Marzenna Bartoszewicz

Metabolic profiles of exudates from chronic leg ulcerations.

&NA; Chronic leg ulceration is a disease usually associated with other comorbidities, and significantly reduces patient quality of life. Infected leg ulcers can lead to limb‐threatening sequelae or mortality. Leg ulcerations are colonized by a number of microbes that are able to cause life‐threating infections in susceptible patients. Wound exudate is a body fluid that collects metabolites from patient eukaryotic cells and from prokaryotic bacterial communities inhabiting the wound. This study aimed at identification of metabolites in exudates collected from chronic leg ulcers, and correlation of this metabolome with patient comorbidities and microbiological status of the wound. By means of NMR spectroscopy we detected 42 metabolites of microbial or patient origin. The metabolites that were in abundance in exudates analyzed were lactate, lysine, and leucine. Metabolites were associated with the presence of neutrophils in wounds and destruction of high quantities of microbes, but also with hypoxia typical for venous insufficiency. The combination of nuclear magnetic resonance spectroscopy technique and partial least squares discriminant analysis allowed us to further discriminate groups of metabolites with regards to potential clinical meaning. For example, to discriminate between S.aureus versus all other isolated microbial species, or between patients suffering from type I or II diabetes versus patients without diabetes. Therefore, wound exudate seems to be highly applicable material for discriminant analysis performed with the use of NMR technique to provide for rapid metabolomics of chronic wound status. HighlightsNMR technique is highly applicable for evaluation of processes taking place within a wound.The wound exudate is a very useful material for these analyses.Wound exudate metabolites might be used as biomarkers of wound status.

A comparison of an antibacterial sandwich dressing vs dressing containing silver.

The purpose of this study was to compare the efficacy of dressings containing octenidine vs. dressings containing silver in the wound healing in the course of a chronic venous disease. There were two groups of 40 patients who met the inclusion criteria and who did not meet the exclusion criteria. The patients were randomly assigned into the groups (envelope method). The first, “O group” was treated with octenidine‐based dressings. The second, “S group” was treated with silver dressings. The study lasted for 56 days. All patients in the research were treated with medical compression stockings with cotton understockings. Microbiological eradication was observed on the 28th day of the study among 33% of patients in the treatment group vs. 6% in control group. On the 56th day of the treatment, these percentages equalled 72% and 35%. The rate of healing was faster in the 0 group than in the S group. In the wounds <10 cm2 it was faster by 1.35 cm2/week and in wounds >10 cm2 it equalled 3.44 cm2. The reduction of pain level was 37.5% higher in the O group, in contrast with the S group. One change of a dressing in the O group led to a 0.06 cm2 greater wound size reduction and in the case of wounds >10 cm2 to 0.29 cm2 reduction compared with the S group. The presented results indicate that the efficacy of dressings containing octenidine is higher compared to silver dressings.

Bad to the Bone: On In Vitro and Ex Vivo Microbial Biofilm Ability to Directly Destroy Colonized Bone Surfaces without Participation of Host Immunity or Osteoclastogenesis.

Bone infections are a significant public health burden associated with morbidity and mortality in patients. Microbial biofilm pathogens are the causative agents in chronic osteomyelitis. Research on the pathogenesis of osteomyelitis has focused on indirect bone destruction by host immune cells and cytokines secondary to microbial insult. Direct bone resorption by biofilm pathogens has not yet been seriously considered. In this study, common osteomyelitis pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Streptococcus mutans) were grown as biofilms in multiple in vitro and ex vivo experiments to analyze quantitative and qualitative aspects of bone destruction during infection. Pathogens were grown as single or mixed species biofilms on the following substrates: hydroxyapatite, rat jawbone, or polystyrene wells, and in various media. Biofilm growth was evaluated by scanning electron microscopy and pH levels were monitored over time. Histomorphologic and quantitative effects of biofilms on tested substrates were analyzed by microcomputed tomography and quantitative cultures. All tested biofilms demonstrated significant damage to bone. Scanning electron microscopy indicated that all strains formed mature biofilms within 7 days on all substrate surfaces regardless of media. Experimental conditions impacted pH levels, although this had no impact on biofilm growth or bone destruction. Presence of biofilm led to bone dissolution with a decrease of total volume by 20.17±2.93% upon microcomputed tomography analysis, which was statistically significant as compared to controls (p <0.05, ANOVA). Quantitative cultures indicated that media and substrate did not impact biofilm formation (Kruskall-Wallis test, post-hoc Dunne’s test; p <0.05). Overall, these results indicate that biofilms associated with osteomyelitis have the ability to directly resorb bone. These findings should lead to a more complete understanding of the etiopathogenesis of osteomyelitis, where direct bone resorption by biofilm is considered in addition to the well-known osteoclastic and host cell destruction of bone.

