Topical antibacterial agents for wound care: a primer

Topical Antibacterials in Dermatology

Topical antibacterials are commonly used for superficial pyodermas such as impetigo and treatment or prevention of infections following minor cuts, abrasions, burns, and surgical wounds. Several antibiotics and antiseptics are available for use in different indications. One of the major uses of topical antibacterials is acne in which benzoyl peroxide is the drug of the first choice either singly or in combination with antibiotics or retinoids. Mupirocin and fusidic acid are the two most commonly used antibiotics for the treatment of superficial pyodermas and eradication of staphylococcal carrier state. Bacterial resistance to topical antibiotics is a growing concern and topical antiseptics such as gentian violet are getting renewed interest as alternatives. Incidence of contact dermatitis is a limiting factor for the use of several topical antibacterials. Although many botanical products have demonstrated in vitro activities against skin pathogens, their clinical utilities remain to be established by good-quality clinical trials.

Polyvinyl Alcohol/Chitosan/Polyhexamethylene Biguanide Phase Separation System: A Potential Topical Antibacterial Formulation with Enhanced Antimicrobial Effect

An aqueous polyvinyl alcohol (PVA)/chitosan (CHT)/polyhexamethylene biguanide (PHMB) blends (PVA/CHT/PHMB blends) has been developed as a potential low dose topical antibacterial formulation with enhanced antimicrobial effect. The preparation of PVA/CHT/PHMB blends was quite facilely, with just dissolved PVA, CHT, PHMB in water in order. There was the aggregates with 100 nm size around induced by phase separation in the blends and an aqueous two-phase system (ATPS) formed, as non-ionic polymer PVA formed a continuous phase and cationic polymer CHT and PHMB formed dispersed phases. The minimum inhibitory concentration (MIC) of PHMB in the PVA/CHT/PHMB blends was 0.5μg/mL, which was four times lower than the MIC of PHMB individually. A phase separation increased zeta potential mechanism was proposed to explain the enhanced antibacterial activities. In addition, the blends could easily form film on the skin surface with good water vapor permeability and be used as a liquid bandage to accelerate the scratch wound healing process of nude mouse. These findings provide experimental evidence that the PHMB-functionalized blends could be further explored as low-dose topical antibacterial formulations, and the nano-sized phase separation strategy could be used to design novel low-dose topical antibacterial formulations with an enhanced antimicrobial effect.

Does antibiotic use accelerate or retard cutaneous repair? A systematic review in animal models

BACKGROUND

The presence of infections is one of the main factors that leads to delays in healing or non-closure of cutaneous wounds. Although the goal of antibiotic use is to treat or prevent infection, there is currently no agreement on the effectiveness of these products.

AIM

The aim of this study was to evaluate the efficacy of antibiotic use during the healing process of skin wounds in animal models not intentionally infected, as well as to analyze the advances and limitations of the studies carried out in this field.

MAIN METHODS

This systematic review was performed according to the PRISMA guidelines, using a structured search on the MedLine (PubMed) and Scopus platforms to retrieve studies published until August 29, 2018, 13:35p.m. The studies included were limited to those that used excision or incision wound models and that were not intentionally infected. The data for the animal models, antibiotic used, and the main results of the studies were extracted, and compared where possible. Bias analysis and methodological quality assessments were examined through the SYRCLE's Risk of Bias tool.

KEY FINDINGS

Twenty-seven studies were selected. Overall, the effects of the antibiotic on the wound decreased inflammatory cell infiltration and promoted an increased number of fibroblasts, extracellular matrix constituents, re-epithelialization and tissue strength. A great deal of important information about the methodology was not presented, such as: the statistical analysis used, the animal model (sex and age), antibiotic dosage, blinding and randomization of the animals chosen.

SIGNIFICANCE

Based on the results found, we believe that antibiotic therapy can be considered a viable alternative for the treatment of cutaneous wounds. However, current evidence obtained from the methodological quality analysis points towards a high risk of bias. This is due to the incomplete characterization of the experimental design and treatment protocol, which compromises the reproducibility of the studies.

