Randomized, placebo-controlled, double-blind clinical trial to evaluate the efficacy of polyhexanide for topical decolonization of MRSA carriers

The Effectiveness of Polyhexanide in Treating Wound Infections Due to Methicillin-Resistant Staphylococcus Aureus: A Prospective Analysis

Purpose

Polyhexanide is a safe and effective wound care antiseptic commonly used in clinics as wound rinsing solution and gel. However, the efficacy of Polyhexanide in treatment of wound infected with MRSA (methicillin-resistant Staphylococcus aureus) is unknown. The aim of this study is to assess the effectiveness of polyhexanide with povidone iodine in treating wound infected with MRSA.

Patients and Methods

A prospective analysis of 62 patients with wound infections, who were admitted to our department from 2016 to 2020, was conducted in order to assess the efficacy of different treatment approaches. The patients were divided into two groups: the experimental group and the control group. In the experimental group, 30 patients underwent treatment with a combination of diluted povidone iodine and polyhexanide immersion. Conversely, in the control group, 32 patients received treatment with diluted povidone iodine along with systemic antibiotic therapy. The time required for dressing changes, bacterial clearance rates, and the Bates-Jasen wound assessment tool (BWAT) scores were utilized as indicators to evaluate the effectiveness of the treatments.

Results

In our study, the findings indicated that the experimental group exhibited a lesser number of days for the bacteria culture to turn negative compared to the control group, with statistical significance (p<0.05). Furthermore, the decline in the BWAT score was significantly greater in the experimental group than in the control group (p<0.05). However, no significant differences were observed in terms of dressing times and wound coverage between the two groups (p>0.05).

Conclusion

Polyhexanide combined with povidone iodine can effectively remove MRSA infection in wounds and reduce antibiotic dosages.

Eradication of community-onset Methicillin-resistant Staphylococcus aureus carriage: a narrative review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases infection risk in both patients and healthy individuals. Decolonization therapy has been proven to reduce S. aureus infections, but data on the effectiveness of individual decolonization strategies in community-onset MRSA carriage are scarce.

OBJECTIVES

The aim of this narrative review was to summarize the evidence on strategies for the elimination of MRSA colonization in community-onset MRSA carriers.

SOURCES

PubMed database was searched for studies on MRSA eradication, from inception to July 2023.

CONTENT

Topical therapy is proven to be effective in nasal-only carriage and in temporary load reduction. Mupirocin nasal ointment in combination with chlorhexidine body wash is highly effective in nasal-only MRSA carriers in the community as well. In patients with extra-nasal colonization, addition of orally administered antibiotics likely increases success rates compared with topical therapy alone. Studies on systemic treatment of extra-nasal MRSA decolonization are subject to a high heterogeneity of antimicrobial agents, treatment duration, and control groups. The majority of evidence supports the use of a combination of topical therapy with rifampin and another antimicrobial agent. Decolonization treatment with probiotics is a promising novel non-antibiotic strategy. However, achieving long-term decolonization is more likely in countries with low MRSA prevalence, given the risk of recolonization in a context of high MRSA prevalence.

IMPLICATIONS

The decision to pursue community-onset MRSA eradication treatment in the individual patient should be based on the combination of the treatment objective (short-term bacterial load reduction in health care settings vs. long-term eradication in community settings), and the likelihood of successful decolonization. The latter is influenced by both individual risk factors for treatment failure, and the risk of recolonization. The addition of a combination of systemic antibiotics is rational for extra-nasal long-term decolonization. To determine the most effective systemic antimicrobial agents in MRSA decolonization, more research is needed.

