Development of an advanced multiwavelength emission detector for the analytical ultracentrifuge.

An advanced design of the analytical ultracentrifuge with multiwavelength emission detection (MWE-AUC) is presented which offers outstanding performance concerning the spectral resolution and range flexibility as well as the quality of the data acquired. The excitation by a 520 nm laser is complemented with a 405 nm laser. An external spectrograph with three switchable tunable gratings permits optimisation of the spectral resolution in an order of magnitude range while keeping the spectral region broad. The new system design leads also to a significant reduction of systematic signal noise and allows the assessment and control of inner filter effects. Details regarding the very large signal dynamic range are presented, an important aspect when studying samples in a broad concentration range of up to five orders of magnitude. Our system is validated by complementary studies on two biological systems, fluorescent BSA and GFP, using the commercial Optima AUC with absorbance detection for comparison. Finally, we demonstrate the capabilities of our second generation MWE-AUC with respect to multiwavelength characterisation of gold nanoclusters, which exhibit specific fluorescence depending on their structure. Overall, this work depicts an important stepping stone for the concept of multiwavelength emission detection in AUC. The MWE-AUC developed, being to our knowledge the first and sole one of its kind, has reached the development level suitable for the future in-depth studies of size-, shape- and composition-dependent emission properties of colloids.

Opportunities and challenges for monitoring a recolonizing large herbivore using citizen science.

Monitoring is a prerequisite for evidence-based wildlife management and conservation planning, yet conventional monitoring approaches are often ineffective for species occurring at low densities. However, some species such as large mammals are often observed by lay people and this information can be leveraged through citizen science monitoring schemes. To ensure that such wildlife monitoring efforts provide robust inferences, assessing the quantity, quality, and potential biases of citizen science data is crucial. For Eurasian moose (Alces alces), a species currently recolonizing north-eastern Germany and occurring in very low numbers, we applied three citizen science tools: a mail/email report system, a smartphone application, and a webpage. Among these monitoring tools, the mail/email report system yielded the greatest number of moose reports in absolute and in standardized (corrected for time effort) terms. The reported moose were predominantly identified as single, adult, male individuals, and reports occurred mostly during late summer. Overlaying citizen science data with independently generated habitat suitability and connectivity maps showed that members of the public detected moose in suitable habitats but not necessarily in movement corridors. Also, moose detections were often recorded near roads, suggestive of spatial bias in the sampling effort. Our results suggest that citizen science-based data collection can be facilitated by brief, intuitive digital reporting systems. However, inference from the resulting data can be limited due to unquantified and possibly biased sampling effort. To overcome these challenges, we offer specific recommendations such as more structured monitoring efforts involving the public in areas likely to be roamed by moose for improving quantity, quality, and analysis of citizen science-based data for making robust inferences.

Determination of 2D Particle Size Distributions in Plasmonic Nanoparticle Colloids via Analytical Ultracentrifugation: Application to Gold Bipyramids.

Multidimensional particle properties determine the product properties in numerous advanced applications. Accurate and statistically meaningful measurements of complex particles and their multidimensional distributions are highly challenging but strongly needed. 2D particle size distributions of plasmonic nanoparticles of complex regular shape can be obtained from analytical ultracentrifugation experiments via the optical back coupling method. A workflow for the calculation of frictional properties of arbitrarily shaped nanoparticles was developed based on bead shell models and applied to gold bipyramids with a pentagonal cross-section. The obtained 2D particle length-diameter distributions and the reduced cumulative 1D length and diameter distributions were compared to transmission electron microscopy measurements. While we find very good agreement for most measurements, the obtained length and diameter distributions were shifted by a few nanometers for some samples. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron tomography, and finite element modeling indicate that the shift originated from a slight mismatch between the assumed shape of the simulated perfect bipyramids and the real particle shape and composition due to the presence of silver in the particles. This study demonstrates the feasibility of the applied techniques for complex shape analysis of nanoparticle ensembles with unmatched particle count numbers.

Nanomechanical Stability of Laterally Heterogeneous Films of Corrosion Inhibitor Molecules Obtained by Microcontact Printing on Au Model Substrates.

