Comparative efficacy of three antiseptics as surgical skin preparations in dogs

OBJECTIVE

To compare the antimicrobial efficacy of a 2% chlorhexidine gluconate and 70% ethanol solution (CG+A) with that of F10 Skin Prep Solution (F10) and electrochemically activated water (EAW) when used as a surgical preparation in canine patients.

STUDY DESIGN

Prospective randomized clinical study.

SAMPLE POPULATION

One hundred sixteen dogs presented for ovariohysterectomy.

METHODS

Dogs were randomly divided into 1 of the 3 antiseptic groups (CG+A, F10, EAW). Skin samples with replicating organism detection and counting plates were taken at 4 different perioperative sites and time intervals (postskin preparation, postskin antisepsis, 2 hours after the second sample, and at the end of surgery) during ovariohysterectomies performed by students. The colony forming unit (CFU) counts from each sample were quantified according to the level of bacterial contamination. Zero CFU was defined as no contamination, 1-12 CFU was defined as low contamination, and greater than 12 CFU was defined as high contamination. The 3 antiseptics were compared with respect to the level of contamination.

RESULTS

There was no difference in the level of colonization between the antiseptics at the first sampling time (P = .454). However, the level of contamination for CG+A was lower compared with F10 and EAW at the second, third, and fourth sampling times (P =  .001, P =  .01, P =  .02, respectively).

CONCLUSION

CG+A was more effective at achieving a zero CFU count and low levels of contamination compared with F10 and EAW for surgical preparation in dogs undergoing ovariohysterectomy.

CLINICAL SIGNIFICANCE

This study does not provide evidence to support the use of F10 and EAW instead of CG+A for the surgical skin preparation of dogs undergoing ovariohysterectomy.

[Accidental central venous administation of 0.1 % chlorhexidine mouthwash]

Medication errors are frequent and a serious safety concern. Chlorhexidine (CHX) is used daily in healthcare as a disinfectant. Its accidental intravascular injection is scarcely described. Serious complications, such as acute respiratory distress syndrome (ARDS) could be a consequence. We describe a case of central venous administration of 0.1% CHX mouthwash, its potential complications and possibilities of treatment. In contrast to another case report our patient had no detectable adverse side effects. The immediate hemofiltration and cleansing of the i. v. line may have contributed to this favorable outcome.

Anaphylaxis after disinfection with 2% chlorhexidine wand applicator

A 54-year-old man with end-stage renal failure attended for dialysis. Within seconds of applying 2% w/v chlorhexidine (ChloraPrep 3 mL Wand Applicator) to the skin surrounding the insertion point of his dialysis catheter (Tesio catheter), he developed pruritus, urticaria, shortness of breath, hypotension and reduced responsiveness. Treatment for anaphylaxis was initiated with rapid improvement of his symptoms, and he made a full recovery. Allergy to chlorhexidine was confirmed with skin testing, and the patient was warned against all future exposure to chlorhexidine. Subsequent dialysis without chlorhexidine was uneventful.

Intraoperative chlorhexidine irrigation to prevent infection in total hip and knee arthroplasty

Background

Surgical site irrigation during total hip (THA) and total knee (TKA) arthroplasty is a routine practice among orthopaedic surgeons to prevent periprosthetic joint infection. The purpose of this study was to evaluate the effect of chlorhexidine gluconate (CHG) irrigation on infection rates following THA and TKA.

Methods

Arthroplasties performed before September 2014 served as controls. THA performed before September 2014 (N = 253) underwent intraoperative irrigation with 0.9% saline followed by a 2-minute soak with <2% dilute povidone-iodine. TKA (N = 411) patients underwent only intraoperative saline irrigation. After October 2014, all patients (248 TKA and 138 THA) received intraoperative irrigation with 0.9% saline and periodic 0.05% CHG solution followed by a final 1-minute soak in CHG with immediate closure afterward.

Results

In this 2:1 comparison of consecutive patients, there were no differences in patient demographics between the 2 groups. No difference was noted in wound healing concerns subjectively, and no statistically significant association in nonsurgical site infections, superficial surgical site infection, and deep surgical site infection rates between the 2 groups (nonsurgical site infections [THA: P = .244, TKA: P = .125]; superficial surgical site infection [THA: P = .555, TKA: P = .913]; and deep surgical site infection [THA: P = .302, TKA: P = .534]).

Conclusions

We were unable to discern a difference in infection rates between chlorhexidine irrigation and our prior protocols using dilute Betadine for THA and 0.9% saline for TKA. The theoretic advantages of dilute CHG retention during closure appear to be safe without infectious concerns.

Synergistic bactericidal activity of chlorhexidine-loaded, silver-decorated mesoporous silica nanoparticles

Combination of chlorhexidine (CHX) and silver ions could engender synergistic bactericidal effect and improve the bactericidal efficacy. It is highly desired to develop an efficient carrier for the antiseptics codelivery targeting infection foci with acidic microenvironment. In this work, monodisperse mesoporous silica nanoparticle (MSN) nanospheres were successfully developed as an ideal carrier for CHX and nanosilver codelivery through a facile and environmentally friendly method. The CHX-loaded, silver-decorated mesoporous silica nanoparticles (Ag-MSNs@CHX) exhibited a pH-responsive release manner of CHX and silver ions simultaneously, leading to synergistically antibacterial effect against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Moreover, the effective antibacterial concentration of Ag-MSNs@CHX showed less cytotoxicity on normal cells. Given their synergistically bactericidal ability and good biocompatibility, these nanoantiseptics might have effective and broad clinical applications for bacterial infections.

