Fosfomycin-meropenem synergistic combination against NDM carbapenemase-producing Klebsiella pneumoniae strains.

Carbapenemase-producing Enterobacteriaceae (CPE) are an increasing threat to global public health. Treatment of CPE isolates, like New Delhi metallo-ß-lactamase (NDM), is limited and often necessitates combination therapies. The aim of this study was to evaluate the synergistic meropenem/fosfomycin combination against K.pneumoniae-producing NDM isolates. Fosfomycin/meropenem, fosfomycin/colistin and meropenem/colistin were tested alone and in combination, using e-test and time-kill assay against 20 clinical carbapenemase-producing K. pneumonia (CPKp NDM) isolates collected from September 2022 to December 2022. K. pneumoniae strains were resistant to meropenem, ceftazidime/avibactam and ceftolozano/tazobactam, 75% and 80% of isolates were susceptible for cefiderocol and for colistin respectively. Fosfomycin/meropenem combination was synergic in 95% (n=19) strains. Fosfomycin/colistin and colistin/meropenem combination showed only 10% synergistic combination strains. In 16 isolates (80%) indifference action for fosfomycin/colistin and colistin/meropenem was reported. For 0.8% of CpKP NDM isolates colistin/meropenem and fosfomycin/colistin combinations found to be antagonistic. In this study, time kill assay showed combination therapies action versus K.pneumoniae metallo-b-lactamase producing (NDM) strains and confirmed the synergistic action of fosfomycin/meropenem combination. In vitro synergy testing should be routinely performed in multidrug resistance infections and combo therapies can be used as a possible alternative in targeted patients with the goal of reducing overall antibiotic costs.

Elucidations on the Performance and Reversibility of Treatment with Hyaluronic Acid Based Dermal Fillers: In vivo and in vitro Approaches.

Purpose: The aim of this study was to investigate the performance and the reversibility of different classes of Hyaluronic Acid (HA) dermal fillers. We analysed 4 HA based fillers, belonging to 3 different chemical classes of products, commonly used in the field of wrinkles correction: linear HA 8 mg/mL (Viscoderm 0.8), thermically stabilized hybrid complexes of high and low molecular weight HA molecules at a concentration of 32 mg/mL and 45 mg/mL respectively (Profhilo and Profhilo Structura) and cross-linked HA 25 mg/mL (Aliaxin GP). Methods: The products were tested by a well-established animal model. The generated implants were analyzed through High-Frequency Ultrasound technology. Then, reversibility of the treatment was evaluated by enzymatic degradation kinetics studies, characterised by a combined approach of Carbazole assay and HP-SEC/TDA method. Results: Implants generated by linear HA 8 mg/mL remained detectable by ultrasound acquisition for 4 weeks, whereas those generated by injection of HA hybrid complex 32 mg/mL were detectable for 10 weeks. HA hybrid complex 45 mg/mL and cross-linked HA 25 mg/mL were detectable for 29 and at least 33 weeks, respectively. Enzymatic degradation kinetics studies demonstrated that the HA content in HA hybrid complex 45 mg/mL was almost completely depolymerized and homogeneous after 3 h of treatment. For cross-linked HA 25 mg/mL, 24 h of incubation are needed to obtain the same degree of depolymerization. Conclusion: The study confirmed the ability of the experimental model to predict the behaviour of HA based dermal fillers in vivo and showed the innovative aspects of HA hybrid complex 45 mg/mL, that combines the high-safety profile, in terms of reversibility of the treatment, of the linear HA-based products with the durability of a high degree cross-linked gels, paving the way to the chance to be used for a wide range of applications in the field of aesthetic medicine.

Evaluation of Wound Healing Activity of Salvia haenkei Hydroalcoholic Aerial Part Extract on in vitro and in vivo Experimental Models.

PURPOSE: The aim of the present study was to evaluate the potential wound healing activity of the hydroalcoholic extract of Salvia haenkei on in vitro and in vivo experimental models. MATERIALS AND METHODS: Preliminary analytical characterization of the hydroalcoholic extract of Salvia haenkei was made by reversed-phase high performance liquid chromatography (RP-HPLC) that permitted identification of a qualitative fingerprint of the extract of aerial parts. The wound healing activity of the hydroalcoholic extract of Salvia haenkei was evaluated in vitro by the scratch assay on human dermal fibroblasts and human epidermal keratinocytes and in vivo by standardized mouse excisional splinting model. Real-time PCR (RT-PCR) experiments were performed to analyze gene expression levels of inflammatory markers. RESULTS: The scratch assay tests showed that the treatment with the hydroalcoholic extract of Salvia haenkei did not induce an increase in the fibroblasts migration rate with respect to the positive control. Instead, the hydroalcoholic extract of Salvia haenkei was effective in improving the wound closure rate on keratinocyte cell cultures with an almost total invasion of the scratch after 48 h of treatment; whereas the positive control, at the same time point, showed only a 67% reduction of the wound size. In vivo experiments showed that the groups treated with the extract of Salvia haenkei completely re-epithelized the wound in 2.7 days, a timing that was comparable with the action of the positive control that took only 2.1 days. Gene expression analysis showed that Salvia haenkei positively regulated the signaling pathway of the nuclear factor-κB (NF-κB) transcription factor. CONCLUSION: The results suggested that the hydroalcoholic extract of Salvia haenkei induced a clear wound healing effect.

A novel animal model for residence time evaluation of injectable hyaluronic acid-based fillers using high-frequency ultrasound-based approach.

BACKGROUND: Hyaluronic acid (HA)-based devices are among the most popular filler agents for skin rejuvenation. One of the principal goals is the improvement in residence time of HA-based products, to increase their performance and reduce frequency of the treatment. So, understanding fillers, behavior after subcutaneous injection is a fundamental aspect for discovery and optimization of new products. Current in vivo approaches to detect/quantify injected HA fillers are not always well optimized or easy to apply. OBJECTIVE: To develop more efficacious and noninvasive diagnostic tools to make a quantitative evaluation of the degradation of fillers in a small animal model. MATERIALS AND METHODS: We evaluated the residence time of different HA-based fillers, fluorescein-labeled and not, injected subcutaneously in mice. Volumes of fillers were monitored through high-frequency ultrasound (HF-US) method while fluorescence intensity through the well-established fluorescence living imaging method. To confirm the effectiveness of HF-US, obtained volumetric measurements were compared with fluorescence intensity values. RESULTS: Both the presented methods revealed the same degradation kinetics for the tested products. CONCLUSION: The two used methods are fully comparable and quantitatively accurate. The presented approach has been proved to be noninvasive, sensitive, and reproducible.