Comparison of chlorhexidine and alcohol-based antisepsis on the paralumbar fossa in cattle.

OBJECTIVE: To determine skin reaction, post-treatment reduction (immediate effect), and 1 hour post-treatment reduction (sustained effect) of aerobic bacterial colony forming units (CFU) following three antiseptic protocols in cattle. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: Eighteen cows. METHODS: Three sites in each paralumbar fossa were clipped and randomly assigned to one of three treatment groups: 5 minute 4% chlorhexidine gluconate scrub (CHG); 90 second 80% ethanol scrub (ET); 90 second 70% isopropyl alcohol scrub (IPA). All sites were monitored at all sampling time points and at 24 hours following treatment for adverse skin reaction. Samples were collected pre-, immediately post-, and 1 hour post-treatment and plated in duplicate. Bacterial counts were shifted to eliminate zeroes, log10 transformed, and averaged. ANOVA was used to compare differences in mean reduction in log10 CFU/ml between groups. RESULTS: Reduction in log10CFU/ml was more pronounced immediately after application of IPA (p = .001) and ET (p = .001) than CHG. This reduction was better sustained after preparation with CHG than ET (p = .005) but not IPA. Immediate and sustained reductions in bacterial loads did not differ after application of IPA or ET. No adverse skin reactions were noted. CONCLUSIONS: Skin preparation with alcohol-based antiseptics was well tolerated and improved immediate bacterial reduction compared to CHG. This reduction was better sustained 1 hour after application of CHG than ET, but no difference was detected between CHG and IPA. CLINICAL RELEVANCE: Lack of adverse skin reaction and performance provide evidence to support skin preparation with alcohol-based antiseptics in cattle.

Disinfection of needleless connectors to reduce Staphylococcus aureus bacterial load.

HIGHLIGHTS: Compare effectiveness of chemical disinfectants in reducing S. aureus. Five disinfectants reduced the bacterial load, especially chlorhexidine solutions. Focus on Brazilian clinical practice of needleless connector disinfection. PURPOSE: This study aimed to gain further knowledge about the comparative effectiveness of chemical disinfectants in reducing the bacterial load of NCs inoculated with S. aureus. METHODS: Disinfection of needleless connectors was undertaken in vitro against S. aureus comparing 70% isopropyl alcohol (IPA), 70% ethanol, 0.5% and 2% chlorhexidine in 70% IPA applied with gauze, and 70% IPA single-use cap (Site-Scrub®). RESULTS: All disinfectants reduced the bacterial load (P<0.001), especially the chlorhexidine solutions. Mechanical friction should follow guidelines. CONCLUSION: This study found that all tested disinfectants effectively reduced the bacterial load and more clinical studies must be developed with a focus on the Brazilian clinical practice of needleless connector disinfection.

Activation of short-chain ketones and isopropanol in sulfate-reducing bacteria.

BACKGROUND: Degradation of acetone by aerobic and nitrate-reducing bacteria can proceed via carboxylation to acetoacetate and subsequent thiolytic cleavage to two acetyl residues. A different strategy was identified in the sulfate-reducing bacterium Desulfococcus biacutus that involves formylation of acetone to 2-hydroxyisobutyryl-CoA. RESULTS: Utilization of short-chain ketones (acetone, butanone, 2-pentanone and 3-pentanone) and isopropanol by the sulfate reducer Desulfosarcina cetonica was investigated by differential proteome analyses and enzyme assays. Two-dimensional protein gel electrophoresis indicated that D. cetonica during growth with acetone expresses enzymes homologous to those described for Desulfococcus biacutus: a thiamine diphosphate (TDP)-requiring enzyme, two subunits of a B12-dependent mutase, and a NAD+-dependent dehydrogenase. Total proteomics of cell-free extracts confirmed these results and identified several additional ketone-inducible proteins. Acetone is activated, most likely mediated by the TDP-dependent enzyme, to a branched-chain CoA-ester, 2-hydroxyisobutyryl-CoA. This compound is linearized to 3-hydroxybutyryl-CoA by a coenzyme B12-dependent mutase followed by oxidation to acetoacetyl-CoA by a dehydrogenase. Proteomic analysis of isopropanol- and butanone-grown cells revealed the expression of a set of enzymes identical to that expressed during growth with acetone. Enzyme assays with cell-free extract of isopropanol- and butanone-grown cells support a B12-dependent isomerization. After growth with 2-pentanone or 3-pentanone, similar protein patterns were observed in cell-free extracts as those found after growth with acetone. CONCLUSIONS: According to these results, butanone and isopropanol, as well as the two pentanone isomers, are degraded by the same enzymes that are used also in acetone degradation. Our results indicate that the degradation of several short-chain ketones appears to be initiated by TDP-dependent formylation in sulfate-reducing bacteria.