The Two-Component System ChtRS Contributes to Chlorhexidine Tolerance in Enterococcus faecium

Enterococcus faecium is one of the primary causes of nosocomial infections. Disinfectants are commonly used to prevent infections with multidrug-resistant E. faecium in hospitals. Worryingly, E. faecium strains that exhibit tolerance to disinfectants have already been described. We aimed to identify and characterize E. faecium genes that contribute to tolerance to the disinfectant chlorhexidine (CHX). We used a transposon mutant library, constructed in a multidrug-resistant E. faecium bloodstream isolate, to perform a genome-wide screen to identify genetic determinants involved in tolerance to CHX. We identified a putative two-component system (2CS), composed of a putative sensor histidine kinase (ChtS) and a cognate DNA-binding response regulator (ChtR), which contributed to CHX tolerance in E. faecium Targeted chtR and chtS deletion mutants exhibited compromised growth in the presence of CHX. Growth of the chtR and chtS mutants was also affected in the presence of the antibiotic bacitracin. The CHX- and bacitracin-tolerant phenotype of E. faecium E1162 was linked to a unique, nonsynonymous single nucleotide polymorphism in chtR Transmission electron microscopy showed that upon challenge with CHX, the ΔchtR and ΔchtS mutants failed to divide properly and formed long chains. Normal growth and cell morphology were restored when the mutations were complemented in trans Morphological abnormalities were also observed upon exposure of the ΔchtR and ΔchtS mutants to bacitracin. The tolerance to both chlorhexidine and bacitracin provided by ChtRS in E. faecium highlights the overlap between responses to disinfectants and antibiotics and the potential for the development of cross-tolerance for these classes of antimicrobials.

Skin antisepsis with chlorhexidine versus iodine for the prevention of surgical site infection: A systematic review and meta-analysis

BACKGROUND

Surgical site infection (SSI) is one of the most frequent health care-associated infections. One of the practices to reduce their incidence is preoperative skin antisepsis. Two of the most commonly active components used are chlorhexidine gluconate and povidone iodine. Of 3 reviews conducted between 2010 and 2012 comparing antiseptics, 2 were in favor of chlorhexidine; however, the latest was unable to draw conclusions.

PURPOSE

To verify whether recent evidence supports the hypothesis that chlorhexidine in preoperative antisepsis is more efficient than other antiseptics in reducing SSI rates.

PROCEDURES

We conducted a systematic review from 2000-2014 in all languages. The primary end point was SSI incidence and secondary skin bacterial colonization.

RESULTS

Nineteen studies were included. Meta-analysis were conducted for comparable studies for both outcomes. The results of the meta-analysis, including all of the studies in which chlorhexidine was compared with iodophor, were in favor of chlorhexidine for both SSI incidence (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.52-0.92) and bacterial skin colonization (RR, 0.45; 95% CI, 0.36-0.55).

CONCLUSIONS

There is moderate-quality evidence supporting the use of chlorhexidine for preoperative skin antisepsis and high-quality evidence that the use of chlorhexidine is associated with fewer positive skin cultures. Further rigorous trials will be welcomed to attain stronger evidence as to the best antiseptic to be used before surgery.

Use of Chlorhexidine Preparations in Total Joint Arthroplasty

Prosthetic joint infection (PJI) is a serious complication after total joint arthroplasty (TJA). Chlorhexidine is a widely used antiseptic because of its rapid and persistent action. It is well tolerated and available in different formulations at various concentrations. Chlorhexidine can be used for pre-operative skin cleansing, surgical site preparation, hand antisepsis of the surgical team and intra-articular irrigation of infected joints. The optimal intra-articular concentration of chlorhexidine gluconate in irrigation solution is 2%, to provide a persistent decrease in biofilm formation, though cytotoxicity might be an issue. Although chlorhexidine is relatively cheap, routine use of chlorhexidine without evidence of clear benefits can lead to unnecessary costs, adverse effects and even emergence of resistance. This review focuses on the current applications of various chlorhexidine formulations in TJA. As the treatment of PJI is challenging and expensive, effective preparations of chlorhexidine could help in the prevention and control of PJI.

The efficacy of daily chlorhexidine bathing for preventing healthcare-associated infections in adult intensive care units

BACKGROUND/AIMS

Healthcare-associated infections (HAIs) in critically ill patients with prolonged length of hospital stay and increased medical costs. The aim of this study is to assess whether daily chlorhexidine gluconate (CHG) bathing will significantly reduce the rates of HAIs in adult intensive care units (ICUs).

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched until December 31, 2014 to identify relevant studies. Two authors independently reviewed and extracted data from included studies. All data was analyzed by Review Manager version 5.3.

RESULTS

Fifteen studies including three randomized controlled trials and 12 quasi-experimental studies were available in this study. The outcomes showed that daily CHG bathing were associated with significant reduction in the rates of primary outcomes: catheter-related bloodstream infection (risk ratio [RR], 0.44; 95% confidence interval [CI], 0.32 to 0.63; p < 0.00001), catheter-associated urinary tract infection (RR, 0.68; 95% CI, 0.52 to 0.88; p = 0.004), ventilator-associated pneumonia (RR, 0.73; 95% CI, 0.57 to 0.93; p = 0.01), acquisition of methicillin-resistant Staphylococcus aureus (RR, 0.78; 95% CI, 0.68 to 0.91; p = 0.001) and vancomycin-resistant Enterococcus (RR, 0.56; 95% CI, 0.31 to 0.99; p = 0.05).

CONCLUSIONS

Our study suggests that the use of daily CHG bathing can significantly prevent HAIs in ICUs. However, more well-designed studies are needed to confirm these findings.