Self-assembled monolayers of corrosion inhibitors of the mercaptobenzimidazole family, SH-BimH, SH-BimH-5NH2, and SH-BimH-5OMe, were formed on template-stripped ultraflat Au surfaces using microcontact printing, and subsequently analyzed using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and AFM-force spectroscopy (AFM-FS) using a quantitative imaging (QI) mode. Printing of all used inhibitor molecules resulted in clear patterns and in slightly more compact films compared to immersion. The stability of the monolayers is further probed by AFM-FS. Adhesion values of laterally heterogeneous inhibitor-modified surfaces compared to bare Au surfaces, nonpatterned areas, and fully covered surfaces are analyzed and discussed. Microcontact printing confers a superior nanomechanical stability to imidazole-modified films of the printed surface patches as compared to homogeneously covered surfaces by immersion into the inhibitor solution.

Combination of isothiocyanates and antibiotics increases susceptibility against Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Serratia marcescens.

BACKGROUND: The development and spread of multidrug-resistant organisms (MDRO) is evolving rapidly worldwide. Although effective antibiotics are still available, some infections are difficult to treat. Among MDROs, S. marcescens and A. baumannii are among the difficult-to-treat pathogens causing for instance sepsis and urinary tract infections (UTI). Isothiocyanates (ITC) are natural plant products. The antimicrobial properties of ITC appear to be more effective in combination with some antibiotics. PURPOSE: We investigated a mixture of ITC from nature-identical plant extracts of nasturtium and horseradish in different combined concentrations with broad-spectrum antibiotics against S. marcescens, A. baumannii, E. coli, K. pneumoniae and P. mirabilis. METHODS: First, we investigated the antibacterial activity of the compounds by standard agar disc diffusion test. Next, we evaluated the minimum inhibitory concentrations (MIC) via broth dilution tests. Checkerboard technique was used to assess antimicrobial effects against sulfamethoxazole-trimethoprim, ampicillin-sulbactam, nitrofurantoin, Fosfomycin, ciprofloxacin and imipenem combined with various concentrations of ITC. RESULTS: S. marcescens strains 1-3 showed reversal of resistance at >0.075 µg/mL ITC in combination with nitrofurantoin, whereas 0.05 µg/mL ITC increased antimicrobial susceptibility. Combination of fosfomycin with 0.003 µg/mL ITC resulted in increased efficacy against resistant S. marcescens strains, E. coli, K. pneumoniae and P. mirabilis. Remarkable additive antimicrobial activity was observed at 0.03 µg/mL and 0.06 µg/mL ITC in combination with 0.125 µg/mL imipenem (FIC > 0.5). CONCLUSION: The combination of ITC and antibiotics is a promising approach for the treatment of UTI caused by MDRO. The ITC combination with selected antibiotics had synergistic and additive effects.

Displacement Effects of Conservation Grazing on Red Deer (Cervus elaphus) Spatial Behaviour.

Conservation grazing uses semi-feral or domesticated herbivores to limit encroachment in open areas and to promote biodiversity. However, we are still unaware of its effects on wild herbivores. This study investigates the influence of herded sheep and goats on red deer (Cervus elaphus) spatial behavior by testing three a-priori hypotheses: (i) red deer are expected to avoid areas used by livestock, as well as adjacent areas, when livestock are present, albeit (ii) red deer increase the use of these areas when sheep and goats are temporarily absent and (iii) there is a time-lagged disruption in red deer spatial behavior when conservation grazing practice ends. Using GPS-telemetry data on red deer from a German heathland area, we modelled their use of areas grazed by sheep and goats, using mixed-effect logistic regression. Additionally, we developed seasonal resource selection functions (use-availability design) to depict habitat selection by red deer before, during, and after conservation grazing. Red deer used areas less during conservation grazing throughout all times of the day and there was no compensatory use during nighttime. This effect mostly persisted within 21 days after conservation grazing. Effects on habitat selection of red deer were detectable up to 3000 meters away from the conservation grazing sites, with no signs of either habituation or adaption. For the first time, we demonstrate that conservation grazing can affect the spatio-temporal behavior of wild herbivores. Our findings are relevant for optimizing landscape and wildlife management when conservation grazing is used in areas where wild herbivores are present.

Effect of didecyl dimethyl ammonium chloride-impregnated washcloth wipe whole-body bathing on catheter-related blood stream infections and central venous line-associated infections in adult intensive care units.

