Comparison of antibiofilm activity of low-concentrated hypochlorites vs polyhexanide-containing antiseptic.

Chronic wound infection is highly associated with morbidity and endangers the patient's life. Therefore, wound care products must have a potent antimicrobial and biofilm-eradicating effect. In this work, the antimicrobial/antibiofilm activity of two low-concentrated chlorine-based and releasing solutions was investigated on a total of 78 strains of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, using the cohesive spectrum of in vitro settings, including microtiter plate models, biofilm-oriented antiseptic test, cellulose-based biofilm model, biofilm bioreactors and Bioflux model. The antiseptic containing polyhexamethylene biguanide was used in the character of usability control of performed tests. The results obtained by static biofilm models indicate that low-concentrated chlorine-based and releasing solutions display none to moderate antibiofilm activity, while data obtained by means of the Bioflux model, providing flow conditions, indicate the moderate antibiofilm activity of substances compared with the polyhexanide antiseptic. Considering in vitro data presented in this manuscript, the earlier reported favorable clinical results of low-concentrated hypochlorites should be considered rather an effect of their rinsing activity combined with low cytotoxicity but not the antimicrobial effect per se. For the treatment of heavily biofilm-infected wounds, polyhexanide should be considered the agent of choice because of its higher efficacy against pathogenic biofilms.

Ethanol is indispensable for virucidal hand antisepsis and without toxic risks in daily use.

The approval of ethanol by the Biocidal Products Regulation has been under evaluation since 2007 due to controversial opinions on the risk assessment. Because of this critical situation, 2022 a memorandum was published to verify whether the use of ethanol for hand antisepsis poses any hazard. On the basis of the memorandum a toxicological evaluation of ethanol-based hand rubs is given.

Investigating the Mutagenicity of a Cold Argon-Plasma Jet in an HET-MN Model.

OBJECTIVE: So-called cold physical plasmas for biomedical applications generate reactive oxygen and nitrogen species and the latter can trigger DNA damage at high concentrations. Therefore, the mutagenic risks of a certified atmospheric pressure argon plasma jet (kINPen MED) and its predecessor model (kINPen 09) were assessed. METHODS: Inner egg membranes of fertilized chicken eggs received a single treatment with either the kINPen 09 (1.5, 2.0, or 2.5 min) or the kINPen MED (3, 4, 5, or 10 min). After three days of incubation, blood smears (panoptic May-Grünwald-Giemsa stain) were performed, and 1000 erythrocytes per egg were evaluated for the presence of polychromatic and normochromic nuclear staining as well as nuclear aberrations and binucleated cells (hen's egg test for micronuclei induction, HET-MN). At the same time, the embryo mortality was documented. For each experiment, positive controls (cyclophosphamide and methotrexate) and negative controls (NaCl-solution, argon gas) were included. Additionally, the antioxidant potential of the blood plasma was assessed by ascorbic acid oxidation assay after treatment. RESULTS: For both plasma sources, there was no evidence of genotoxicity, although at the longest plasma exposure time of 10 min the mortality of the embryos exceeded 40%. The antioxidant potential in the egg's blood plasma was not significantly reduced immediately (p = 0.32) or 1 h (p = 0.19) post exposure to cold plasma. CONCLUSION: The longest plasma treatment time with the kINPen MED was 5-10 fold above the recommended limit for treatment of chronic wounds in clinics. We did not find mutagenic effects for any plasma treatment time using the either kINPen 09 or kINPen MED. The data provided with the current study seem to confirm the lack of a genotoxic potential suggesting that a veterinary or clinical application of these argon plasma jets does not pose mutagenic risks.

Poly (hexamethylene biguanide) adsorption on hydrogen peroxide treated Ti-Al-V alloys and effects on wettability, antimicrobial efficacy, and cytotoxicity.