Aqueous Chlorhexidine for Intravitreal Injection Antisepsis: A Case Series and Review of the Literature

PURPOSE

To determine the incidence of endophthalmitis in a large clinical series using aqueous chlorhexidine for antisepsis before intravitreal injection and to review the ophthalmic literature regarding chlorhexidine efficacy and safety.

DESIGN

Multicenter retrospective case series.

PARTICIPANTS

All patients receiving intravitreal injections from 7 retinal specialists.

METHODS

An audit of intravitreal injections performed by retinal specialists who exclusively used aqueous chlorhexidine 0.05% or 0.1% for prophylaxis of infective endophthalmitis was undertaken. The incidence of endophthalmitis was determined from August 1, 2011, to February 28, 2015. A literature review was performed to critically appraise the ocular safety and efficacy of aqueous chlorhexidine.

MAIN OUTCOME MEASURES

Incidence of endophthalmitis after intravitreal injections.

RESULTS

A total of 40 535 intravitreal injections were performed by 7 retinal specialists across 3 centers. Chlorhexidine was well tolerated, and only 1 patient with a suspected allergic reaction was noted. Three cases of endophthalmitis were identified with 1 culture-positive case. The 0.0074% (1 in 13 512) per-injection rate of endophthalmitis in this series compares favorably with previous series in which povidone-iodine has been used.

CONCLUSIONS

Aqueous chlorhexidine was associated with a low rate of postinjection endophthalmitis and was well tolerated by patients.

Comparison of Decontamination Methods for Human Skin Grafts

Skin grafts intended for autologous transplant may be dropped on the operating room floor during handling. The authors examined optimal procedures for decontaminating tissue intended for burn surgery. Porcine skin (5 × 5 cm sections) harvested from expired animals using standard procedures was inoculated with either 10(6) CFU/ml Staphylococcus aureus or Klebsiella pneumoniae. Decontaminating strategies were compared: 10% povidone iodine, 0.04% chlorhexidine, or 50 U/ml bacitracin for injection, and mechanical agitation using normal saline or sterile water; each agent was applied for 60 seconds. Each skin section was blended and plated on agar for bacterial enumeration using the spread plate method. Tissue viability was evaluated in parallel using a cell viability reagent, along with a control (heat at 200 °C for 5 min). Bacterial counts were log transformed; one-way ANOVA with Tukey-Kramer HSD analysis were performed. Concentration of organisms <10(5) CFU/g was considered clinically insignificant colonization. Eight donors provided 21 S. aureus and six K. pneumoniae samples. After exposure, mean organism concentration (CFU/g) was <10(5) for povidone iodine (S. aureus 2.83 × 10(4); K. pneumoniae 1.85 × 10(4)), chlorhexidine (S. aureus 4.52 × 10(4); K. pneumoniae 1.77 × 10(4)), and normal saline (K. pneumoniae 8.76 × 10(4)) treated groups. After log transform, only povidone iodine and chlorhexidine were found to be different from control in both groups. Viability was decreased in the positive control group, but not in treatment groups. Agents routinely used for surgical skin prep (povidone iodine and chlorhexidine), reduced both Gram-positive and Gram-negative contamination in tissue intended for skin grafting procedures. Antiseptic treatments did not impair the cellular viability of porcine skin.

Chlorhexidine Bathing Effects on Health-Care-Associated Infections

BACKGROUND

Health-care-associated infections (HAIs), infections that patients contract during the course of their hospitalization, are receiving a growing amount of attention. Heavy skin bacterial colonization aids in the transmission and development of HAIs. Nurses frequently use bathing with chlorhexidine gluconate (CHG) to reduce patients' cutaneous microbial burden. This intervention has been shown to have promising but mixed results in the prevention of HAIs.

PURPOSE

This article reviews the literature for evidence on the impact of CHG bathing on HAIs.

METHOD

A literature search was conducted to identify peer-reviewed studies and meta-analyses that examined the impact of CHG bathing on HAIs using PubMed and CINAHL with the following search terms: CHG bathing AND healthcare associated infections, surgical site infections ( SSIs), central line associated bloodstream infections ( CLABSIs), ventilator-associated pneumonias ( VAP), catheter-associated urinary-tract infections ( CAUTIs), and Clostridium difficile-associated disease. The initial search identified 23 articles for review. Additional studies were identified by searching references used in original studies or review articles on this topic.

PRINCIPLE FINDINGS

There is good evidence to support incorporating a CHG bathing regimen to reduce the incidence of CLABSIs, SSIs, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) HAIs.

CONCLUSION

As CHG becomes a standard practice to prevent HAIs, it is important to monitor for adverse reactions and evidence of resistance/susceptibility.

An antibacterial copper composite more bioactive than metallic silver

Although known for its biocidal activity, copper is still not considered as a viable alternative to silver in many of its biocidal applications, mainly because it is generally considered to be a milder antibacterial metal. As copper is much cheaper than silver (1/100), it is potentially more accessible to the health and hygiene needs of third-world countries, to large volume consumer products, and to large-scale agricultural and water treatment needs. Therefore, enhancing the biocidal efficacy of copper is a sought-after goal. We report a method for achieving this goal: by entrapping molecules of the biocidal agent chlorhexidine (CH) within a metallic copper metal powder, using a new materials methodology, the antibacterial efficacy of copper towards two model nosocomial opportunistic bacteria - the Gram-negative Pseudomonas aeruginosa and the Gram-positive Staphylococcus epidermidis- is enhanced to provide a powerful antibacterial agent exceeding the activity of silver. ICP-MS elemental analysis and UV-spectroscopy indicated that the enhanced bactericidal effects of the synthesized composite, CH@Cu, are associated with the sustained release of both copper ions and CH, giving rise to synergistically enhanced activity.