Viral Inactivation with Emphasis on SARS-CoV-2 Using Physical and Chemical Disinfectants.

BACKGROUND: Recently, an outbreak of a novel human coronavirus SARS-CoV-2 has become a world health concern leading to severe respiratory tract infections in humans. Virus transmission occurs through person-to-person contact, respiratory droplets, and contaminated hands or surfaces. Accordingly, we aim at reviewing the literature on all information available about the persistence of coronaviruses, including human and animal coronaviruses, on inanimate surfaces and inactivation strategies with biocides employed for chemical and physical disinfection. METHOD: A comprehensive search was systematically conducted in main databases from 1998 to 2020 to identify various viral disinfectants associated with HCoV and methods for control and prevention of this newly emerged virus. RESULTS: The analysis of 62 studies shows that human coronaviruses such as severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV), canine coronavirus (CCV), transmissible gastroenteritis virus (TGEV), and mouse hepatitis virus (MHV) can be efficiently inactivated by physical and chemical disinfectants at different concentrations (70, 80, 85, and 95%) of 2-propanol (70 and 80%) in less than or equal to 60 s and 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Additionally, glutaraldehyde (0.5-2%), formaldehyde (0.7-1%), and povidone-iodine (0.1-0.75%) could readily inactivate coronaviruses. Moreover, dry heat at 56°C, ultraviolet light dose of 0.2 to 140 J/cm2, and gamma irradiation could effectively inactivate coronavirus. The WHO recommends the use of 0.1% sodium hypochlorite solution or an ethanol-based disinfectant with an ethanol concentration between 62% and 71%. CONCLUSION: The results of the present study can help researchers, policymakers, health decision makers, and people perceive and take the correct measures to control and prevent further transmission of COVID-19. Prevention and decontamination will be the main ways to stop the ongoing outbreak of COVID-19.

Design and biological evaluation of novel HIV-1 protease inhibitors with isopropanol as P1' ligand to enhance binding with S1' subsite.

Newly designed HIV-1 protease inhibitors that maximize interactions with the protein backbone, especially in the form of hydrogen bonds, may enhance the antiviral potency of these compounds and minimize acquisition of drug-resistant mutations. Herein, we described a series of new HIV-1 PIs containing phenols as the P2 ligands and chiral isopropanol as the P1' ligands, in combination with 4-trifluoromethylphenylsulfonamide or 4-nitrophenylsulfonamide as the P2' ligands. And most of these compounds exhibited nanomolar inhibitory potency. In particular, inhibitors 13c and 13e with 4-trifluoromethylphenylsulfonamide as the P2' ligand and (R) - isopropanol as the P1' ligand, exhibited antiviral IC50 values of 1.64 nM and 2.33 nM, respectively. Furthermore, they also showed remarkable activity against wild-type and DRV-resistant HIV-1 variants that raised the prospect of designing more effective PIs further.

Dielectrophoretic analysis of the impact of isopropyl alcohol on the electric polarisability of Escherichia coli whole-cells.

Whole-cell biocatalysts are versatile tools in (industrial) production processes; though, the effects that impact the efficiency are not fully understood yet. One main factor that affects whole-cell biocatalysts is the surrounding medium, which often consists of organic solvents due to low solubility of substrates in aqueous solutions. It is expected that organic solvents change the biophysical and biochemical properties of the whole-cell biocatalysts, e.g. by permeabilising the cell membrane, and thus analysis of these effects is of high importance. In this work, we present an analysis method to study the impact of organic solvents on whole-cell biocatalysts by means of dielectrophoresis. For instance, we evaluate the changes of the characteristic dielectrophoretic trapping ratio induced by incubation of Escherichia coli, serving as a model system, in an aqueous medium containing isopropyl alcohol. Therefore, we could evaluate the impact on the electric polarisability of the cells. For this purpose, a special microchannel device was designed and Escherichia coli cells were genetically modified to reliably synthesise a green fluorescent protein. We could demonstrate that our method was capable of revealing different responses to small changes in isopropyl alcohol concentration and incubation duration. Complementary spectrophotometric UV-Vis (ultraviolet-visible light) absorbance analysis of released NAD(P)+/NAD(P)H cofactor and proteins confirmed our results. Based on our results, we discuss the biophysical effects taking place during incubation. Graphical abstract.

