Comparison of the antimicrobial efficacy of povidone-iodine-alcohol versus chlorhexidine-alcohol for surgical skin preparation on the aerobic and anaerobic skin flora of the shoulder region

Topical Preparations for Reducing Cutibacterium acnes Infections in Shoulder Surgery: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

BACKGROUND

Cutibacterium acnes (C acnes) is a commensal skin bacterium, primarily found in sebaceous glands and hair follicles, with a high prevalence in the shoulder region. It is the most common pathogenic organism in prosthetic joint infections after shoulder arthroplasty. Because of its low virulence, its diagnosis remains difficult.

PURPOSE

To evaluate the relative effects of topical preparations in reducing C acnes in shoulder surgery.

STUDY DESIGN

Meta-analysis; Level of evidence, 1.

METHODS

We searched the MEDLINE, Embase, PsychINFO, and Cochrane Library databases in March 2022. Randomized controlled trials (RCTs) comparing any form of topical preparation in arthroscopic or open shoulder surgery were included. The primary outcome was a reduction in the number of positive C acnes cultures. Secondary outcomes were adverse events related to the application of topical preparations. We performed a network meta-analysis to facilitate simultaneous comparisons between multiple preparations across studies. We calculated differences between preparations using odds ratios and their 95% CIs. The risk of bias was assessed using the Cochrane risk-of-bias tool.

RESULTS

The search yielded 17 RCTs (1350 patients), of which 9 were suitable for the network meta-analysis (775 patients). Overall, 2 RCTs were deemed as having a low risk of bias, and 15 raised "some concerns" of bias. Preparations included benzoyl peroxide (BPO), BPO combined with clindamycin, chlorhexidine gluconate, hydrogen peroxide, povidone-iodine, and water with soap. Only BPO resulted in significantly lower odds of a positive C acnes culture compared with placebo or soap and water (odds ratio, 0.12 [95% CI, 0.04-0.36]). There was no statistically significant difference with all other topical preparations. The only adverse events were skin irritation from BPO and chlorhexidine gluconate in a small number of reported cases.

CONCLUSION

BPO was the most effective topical agent in reducing the prevalence of C acnes in shoulder surgery. These results were limited by a combination of indirect and direct data. Future studies should focus on establishing the optimal frequency and duration of preoperative BPO to further reduce the burden of C acnes.

REGISTRATION

CRD42022310312 (PROSPERO).

New Insights into Cutaneous Asepsis: Synergism between Pfaffia and Rosemary Extracts

(1) Background: In hospitals, medical and dental clinics, antiseptics or disinfectants play an essential role in the control of nosocomial infections. This study aimed to evaluate R. officinalis and P. paniculata glycolic extracts regarding: (I) their antimicrobial action on planktonic and biofilm (monotypic and cutaneous biofilm model-S. aureus, S. epidermidis and C. acnes); and (II) their cytotoxicity on human keratinocytes (HaCaT). (2) Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were performed (CLSI protocol M7-A6 and M11-A8). MTT analysis was used to evaluate the antibiofilm activity of the extracts on biofilms and their cytotoxicity on human keratinocytes. (3) Results: The combined glycolic extracts MIX A (75% P. paniculata + 25% R. officinalis); MIX B (50% P. paniculata + 50% R. officinalis); and MIX C (25% P. paniculata + 75% R. officinalis) promoted MBC values by 50 mg/mL on S. aureus, absent on S. epidermidis, and ranged 6.25-50 mg/mL for C. acnes. The cutaneous biofilm model was reduced more than 90%. In addition, it showed biocompatibility with human keratinocytes, resulting in percentages of viability greater than 50%. (4) Conclusions: The combination of extracts promoted antimicrobial action on planktonic cultures, and monotypic and heterotypic biofilms of skin pathogens. Additionally, these extracts are biocompatible against human keratinocytes.

Best products for skin antisepsis

BACKGROUND

Skin antiseptics are used for several purposes before surgical procedures, for bathing high-risk patients as a means of reducing central line-associated infections and other health care associated infections.

METHODS

A PubMed search was performed to update the evidence on skin antiseptic products and practices.

