advances in burn care have accelerated within the last 50 years. The principal modalities of and approaches to burn treatment include dressings, antimicrobials, fluid resuscitation, burn wound excision, skin grafting, and use of skin substitutes. This review presents a historical outline of these approaches, their current status, and prospects for the future of burn care.