Application of Rotating Magnetic Fields Increase the Activity of Antimicrobials Against Wound Biofilm Pathogens

Infective complications are a major factor contributing to wound chronicity and can be associated with significant morbidity or mortality. Wound bacteria are protected in biofilm communities and are highly resistant to immune system components and to antimicrobials used in wound therapy. There is an urgent medical need to more effectively eradicate wound biofilm pathogens. In the present work, we tested the impact of such commonly used antibiotics and antiseptics as gentamycin, ciprofloxacin, octenidine, chlorhexidine, polihexanidine, and ethacridine lactate delivered to Staphylococcus aureus and Pseudomonas aeruginosa biofilms in the presence of rotating magnetic fields (RMFs) of 10–50 Hz frequency and produced by a customized RMF generator. Fifty percent greater reduction in biofilm growth and biomass was observed after exposure to RMF as compared to biofilms not exposed to RMF. Our results suggest that RMF as an adjunct to antiseptic wound care can significantly improve antibiofilm activity, which has important translational potential for clinical applications.

Development and biological evaluation of Ti6Al7Nb scaffold implants coated with gentamycin-saturated bacterial cellulose biomaterial

Herein we present an innovative method of coating the surface of Titanium-Aluminium-Niobium bone scaffold implants with bacterial cellulose (BC) polymer saturated with antibiotic. Customized Ti6Al7Nb scaffolds manufactured using Selective Laser Melting were immersed in a suspension of Komagataeibacter xylinus bacteria which displays an ability to produce a 3-dimensional structure of bio-cellulose polymer. The process of complete implant coating with BC took on average 7 days. Subsequently, the BC matrix was cleansed by means of alkaline lysis and saturated with gentamycin. Scanning electron microscopy revealed that BC adheres and penetrates into the implant scaffold structure. The viability and development of the cellular layer on BC micro-structure were visualized by means of confocal microscopy. The BC-coated implants displayed a significantly lower cytotoxicity against osteoblast and fibroblast cell cultures in vitro in comparison to non-coated implants. It was also noted that gentamycin released from BC-coated implants inhibited the growth of Staphylococcus aureus cultures in vitro, confirming the suitability of such implant modification for preventing hostile microbial colonization. As demonstrated using digital microscopy, the procedure used for implant coating and BC chemical cleansing did not flaw the biomaterial structure. The results presented herein are of high translational value with regard to future use of customized, BC-coated and antibiotic-saturated implants designed for use in orthopedic applications to speed up recovery and to reduce the risk of musculoskeletal infections.

The influence of antibiotics and dietary components on gut microbiota

The gut microbiota acts as a real organ. It exerts important metabolic functions, and regulates the inflammatory response by stimulating the immune system. Gut microbial imbalance (dysbiosis) has been linked to important human diseases and inflammation-related disorders. The symbiotic interactions between resident microorganisms and the gastrointestinal tract significantly contribute to maintaining gut homeostasis. The present review summarizes our knowledge regarding the impact of different antibiotics causing such long-term consequences as decreased microbial diversity, modulation of the Bacteroidetes/Firmicutes ratio, Clostridium difficile overgrowth, and increased expansion of the opportunistic pathogens Salmonella typhimurium, Escherichia spp., and Klebsiella spp. Also, food additives, such as emulsifiers and artificial sweeteners, which are meant to reduce the risk of obesity and diabetes, may actually increase the risk of diseases due to microbial alterations. On the other hand, dietary components such as polyphenols, omega-3 acids or curcumin may positively affect gut microbiota composition.