RESULTS

Current guidelines for prevention of surgical site infections (SSIs) recommend preoperative baths or showers with a plain or antimicrobial soap prior to surgery, but do not make recommendations on the timing of baths, the total number of baths needed, or about the use of chlorhexidine gluconate (CGH)-impregnated cloths. Randomized controlled trials have demonstrated that pre-operative surgical hand antisepsis using an antimicrobial soap or alcohol-based hand rub yields similar SSI rates. Other studies have reported that using an alcohol-based hand rub caused less skin irritation, was easier to use, and required shorter scrub times than using antimicrobial soap. Current SSI prevention guidelines recommend using an alcohol-containing antiseptic for surgical site infection. Commonly used products contain isopropanol combined with either CHG or with povidone-iodine. Surgical site preparation protocols for shoulder surgery in men may need to include coverage for anaerobes. Several studies suggest the need to monitor and improve surgical site preparation techniques. Daily bathing of intensive care unit (ICU) patients with a CHG-containing soap reduces the incidence of central line-associated bloodstream infections (CLABSIs). Evidence for a similar effect in non-ICU patients is mixed. Despite widespread CHG bathing of ICU patients, numerous barriers to its effective implementation exist. Measuring CHG levels on the skin is useful for identifying gaps in coverage and suboptimal skin concentrations. Using alcohol-based products with at least 2% CHG for skin preparation prior to central line insertion reduces CLABSIs.

CONCLUSIONS

Progress has been made on skin antisepsis products and protocols, but improvements in technique are still needed.

Chronological changes in the rate of surgical field contamination in the shoulder joint

BACKGROUND

In shoulder surgery, low-virulence bacteria such as Cutibacterium acnes and coagulase-negative staphylococci can cause postoperative infection. However, the degree of sterility during surgery after disinfection is not known, and the efficacy of double skin preparation for such bacteria is unclear. This study aimed to evaluate chronological changes in the surgical field contamination rate in the shoulder joint and to compare single and double skin preparation.

METHODS

In total, 126 shoulders in 121 patients undergoing shoulder surgery (64 men, 62 women; mean age 64 years) were enrolled. Patients were divided into two groups: single skin preparation, where the site was painted with 10% povidone iodine, and double skin preparation, where the site was treated with 1% chlorhexidine gluconate/83% isopropyl alcohol and painted 10% povidone iodine. Swab samples from the axillary and proximal areas in the surgical field were collected chronologically before starting surgery and at 30, 60, and 120 min after starting surgery (MAS). The contamination rate of each sample was compared and detected species were evaluated.

RESULTS

The contamination rate for the axillary area was 48.4%, 85.9%, 95.3%, and 97.1% in the single-preparation group and 32.3%, 72.6%, 87.1%, and 91.2% in the double-preparation group before starting surgery and 30, 60, and 120 MAS, respectively, and that the proximal area was 12.5%, 26.6%, 29.7%, and 35.3% in the single-preparation group and 16.1%, 19.4%, 27.4%, and 38.2% in the double-preparation group, respectively. Significant differences were not seen between the groups by area or time point. Most detected species were Cutibacterium acnes and coagulase-negative staphylococci.

CONCLUSIONS

The incidence of surgical field contamination in shoulder joint was high from immediately after starting surgery. In the axillary area, the contamination rates exceeded 70% from 30 MAS in both groups. Measures against infection should be instituted considering these findings when performing shoulder surgery.

Bacterial reservoir in deeper skin is a potential source for surgical site and biomaterial-associated infections

BACKGROUND

The origin of surgical site and biomaterial-associated infection is still elusive. Micro-organisms contaminating the wound may come from the air in the operating theatre, the surgical team or the skin of the patient. The skin of patients is disinfected prior to surgery, but bacteria deeper in the skin (e.g. in sweat glands or sebaceous glands) may not be reached.

METHODS

A preliminary cohort study was performed to study the origin of surgical site and biomaterial-associated infection between May 2020 and February 2021. In order to investigate whether cutaneous microbiota colonize the wound when released from the skin upon cutting, aerobic and anaerobic bacteria were isolated, quantified and identified from the skin of 99 patients undergoing trauma surgery, before and after skin disinfection, from knife blades and from the wound directly after the first cut.

RESULTS

Ninety-nine percent of the patients were culture-positive before disinfection with chlorhexidine. Of these, 40% were still culture-positive after disinfection. Of these, 54% had a positive culture of the wound after cutting the skin. Twenty percent of the patients with a negative culture after disinfection had a positive wound culture after cutting the skin. Staphylococcus epidermidis and Cutibacterium acnes were the most commonly cultured bacterial species. In 9% of cases, more than 100 bacterial colonies were cultured from the wound; this may cause biomaterial-associated infection.

CONCLUSION

Bacteria residing in the skin and not eradicated by disinfection may enter the surgical wound upon cutting, resulting in contamination which may cause biomaterial-associated infection.