Dynamics of plasma levels of specific IgE in chlorhexidine allergic patients with and without accidental re-exposure

BACKGROUND

Chlorhexidine is an effective disinfectant, which may cause severe allergic reactions. Plasma level of specific IgE to chlorhexidine (ImmunoCAP(®) ) has high estimated sensitivity and specificity when measured within 6 months of allergic reaction, but knowledge of the dynamics over longer time periods is lacking and it is unknown whether levels fall below <0.35 kUA/L in patients with previously elevated levels. It is also unclear whether re-exposure influences levels of specific IgE.

OBJECTIVE

To investigate the dynamics of specific IgE in chlorhexidine allergic patients with and without re-exposure.

METHODS

All patients diagnosed with chlorhexidine allergy in the Danish Anaesthesia Allergy Centre January 1999 to March 2015 were invited to participate. The study included blood samples from the time of reaction and time of investigation and blood samples drawn prospectively over several years.

RESULTS

Overall, 23 patients were included. Specific IgE within hours of reaction was available in eight patients and was >0.35 kUA/L in six of these. During allergy investigations, usually 2-4 months later, specific IgE was >0.35 kUA/L in 22 of 23 patients. In the following months/years specific IgE declined <0.35 kUA/L in 17 of 23 patients (most rapidly within 4 months). Nine re-exposures in the healthcare setting were reported by seven patients (35%). Most re-exposures caused symptoms and were followed by an increase in specific IgE. Two patients with specific IgE <0.35 kUA/L reacted upon re-exposure.

CONCLUSIONS & CLINICAL RELEVANCE

Time from reaction should be considered when interpreting specific IgE results. Specific IgE is >0.35 kUA/L in most patients at time of reaction but should be repeated after a few weeks/months if negative. The optimal sampling time seems to be >1 month and <4 months. A value <0.35 kUA/L neither excludes allergy nor implies loss of reactivity in previously sensitized patients. Re-exposures are common, often iatrogenic, and can cause a rebound in specific IgE.

Potential hazards due to food additives in oral hygiene products

Food additives used to preserve flavor or to enhance the taste and appearance of foods are also available in oral hygiene products. The aim of this review is to provide information concerning food additives in oral hygiene products and their adverse effects. A great many of food additives in oral hygiene products are potential allergens and they may lead to allergic reactions such as urticaria, contact dermatitis, rhinitis, and angioedema. Dental practitioners, as well as health care providers, must be aware of the possibility of allergic reactions due to food additives in oral hygiene products. Proper dosage levels, delivery vehicles, frequency, potential benefits, and adverse effects of oral health products should be explained completely to the patients. There is a necessity to raise the awareness among dental professionals on this subject and to develop a data gathering system for possible adverse reactions.

A Randomized Trial Comparing Skin Antiseptic Agents at Cesarean Delivery

BACKGROUND

Preoperative skin antisepsis has the potential to decrease the risk of surgical-site infection. However, evidence is limited to guide the choice of antiseptic agent at cesarean delivery, which is the most common major surgical procedure among women in the United States.

METHODS

In this single-center, randomized, controlled trial, we evaluated whether the use of chlorhexidine-alcohol for preoperative skin antisepsis was superior to the use of iodine-alcohol for the prevention of surgical-site infection after cesarean delivery. We randomly assigned patients undergoing cesarean delivery to skin preparation with either chlorhexidine-alcohol or iodine-alcohol. The primary outcome was superficial or deep surgical-site infection within 30 days after cesarean delivery, on the basis of definitions from the Centers for Disease Control and Prevention.

RESULTS

From September 2011 through June 2015, a total of 1147 patients were enrolled; 572 patients were assigned to chlorhexidine-alcohol and 575 to iodine-alcohol. In an intention-to-treat analysis, surgical-site infection was diagnosed in 23 patients (4.0%) in the chlorhexidine-alcohol group and in 42 (7.3%) in the iodine-alcohol group (relative risk, 0.55; 95% confidence interval, 0.34 to 0.90; P=0.02). The rate of superficial surgical-site infection was 3.0% in the chlorhexidine-alcohol group and 4.9% in the iodine-alcohol group (P=0.10); the rate of deep infection was 1.0% and 2.4%, respectively (P=0.07). The frequency of adverse skin reactions was similar in the two groups.

CONCLUSIONS

The use of chlorhexidine-alcohol for preoperative skin antisepsis resulted in a significantly lower risk of surgical-site infection after cesarean delivery than did the use of iodine-alcohol. (Funded by the National Institutes of Health and Washington University School of Medicine in St. Louis; ClinicalTrials.gov number, NCT01472549.).

Evaluation of a hydrophobic gel adhering to the gingiva in comparison with a standard water-soluble 1% chlorhexidine gel after scaling and root planing in patients with moderate chronic periodontitis. A randomized clinical trial

OBJECTIVES

To evaluate the clinical, microbiological and enzymatic activity of a hydrophobic chlorhexidine-based gingiva-adhering gel containing herbal ingredients, compared with a commercially available 1% chlorhexidine water-soluble gel, during non-surgical therapy of moderate chronic periodontitis.

METHODS

A total of 34 subjects participated in this 6-month blinded randomized parallel controlled trial (ISRCTN35210084). After scaling and root planing (SRP), test group received the gel, by rubbing on the gingiva, once every second day, for 14 days. The control group received the control gel twice daily. Clinical parameters considered were the approximal plaque index, simplified oral hygiene index, modified gingival index, bleeding on probing, probing depth and clinical attachment level (primary outcome), assessed at baseline, 3 and 6 months, together with the frequency of detection of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis (P.g.), Prevotella intermedia, Treponema denticola (T.d.), Tannerella forsythia (T.f.), and activity of neutrophil elastase and myeloperoxidase (secondary outcomes).