OBJECTIVE: To investigate the effect of daily whole-body bathing (WBB) using disposable washcloth wipes/caps impregnated with an antiseptic solution containing the quaternary ammonium base compound didecyl dimethyl ammonium chloride (DDAC). METHODS: A prospective double-blind randomized crossover trial was conducted to compare WBB of adult intensive care unit (ICU) patients with washcloth wipes/caps impregnated with either regular cleanser/shampoo or the antiseptic DDAC. The clinical trial was performed in a medical ICU (MICU) and a surgical ICU (SICU). The study period was divided into two 6-month intervals with alternating treatment regimens. RESULTS: A total of 1540 ICU patients (total length of ICU stay 10 470 days) were included in the trial. Compared to controls, DDAC bathing was found to be associated with reduced incidence rates per 1000 patient days for central-venous-line-associated infections (CLAIs) caused by Gram-positive bacteria (GPB) from 16.39 (95%CI 13.1-20.3) in the control group to 7.28 (95%CI 5.2-9.9) in the intervention group (p 0.01). A stratified analysis by unit showed that the incidence rates of CLAI due to GPB were reduced by the intervention in both the MICU and the SICU from 21.2 (95%CI 15.8-27.7) to 9.3 (95%CI 5.8-14.1) (p < 0.01) and from 12.1 (95%CI 8.3-17.0) to 5.7 (95%CI 3.4-9.1) (p 0.01), respectively. There was a trend towards reduction in catheter-related bloodstream infections (CRBSIs) and bloodstream infections (BSIs); however, this did not reach statistical significance due to carry-over effects and small numbers. CONCLUSIONS: Given the growing need for new concepts to prevent and control healthcare-associated infections, DDAC may be a new and promising agent for WBB of ICU patients.

Genomic Investigation and Successful Containment of an Intermittent Common Source Outbreak of OXA-48-Producing Enterobacter cloacae Related to Hospital Shower Drains.

The hospital environment has been reported as a source of transmission events and outbreaks of carbapenemase-producing Enterobacterales. Interconnected plumbing systems and the microbial diversity in these reservoirs pose a challenge for outbreak investigation and control. A total of 133 clinical and environmental OXA-48-producing Enterobacter cloacae isolates collected between 2015 and 2021 were characterized by whole-genome sequencing (WGS) to investigate a prolonged intermittent outbreak involving 41 patients in the hematological unit. A mock-shower experiment was performed to investigate the possible acquisition route. WGS indicated the hospital water environmental reservoir as the most likely source of the outbreak. The lack of diversity of the blaOXA-48-like harbouring plasmids was a challenge for data interpretation. The detection of blaOXA-48-like-harboring E. cloacae strains in the shower area after the mock-shower experiment provided strong evidence that showering is the most likely route of acquisition. Initially, in 20 out of 38 patient rooms, wastewater traps and drains were contaminated with OXA-48-positive E. cloacae. Continuous decontamination using 25% acetic acid three times weekly was effective in reducing the trap/drain positivity in monthly environmental screening but not in reducing new acquisitions. However, the installation of removable custom-made shower tubs did prevent new acquisitions over a subsequent 12-month observation period. In the present study, continuous decontamination was effective in reducing the bacterial burden in the nosocomial reservoirs but was not sufficient to prevent environment-to-patient transmission in the long term. Construction interventions may be necessary for successful infection prevention and control. IMPORTANCE The hospital water environment can be a reservoir for a multiward outbreak, leading to acquisitions or transmissions of multidrug-resistant organisms in a hospital setting. The majority of Gram-negative bacteria are able to build biofilms and persist in the hospital plumbing system over a long period of time. The elimination of the reservoir is essential to prevent further transmission and spread, but proposed decontamination regimens, e.g., using acetic acid, can only suppress but not fully eliminate the environmental reservoir. In this study, we demonstrated that colonization with multidrug-resistant organisms can be acquired by showering in showers with contaminated water traps and drains. A construction intervention by installing removable and autoclavable shower inserts to avoid sink contact during showering was effective in containing this outbreak and may be a viable alternative infection prevention and control measure in outbreak situations involving contaminated shower drains and water traps.

IRIXS Spectrograph: an ultra high-resolution spectrometer for tender RIXS.

The IRIXS Spectrograph represents a new design of an ultra-high-resolution resonant inelastic X-ray scattering (RIXS) spectrometer that operates at the Ru L3-edge (2840 eV). First proposed in the field of hard X-rays by Shvyd'ko [(2015), Phys. Rev. A, 91, 053817], the X-ray spectrograph uses a combination of laterally graded multilayer mirrors and collimating/dispersing Ge(111) crystals optics in a novel spectral imaging approach to overcome the energy resolution limitation of a traditional Rowland-type spectrometer [Gretarsson et al. (2020), J. Synchrotron Rad. 27, 538-544]. In combination with a dispersionless nested four-bounce high-resolution monochromator design that utilizes Si(111) and Al2O3(110) crystals, an overall energy resolution better than 35 meV full width at half-maximum has been achieved at the Ru L3-edge, in excellent agreement with ray-tracing simulations.