Polyhexanide-Releasing Membranes for Antimicrobial Wound Dressings: A Critical Review

The prevalence of chronic, non-healing skin wounds in the general population, most notably diabetic foot ulcers, venous leg ulcers and pressure ulcers, is approximately 2% and is expected to increase, driven mostly by the aging population and the steady rise in obesity and diabetes. Non-healing wounds often become infected, increasing the risk of life-threatening complications, which poses a significant socioeconomic burden. Aiming at the improved management of infected wounds, a variety of wound dressings that incorporate antimicrobials (AMDs), namely polyhexanide (poly(hexamethylene biguanide); PHMB), have been introduced in the wound-care market. However, many wound-care professionals agree that none of these wound dressings show comprehensive or optimal antimicrobial activity. This manuscript summarizes and discusses studies on PHMB-releasing membranes (PRMs) for wound dressings, detailing their preparation, physical properties that are relevant to the context of AMDs, drug loading and release, antibacterial activity, biocompatibility, wound-healing capacity, and clinical trials conducted. Some of these PRMs were able to improve wound healing in in vivo models, with no associated cytotoxicity, but significant differences in study design make it difficult to compare overall efficacies. It is hoped that this review, which includes, whenever available, international standards for testing AMDs, will provide a framework for future studies.

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.

Efficacy of universal preoperative decolonization with Polyhexanide in primary joint arthroplasty on surgical site infections. A multicenter before-and after-study

Background

Surgical site infections (SSI) are rare but severe complications after total joint arthroplasty (TJA). Decolonization measures prior to elective orthopedic surgeries have shown to reduce the risk of SSI with Staphylococcus aureus (S. aureus).

Objective

To determine the efficacy of universal decolonization with Polyhexanide on SSI rates with a focus on Staphylococcus aureus in patients with TJA.

Methods

Patients scheduled for elective hip or knee TJA in 5 participating certified orthopedic centers were included between 2015 and 2018 into this before and after study. Data on patients, surgeries and infections were prospectively collected. CDC-criteria were used to define and categorize Infections within 90 days after surgery. From January 2017 on, patients received decolonization sets containing Polyhexanide. Patients performed a 5 day decolonization regimen starting 4 days prior to surgery which included wipes, nasal decontamination and oral solution.

Results

Thirteen thousand, three hundred fifteen patients received TJA. During intervention 4437 decolonization sets were distributed among 7175 patients.

Overall SSI rates increased from 0.68 /100 surgeries to 0.91/ 100 surgeries after implementation of the intervention (IRR 1.32; 95% CI 0.90–1.96). Time series analysis identified an increasing trend of SSI prior to the intervention. After implementation overall SSI rates plateaued. Regression analysis revealed surgery during intervention period to be an independent risk factor for developing a SSI (OR 1.34; 95%CI 1.18–1.53).

Initial SSI rates due to S. aureus were 0.24/100 surgeries and decreased to 0.14/100 surgeries (IRR 0.57; 95% CI 0.25–1.22) after introduction of decolonization. Regression analysis revealed surgery during intervention period to be an independent protective factor for developing a SSI with S. aureus (OR 0.57, 95% CI: 0.33–0.99).

Overall deep S. aureus SSI decreased significantly from 0.22/100 surgeries to 0.00/100 surgeries in patients adherent to protocol (IRR 0.00, 95% CI 0.00–.85).

Conclusion

Universal decolonization with Polyhexanide did not reduce overall surgical site infections, but was effective in reducing Staphylococcus aureus - surgical site infections following elective joint arthroplasty. Polyhexanide could extend the list of alternatives to already established decolonization strategies.

Trial registration

The trial was registered at the German Registry for clinical studies www.drks.de (DRKS00011505).

Staphylococcus aureus nasal decolonization strategies: a review

Introduction: Staphylococcus aureus (S. aureus) infections are associated with increased morbidity, mortality and health-care costs. Persistent nasal carriage of S. aureus found in 10-30% of the general population, constitutes a risk factor for these infections. Nasal decolonization is one of the used strategies to prevent this risk in some situations. Areas covered: Mupirocin nasal ointment has been used for the nasal decolonization and prevention of staphylococcal infections in various settings like surgeries. However, rising rates of resistance to mupirocin require the development of new decolonization agents. In this review, we will discuss mupirocin, its origins, studies that proved its efficacy and the associated resistance, as well as other decolonization agents under investigation. Expert opinion: As some limitations exist to mupirocin use, further research for alternatives is encouraged. Some old approved antiseptics (chlorhexidine, povidone-iodine) or antibiotics (rifampicin, bacitracin) have been investigated for their efficacy in this indication. Other new agents (tea tree oil, retapamulin, LTX-109, XF-73, phages, lysostaphin, squalamine analogues, etc.) are being studied. Some of them are still in preclinical phases, and others have reached clinical trials, but further research is needed. Special interest should be given to single dose decolonization strategies and to molecules that do not select resistant strains.