RESULTS

At 3 and 6 months, all clinical parameters improved significantly, without significant intergroup differences, except OHI-S, which improved at 3 months (P < 0.05). Microbiological data resulted in no significant intergroup differences at baseline and 6 months. At 3 months, significant differences for P.g., T.f. and T.d. were noted. A significant reduction of neutrophil elastase after 3 and 6 months was observed (P < 0.005), without significant intergroup differences. For myeloperoxidase, significant reductions were noted in both groups (P < 0.005 and P < 0.05), but no significant intergroup differences. The tested product seemed to have an increased efficacy, due to longer persistence on the gingiva, with reduced application frequency.

CONCLUSIONS

Both products had a relatively similar influence on the clinical, microbiological and enzymatic outcomes at 3 and 6 months after SRP.

Bactericidal activity of 3 cutaneous/mucosal antiseptic solutions in the presence of interfering substances: Improvement of the NF EN 13727 European Standard?

OBJECTIVE

There is no standard protocol for the evaluation of antiseptics used for skin and mucous membranes in the presence of interfering substances. Our objective was to suggest trial conditions adapted from the NF EN 13727 standard, for the evaluation of antiseptics used in gynecology and dermatology.

METHODS

Three antiseptic solutions were tested in vitro: a chlorhexidine-benzalkonium (CB) combination, a hexamidine-chlorhexidine-chlorocresol (HCC) combination, and povidone iodine (P). The adaptation of trial conditions to the standard involved choosing dilutions, solvent, and interfering substances. The activity of solutions was assessed on the recommended strains at concentrations of 97% (pure solution), 50%, and 10% (diluted solution), and 1%. A logarithmic reduction ≥ 5 was expected after 60seconds of contact, to meet requirements of bactericidal activity.

RESULTS

HCC did not present any bactericidal activity except on P. aeruginosa at a concentration of 97%. P was not bactericidal on E. hirae at any concentration and on S. aureus at 97%. CB had the most homogeneous bactericidal activity with a reduction>5 log on the 4 bacterial strains at concentrations of 97%, 50% and 10%.

CONCLUSION

Adapting the NF EN 13727 standard allowed assessing the 3 tested solutions: only CB was bactericidal in dirty conditions. This study proved the possibility of validating antiseptic choice in vitro, in current practice conditions, for adjunctive treatment of skin and mucous membranes disorders, primarily of bacterial origin or with a potential of superinfection.

Polybiguanide (PHMB) loaded in PLA scaffolds displaying high hydrophobic, biocompatibility and antibacterial properties

Polyhexamethylenebiguanide hydrochloride (PHMB), a low molecular weight polymer related to chlorohexidine (CHX), is a well-known antibacterial agent. In this study, polylactide (PLA) nanofibers loaded with PHMB were produced by electrospinning to obtain 3D biodegradable scaffolds with antibacterial properties. PLA fibers loaded with CHX were used as control. The electrospun fibers were studied and analyzed by SEM, FTIR, DSC and contact angle measurements. PHMB and CHX release from loaded scaffolds was evaluated, as well as their antibacterial activity and biocompatibility. The results showed that the nanofibers became smoother and their diameter smaller with increasing the amount of loaded PHMB. This feature led to an increase of both surface roughness and hydrophobicity of the scaffold. PHMB release was highly dependent on the hydrophilicity of the medium and differed from that determined for CHX. Lastly, PHMB-loaded PLA scaffolds showed antibacterial properties since they inhibited adhesion and bacterial growth, and exhibited biocompatible characteristics for the adhesion and proliferation of both fibroblast and epithelial cell lines.

Chlorhexidine: an unrecognised cause of anaphylaxis

Chlorhexidine is a highly effective antiseptic and disinfectant. In the past 20 years there has been a substantial increase in the number of chlorhexidine containing products used in healthcare. Anaphylaxis to chlorhexidine was first reported in 1984 and was almost always seen in men. However, in the last 4 years we have observed a surge in confirmed cases of anaphylaxis to chlorhexidine, with increasing numbers of female patients recently diagnosed. Yet, awareness of chlorhexidine as a cause of anaphylaxis is low because it is not a drug but a 'hidden' allergen, for example as a coating on medical devices such as central lines and urinary catheters. Patients will often have more than one allergic/anaphylactic reaction before the diagnosis is suspected. We have observed that there is poor recognition of an initial allergic reaction to chlorhexidine, which is well described. This, alongside poor labelling of chlorhexidine containing products, has resulted in further inadvertent exposure resulting in severe anaphylaxis. Prompt referral to a specialist allergy centre ensures appropriate investigations, diagnosis and management. Increasing awareness of the potential risk of life-threatening anaphylaxis associated with chlorhexidine use is vital, particularly in perioperative procedures. Healthcare workers are fundamental in avoiding and preventing further reactions to chlorhexidine containing products in patients diagnosed with anaphylaxis to chlorhexidine.

New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes

Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(α-aminoacyl)-α,ω-diol-diester monomer. The polymer having L-leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and polyhexamethylenebiguanide) and enzymes (e.g. α-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells.

Standardized testing with chlorhexidine in perioperative allergy--a large single-centre evaluation

BACKGROUND

Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated provocation model exists, and other diagnostic tests have never been evaluated. The aims were to estimate (i) the prevalence of chlorhexidine allergy in perioperative allergy and (ii) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy.