Rare case of ballooning herniation of the tympanic membrane.

Herniation of the tympanic membrane is a rare benign malformation of the tympanic membrane into the external auditory canal. It may be asymptomatic or associated with symptoms such as aural fullness, tinnitus, otalgia or hearing loss. We present a case of a symptomatic herniation of the tympanic membrane and its surgical therapy with hernia excision and tympanoplasty. An internal review board exemption was obtained.

Chronic otorrhoea, otalgia and hearing loss not responding to antibiotics and tympanoplasty surgery.

Chronic otorrhoea from a tympanic membrane perforation is common. We present the case of a patient who had already received seemingly adequate treatment for his condition in the past. Yet, he presented to our outpatient clinic with worsening otalgia and otorrhoea, progressive hearing loss and a new tympanic membrane perforation. After a thorough otological evaluation, the patient's medical history and the histological specimen from a previous operation were reviewed. The findings met the diagnostic criteria of eosinophilic otitis media. After treatment with topic triamcinolone through the perforated tympanic membrane, the patient's otalgia subsided, hearing levels were improved and the size of the tympanic membrane perforation decreased.

Challenges in interpretation of WGS and epidemiological data to investigate nosocomial transmission of vancomycin-resistant Enterococcus faecium in an endemic region: incorporation of patient movement network and admission screening.

OBJECTIVES: VRE are listed, by the WHO, among the leading resistant pathogens causing greatest public concern; hence the spread and transmission of VRE, especially in hospitalized patients, need to be monitored. Despite the advancements in typing methods since the implementation of WGS for outbreak investigations, data interpretation, especially for vancomycin-resistant Enterococcus faecium (VREfm) in an endemic setting, remains challenging. In this study we explored the potential added benefit of incorporating patient movement data and admission screening to accurately estimate the magnitude of an outbreak. METHODS: We sequenced 73 VREfm isolates from patients with bacteraemia (n = 43) and rectal colonization (n = 30/32). Genetic relatedness was determined by SNP distance (≤10) between isolates. Patient movements were visualized in a movement network, along with contact intensity and rectal colonization status prior to infection onset. RESULTS: ST117, ST80 and ST203 were the predominant STs in our study population. Forty-four percent (18/41) of VREfm bacteraemia cases were of endogenous origin. SNP analysis of infection and colonization isolates revealed nine clonal groups. Eighty-six percent (37/43) of the patients were visualized in a transmission network due to spatiotemporal overlap. Nineteen out of 43 (44%) belonged to five transmission clusters. Incorporation of prior colonization status revealed that transmission was very likely in only 63% (12/19) of patients in these transmission clusters. DISCUSSION: Although interpretation of WGS data is challenging, incorporation of patient movement data and colonization status by admission screening of high-risk patients may provide additional resolution when interpreting the magnitude of an outbreak in an endemic setting.

Antimicrobial effects of mustard oil-containing plants against oral pathogens: an in vitro study.

BACKGROUND: The present study examines the antimicrobial activity of nasturtium herb (Tropaeoli maji herba) and horseradish root (Armoraciae rusticanae radix) against clinically important oral bacterial pathogens involved in periodontitis, gingivitis, pulpitis, implantitis and other infectious diseases. METHODS: A total of 15 oral pathogens, including members of the genera Campylobacter, Fusobacterium, Prevotella, Parvimonas, Porphyromonas, Tanerella, Veillonella, and HACEK organisms, were exposed to [1] a combination of herbal nasturtium and horseradish using a standardized gas test and [2] a mixture of synthetic Isothiocyantes (ITCs) using an agardilution test. Headspace gas chromatography mass spectrometry was employed to quantify the amount of allyl-, benzyl-, and 2- phenyl- ethyl-ITC. RESULTS: With exception of Veillonella parvula, all tested species were highly susceptible to herbal nasturtium and horseradish in the gas test with minimal inhibitory concentrations (MICs) between 50/20 mg and 200/80 mg and to synthetic ITCs in the agardilution with MICs between 0.0025 and 0.08 mg ITC/mL, respectively. Minimal bactericidal concentrations extended from 0.005 mg ITC/mL to 0.34 mg ITC/mL. CONCLUSIONS: ITCs may be considered an interesting alternative to antibiotics for prevention and treatment of oropharyngeal infections, periodontitis and related diseases. Furthermore, the suitability of ITCs for endocarditis prophylaxis in dental procedures might be worth further investigation.

