Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds

<p>Abstract</p> <p>Background</p> <p>Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s.</p> <p>Method</p> <p>We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium^®Comfort Gel) within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain was evaluated in quadruplicate.</p> <p>Results</p> <p>The hand gel (85% ethanol, w/w) was found to reduce all 11 Gram-positive and all 16 Gram-negative bacteria by more than 5 log₁₀steps within 15 s, not only against the ATCC test strains but also against corresponding clinical isolates. In addition, a log₁₀reduction > 5 was observed against all tested emerging bacterial pathogens.</p> <p>Conclusion</p> <p>The ethanol-based hand gel was found to have a broad spectrum of bactericidal activity in only 15 s which includes the most common species causing nosocomial infections and the relevant emerging pathogens. Future research will hopefully help to find out if a shorter application time for the post contamination treatment of hands provides more benefits or more risks.</p

Eradication of methicillin-resistant Staphylococcus aureus with an antiseptic soap and nasal mupirocin among colonized patients – an open uncontrolled clinical trial

BACKGROUND: Aim of the study was to determine the clinical efficacy of a new antiseptic liquid soap (Stellisept(® )scrub), based on the combination of undecylenamidopropyltrimonium methosulphate (4%) and phenoxyethanol (2%), for eradication of MRSA among colonized patients who do not receive antibiotic therapy. METHODS: Over two years 50 MRSA patients in 6 hospitals were observed. Treatment was defined as the daily application of Stellisept scrub for the antiseptic body and hair wash (at least 60 s) in combination with nasal mupirocin. A treatment cycle was a minimum of 5 days treatment. Screening was carried out at least 48 h after the treatment cycle was finished, with 24 h between each of the requested three or more samplings, which included the nasopharynx, groin, axilla, perineum and other MRSA-positive skin areas. RESULTS: Fifteen cases were retrospectively excluded (lack of outcome documentation, concomitant antibiotic therapy, open wounds). All 35 patients had colonization with MRSA before antiseptic treatment on the skin, in the groin (80%), the axilla (25.7%), the perineum (20%) or other skin areas (14.3%). Colonization at more than one skin sites was found in 34.3%. Nasal colonization was found in 21 of 28 patients (75%), 7 patients were without nasal screening prior to the antiseptic treatment. After one treatment cycle MRSA was eradicated in 25 patients (71.4%), after a second cycle the total eradication rate was 91.4%, after a third cycle the rate increased to 94.2%. No patient discontinued the antiseptic treatment due to dermal intolerance of the product. CONCLUSIONS: Progressive eradication of MRSA carriage was observed with the antiseptic soap and mupirocin. The eradication rate was not biased by concomitant antibiotic treatment, screening during treatment or lack of evidence for colonization in contrast to other studies with other preparations

Efficacy of two distinct ethanol-based hand rubs for surgical hand disinfection – a controlled trial according to prEN 12791

BACKGROUND: Aim of the study was to determine the efficacy of two distinct ethanol-based hand rubs for surgical hand disinfection in a controlled cross-over trial according to prEN 12791. METHODS: 20 subjects were included. Hands were washed for 1 min with soap. The bacterial prevalue was obtained by rubbing finger tips in TSB for 1 min. Then, each subject treated the hands with the reference procedure (n-propanol, 60% v/v) or the product (Sterillium(®) Rub, based on 80% ethanol; Avagard, based on 61% ethanol and 1% chlorhexidine gluconate) which were all applied in 3 to 4 portions each of 3 ml for a total of 3 min. Bacterial postvalues (immediate effect) were taken from one hand, the other hand was gloved for 3 h. After gloves were taken off the second postvalue was taken for the assessment of a sustained effect. RESULTS: Bacterial pre-values were between 4.38 ± 0.66 and 4.46 ± 0.71. Sterillium(® )Rub achieved the required immediate (mean log(10)-reduction of 2.59 ± 1.19) and sustained effect (1.73 ± 1.08) compared with the reference treatment (immediate effect: 2.58 ± 1.16; sustained effect: 1.67 ± 0.96). Avagard, however, did not achieve the required immediate (1.82 ± 1.40) and sustained effect (1.41 ± 1.08) in comparison to the reference disinfection (immediate effect: 2.98 ± 0.90; sustained effect: 2.56 ± 1.17; p < 0.01; Wilcoxon test). CONCLUSION: Based on our data, Sterillium(® )Rub can be regarded to be effective for surgical hand disinfection, but Avagard can not. The addition of 1% chlorhexidine gluconate to 61% ethanol (w/w) did not outweigh an ethanol concentration of 80% (w/w)

Pitfalls in efficacy testing – how important is the validation of neutralization of chlorhexidine digluconate?