METHODS

We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004-2012. The following tests were performed: specific IgE (Immunocap® ; Phadia AB, Sweden), histamine release test (HR) (RefLab ApS, Denmark), skin prick test (SPT) and intradermal test (IDT). Positivity criteria were as follows: specific IgE >0.35 kUA/l; HR class 1-12; SPT mean wheal diameter ≥3 mm; IDT mean wheal diameter ≥ twice the diameter of negative control. Chlorhexidine allergy was post hoc defined as a relevant clinical reaction to chlorhexidine combined with two or more positive tests. Based on this definition, sensitivity and specificity were estimated for each test.

RESULTS

In total, 22 of 228 patients (9.6%) met the definition of allergy to chlorhexidine. Estimated sensitivity and specificity were as follows: specific IgE (sensitivity 100% and specificity 97%), HR (sensitivity 55% and specificity 99%), SPT (sensitivity 95% and specificity 97%) and IDT (sensitivity 68% and specificity 100%).

CONCLUSIONS

In patients investigated for suspected perioperative allergic reactions, 9.6% were diagnosed with allergy to chlorhexidine. Using our definition of chlorhexidine allergy, the highest combined estimated sensitivity and specificity was found for specific IgE and SPT.

Human osteoblast damage after antiseptic treatment

PURPOSE

Antiseptics are powerful medical agents used for wound treatment and decontamination and have a high potential for defeating joint infections in septic surgery. Both chlorhexidine and polyhexanide are frequently used in clinical practice and have a broad antimicrobial range, but their effect on human osteoblasts has not been sufficiently studied. Our objective was to investigate the toxic effects of polyhexanide and chlorhexidine on human osteoblasts in vitro to evaluate their clinical applicability in septic surgery.

METHODS

We isolated and cultivated human osteoblasts in vitro and assayed the toxic effects of chlorhexidine 0.1% and polyhexanide 0.04%, concentrations commonly applied in clinical practice. Toxicity analysis was performed by visualisation of cell structure, lactate dehydrogenase (LDH) activity and evaluation of vital cells. Toxicity was evaluated by microscopic inspection of cell morphology, trypan blue staining and determination of LDH release.

RESULTS

Damaged cell structure could be shown by microscopy. Both antiseptics promoted LDH activity after incubation with osteoblasts. The evaluation of vital osteoblasts showed a significant decrease of vital cells.

CONCLUSIONS

Both antiseptics induced significant cell death of osteoblasts at optimum exposure. We therefore recommend cautious use of polyhexanide and chlorhexidine in septic surgery to avoid severe osteoblast toxicity.

Chlorhexidine in cosmetic products - a market survey

BACKGROUND

Chlorhexidine may cause type I and type IV allergy. Some chlorhexidine-allergic individuals have been exposed in the healthcare setting as patients or healthcare workers, but for others the source of sensitization is unknown. Chlorhexidine may be used as a preservative or an antimicrobial agent in cosmetic products at a concentration up to 0.3%, as set by the European Cosmetics Directive (now Regulations).

OBJECTIVES

To identify cosmetic product types containing chlorhexidine, and to measure the concentration of chlorhexidine in selected products.

METHODS

Between February 2013 and April 2013, we checked for chlorhexidine in cosmetic products in 14 supermarkets, one hairdressing salon and one beauty and retail store in Copenhagen, Denmark by reading the ingredient labels. The chlorhexidine concentration was measured in 10 selected products by high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector.

RESULTS

Chlorhexidine was found in 80 of 2251 checked products (3.6%) in the following categories: hair products (57/760), creams (9/324), face washes (4/24), wet wipes (4/63), skin tonics (3/22), make-up removers (2/25), and mouth washes (1/17). Chlorhexidine concentrations were 0.01-0.15%.

CONCLUSIONS

We found chlorhexidine in various cosmetic product types, predominantly aimed at females, and in hair products. The measured chlorhexidine concentrations were all within the permitted limit. The relevance for allergic sensitization should be further explored.

Chlorhexidine for the prevention of bloodstream infection associated with totally implantable venous ports in patients with solid cancers

PURPOSE

To evaluate the preventive effects of topical skin disinfection with chlorhexidine on bloodstream infection (BSI) associated with totally implantable venous port (Port-A).

METHODS

Two consecutive cohorts of solid cancer patients were prospectively followed for the occurrence of Port-A associated BSI (PABSI). The first cohort used povidone-iodine as topical skin disinfection and the second cohort used chlorhexidine. The primary endpoint was the time to first PABSI. Propensity score analysis was applied. The preventive effects of chlorhexidine were analyzed by Cox proportional hazards models.

RESULTS

There were 396 patients (81,752 catheter-days) in the iodine cohort and 497 (99,977 catheter-days) in the chlorhexidine cohort. Gram-negative bacteria were the most common pathogens to cause first episode of PABSI (iodine cohort (I) vs chlorhexidine cohort (C) and 0.404 vs 0.450 per 1,000 catheter-day), followed by Gram-positive bacteria (I vs C and 0.269 vs 0.110 per 1,000 catheter-day), and fungi (I vs C and 0.098 vs 0.070 per 1,000 catheter-day). Three hundred forty-three patients were selected from each cohort by propensity score match analysis. Chlorhexidine use was associated with a significant improvement on time to first PABSI caused by Gram-positive bacteria (log-rank test, p=0.00175; HR=0.35, 95 % CI, 0.14-0.85, p=0.02). No significant preventive effects of chlorhexidine on time to first PABSI caused by Gram-negative bacteria or fungi was found.

CONCLUSIONS

Chlorhexidine topical skin disinfection may prevent PABSI caused by Gram-positive bacteria in patients with solid cancers. The nonsignificant effect on preventing overall PABSI may be attributed to the high incidence of Gram-negative bacteria related PABSI.