An interesting increase in immediate and residual efficacy of a trade mark of alcoholic 2% chlorhexidine gluconate, with and without dye, has been demonstrated by an in vitro study with ATCC micro-organisms and strains isolated from ICU patients.

AIM: ChloraPrep™ (CHP) is a clear solution of 2% (w/v) chlorhexidine (CHG) in 70% (v/v) isopropyl alcohol (IPA) administered with a specially designed sterile single-use applicator in which a tinting agent can be added to the CHP solution upon activation of applicator immediately prior to patient skin preparation (CHP+T). This study investigated whether the immediate and residual efficacy of CHP vs CHP+T and a stock solution of 2% CHG in 70% IPA varied, and whether CHP was compromised by the addition of the dye. METHODS AND RESULTS: We compared the immediate and residual activity (in 1 min) of 70% IPA with that of 2% CHG in 70% IPA stock solution prepared in the laboratory against CHP+T and CHP, against 22 micro-organisms (5 ATCC and 18 clinical isolates) on germ-carriers. CHP and CHP+T demonstrated superior immediate and residual efficacy compared to the 70% IPA plus 2% CHG in 70% IPA stock solutions. Each antiseptic tested showed greater efficacy against the Gram-positive bacteria than against the Gram-negative bacteria. However, their antimicrobial effect on yeasts was even lower. CONCLUSIONS: CHP and CHP+T have superior immediate and residual efficacy compared to stock 70% IPA and 2% CHG in 70% IPA solutions, and CHP+T is not affected by the tinting agent. SIGNIFICANCE AND IMPACT OF THE STUDY: ChloraPrep is a product which can be stained just before use. We have demonstrated that the immediate and residual efficacy of the antimicrobial solution is not compromised by the dye. The efficacy of CHP is greater against bacteria than against yeasts obtained from ICU patients. Interestingly, CHP is more effective against bacteria than a formula made in the laboratory with the same basic components (2% chlorhexidine and 70% IPA). The intermittent heat sterilization process of the commercial preparation might hypothetically have improved the residual activity of the CHP solutions.

Cardiac Function is not Susceptible to Moderate Disassembly of Mitochondrial Respiratory Supercomplexes.

: Mitochondrial respiratory chain supercomplexes (RCS), particularly, the respirasome, which contains complexes I, III, and IV, have been suggested to participate in facilitating electron transport, reducing the production of reactive oxygen species (ROS), and maintaining the structural integrity of individual electron transport chain (ETC) complexes. Disassembly of the RCS has been observed in Barth syndrome, neurodegenerative and cardiovascular diseases, diabetes mellitus, and aging. However, the physiological role of RCS in high energy-demanding tissues such as the heart remains unknown. This study elucidates the relationship between RCS assembly and cardiac function. Adult male Sprague Dawley rats underwent Langendorff retrograde perfusion in the presence and absence of ethanol, isopropanol, or rotenone (an ETC complex I inhibitor). We found that ethanol had no effects on cardiac function, whereas rotenone reduced heart contractility, which was not recovered when rotenone was excluded from the perfusion medium. Blue native polyacrylamide gel electrophoresis revealed significant reductions of respirasome levels in ethanol- or rotenone-treated groups compared to the control group. In addition, rotenone significantly increased while ethanol had no effect on mitochondrial ROS production. In isolated intact mitochondria in vitro, ethanol did not affect respirasome assembly; however, acetaldehyde, a byproduct of ethanol metabolism, induced dissociation of respirasome. Isopropanol, a secondary alcohol which was used as an alternative compound, had effects similar to ethanol on heart function, respirasome levels, and ROS production. In conclusion, ethanol and isopropanol reduced respirasome levels without any noticeable effect on cardiac parameters, and cardiac function is not susceptible to moderate reductions of RCS.

Efforts to improve diagnosis of bacteraemia by reducing blood culture contamination in an emergency department: strategies and outcome.