A microbiology study on the wounds of pediatric patients undergoing spinal fusion for scoliosis

PURPOSE

Surgical site infection is a significant complication in posterior spinal fusion for scoliosis in pediatric and adolescent patients. Current literature demonstrates a lack of consensus regarding best prophylactic systemic and topical antibiotic regimens for reducing infection rates. This study aims to identify which common microbes are present at particular locations in the spine, and whether these are covered by our current systemic and topical antibiotic prophylaxis regimens.

METHODS

A prospective observational study at a National Children's Hospital was conducted on 21 consecutive patients who underwent elective surgery for spinal deformity. Swabs were taken from four layers of the spine, including the superficial skin surface at the start of the case (after surgical site preparation with povidone-iodine), the deep dermis, and the deep surgical bed at the end of exposure and again after the corrective maneuver prior to closure. At each layer, swabs were taken from the proximal, middle, and distal portion of the wound. Swabs were sent to the laboratory for culture and susceptibility testing.

RESULTS

Thirteen (62%) of patients had positive microbial growth. Two microbes were identified, Staphylococcus epidermidis (9.5% of patients) and Cutibacterium acnes (Propionibacterium acnes) (52% of patients). 100% of these microbes were sensitive to cefazolin and vancomycin. 3% of patients had positive growth at the skin layer, 32% positive at the dermal layer, 17% positive after exposure, and 40% positive at the conclusion of the case (p = 0.006). No difference was observed in microbial presence in the upper thoracic, lower thoracic and lumbar spine.

CONCLUSION

Despite adequate surgical site preparation and sterile procedure, microbial contamination remains abundant in the dermal layer and deeper in the spinal wound throughout the case.

Evaluation of the role of povidone‑iodine in the prevention of surgical site infections

Background

The occurrence of surgical site infections (SSIs) is associated with increased risk of mortality, development of other infections, and the need for reintervention, posing a significant health burden. The aim of this review was to examine the current data and guidelines around the use of antiseptic povidone‑iodine (PVP-I) for the prevention of SSIs at each stage of surgical intervention.

Methods

A literature search for selected key words was performed using PubMed. Additional papers were identified based on author expertise.

Results

Scientific evidence demonstrates that PVP-I can be used at every stage of surgical intervention: preoperative, intraoperative, and postoperative. PVP-I is one of the most widely used antiseptics on healthy skin and mucous membranes for preoperative surgical site preparation and is associated with a low SSI rate. For intraoperative irrigation, aqueous PVP-I is the recommended agent and has been demonstrated to decrease SSIs in a range of surgical settings, and for postoperative wound healing, there is a growing body of evidence to support the use of PVP-I.

Conclusions

There is a need for more stringent study designs in clinical trials to enable meaningful comparisons between antiseptic agents, particularly for preoperative skin preparation. The use of a single agent (PVP-I) at each stage of surgical intervention could potentially provide advantages, including economic benefits, over agents that can only be used at discrete stages of the surgical procedure.

Key message

Evidence supports the use of PVP-I at all stages of surgical intervention, from preoperative measures (including skin preparation, preoperative washing, and nasal decolonization) to intraoperative irrigation, through to postoperative wound management. However, there is a need for more stringent study designs in clinical trials to enable meaningful comparisons between antiseptic agents, particularly for preoperative skin preparation.

Advanced Skin Antisepsis: Application of UVA-Cleavable Hydroxyethyl Starch Nanocapsules for Improved Eradication of Hair Follicle-Associated Microorganisms

Hair follicles constitute important drug delivery targets for skin antisepsis since they contain ≈25% of the skin microbiome. Nanoparticles are known to penetrate deeply into hair follicles. By massaging the skin, the follicular penetration process is enhanced based on a ratchet effect. Subsequently, an intrafollicular drug release can be initiated by various trigger mechanisms. Here, we present novel ultraviolet A (UVA)-responsive nanocapsules (NCs) with a size between 400 and 600 nm containing hydroxyethyl starch (HES) functionalized by an o-nitrobenzyl linker. A phase transfer into phosphate-buffered saline (PBS) and ethanol was carried out, during which an aggregation of the particles was observed by means of dynamic light scattering (DLS). The highest stabilization for the target medium ethanol as well as UVA-dependent release of ethanol from the HES-NCs was achieved by adding 0.1% betaine monohydrate. Furthermore, sufficient cytocompatibility of the HES-NCs was demonstrated. On ex vivo porcine ear skin, a strong UVA-induced release of the model drug sulforhodamine 101 (SR101) could be demonstrated after application of the NCs in cyclohexane using laser scanning microscopy. In a final experiment, a microbial reduction comparable to that of an ethanol control was demonstrated on ex vivo porcine ear skin using a novel UVA-LED lamp for triggering the release of ethanol from HES-NCs. Our study provides first indications that an advanced skin antisepsis based on the eradication of intrafollicular microorganisms could be achieved by the topical application of UVA-responsive NCs.