Antimicrobial activity of common mouthwash solutions on multidrug-resistance bacterial biofilms

Background

Periodontal bacteria occur in both planktonic and biofilm forms. While poor oral hygiene leads to accumulation of bacteria, reducing these microbes is the first step toward good oral hygiene. This is usually achieved through the use of mouthwash solutions. However, the exact antibacterial activity of mouthwash solution, especially when bacteria form biofilms, is yet to be determined. In this study, we evaluated the antibacterial activity of common mouthwash solutions against standard bacteria in their planktonic and biofilm states.

Methods

Standard bacterial strains were cultured, and biofilm were formrd. Thereafter, using standard method for determination of minimum inhibitory concentrations (MIC) values of various mouthwash solutions were determined.

Results

Results show that common mouthwash solutions have variable antibacterial activity depending on their major active components. Only mouthwash solutions containing chlorohexidine gluconate or cetylpyridinum chloride exhibited activity against majority, but not all tested bacterial strains in their biofilm state. Additionally, bacteria are generally less susceptible to all mouthwash solutions in their biofilm as compared to planktonic state.

Conclusions

While mouthwash solutions have variable antibacterial activity, bacteria in their biofilm state pose a challenge to dental hygiene/care where bacteria become not susceptible to majority of available mouthwash solutions.

In vitro comparison of the effectiveness of polihexanide and chlorhexidine against canine isolates of Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Malassezia pachydermatis

BACKGROUND

Polihexanide (polyhexamethylene biguanide) is an antiseptic substance that plays a prominent role in the treatment of critically colonized or infected acute and chronic wounds in humans.

HYPOTHESIS/OBJECTIVES

The aim of this study was to assess the in vitro antimicrobial efficacy of polihexanide against canine isolates of Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Malassezia pachydermatis and compare it with 4.5% chlorhexidine digluconate for two different contact times.

METHODS

Ten isolates of each organism were incubated at 37°C for 3 and 5 min, respectively, with each antiseptic diluted 1:2 to 1:4096 in phosphate-buffered saline.

RESULTS

Both products showed excellent antimicrobial activity against all isolates tested. No significant differences in antimicrobial efficacy between antiseptics for all isolates were found. With the exception of one isolate of M. pachydermatis at 3 min exposure time, all isolates were completely killed by a dilution of 1:32 of polihexanide as well as chlorhexidine at both exposure times. Although the mean values of break-point concentrations for both antiseptics increased with the longer exposure time of 5 min, there were no significant differences between the two exposure times. The P. aeruginosa isolates were more susceptible than S. pseudintermedius for both antiseptics, and break-point dilutions were significantly higher compared with break-point dilutions obtained by all other treatments.

CONCLUSIONS AND CLINICAL IMPORTANCE

The results indicate that polihexanide has comparable in vitro antimicrobial efficacy to chlorhexidine and presents a potential alternative agent for skin and wound antisepsis in veterinary medicine.

A randomized controlled trial of 1% aqueous chlorhexidine gluconate compared with 10% povidone-iodine for topical antiseptic in neonates: effects on blood culture contamination rates

We conducted a randomized controlled trial in neonates with birth weight greater than or equal to 1,500 g that compared 1% aqueous chlorhexidine gluconate (CHG) with 10% povidone-iodine (PI) as a topical antiseptic. We found 1% CHG to be more effective than 1% PI in reducing blood culture contamination rates, and no contact dermatitis was observed.

A reprofiled drug, auranofin, is effective against metronidazole-resistant Giardia lamblia

Giardiasis is one of the most common causes of diarrheal disease worldwide. Treatment is primarily with 5-nitro antimicrobials, particularly metronidazole. Resistance to metronidazole has been described, and treatment failures can occur in up to 20% of cases, making development of alternative antigiardials an important goal. To this end, we have screened a chemical library of 746 approved human drugs and 164 additional bioactive compounds for activity against Giardia lamblia. We identified 56 compounds that caused significant inhibition of G. lamblia growth and attachment. Of these, 15 were previously reported to have antigiardial activity, 20 were bioactive but not approved for human use, and 21 were drugs approved for human use for other indications. One notable compound of the last group was the antirheumatic drug auranofin. Further testing revealed that auranofin was active in the low (4 to 6)-micromolar range against a range of divergent G. lamblia isolates representing both human-pathogenic assemblages A and B. Most importantly, auranofin was active against multiple metronidazole-resistant strains. Mechanistically, auranofin blocked the activity of giardial thioredoxin oxidoreductase, a critical enzyme involved in maintaining normal protein function and combating oxidative damage, suggesting that this inhibition contributes to the antigiardial activity. Furthermore, auranofin was efficacious in vivo, as it eradicated infection with different G. lamblia isolates in different rodent models. These results indicate that the approved human drug auranofin could be developed as a novel agent in the armamentarium of antigiardial drugs, particularly against metronidazole-resistant strains.

Review of immobilized antimicrobial agents and methods for testing

Antimicrobial surfaces for food and medical applications have historically involved antimicrobial coatings that elute biocides for effective kill in solution or at surfaces. However, recent efforts have focused on immobilized antimicrobial agents in order to avoid toxicity and the compatibility and reservoir limitations common to elutable agents. This review critically examines the assorted antimicrobial agents reported to have been immobilized, with an emphasis on the interpretation of antimicrobial testing as it pertains to discriminating between eluting and immobilized agents. Immobilization techniques and modes of antimicrobial action are also discussed.

An ex vivo bacteriologic study comparing antiseptic techniques for natural orifice translumenal endoscopic surgery (NOTES) via the gastrointestinal tract

BACKGROUND

NOTES via the gastrointestinal tract raises the specter of intra-peritoneal infection. Various anti-microbial techniques have been employed in animal and human survival studies, including saline lavage, intravenous and topical antibiotics, and povidone-iodine, although there is a paucity of data regarding their general effectiveness.