OBJECTIVE: To assess the strategies and outcome for reducing blood culture contamination in order to improve the diagnosis of bacteraemia. METHODS: The interventional study was conducted at a tertiary care hospital in Karachi from January 1, 2013, to December 31, 2016. The blood culture contamination data related to the first year of the study was taken as the baseline pre-intervention data. Strategies were planned as intervention for improvement by consolidating training and education in the form of dedicated lectures, practising on mannequins and developing in-house video, replacing povidone with 2% chlorhexidine preparation spray plus 70% isopropyl alcohol swabs and inducting dedicated phlebotomy team whose only responsibility was blood sample collection and minimising the probability of error. RESULTS: In 2013, there were 8868 samples; 7402 in 2014; 6897 in 2015; and 9756 samples in 2016. The contamination rate in 2013 was 8% which went down to 7.75% in 2014, 4.25% in 2015 and 3.9% in 2016. The decline became statistically significant (p<0.001) after implementing a dedicated phlebotomy team in the emergency department. CONCLUSIONS: Apart from teaching and training, the concept of blood culture collection kit with checklist and dedicated blood collection team was found to be vital in reducing blood culture contamination.

High Environmental Stability of Hepatitis B Virus and Inactivation Requirements for Chemical Biocides.

Hepatitis B virus (HBV) infection is considered a major public health problem worldwide, and a significant number of reports on nosocomial and occupational outbreaks have been reported. This systematic investigation of HBV stability and susceptibility to different antiseptics revealed that HBV infectivity was very stable, with a half-life of >22 days at 37°C. At 4°C, infectivity was barely reduced for up to 9 months. Different alcohols and commercially available hand antiseptics had a virucidal effect against HBV. We propose that very strict compliance with established hygienic guidelines should be mandatory to avoid and prevent HBV infections.

Thoughts on What Chemists Can Contribute to Fighting SARS-CoV-2 - A Short Note on Hand Sanitizers, Drug Candidates and Outreach.

The SARS-CoV-2 outbreak causing the respiratory disease COVID-19 has left many chemists in academia without an obvious option to contribute to fighting the pandemic. Some of our recent experiences indicate that there are ways to overcome this dilemma. A three-pronged approach is proposed.

Isolation of 1-(3',4'-Dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol from Grape Seed Extract and Evaluation of its Antioxidant and Antispasmodic Potential.

HPLC profiling of phenolics in grape seed extracts revealed a prominent peak of an unknown substance with concentrations up to 5.3%. Spectroscopic data allowed the identification of the compound 1 as 1-(3',4'-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol. 1 is known to be produced from catechin and epicatechin through anaerobic bacteria from human, as well as the rat, intestines. It was hypothesized that the marc remaining after expression of juice from grapes became infested during storage, resulting in the production of 1. Because compound 1 is infrequently found in nature and has never been found in grape seeds, its presence may be considered a marker of an unwanted anaerobic bacterial process occurring during production. The antioxidant potential of 1 was determined by DPPH, ABTS, and FRAP (ferric reducing antioxidant power) assays and compared to the potential of the following compounds: phloroglucine, pyrogallol, gallic acid, catechin, and epicatechin. Furthermore, it was established that 1 significantly reduced guinea pig ileum contraction induced by histamine.

Instantaneous Response of Bacteria to External Stimuli Monitored by Syringe Spray Mass Spectrometry.

Microbial adaptation to environmental stress involves complex adaptations of bacteria. Many such responses are transient and dynamic. However, monitoring the dynamic responses of live bacteria to stimulations at the molecular level remain a challenge. This work describes the development of syringe spray mass spectrometry (MS) method that allows direct analyses of molecules released by the bacteria in responses to external stimuli with second level time resolution. We report the application of this technique to visualize the dynamic release of small molecules from Escherichia coli ( E. coli) under ethanol and isopropanol treatments. With the unique time-resolved capability, detailed destruction process of alcohol on bacteria cell wall could be observed. Compared to other ethanol concentrations, 75% ethanol showed stronger damages to lipopolysaccharide (LPS) and peptidoglycan located on E. coli cell wall. Furthermore, isopropanol showed stronger liposolubility and permeability, and an equilibrium could be achieved in a much shorter time.

0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison.

OBJECTIVE: Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms. MATERIALS AND METHODS: Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus. RESULTS: Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively. CONCLUSION: In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.