IRIXS: a resonant inelastic X-ray scattering instrument dedicated to X-rays in the intermediate energy range.

A new resonant inelastic X-ray scattering (RIXS) instrument has been constructed at beamline P01 of the PETRA III synchrotron. This instrument has been named IRIXS (intermediate X-ray energy RIXS) and is dedicated to X-rays in the tender-energy regime (2.5-3.5 keV). The range covers the L2,3 absorption edges of many of the 4d elements (Mo, Tc, Ru, Rh, Pd and Ag), offering a unique opportunity to study their low-energy magnetic and charge excitations. The IRIXS instrument is currently operating at the Ru L3-edge (2840 eV) but can be extended to the other 4d elements using the existing concept. The incoming photons are monochromated with a four-bounce Si(111) monochromator, while the energy analysis of the outgoing photons is performed by a diced spherical crystal analyzer featuring (102) lattice planes of quartz (SiO2). A total resolution of 100 meV (full width at half-maximum) has been achieved at the Ru L3-edge, a number that is in excellent agreement with ray-tracing simulations.

Cryo-focused ion beam preparation of perovskite based solar cells for atom probe tomography.

Focused-ion beam lift-out and annular milling is the most common method used for obtaining site specific specimens for atom probe tomography (APT) experiments and transmission electron microscopy. However, one of the main limitations of this technique comes from the structural damage as well as chemical degradation caused by the beam of high-energy ions. These aspects are especially critical in highly-sensitive specimens. In this regard, ion beam milling under cryogenic conditions has been an established technique for damage mitigation. Here, we implement a cryo-focused ion beam approach to prepare specimens for APT measurements from a quadruple cation perovskite-based solar cell device with 19.7% efficiency. As opposed to room temperature FIB milling we found that cryo-milling considerably improved APT results in terms of yield and composition measurement, i.e. halide loss, both related to less defects within the APT specimen. Based on our approach we discuss the prospects of reliable atom probe measurements of perovskite based solar cell materials. An insight into the field evaporation behavior of the organic-inorganic molecules that compose the perovskite material is also given with the aim of expanding the applicability of APT experiments towards nano-characterization of complex organo-metal materials.

Structure and Dynamics of Confined Liquids: Challenges and Perspectives for the X-ray Surface Forces Apparatus.

The molecular-scale structure and dynamics of confined liquids has increasingly gained relevance for applications in nanotechnology. Thus, a detailed knowledge of the structure of confined liquids on molecular length scales is of great interest for fundamental and applied sciences. To study confined structures under dynamic conditions, we constructed an in situ X-ray surface forces apparatus (X-SFA). This novel device can create a precisely controlled slit-pore confinement down to dimensions on the 10 nm scale by using a cylinder-on-flat geometry for the first time. Complementary structural information can be obtained by simultaneous force measurements and X-ray scattering experiments. The in-plane structure of liquids parallel to the slit pore and density profiles perpendicular to the confining interfaces are studied by X-ray scattering and reflectivity. The normal load between the opposing interfaces can be modulated to study the structural dynamics of confined liquids. The confinement gap distance is tracked simultaneously with nanometer precision by analyzing optical interference fringes of equal chromatic order. Relaxation processes can be studied by driving the system out of equilibrium by shear stress or compression/decompression cycles of the slit pore. The capability of the new device is demonstrated on the liquid crystal 4'-octyl-4-cyano-biphenyl (8CB) in its smectic A (SmA) mesophase. Its molecular-scale structure and orientation confined in 100 nm to 1.7 µm slit pores was studied under static and dynamic nonequilibrium conditions.

In Situ Mechanical Analysis of the Nanoscopic Solid Electrolyte Interphase on Anodes of Li-Ion Batteries.

The interfacial decomposition products forming the so-called solid-electrolyte interphase (SEI) significantly determine the destiny of a Li-ion battery. Ultimate knowledge of its detailed behavior and better control are required for higher rates, longer life-time, and increased safety. Employing an electrochemical surface force apparatus, it is possible to control the growth and to investigate the mechanical properties of an SEI in a lithium-ion battery environment. This new approach is here introduced on a gold model system and reveals a compressible film at all stages of SEI growth. The demonstrated methodology provides a unique tool for analyzing electrochemical battery interfaces, in particular in view of alternative electrolyte formulations and artificial interfaces.