AIM

To assess the effectiveness of existing sterilization techniques for NOTES by quantifying and speciating colony-forming units (CFUs) before and after treatment.

DESIGN

Ex vivo animal studies; bacteriological study.

METHODS

Stomachs and distal colons were harvested en bloc from ten fasted adult white pigs following euthanasia. Half received cefazolin 1 g intravenously prior to killing. Multiple tissue samples were obtained from each resected organ. Each tissue sample was then assigned to one of five treatment arms: (1) normal saline, (2) Betadine, (3) cefazolin/metronidazole suspension, (4) chlorhexidine, (5) no treatment. Fifteen samples were used per arm. After treatment, the mucosal surface of each sample was swabbed and inoculated in normal saline, followed by serial dilutions, which were then plated onto sheep's blood agar plates and incubated under aerobic and anaerobic conditions. CFUs were quantified and speciated.

RESULTS

Median bacterial density was estimated to be 8.0 × 10(5) CFUs/ml (stomach) and 1.9 × 10(6) CFUs/ml (colon). The predominant organisms were Escherichia coli (stomach) and both E. coli and Enterococcus sp. (colon). Saline and antibiotic suspension lavages caused a 1-log reduction in stomach and colon. Betadine/chlorhexidine lavage resulted in a 4-log reduction. Intravenous antibiotics alone resulted in a 4-log reduction. Combining intravenous antibiotics and either Betadine or chlorhexidine decreased counts to the 10(1) level. By Kruskal-Wallis method, differences were statistically significant (p = 0.001).

CONCLUSIONS

The use of intravenous antibiotics in addition to topical Betadine or chlorhexidine effectively reduced microbial burden in both gastric and colonic mucosa in this porcine model to the 10(1) level.

A review of topical therapy for skin infections with bacteria and yeast

BACKGROUND

Cutaneous infections with bacteria and yeasts are common in small animal practice. Treatment with systemic antibiotics or antifungal agents may not be ideal, because of the increasing development of multiresistant organisms, the cost and the possible adverse effects. Topical antimicrobials may be used as adjunctive therapy to systemic treatment or as sole therapy instead of systemic treatment.

OBJECTIVE

This literature review evaluated studies on topical antimicrobial treatment of skin infections.

METHODS

In vitro and in vivo studies evaluating topical antimicrobial agents were identified using a number of electronic and manual searches of textbooks and articles. Studies were evaluated, and the evidence for or against the use of the topical agents was extracted.

RESULTS

There is good evidence for the efficacy of chlorhexidine and, to a lesser degree, benzoyl peroxide in canine bacterial skin infections. There is limited evidence for the efficacy of silver sulfadiazine and medical honey against bacterial skin infections in the dog, and for the efficacy of hydrogen peroxide and stannous fluoride in the horse. Good evidence supports the use of a combination of chlorhexidine and miconazole in dogs with cutaneous Malassezia infections. There is insufficient evidence to recommend any other topical therapy for use in cutaneous infections.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although many antimicrobial topicals are marketed in veterinary dermatology, the efficacy has been reported for only a minority of agents. Randomized controlled trials evaluating various topical treatments are therefore urgently needed.

Medical legal complications of cutaneous surgery

Complications in surgery are an unfavorable outcome as a result of a procedure. These can occur intraoperatively, immediately after or in the distant future. Minimizing the risk and prompt treatment of complications is important to avoid potentially disastrous outcomes. This article will review the more common complications of cutaneous surgery and then analyze the legal consequences of these complications.

Effects of chlorhexidine oral decontamination on respiratory colonization during mechanical ventilation in intensive care unit patients

We conducted a retrospective cohort study to assess respiratory colonization before and after the use of chlorhexidine oral decontamination among a cohort of intensive care unit patients who received mechanical ventilation. We observed a decrease in the prevalence of Enterobacteriaceae and an increase in the incidence of fungal colonization. Chlorhexidine oral decontamination might have a differential effect on respiratory colonization.

Severe anaphylactic reaction to chlorhexidine during total hip arthroplasty surgery. A case report

Two consecutive hip surgery procedures in the same patient were aborted following a severe anaphylactic reaction of the patient. After the second procedure, the patient was diagnosed to be allergic to chlorhexidine, a component of the gel used to insert a urinary catheter. Chlorhexidine allergy is rare, and the delayed presentation may make it easy to overlook. In hip arthroplasty surgery, this may result in an abandoned procedure and the need for re-operation.

Bacteriostatic effect of copaiba oil (Copaifera officinalis) against Streptococcus mutans

This study evaluated the inhibitory activity of copaiba oil (Copaifera officinalis against the cariogenic microorganism, Streptococcus mutans. For such purpose, a minimum inhibition concentration test of copaiba oil against S. mutans was performed, using the serial dilution in broth technique, with a negative control, a positive control (0.12% chlorhexidine) and a 10% copaíba oil solution as a test. A minimum bactericidal concentration test with tubes presenting microbial inhibition was also conduced. In the minimum inhibitory concentration test, copaiba oil showed inhibition of bacterial growth at all concentrations tested up to 0.78 µL/mL of the 10% copaiba oil solution in the broth. In addition, the negative control had no inhibition, and the 0.12% chlorhexidine solution was effective up to 6.25 µL/mL in the broth. Copaiba oil showed a bacteriostatic activity against S. mutans at low concentrations, and could be a an option of phytotherapic agent to be used against cariogenic bacteria in the prevention of caries disease.