Efficacy and dermal tolerance of a novel alcohol-based skin antiseptic in horses.

OBJECTIVE: To determine the efficacy and dermal tolerance of a novel alcohol-based skin antiseptic (ABSA) in horses. STUDY DESIGN: Experimental study. ANIMAL POPULATION: Systemically healthy horses (n = 25) with no history or clinical signs of skin disease. METHODS: Four clipped sites on the abdomen were randomly assigned to a skin preparation protocol: saline (negative control; NC), chlorhexidine gluconate followed by isopropyl alcohol (positive control; PC), saline followed by the ABSA (ABSA A), or a commercially available horse shampoo followed by the ABSA (ABSA B). Microbiological swabs were obtained from each site and cultured on MacConkey and mannitol salt agar plates. Colony-forming units were counted 18-24 hours later. All sites were scored for signs of skin reaction before, immediately after, 1 hour after, and 24 hours after skin preparation. RESULTS: The PC, ABSA A, and ABSA B methods reduced skin microbial burden compared with the NC method (P < .001), but no difference was detected between antiseptic products. Preparation time did not differ between ABSA A and ABSA B methods (P = 0.108); both were faster than the PC method (P < 0.001 for both). Skin reactions were most abundant 24 hours after skin preparation (30.5%), but there was no significant association with antiseptic used, and no horses required veterinary treatment. CONCLUSION: The ABSA preparations tested in this study were as effective and well tolerated as a chlorhexidine gluconate-based method, but required less time in healthy horses. CLINICAL SIGNIFICANCE: The ABSA tested here provides an efficacious, fast-acting, and well-tolerated alternative to achieve skin antisepsis in healthy horses. These results justify further investigation in clinical cases.

Vehicle effects on human stratum corneum absorption and skin penetration.

This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [14C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

Improving isopropanol tolerance and production of Clostridium beijerinckii DSM 6423 by random mutagenesis and genome shuffling.

Random mutagenesis and genome shuffling was applied to improve solvent tolerance and isopropanol/butanol/ethanol (IBE) production in the strictly anaerobic bacteria Clostridium beijerinckii DSM 6423. Following chemical mutagenesis with N-methyl-N-nitro-N-nitrosoguanidine (NTG), screening of putatively improved strains was done by submitting the mutants to toxic levels of inhibitory chemicals or by screening for their tolerance to isopropanol (>35 g/L). Suicide substrates, such as ethyl or methyl bromobutyrate or alcohol dehydrogenase inhibitors like allyl alcohol, were tested and, finally, 36 mutants were isolated. The fermentation profiles of these NTG mutant strains were characterized, and the best performing mutants were used for consecutive rounds of genome shuffling. Screening of strains with further enhancement in isopropanol tolerance at each recursive shuffling step was then used to spot additionally improved strains. Three highly tolerant strains were finally isolated and able to withstand up to 50 g/L isopropanol on plates. Even if increased tolerance to the desired end product was not always accompanied by higher production capabilities, some shuffled strains showed increased solvent titers compared to the parental strains and the original C. beijerinckii DSM 6423. This study confirms the efficiency of genome shuffling to generate improved strains toward a desired phenotype such as alcohol tolerance. This tool also offers the possibility of obtaining improved strains of Clostridium species for which targeted genetic engineering approaches have not been described yet.

Antimicrobial activity of Butyl acetate, Ethyl acetate and Isopropyl alcohol on undesirable microorganisms in cosmetic products.