Real-Time Monitoring of Interactions between Solid-Supported Lipid Vesicle Layers and Short- and Medium-Chain Length Alcohols: Ethanol and 1-Pentanol.

Lipid bilayers represent the interface between the cell and its environment, serving as model systems for the study of various biological processes. For instance, the addition of small molecules such as alcohols is a well-known process that modulates lipid bilayer properties, being considered as a reference for general anesthetic molecules. A plethora of experimental and simulation studies have focused on alcohol's effect on lipid bilayers. Nevertheless, most studies have focused on lipid membranes formed in the presence of alcohols, while the effect of n-alcohols on preformed lipid membranes has received much less research interest. Here, we monitor the real-time interaction of short-chain alcohols with solid-supported vesicles of dipalmitoylphosphatidylcholine (DPPC) using quartz crystal microbalance with dissipation monitoring (QCM-D) as a label-free method. Results indicate that the addition of ethanol at different concentrations induces changes in the bilayer organization but preserves the stability of the supported vesicle layer. In turn, the addition of 1-pentanol induces not only changes in the bilayer organization, but also promotes vesicle rupture and inhomogeneous lipid layers at very high concentrations.

Hop Extract Acts as an Antioxidant with Antimicrobial Effects against Propionibacterium Acnes and Staphylococcus Aureus.

Acne is associated with hyperkeratosis, elevated levels of skin sebum and growth of Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). Furthermore, P. acnes promotes inflammation by inducing IL-6 production and oxidative stress. The aim of this study was to assess the antioxidant, anti-inflammatory and antibacterial potential of a hop-CO2-extract with 50% humulone and lupulone. The susceptibility of P. acnes and S. aureus to the hop extract was tested by using the broth microdilution technique. The minimal inhibitory concentrations (MIC) for P. acnes and S. aureus were 3.1 and 9.4 µg/mL, respectively. In addition, the hop extract showed an antioxidative effect with a half maximal inhibitory concentration (IC50) of 29.43 µg/mL as well as additional anti-inflammatory effects by reducing the IL-6 expression (IC50: 0.8 µg/mL). In addition, a gel formulation with 0.3% hop extract (w/w) had antibacterial activity against P. acnes and S. aureus (inhibition zone value: 5.5 mm and 3 mm, respectively) which was significantly superior to the placebo gel. The positive control (a gel with the antibiotic clindamycin) showed an inhibition zone of 9 mm. Due to its antioxidant, anti-inflammatory and antibacterial effects hop extract might be a treatment option for acne-prone skin.

Treating urinary tract infections due to MDR E. coli with Isothiocyanates - a phytotherapeutic alternative to antibiotics?

BACKGROUND: Multidrug-resistant (MDR) bacteria are increasingly causing urinary tract infections (UTI), which has been linked to frequent use of antibiotics. Alternative treatment regimens are urgently needed and natural isothiocyanates (ITC) may represent one. ITCs are natural plant products found in nasturtium (Tropaeoli majoris herba) and horseradish (Armoraciae rusticanae radix). PURPOSE: The objectives were to (1) assess the antimicrobial effects of nature-identical ITCs for UTI treatment caused by uropathogenic E. coli (UPEC), (2) to evaluate a potential influence of antimicrobial resistance on ITC susceptibility, and (3) to test whether ITCs affect UPEC penetration into human uroepithelial cells. METHODS: We tested 217 clinical UPEC isolates, 54.5% of which were classified as MDR, for susceptibility against ITCs. ITC susceptibility testing was performed by broth dilution using a mixture of three synthetic ITCs. Internalization was tested using human T-24 bladder carcinoma cells in an internalization assay co-incubated with UPEC (n = 5) and ITCs. RESULTS: The mean minimal inhibitory concentration (MIC) 90 was 0.17 mg/ml, showing very high susceptibility against ITCs. Interestingly, MDR E. coli were significantly less susceptible than non-MDR strains (p = .01). Internalization of UPEC was decreased by 31.9% in the mean when treated with ITCs. Overall, ITCs exerted a strong antimicrobial activity against clinical UPEC isolates and reduced internalization into uroepithelial cells. CONCLUSION: ITCs might present a promising treatment alternative for UTIs, expressing both high antimicrobial activity as well as blocking the pathogenic process of human cell penetration by UPEC. Clinical studies, however, are needed to confirm activity of ITCs in UTIs in vivo.