[Shoulder periprosthetic infections-what to do? : Diagnosis and treatment]

Treatment of an infected shoulder prosthesis differs significantly from other joint infections because of the unique microbiome, dominated by Cutibacterium acnes. The cause of an infection, its time of onset, the bacterial spectrum and comorbidities have to be considered for evaluation and treatment. The diagnostic workup is sometimes complex, and the recognition of a chronic and low-grade infection is often difficult because typical clinical and laboratory markers may be normal. Treatment is surgical; the therapeutic spectrum ranges from arthroscopic irrigation and open debridement with the exchange of components to one- and two-stage revisions using antibiotic-loaded spacers. Early detection and a targeted, appropriate therapy are crucial to avoid extensive soft tissue and bone damage.

Role of wound microbiome, strategies of microbiota delivery system and clinical management

Delayed wound healing is one of the most global public health threats affecting nearly 100 million people each year, particularly the chronic wounds. Many confounding factors such as aging, diabetic disease, medication, peripheral neuropathy, immunocompromises or arterial and venous insufficiency hyperglycaemia are considered to inhibit wound healing. Therapeutic approaches for slow wound healing include anti-infection, debridement and the use of various wound dressings. However, the current clinical outcomes are still unsatisfied. In this review, we discuss the role of skin and wound commensal microbiota in the different healing stages, including inflammation, cell proliferation, re-epithelialization and remodelling phase, followed by multiple immune cell responses to commensal microbiota. Current clinical management in treating surgical wounds and chronic wounds was also reviewed together with potential controlled delivery systems which may be utilized in the future for the topical administration of probiotics and microbiomes. This review aims to introduce advances, novel strategies, and pioneer ideas in regulating the wound microbiome and the design of controlled delivery systems.

Comparison of two alcohol hand rubbing techniques regarding hand surface coverage among hospital workers: a quasi-randomized controlled trial

BACKGROUND

The adapted 6-step without interlock (A6Sw/oI) hand rub technique, commonly practiced in Japan, adds the "wrist" but omits the "interlock" step compared to the WHO 6-step technique (WHO6S). The first objective of this study was to assess the differences of the two techniques regarding surface coverage. The second objective was to analyze the coverage differences between hand sizes.

METHODS

Hospital workers went under stratified quasi-randomization by glove size. The overall mean coverage, and the coverage of the sections of the hands were evaluated by fluorescent dye-based coverage assessment using a digital device with artificial intelligence technology.

RESULTS

Total of 427 workers were randomly allocated to WHO6S (N = 215) or the A6Sw/oI (N = 212). The overall mean dorsum coverage by WHO6S and A6Sw/oI was 90.6% versus 88.4% (p < 0.01), and the percentage of the participants with insufficient coverage of the backs of the four fingers ranged from 0.0-7.4% versus 28.2-51.4% (p < 0.001). Dorsum coverage varied largely between hand size for both techniques, and significant differences were found between small and large hands.

CONCLUSION

The WHO6S was superior to the locally adapted technique regarding hand surface coverage. Hand size should be considered when assessing coverage differences between procedures. No trial registrations or fundings.

Comparison of two different antiseptics regarding intracutaneous microbial load after preoperative skin cleansing in total knee and hip arthroplasties

Periprosthetic infections (PPIs) are a serious concern in total knee and hip arthroplasty, and they have an increasing incidence. To prevent PPI, preoperative skin disinfection, as a key element of antisepsis, represents an important part of infection prevention. However, no specific antiseptic agent is endorsed by the relevant guidelines. The purpose of this retrospective, not randomized study was to investigate the difference in the residual bacteria load between an approved antiseptic with an alcohol-based solution with additional benzalkonium chloride (BAC) and an alcohol-based solution with additional octenidine dihydrochloride (OCT) at two different time periods. In 200 consecutive patients with total knee or hip arthroplasty, skin samples from the surgical sites were collected after skin disinfection with BAC (100 g solution contain: propan-2-ol 63.0 g, benzalkonium chloride 0.025 g) or OCT (100 g solution contain: octenidine dihydrochloride 0.1 g, propan-1-ol, 30.0 g, propan-2-ol 45.0 g) (100 patients per group). Following the separation of cutis and subcutis and its processing, culture was performed on different agar plates in aerobic and anaerobic environments. In the case of bacteria detection, the microbial identification was determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and the number of contaminated samples was compared between the groups. Additionally, multiple regression analysis was performed to examine the effect of the type of disinfectant, BMI, age, sex, rheumatoid arthritis, diabetes mellitus, skin disorders, smoking status, and localization of skin samples on positive bacteria detection. A total of 34 samples were positive for bacteria in the BAC group, while only 17 samples were positive in the OCT group (p = 0.005). Disinfectant type was the only significant parameter in the multiple regression analysis (p = 0.006). A significantly higher contamination rate of the subcutis was shown in the BAC group compared to the OCT group (19 vs. 9, p = 0,003). After the change from BAC to OCT in preoperative skin cleansing in the hip and knee areas, the number of positive cultures decreased by 50%, which might have been caused by a higher microbicidal activity of OCT. Therefore, the use of OCT in preoperative cleansing may reduce the risk of PPI in hip and knee surgery. Randomized controlled trials are required to confirm the effect and to evaluate if it reduces the risk of PPI.