OBJECTIVE: The microbiological contamination risk of a cosmetic product has to be assessed by the manufacturer, according to the composition, to determine whether microbiological testing is required. Certain ingredients in cosmetic formulations help to create an environment hostile towards microbial growth. In this study, the influence on microbial survival of some solvents used in nail varnishes was evaluated. The purpose of this study was two-fold. The first was to define the thresholds to be considered for the exemption of products from microbiological testing. The second was to assess the cross-contamination risk linked to the use on successive consumers of solvent-based products in beauty salons. METHODS: Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans and Trichophyton rubrum were exposed to various concentrations of ethyl acetate, butyl acetate and isopropyl alcohol in culture medium to estimate their MIC (minimum inhibitory concentration). These strains are relevant to cosmetic products as they are associated with skin and nail infections. Mixtures of the three solvents, which are characteristic of nail varnish compositions, were also tested for their cidal activity. RESULTS: Ethyl and butyl acetates had a stronger impact than isopropyl alcohol: the MIC of ethyl and butyl acetate is ≤5% for all of the tested strains, whereas that of isopropyl alcohol is ≤10%. Various combinations of the three solvents tested showed a significant effect on both fungal and bacterial strains (greater than 3 log reduction in 15 min for the bacterial test strains and in 30 min for T. rubrum). CONCLUSION: Products containing more than 5% ethyl or butyl acetate or more than 10% isopropyl alcohol are hostile towards microbial growth. These products can therefore be considered as microbiologically low risk during both production and use, and so do not require microbiological testing (challenge test and end-product testing). Moreover, the nine tested mixtures of these three solvents - which are characteristic of nail varnish compositions - all have a high cidal activity on the tested strains within a short time. The risk of cross-contamination can therefore be considered as controlled when the nail varnishes are applied on successive clients in beauty salons.

Efficiency of Local Antiseptic Alkosol (Ethanol, Isopropanol-30g and Ortophenilphenol) and Povidone Iodide on the Incidence Of Surgical Site Infection After Inguinal Hernioplasty.

BACKGROUND: The risk of wound infection after elective inguinal hernia repair depends on several factors. One of the most important factors is the preoperative skin preparation. The use of antisepsis is performed to reduce the risk of surgical site infections (SSIs) and to remove causing organisms. This work compares two different agent forms for preoperative skin preparation to prevent SSIs. OBJECTIVES: The objective of the study is comparing the effects of two different agents used for preoperative skin preparation and prevention of SSIs. MATERIAL AND METHODS: 100 adult patients were divided and randomized into two groups, each containing 50 patients. Both groups included patients that are scheduled for elective Lichtenstein inguinal hernia repair. The first group includes patients whose skin preparations were done with povidone iodine (PI) only. The second group included patients that are treated with two antiseptics; Alkosol (96% ethanol, isopropanol-30g and ortophenilphenol-0.1g) and povidone iodide. Alkosol is applied before the induction of anesthesia. The povidone iodide is applied after Alkosol has evaporated. The presence of bacterial growth in the wound was determined 24 and 48 hours after operation. Swabs were used to take samples, which were then cultivated to check for bacterial growth. The presence of infection was also determined by the following criteria: pain or tenderness, induration, erythema, local warmth of the wound etc. RESULTS: The surgeon or clinician declared that after 24 hours the wound was infected in 20 patients in the control group and in 22 patients after 48 hours. In the Alkosol (96% ethanol, isopropanol-30g and ortophenilphenol-0.1g) and povidone iodide group infection was declared in only 3 patients after 24 hours. DISCUSSION: Compared to the use of providone only, the use of Alkosol (96% ethanol, isopropanol-30g and ortophenilphenol-0.1g) and povidone iodide has many advantages and was associated with lower rates of SSIs following clean surgery. A larger trial is warranted in order to add definitive and more conclusive data to the current evidence base.

Impedance spectroscopy for the non-destructive evaluation of in vitro epidermal models.

PURPOSE: Reconstructed human epidermis (RHE) is standardly used for the risk assessment of chemical compounds. However, analysis is dependent on invasive methods such as histological processing or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining. METHODS: As an alternative, we have developed a non-destructive technology to analyze the integrity of epidermal equivalents based on impedance spectroscopy. RHEs were generated and impedance spectra were recorded. from these spectra, we extrapolated electrical characteristics such as the capacitance and the ohmic resistance. Furthermore, the measurable electrical parameters were used to quantify the effects of mechanical and chemical disruption of the epidermal integrity. RESULTS: A fully matured RHE exhibits typical impedance spectra in a frequency ranging between 1 Hz and 100 kHz, which is comparable to the spectra of freshly isolated human epidermal biopsies. We could show that, during RHE maturation, these characteristics change significantly. Thus, capacitance and ohmic resistance can be employed as a criterion for the quality control of skin equivalents. Additionally, our application of impedance spectroscopy reveals sufficient sensitivity to detect a transient decreased ohmic resistance caused by 2-propanol, which is classified as a non-irritant by MTT assays. CONCLUSION: These results indicate that impedance spectroscopy can be employed as a non-destructive complementary method to assess mild irritative effects, which is currently not possible.