<p>Abstract</p> <p>Background</p> <p>Effective neutralization of active agents is essential to obtain valid efficacy results, especially when non-volatile active agents like chlorhexidine digluconate (CHG) are tested. The aim of this study was to determine an effective and non-toxic neutralizing mixture for a propan-1-ol solution containing 2% CHG.</p> <p>Methods</p> <p>Experiments were carried out according to ASTM E 1054-02. The neutralization capacity was tested separately with five challenge microorganisms in suspension, and with a rayon swab carrier. Either 0.5 mL of the antiseptic solution (suspension test) or a saturated swab with the antiseptic solution (carrier test) was added to tryptic soy broth containing neutralizing agents. After the samples were mixed, aliquots were spread immediately and after 3 h of storage at 2 – 8°C onto tryptic soy agar containing a neutralizing mixture.</p> <p>Results</p> <p>The neutralizer was, however, not consistently effective in the suspension test. Immediate spread yielded a valid neutralization with <it>Staphylococcus aureus, Staphylococcus epidermidis </it>and <it>Corynebacterium jeikeium </it>but not with <it>Micrococcus luteus </it>(p < 0.001) and <it>Candida albicans </it>(p < 0.001). A 3-h storage period of the neutralized active agents in suspension resulted in significant carry-over activity of CHG in addition against <it>Staphylococcus epidermidis </it>(p < 0.001) and <it>Corynebacterium jeikeium </it>(p = 0.044). In the carrier test, the neutralizing mixture was found to be effective and non toxic to all challenge microorganisms when spread immediately. However, after 3 h storage of the neutralized active agents significant carry-over activity of CHG against <it>Micrococcus luteus </it>(p = 0.004; Tukey HSD) was observed.</p> <p>Conclusion</p> <p>Without effective neutralization in the sampling fluid, non-volatile active ingredients will continue to reduce the number of surviving microorganisms after antiseptic treatment even if the sampling fluid is kept cold straight after testing. This can result in false-positive antiseptic efficacy data. Attention should be paid during the neutralization validation process to the amount of antiseptic solution, the storage time and to the choice of appropriate and sensitive microorganisms.</p

Insufficient neutralization in testing a chlorhexidine-containing ethanol-based hand rub can result in a false positive efficacy assessment

BACKGROUND: Effective neutralization in testing hand hygiene preparations is considered to be a crucial element to ensure validity of the test results, especially with the difficulty to neutralize chlorhexidine gluconate. Aim of the study was to measure the effect of chemical neutralization under practical test conditions according to EN 1500. METHODS: We have investigated two ethanol-based hand rubs (product A, based on 61% ethanol and 1% chlorhexidine gluconate; product B, based on 85% ethanol). The efficacy of products (application of 3 ml for 30 s) was compared to 2-propanol 60% (v/v) (two 3 ml rubs of 30 s each) on hands artificially contaminated with Escherichia coli using a cross-over design with 15 volunteers. Pre-values were obtained by rubbing fingertips for 1 minute in liquid broth. Post-values were determined by sampling immediately after disinfection in liquid broth with and without neutralizers (0.5% lecithin, 4% polysorbate 20). RESULTS: The neutralizers were found to be effective and non-toxic. Without neutralization in the sampling fluid, the reference disinfection reduced the test bacteria by 3.7 log(10), product B by 3.3 log(10 )and product A by 4.8 log(10 )(P = 0.001; ANOVA). With neutralization the reference disinfection reduced the test bacteria by 3.5 log(10), product B by 3.3 log(10 )and product A by 2.7 log(10 )(P = 0.011; ANOVA). In comparison to the reference treatment Product B lead to a lower mean reduction than the reference disinfection but the difference was not significant (P > 0.1; Wilcoxon-Wilcox test). Without neutralizing agents in the sampling fluid, product A yielded a significantly higher reduction of test bacteria (4.8; P = 0.02) as compared to the situation with neutralizing agents (2.7; P = 0.033). CONCLUSION: The crucial step of neutralization lies in the sampling fluid itself in order to stop any residual bacteriostatic or bactericidal activity immediately after the application of the preparation, especially with chlorhexidine gluconate-containing preparations. This is particularly important at short application times such as the 30 s

Efficacy of two ethanol-based skin antiseptics on the forehead at shorter application times