Wpływ sieci większej (omentum majus) na redukcję biofilmu bakteryjnego z implantów wprowadzonych do jam brzusznych szczurów laboratoryjnych

Biofilm-related infections are considered 60–80% of all nosocomial infections. High biofilm tolerance of such antimicrobials towards antiseptics and antibiotics is the reason why new therapeutic approaches are developed. In the present study, the analysis of the pedunculated omentum majus’s, ability to eradicate Staphylococcus aureus and Klebsiella pneumoniae biofilm from abdominal cavity of laboratory Wistar rats was performed. The pedunculated omentum majus was treated as a prototypic autogenic internal dressing. Obtained results indicate that the omentum majus possesses an ability to sequestrate but not to kill ana-

Narastająca lekooporność Acinetobacter baumannii – rosnące zagrożenie dla oddziałów oparzeniowych

In recent years, the number of nosocomial infections caused by Gram-negative nonfermenting bacilli – Acinetobacter baumannii – has increased dramatically. Its high prevalence in the external environment, in hospitals, and high survival rate in adverse environmental conditions contribute to the fact that A. baumannii is currently one of the most common opportunistic pathogens especially in intensive care or surgical units and in patients with burns. The ability of biofilm formation and rapid rise of antibiotic, antiseptic and disinfectant resistance place Acinetobacter baumannii at the forefront of microorganisms difficult to eradicate. With relation to a decreasing number of antibiotics still effective in treatment of A. baumannii infections, the search for other therapeutic procedures, such as application of antimicrobial dressings or antiseptics is actively performed.

Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid

The aim of the work was the evaluation of selected biological and physicochemical, applicative properties of ethylated ascorbic acid (AAE) compared to ascorbic acid (AA). Thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) were conducted, followed by the evaluation of AAE decomposition by the UV-Vis spectroscopic method including the influence of temperature and pH. Scavenging, antimicrobial activity and cytotoxicity against L929 fibroblasts were also performed. The difference in mass loss between AA and AAE was 30% via TG. DTA revealed characteristic exothermic and endothermic effects. The AAE solution was more thermally stable than AA. The calculated zero-order rate constants of free-radical scavenging kinetics for AAE were in the range of 4.9×10-3-1.35×10-2 s-1. The activation energy for the process was 11,2281 kJ/mol. AAE was active against Staphylococcus (S.) aureus and Enterococcus (E.) faecalis and acted stronger against Candida (C.) albicans than AA. The concentrations of AA ≥2.5% were cytotoxic, whereas in the case of AAE, a 10% concentration was considered cytotoxic. DTG enables the detailed differentiation between AA and AAE. AAE in aqueous solution is more stable compared to AA. The antioxidant activity of AAE is significant. However, the reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicates prolonged activity compared to AA. Variability in the antimicrobial activity of AAE may find practical application in the pharmaceutical and cosmetic industries. The potential for applicative aims may be supported by the relatively low in vitro toxicity of AAE.

Zalety i wady antyseptyków stosowanych w profilaktyce i leczeniu infekcji ran oparzeniowych – okiem mikrobiologa

Septic complications of burn wounds lead to significant deterioration of patient’s health status and to his death eventually. The following microorganisms are the main etiological factors of burn wounds infections: Pseudomonas aeruginosa, Acinetobacter baumanii and Staphylococcus aureus. The results from clinical trials show increasing percentage of antibiotic-resistant strains isolated from burns. Therefore, to eradicate microorganisms, such antiseptics as chlorhexidine, iodine povidone, polyhexanide, hypochlorites and octenidine, are applied in burn antisepsis. In the present paper, the review of data concerning advantages and disadvantages of above-mentioned antiseptics was performed. On the basis of searched data, the octenidine was considered the antiseptic of the highest antimicrobial efficacy and the highest safety of use.