Radiodermatitis - review of treatment options

Radiation dermatitis is one of the commonest side effects of ionizing radiation which is applied in radiotherapy of carcinoma of all localizations, most frequently of tumors of breast, head and neck region, lungs and soft tissue sarcomas. It usually occurs as a complication of breast radiotherapy and thus it is more often recorded in female patients on the skin in the region of breast subjected to radiation. Clinical manifestations of radiation dermatitis can be divided into four phases: acute phase (erythema, dry desquamation, moist desquamation, ulceration and necrosis with resulting re-epithelialization, residual post-inflammatory hyperpigmentation, reduction and suppression of sebaceous and sweat glands and epilation); subacute phase (hyperpigmentation and hypopigmentation, telangiectasia, skin atrophy, even ulceration); chronic phase (skin atrophy, dermal fibrosis and permanent skin epilation) and late phase (increased risk of skin cancer). In order to prevent radiation dermatitis, skin care products should be applied throughout radiotherapy that will decrease the frequency of skin reactions or block them and thus improve life quality. Although the therapy includes not only topical corticosteroids but numerous other products with active ingredients such as aloe vera, calendula, hyaluronic acid, sucralfat, sorbolene, mineral and olive oil, honey, vitamin C, zinc, antimicrobials and silver, common therapeutic consensus has not been reached on their application in radiation dermatitis. Therefore, the treatment should be conducted according to the basic guidelines but tailor-made for each individual patient.

Colistin Induces S. aureus Susceptibility to Bacitracin

Bacitracin has been used in topical preparations with polymyxin B for bacterial infections. Colistin belongs to the polymyxin group of antibiotics and is effective against most Gram-negative bacilli. This study investigated whether colistin could affect the susceptibility of S. aureus to bacitracin. S. aureus isolates were first incubated with colistin and the susceptibility of S. aureus to bacitracin was increased. The effect of the combination of colistin and bacitracin on S. aureus was then confirmed by the checkerboard assay and the time-kill kinetics. The Triton X-100-induced autolysis was significantly increased after S. aureus was exposed to colistin. Exposure to colistin also led to a less positive charge on the cell surface and a significant leakage of Na+, Mg2, K+, Ca2+, Mn2+, Cu2+, and Zn2+. Finally, disruptions on the cell surface and an irregular morphology were observed when the bacteria were exposed to colistin and bacitracin. Bacitracin had a stronger antibacterial activity against S. aureus in the presence of colistin. This could be due to the fact that colistin damaged the bacterial membrane. This study suggests that combination of colistin with bacitracin has a potential for treating clinical S. aureus infections.

Topical Antimicrobial Treatments Can Elicit Shifts to Resident Skin Bacterial Communities and Reduce Colonization by Staphylococcus aureus Competitors

The skin microbiome is a complex ecosystem with important implications for cutaneous health and disease. Topical antibiotics and antiseptics are often employed to preserve the balance of this population and inhibit colonization by more pathogenic bacteria. However, despite their widespread use, the impact of these interventions on broader microbial communities remains poorly understood. Here, we report the longitudinal effects of topical antibiotics and antiseptics on skin bacterial communities and their role in Staphylococcus aureus colonization resistance. In response to antibiotics, cutaneous populations exhibited an immediate shift in bacterial residents, an effect that persisted for multiple days posttreatment. By contrast, antiseptics elicited only minor changes to skin bacterial populations, with few changes to the underlying microbiota. While variable in scope, both antibiotics and antiseptics were found to decrease colonization by commensal Staphylococcus spp. by sequencing- and culture-based methods, an effect which was highly dependent on baseline levels of Staphylococcus Because Staphylococcus residents have been shown to compete with the skin pathogen S. aureus, we also tested whether treatment could influence S. aureus levels at the skin surface. We found that treated mice were more susceptible to exogenous association with S. aureus and that precolonization with the same Staphylococcus residents that were previously disrupted by treatment reduced S. aureus levels by over 100-fold. In all, the results of this study indicate that antimicrobial drugs can alter skin bacterial residents and that these alterations can have critical implications for cutaneous host defense.