<p>Abstract</p> <p>Background</p> <p>Recent research suggests that alcohol-based skin antiseptics exhibit their efficacy on the resident skin flora of the forehead in less than 10 minutes. That is why we have looked at the efficacy of two ethanol-based skin antiseptics applied for 10, 2.5 and 2 minutes on skin with a high density of sebaceous glands. Each experiment was performed in a reference-controlled cross-over design with at least 20 participants. Application of isopropanol (70%, v/v) for 10 minutes to the forehead served as the reference treatment. The clear (skin antiseptic A) and coloured preparations (skin antiseptic B) contain 85% ethanol (w/w). Pre-values and post-values (immediately after the application and after 30 min) were obtained by swabbing a marked area of 5 cm² for about 10 s. Swabs were vortexed in tryptic soy broth containing valid neutralizing agents. After serial dilution aliquots were spread on tryptic soy agar. Colonies were counted after incubation of plates at 36°C for 48 h. The mean log₁₀ reduction of bacteria was calculated. The Wilcoxon matched-pairs signed-ranks test was used for a comparison of treatments.</p> <p>Results</p> <p>Skin antiseptic A applied for 10 min was significantly more effective than the reference treatment. When applied for 2.5 min (three experiments) it was significantly more effective than the reference treatment immediately after application (2.7 versus 2.2 log₁₀ reduction; p < 0.001) and equally effective after 30 min (2.8 versus 2.6 log₁₀ reduction; p = 0.053). Skin antiseptic B applied for 2.5 min (three experiments) was significantly more effective than the reference treatment both immediately after application (2.3 versus 1.9 log₁₀ reduction; p < 0.001) and after 30 min (2.5 versus 2.1 log₁₀ reduction; p = 0.002).</p> <p>Conclusion</p> <p>The clear and coloured skin antiseptics applied for 2.5 min on the skin of the forehead fulfilled the efficacy requirements for skin antisepsis. The shorter application time on skin with a high density of sebaceous glands will allow to act more efficiently in clinical practice.</p

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

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

Suitability of vaccinia virus and bovine viral diarrhea virus (BVDV) for determining activities of three commonly-used alcohol-based hand rubs against enveloped viruses

BACKGROUND: A procedure for including activity against enveloped viruses in the post-contamination treatment of hands has been recommended, but so far no European standard is available to implement it. In 2004, the German Robert Koch-Institute (RKI) and the German Association for the Control of Virus Disease (DVV) suggested that vaccinia virus and bovine viral diarrhea virus (BVDV) should be used as test viruses in a quantitative suspension test to determine the activity of a disinfectant against all enveloped viruses. METHODS: We have studied the activities of three commonly-used alcohol-based hand rubs (hand rub A, based on 45% propan-2-ol, 30% propan-1-ol and 0.2% mecetronium etilsulfate; hand rub B, based on 80% ethanol; hand rub C, based on 95% ethanol) against vaccinia virus and BVDV, and in addition against four other clinically relevant enveloped viruses: herpes simplex virus (HSV) types 1 and 2, and human and avian influenza A virus. The hand rubs were challenged with different organic loads at exposure time of 15, 30 and 60 s. According to the guidelines of both BGA/RKI and DVV, and EN 14476:2005, the reduction of infectivity of each test virus was measured on appropriate cell lines using a quantitative suspension test. RESULTS: All three alcohol-based hand rubs reduced the infectivity of vaccinia virus and BVDV by ≥ 4 log(10)-steps within 15 s, irrespective of the type of organic load. Similar reductions of infectivity were seen against the other four enveloped viruses within 15 s in the presence of different types of organic load. CONCLUSION: Commonly used alcohol-based hand rubs with a total alcohol concentration ≥ 75% can be assumed to be active against clinically relevant enveloped viruses if they effectively reduce the infectivities of vaccinia virus and BVDV in a quantitative suspension test

Emergence of Glutaraldehyde-Resistant Pseudomonas aeruginosa

Objective. In November 2009, routine sampling of endoscopes performed to monitor the effectiveness of the endoscope-cleaning procedure at our hospital detected Pseudomonas aeruginosa. Herein we report the results of the subsequent investigation. Design and Methods. The investigation included environmental cultures for source investigation, molecular analysis by pulsed-field gel electrophoresis (PFGE) to reveal the identity of the strains, and determination of the bactericidal activity of the glutaraldehyde-based disinfectant used for automated endoscope reprocessing. In addition, patient outcome was analyzed by medical chart review, and incidence rates of clinical samples with P. aeruginosa were compared. Setting. The University Hospital of Basel is an 855-bed tertiary care center in Basel, Switzerland. Approximately 1,700 flexible bronchoscopic, 2,500 gastroscopic, 1,400 colonoscopic, 140 endoscopic retrograde cholangiopancreatographic, and 140 endosonographic procedures are performed annually. Results. P. aeruginosa was detected in samples obtained from endoscopes in November 2009 for the first time since the initiation of surveillance in 2006. It was found in the rinsing water and in the drain of 1 of the 2 automated endoscope reprocessors. PFGE revealed 2 distinct P. aeruginosa strains, one in each reprocessor. The glutaraldehyde-based disinfectant showed no activity against the 2 pseudo-outbreak strains when used in the recommended concentration under standard conditions. After medical chart review, 6 patients with lower respiratory tract and bloodstream infections were identified as having a possible epidemiological link to the pseudo-outbreak strain. Conclusions. This is the first description of a pseudo-outbreak caused by P. aeruginosa with reduced susceptibility to an aldehyde-based disinfectant routinely used in the automated processing of endoscope