Impact of Gram-negative bacteria on the treatment of venous leg ulcers

Gram-negative germs with and without multi-resistance are garnering more and more importance. The aim of this study was to investigate the frequency and rate of resistance against antibiotics and to clarify the impact of Gram-negative bacteria, especially with high rates of resistance, for the treatment of venous leg ulcers. This is a retrospective, monocentric, non-randomised open study. Included were all data within 1 year of bacterial swabs of venous leg ulcers. We performed summarization, pooling, and descriptive analysis for frequencies and crossover. We analysed 679 swabs of 285 patients with venous leg ulcers. The mean patient age was 69.78 years. There were 76.1% Gram-positive and 58.2% Gram-negative germs detected; 56.5% of the swabs showed multi-resistance. Gram-negative bacteria were associated with more pain. Exacerbation and relevant aggravation of wounds that led to stationary treatment occurred more frequently. With polihexanid treatment, we saw less Gram-negative flora. This study showed an immediate impact of Gram-negative germs on the patient's pain, the risk for aggravation, and the choice of treatment. Further studies for prophylaxis and treatment of Gram-negative germs in venous leg ulcer therapy are needed.

Susceptibility of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolates of Various Clonal Lineages from Germany to Eight Biocides

Few studies have been conducted on the susceptibility of bacteria to biocides. A total of 182 methicillin-resistant and -susceptible Staphylococcus aureus isolates collected from healthy or diseased humans and animals in Germany were included in the present study. Sixty-three isolates of animal origin and 119 human isolates were tested for their MICs to eight biocides or heavy metals by the broth microdilution method. The MIC₅₀ and MIC₉₀ values of human and animal isolates were equal or differed by not more than 1 dilution step, and statistical analysis revealed that differences between MICs of human and animal isolates were not significant. However, when taking into account the multilocus sequence type (MLST), a strong tendency (P = 0.054) to higher MICs of silver nitrate was detected for clonal complex 398 (CC398) isolates from humans compared to those from animals. Furthermore, a comparison of MIC values from isolates belonging to different clonal lineages revealed that important human lineages such as CC22 and CC5 exhibited significantly (P < 0.05) higher MICs for the biocides chlorhexidine, benzethonium chloride, and acriflavine than the main animal lineage sequence type 398 (ST398). Isolates with elevated MIC values were tested for the presence of biocide and heavy metal tolerance-mediating genes by PCR assays, and the following genes were detected: mepA (n [no. of isolates containing the gene] = 44), lmrS (n = 36), norA (n = 35), sepA (n = 22), mco (n = 5), czrC (n = 3), smr (n = 2), copA (n = 1), qacA and/or -B (n = 1), qacG (n = 2), and qacJ (n = 1). However, only for some compounds was a correlation between the presence of a biocide tolerance gene and the level of MIC values detected.IMPORTANCE Biocides play an essential role in controlling the growth of microorganisms and the dissemination of nosocomial pathogens. In this study, we determined the susceptibility of methicillin-resistant and -susceptible S. aureus isolates from humans and animals to various biocides and heavy metal ions and analyzed differences in susceptibilities between important clonal lineages. In addition, the presence of biocide or heavy metal tolerance-mediating genes was investigated. We demonstrated that important human lineages such as CC22 and CC5 had significantly higher MIC values for chlorhexidine, benzethonium chloride, and acriflavine than the main farm animal lineage, ST398. In addition, it was shown that for some combinations of biocides and tolerance genes, significantly higher MICs were detected for carriers. These findings provide new insights into S. aureus biocide and heavy metal tolerance.