Resveratrol antibacterial activity against Escherichia coli is mediated by Z-ring formation inhibition via suppression of FtsZ expression

Resveratrol exhibits a potent antimicrobial activity. However, the mechanism underlying its antibacterial activity has not been shown. In this study, the antibacterial mechanism of resveratrol was investigated. To investigate induction of the SOS response, a strain containing the lacZ⁺gene under the control of an SOS-inducible sulA promoter was constructed. DNA damage was measured by pulse-field gel electrophoresis (PFGE). After resveratrol treatment, the cells were observed by confocal microscopy. For the RNA silencing assay, ftsZ-specific antisense peptide nucleic acid (PNA) was used. Reactive oxygen species (ROS) production increased in Escherichia coli after resveratrol treatment; however, cell growth was not recovered by ROS quenching, indicating that, in this experiment, ROS formation and cell death following resveratrol treatment were not directly correlated. Resveratrol treatment increased DNA fragmentation in cells, while SOS response-related gene expression levels increased in a dose-dependent manner. Cell elongation was observed after resveratrol treatment. Elongation was induced by inhibiting FtsZ, an essential cell-division protein in prokaryotes, and resulted in significant inhibition of Z-ring the formation in E. coli. The expression of ftsZ mRNA was suppressed by resveratrol. Our results indicate that resveratrol inhibits bacterial cell growth by suppressing FtsZ expression and Z-ring formation.

Role of topical antibiotic prophylaxis in prevention of bacterial translocation into upper trachea in nasally intubated patients undergoing tonsillectomies

INTRODUCTION

The human oropharynx and nasopharynx are home of different bacteria and fungi. The initial sterile endotracheal tube (ETT) transfers mechanically the bacteria from the nasopharynx and oropharynx to the sterile tracheobronchial tree. We investigated the efficacy of Neomycin-Bacitracin combination spray in the prevention of this bacterial translocation through its application over and inside the lumen of the endotracheal tubes preoperatively.

PATIENTS AND METHODS

Ninety patients aged (from 8 to 15 years) with ASA I and II were randomly assigned into 2 groups (45 patients for each): Group I; patients with naso-tracheal intubation which sprayed by placebo spray (Lidocaine) and group II; with naso-tracheal intubation that sprayed with antibiotic spray (combined Neomycin sulphate and Bacitracin) on the outside wall of the tube and inside its lumen. At the end of surgery and immediately after extubation, swabs were taken from the upper trachea using cotton tipped swab for bacterial growth. Inflammatory biomarkers were assessed preoperatively and postoperatively to detect any laboratory differences between both groups.

RESULTS

In the control group, all patients had heavy bacterial contamination and they were at either level 3 or 4 colony forming units. Thirty-two patients (71%) were at level 3 while 13 patients (29%) were at level 4. In the study group, there were 28 (62.2%) patients showed no bacterial growth, 15 (33.3%) patients were level 1, and 2 patients (4.4%) at level 2 colony forming units. There were no clinical differences between the 2 groups. Also, there was no significant difference between the 2 groups regarding to their postoperative body temperature although the inflammatory biomarkers were significantly higher in the control group.

CONCLUSION

Bacterial translocation by endotracheal intubation to the tracheobronchial tree could be prevented by local antibiotic spray application to outer and inner walls of the endotracheal tubes.

Postoperative care of the facial laceration

The purpose of this investigation is to examine factors involved in the postoperative care of traumatic lacerations. An evidence-based comprehensive literature review was conducted. There are a limited number of scientifically proven studies that guide surgeons and emergency room physicians on postoperative care. Randomized controlled trials must be conducted to further standardize the postoperative protocol for simple facial lacerations.

In vitro efficacy of antimicrobial wafers against methicillin-resistant Staphylococcus aureus

Background: Lyophilized wafers have been developed as vehicles for the storage and delivery of therapeutic compounds to exuding wounds. The primary objective of this study was to incorporate a selection of antimicrobial compounds in karaya wafers and measure their efficacy against methicillin-resistant Staphylococcus aureus. Methods: Four antimicrobial compounds, including an antibiotic, were incorporated within karaya gels and freeze–dried to a shaped-disc form suitable for in vitro testing against methicillin-resistant S. aureus. Disc diffusion and Franz diffusion methods were used to quantify the utility and efficacy of these ‘antimicrobial wafers’. Flow rheology and scanning electron microscopy were also used to aid gel and wafer characterization. Results: Lyophilized wafers swelled in simulated wound fluid and released the contained compounds with mixed effect. Povidine–iodine and chlorhexidine were most effective in protein-free buffer while the action of neomycin sulfate was enhanced by the presence of bovine serum albumin. Silver sulfadiazine was the least effective overall.