An effective amount of the antiseptic agent PHMB cannot simply be placed on the surface of titanium alloys where hydrocarbons were removed by different purification procedures. Pre-treatment of Ti6Al4V specimen with 5% H2O2 in 24 h results in extra introduced -OH and -COOH groups as well as an adsorbed water film on the surface, which provide the base for the subsequent formation of a relatively stable and multi-layered PHMB film. The superficially adhering PHMB film produces no adverse effects on MG63 cells within a 48 h-cell culture, but promotes the initial attachment and spreading of the osteoblasts on the modified Ti6Al4V surface within 15 min. After direct bacterial inoculation of the active sample, the PHMB film reacts antimicrobially against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative strains (Pseudomonas aeruginosa, Escherichia coli) after surface contact. The bactericidal efficacy is only slightly reduced after using of the same specimen for re-testing the antibacterial activity. MG63 cells adhere and proliferate within 48 h on a PHMB film-containing Ti6Al4V surface, which has been pre-contaminated with S. aureus. Bacterial biofilms were only revealed in controls without PHMB.

Comparison of the antioxidant potential in urine, saliva and skin.

AIM: Free radicals, oxidative stress and their possible consequences for health are becoming increasingly important in modern medicine. Reactive species influence the organism, potentially causing oxidative cell damage. They can be produced by exogenous sources, or be a product of a variety of not only physiological metabolic processes, such as immune response, but also pathological processes. The antioxidant protection system protects the organism from oxidative damage caused by reactions producing an excess of free radicals. The analysis of antioxidant potential (AOP) is therefore becoming increasingly important for the diagnosis of individual vitality. METHOD: The photochemoluminescence method was used to measure the AOP in urine and saliva, spectrometry was employed to measure the ß-carotene content of the skin. In addition, it was investigated whether the AOP(saliva) correlated with the AOPU(urine) (uric-acid independent AOP) as well as the ß-carotene content of the skin. RESULTS: The AOP was significantly higher in urine than in saliva, and both values were significantly positively correlated with each other. However, there was no significant correlation to the ß-carotene content of the skin. DISCUSSION: The components of the AOPU(urine) are accumulated over time (night), whereas AOP measurement in saliva is like a snapshot, which explains why AOPU(urine) was significantly higher than AOP(saliva), although the two parameters are correlated with each other. ß-carotene is a fat-soluble antioxidant, whereas in our study, only water-soluble antioxidants were determined in the urine. This explains why there is no positive correlation between ß-carotene of the skin and AOP. CONCLUSION: For the characterization of the AOP in epidemiological studies, we recommend determining the AOPU(urine) and parallel to this, the ß-carotene content of the skin.

Are laptop ventilation-blowers a potential source of nosocomial infections for patients?

Inadequately performed hand hygiene and non-disinfected surfaces are two reasons why the keys and mouse-buttons of laptops could be sources of microbial contamination resulting consequently in indirect transmission of potential pathogens and nosocomial infections. Until now the question has not been addressed whether the ventilation-blowers in laptops are actually responsible for the spreading of nosocomial pathogens. Therefore, an investigational experimental model was developed which was capable of differentiating between the microorganisms originating from the external surfaces of the laptop, and from those being blown out via the ventilation-blower duct. Culture samples were taken at the site of the external exhaust vent and temperature controls were collected through the use of a thermo-camera at the site of the blower exhaust vent as well as from surfaces which were directly exposed to the cooling ventilation air projected by the laptop. Control of 20 laptops yielded no evidence of microbial emission originating from the internal compartment following switching-on of the ventilation blower. Cultures obtained at the site of the blower exhaust vent also showed no evidence of nosocomial potential. High internal temperatures on the inner surfaces of the laptops (up to 73°C) as well as those documented at the site of the blower exhaust vent (up to 56°C) might be responsible for these findings.

Can physical stress be measured in urine using the parameter antioxidative potential?

Although regular exercise is known to promote health, it is also well known that competetive sports can lead to an increase of free radical production, and thus to a drop in antioxidative potential. Thus, the present study examined the effect of competetive sports on the antioxidative potential (AOP). Using chemoluminescence, the AOP was measured in the spontaneous urine of leisure and semi-professional athletes during a training camp. Further, the parameters creatinin and uric acid were measured. It was shown that physical stress led to a drop in the antioxidant potential of up to approximately 50%. To compensate for this decline, special antioxidant food is recommended.