Methicillin-resistant Staphylococcus aureus

Since the 1960s, methicillin-resistant Staphylococcus aureus (MRSA) has emerged, disseminated globally and become a leading cause of bacterial infections in both health-care and community settings. However, there is marked geographical variation in MRSA burden owing to several factors, including differences in local infection control practices and pathogen-specific characteristics of the circulating clones. Different MRSA clones have resulted from the independent acquisition of staphylococcal cassette chromosome mec (SCCmec), which contains genes encoding proteins that render the bacterium resistant to most β-lactam antibiotics (such as methicillin), by several S. aureus clones. The success of MRSA is a consequence of the extensive arsenal of virulence factors produced by S. aureus combined with β-lactam resistance and, for most clones, resistance to other antibiotic classes. Clinical manifestations of MRSA range from asymptomatic colonization of the nasal mucosa to mild skin and soft tissue infections to fulminant invasive disease with high mortality. Although treatment options for MRSA are limited, several new antimicrobials are under development. An understanding of colonization dynamics, routes of transmission, risk factors for progression to infection and conditions that promote the emergence of resistance will enable optimization of strategies to effectively control MRSA. Vaccine candidates are also under development and could become an effective prevention measure.

Randomized controlled trial of honey versus mupirocin to decolonize patients with nasal colonization of meticillin-resistant Staphylococcus aureus

BACKGROUND

Mupirocin is used specifically for the eradication of nasal meticillin-resistant Staphylococcus aureus (MRSA), but increasing mupirocin resistance restricts its repeated use. The antibacterial effects of manuka honey have been established in vitro; antibacterial activity of other honeys has also been reported.

AIM

To describe the learning experience from a randomized controlled trial (RCT) comparing the efficacy of medical-grade honey (MGH) with mupirocin 2% for the eradication of nasal MRSA.

METHODS

Patients colonized in the nose with MRSA and age ≥18 years were recruited. Participants received either one or two courses of MGH or mupirocin 2%, three times per day for five consecutive days.

FINDINGS

The proportion of patients who were decolonized after one or two courses of treatment was not significantly different between MGH [18/42; 42.8%; 95% confidence interval (CI): 27.7-59.0] and mupirocin 2% (25/44; 56.8%; 95% CI: 41.0-71.7). Non-nasal MRSA colonization was significantly associated with persistent nasal colonization (odds ratio: 5.186; 95% CI: 1.736-5.489; P = 0.003). The rate of new acquisition of mupirocin resistance was 9.75%.

CONCLUSION

Although not significant, a decolonization rate of 42.8% for MGH was impressive. Our findings suggest that this strategy, which has the potential to combat antimicrobial resistance, should be assessed in similar but larger studies.

Impact of Exposure of Methicillin-Resistant Staphylococcus aureus to Polyhexanide In Vitro and In Vivo

Methicillin-resistant Staphylococcus aureus (MRSA) resistant to decolonization agents such as mupirocin and chlorhexidine increases the need for development of alternative decolonization molecules. The absence of reported severe adverse reactions and bacterial resistance to polyhexanide makes it an excellent choice as a topical antiseptic. In the present study, we evaluated the in vitro and in vivo capacity to generate strains with reduced polyhexanide susceptibility and cross-resistance with chlorhexidine and/or antibiotics currently used in clinic. Here we report the in vitro emergence of reduced susceptibility to polyhexanide by prolonged stepwise exposure to low concentrations in broth culture. Reduced susceptibility to polyhexanide was associated with genomic changes in the mprF and purR genes and with concomitant decreased susceptibility to daptomycin and other cell wall-active antibiotics. However, the in vitro emergence of reduced susceptibility to polyhexanide did not result in cross-resistance to chlorhexidine. During in vivo polyhexanide clinical decolonization treatment, neither reduced polyhexanide susceptibility nor chlorhexidine cross-resistance was observed. Together, these observations suggest that polyhexanide could be used safely for decolonization of carriers of chlorhexidine-resistant S. aureus strains; they also highlight the need for careful use of polyhexanide at low antiseptic concentrations.