Evidence-based skin care management in radiation therapy: clinical update

OBJECTIVES

To present a clinical update on the available evidence for the prevention and management of radiation skin reactions (radiodermatitis).

DATA SOURCES

Research studies, review articles, and clinical practice guidelines.

CONCLUSION

In the past 4 years since the publication of the original article, there has been minimal change in the evidence available to guide decisions and practice in the management of radiation skin reactions. There continues to be insufficient evidence in the literature to recommend a variety of topical or oral agents in the prevention of skin reactions. There have been some recent studies that have impacted decision making and recommendations in the management of skin reactions. Radiation treatment techniques are the most promising intervention in reducing the degree of skin reaction. The use of calendula cream may reduce the incidence of grade 2 or 3 reactions in women with breast cancer. The controversy related to the use of deodorant in the treatment field unfortunately continues in clinical settings, but deodorant use as part of routine hygiene is now recommended for practice.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses need to be aware of the evidence and lack of evidence when recommending interventions to their patients and avoid undue marketing influence when suggesting interventions for the management of skin reactions. Further research is required to evaluate specific interventions in both the prevention and management of radiation dermatitis.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentrations at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications for these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentrations at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications for these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.

Use of Appropriate Antimicrobials in Wound Management

The primary goal of wound management is to achieve a functional closure with minimal scarring. Preventing infection is important to facilitate the healing process. Most simple, uncomplicated wounds do not need systemic antibiotics but benefit from the use of topical antibiotics. Judicious use of antibiotics reduces unnecessary adverse events and helps reduce the development of resistance. Although antibiotics can help reduce infection risk and promote healing, they are not a substitute for good local wound care, in particular irrigation and surgical débridement. This article reviews the role of antibiotics in emergency department wound management.

Evidence-based skin care management in radiation therapy

OBJECTIVES

To review published studies evaluating interventions for the prevention and management of radiation skin reactions/dermatitis.

DATA SOURCES

Research studies, review articles, and clinical practice guidelines.

CONCLUSION

There is insufficient evidence in the literature to recommend specific topical or oral agents in the prevention or management of skin reactions. Recent limited evidence suggests that the use of calendula cream may reduce the incidence of grade 2 and 3 reactions in women with breast cancer. Additionally, early studies evaluating the use of barrier films or creams may improve moist desquamation.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses need to increase their awareness of the evidence or lack of evidence when recommending interventions to their patients. Further research is required to evaluate interventions in the prevention and management of radiation dermatitis.

Topical Application of Bacitracin Ointment Is Associated with Decreased Risk of Mediastinitis after Median Sternotomy

BACKGROUND

The diagnosis of mediastinitis after open-heart surgery is infrequent but dreaded as it carries a high morbidity and mortality. The purpose of this study was to investigate the impact that topical antibacterials would have on the postoperative mediastinitis rate.

METHODS

Data were collected from 2455 consecutive patients who underwent sternotomy and cardiopulmonary bypass for both valvar and ischemic heart disease. Prior to 1999, patients (n = 1036) underwent surgery with standard perioperative intravenous antibiotics but no application of bacitracin. After 1999, patients (n = 1419) underwent surgery with intravenous antibiotics and application of bacitracin ointment to the sternotomy incision after closure.

RESULTS

Cases of mediastinitis occurred in 12 patients (1.2%) not treated with bacitracin, which required re-exploration, sternectomy, and soft tissue closure of the mediastinum. Alternatively, 3 patients (0.2%) in the group treated with bacitracin developed mediastinitis (P < .01). Therefore, the use of topical antibacterials was associated with a 6-fold reduction in the risk of mediastinitis after cardiac surgery. This significant difference in the infection rate was observed even though the percentage of patients with risk factors for mediastinitis was equal to greater than the group not treated with bacitracin. Non-bacitracin versus bacitracin: diabetics, 298 versus 484; emergency operations, 24 versus 50; bilateral internal thoracic grafts, 28 versus 29; and obesity (body mass index >30), 294 versus 396.

CONCLUSIONS

The use of topical antibacterials is associated with a decrease in the risk of mediastinitis after cardiac surgery.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentration at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications of these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.