Efficacy of Three Povidone Iodine Formulations against Cutibacterium acnes Assessed through In Vitro Studies: A Preliminary Study

Cutibacterium acnes (C. acnes, formerly known as Propionibacterium acnes) is the major causative agent of prosthetic joint infections (PJI). Treatment of PJI with antibiotics is difficult due to antibiotic resistance and adverse side effects on patients’ health. Proper disinfection of the surgical site using a variety of povidone iodine formulations could prevent C. acnes infection. In the current study, the efficacy of the three povidone iodine (PVP-I) formulations, viz: PVP-I 10% dermic solution, PVP-I 5% alcoholic solution and PVP-I 4% scrub, was tested against C. acnes, in vitro, in the presence of interfering substances mimicking soiling conditions. C. acnes strain ATCC 6919 was used to test the bactericidal activity of the povidone iodine formulations according to the modified dilution-neutralization method described in French Norm EN standard 13727. A 3-log reduction in the bacterial cell count in 60 s was considered to be significant. The results showed that under experimental conditions, the three PVP-I formulations displayed bactericidal activity against the micro-organism, Cutibacterium acnes, and that the lowest concentration of povidone-iodine active against C. acnes was 0.4%. These results are encouraging as PVP-I offers a low-cost and efficient method of disinfection.

The pencil eraser swab technique to quantify Cutibacterium acnes on shoulder skin

Introduction: Cutibacterium acnes is the most common cause of postoperative infections in orthopaedic shoulder surgery and is hard to eradicate with current measures. Newer strategies focus on reducing bacterial load on the skin before surgery. Several previous studies have used a large number of both described and undescribed sampling techniques. The purpose of this study was to compare three previously described swab techniques to obtain bacterial cultures: Levine's (L) technique, the Z technique and the pencil eraser swab (PES) technique. Methods: Three consecutive skin swabs were collected from the right shoulder, on 15 healthy male volunteers, using Levine's technique, Z technique and PES technique from each participant. To determine the number of living bacteria, serial dilutions were made, and after culturing for 5 d, viable count (VC) was expressed as CFU/mL (with CFU representing colony-forming unit). Results: The PES technique yielded significantly higher VC than the two others. PES: median 3700 CFU/mL, L: 200 CFU/mL and Z: 220 CFU/mL ( p = 0.003 ). There was no significant difference between the methods regarding the number of positive cultures. PES: 14/15, L: 11/15 and Z: 12/15. Conclusions: There is a need to harmonise sampling techniques of C. acnes in order to compare the efficacy of different measures to reduce the bacterial load on the skin before and during surgery. Of the three tested methods, the PES technique is simple and produces the highest bacterial counts.

Meta-analysis of the efficacy of preoperative skin preparation with alcoholic chlorhexidine compared to povidone iodine in orthopedic surgery

Preoperative skin preparation is an effective method to prevent surgical site infections (SSI). Alcoholic chlorhexidine (CHG) and povidone iodine (PV-I) are the most widely used antiseptic agents. This meta-analysis aims to determine their efficacy in reducing natural bacterial skin flora in clean orthopedic surgery. A systematic search was conducted through current literature up to June 2021 to identify clinical randomized trials that compared the efficacy of alcoholic chlorhexidine and povidone iodine in reducing bacterial skin colonization after preoperative skin preparation. A meta-analysis was conducted. Of 235 screened articles, 8 randomized controlled trials were included. The results of the meta-analysis demonstrate a significantly lower positive culture rate in the chlorhexidine group than in the povidone iodine group (RR = 0.53, 95% Cl: 0.32-0.88). The present data show the superiority of chlorhexidine in reducing the normal bacterial flora compared to povidone iodine in clean orthopedic surgery.