MRSA decolonisation using polyhexanide 0.1 % with application where necessary of systemic antibiotics

Background: Increasing infections and drug resistances lead to new treatment concepts in terms of MRSA decolonisation. An antibiotic-free decolonisation treatment with topical antiseptics is of great clinical interest. We investigated the effectiveness of MRSA decolonisation therapy using the topical antiseptic agent polyhexanide 0.1 %. If needed, a systemic antibiotic was added in case of hospitalisation, abscess formation, chronic wounds and others.

Patients and methods: 63 patients were introduced to our outpatient clinic within a period of record of 15 months. 42 (66.7 %) of them were confirmed MRSA-positive and 27 (64.3 %) of these colonised patients were included to the protocol of decolonisation. Patients who followed the protocol of decolonisation (n=27) were investigated in terms of the site of MRSA-colonisation, parameters that minimize the effect of decolonisation, spa types as well as the effectiveness of the topical antiseptic agent polyhexanide 0.1 %.

Results: 22 patients (81.5 %) were successfully decolonised within the group that followed the decolonisation protocol (n=27). Using polyhexanide 0.1 % as single treatment regime seven people (31.8 %) were successfully decolonised, whereas 15 patients (68.2 %) were in need of an additional systemic treatment with antibiotics in order to be decolonised. The implementation of one topical eradication cycle with polyhexanide 0.1 % was effective in case of an exclusive colonisation of the nose (n=3). At maximum, three decolonisation runs were necessary. Within six months of post-eradication investigations no relapses of MRSA were registered.

Conclusions: One third of the decolonised patients were successfully treated with the topical antiseptic polyhexanide 0.1 %, whereas two thirds of the patients that followed the decolonisation protocol were in need of an additional systemic antibiotic.

Decolonization of Staphylococcus aureus carriage

Staphylococcus aureus nasal colonization is a well-known independent risk factor for infection caused by this bacterium. Screening and decolonization of carriers have been proven effective in reducing S. aureus infections in some populations. However, a gap remains between what has been proven effective and what is currently done. We aimed to summarize recommendations and current knowledge of S. aureus decolonization to answer the following questions: Why? For whom? How? When? And what are the perspectives?

Integrated MRSA-Management (IMM) with prolonged decolonization treatment after hospital discharge is effective: a single centre, non-randomised open-label trial

BACKGROUND

Guidelines for the control of hospital-acquired MRSA include decolonization measures to end MRSA carrier status in colonized and infected patients. Successful decolonization typically requires up to 22 days of treatment, which is longer than the average hospital length of stay (LOS). Incomplete decolonization is therefore common, with long-term MRSA carriage as a consequence. To overcome this, we developed an integrated MRSA Management (IMM) by extending MRSA decolonization to the outpatient and domestic setting. The protocol makes use of polyhexanide-based products, in view of reported qac-mediated resistance to chlorhexidine in S. aureus and MRSA.

METHODS

This is a prospective, single centre, controlled, non-randomized, open-label study to evaluate the efficiency of the IMM concept. The outcome of guideline-approved decolonization during hospital stay only (control group; n = 201) was compared to the outcome following IMM treatment whereby decolonization was continued after discharge in the domestic setting or in a long-term care facility (study group; n = 99). As a secondary outcome, the effect of MRSA-status of skin alterations was assessed.

RESULTS

The overall decolonization rate was 47 % in the IMM patient group compared to 12 % in the control group (p < 0.01). The continued treatment after hospital discharge was as effective as treatment completed during hospitalization, with microbiologically-confirmed decolonization (patients with completed regimes only) obtained with 55 % for the IMM group and 43 % for the control group (p > 0.05). For patients with skin alterations (e.g. wounds and entry sites), decolonization success was 50 % if the skin alterations were MRSA-negative at baseline, compared to 22 % success for patients entering the study with MRSA-positive skin alterations (p < 0.01).

CONCLUSIONS

The IMM strategy offers an MRSA decolonization protocol that is feasible in the domestic setting and is equally effective compared with inpatient decolonization treatment when hospital LOS is long enough to complete the treatment. Moreover, for patients with average LOS, decolonization rates obtained with IMM are significantly higher than for in-hospital treatment. IMM is a promising concept to improve decolonization rates of MRSA-carriers for patients who leave the hospital before decolonization is completed.