Search

In the present study, a series of isatin bis-imidathiazole hybrids was designed and synthesized to develop a new class of heterocyclic compounds with improved antimicrobial activity against pathogens responsible for hospital- and community-acquired infections. A remarkable inhibitory activity against Staphylococcus aureus was demonstrated for a subset of compounds (range: 13.8–90.1 µM) in the absence of toxicity towards epithelial cells and human red blood cells. The best performing derivative was further investigated to measure its anti-biofilm potential and its effectiveness against methicillin-resistant Staphylococcus aureus strains. A structure–activity relationship study of the synthesized molecules led to the recognition of some important structural requirements for the observed antibacterial activity. Molecular docking followed by molecular dynamics (MD) simulations identified the binding site of the active compound FtsZ, a key protein in bacterial cell division, and the mechanism of action, i.e., the inhibition of its polymerization. The overall results may pave the way for a further rational development of isatin hybrids as FtsZ inhibitors, with a broader spectrum of activity against human pathogens and higher potency. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are a class of crystalline porous materials with outstanding physical and chemical properties that make them suitable candidates in many fields, such as catalysis, sensing, energy production, and drug delivery. By combining MOFs with polymeric substrates, advanced functional materials are devised with excellent potential for biomedical applications. In this research, Zeolitic Imidazolate Framework 8 (ZIF-8), a zinc-based MOF, was selected together with cellulose, an almost inexhaustible polymeric raw material produced by nature, to prepare cellulose/ZIF-8 composite flat sheets via an in-situ growing single-step method in aqueous media. The composite materials were characterized by several techniques (IR, XRD, SEM, TGA, ICP, and BET) and their antibacterial activity as well as their biocompatibility in a mammalian model system were investigated. The cellulose/ZIF-8 samples remarkably inhibited the growth of Gram-positive and Gram-negative reference strains, and, notably, they proved to be effective against clinical isolates of Staphylococcus epidermidis and Pseudomonas aeruginosa presenting different antibiotic resistance profiles. As these pathogens are of primary importance in skin diseases and in the delayed healing of wounds, and the cellulose/ZIF-8 composites met the requirements of biological safety, the herein materials reveal a great potential for use as gauze pads in the management of wound infections. [ABSTRACT FROM AUTHOR]

The development of green, low cost and sustainable synthetic routes to produce metal nanoparticles is of outmost importance, as these materials fulfill large scale applications in a number of different areas. Herein, snail slime extracted from Helix Aspersa snails was successfully employed both as bio-reducing agent of silver nitrate and as bio-stabilizer of the obtained nanoparticles. Several trials were carried out by varying temperature, the volume of snail slime and the silver nitrate concentration to find the best biogenic pathway to produce silver nanoparticles. The best results were obtained when the synthesis was performed at room temperature and neutral pH. UV–Visible Spectroscopy, SEM-TEM and FTIR were used for a detailed characterization of the nanoparticles. The obtained nanoparticles are spherical, with mean diameters measured from TEM images ranging from 15 to 30 nm and stable over time. The role of proteins and glycoproteins in the biogenic production of silver nanoparticles was elucidated. Infrared spectra clearly showed the presence of proteins all around the silver core. The macromolecular shell is also responsible of the effectiveness of the synthesized AgNPs to inhibit Gram positive and Gram negative bacterial growth. [ABSTRACT FROM AUTHOR]

Isatin and its derivatives are important heterocycles found in nature and present in numerous bioactive compounds which possess various biological activities. Moreover, it is an essential building block in organic synthesis. The discovery of novel compounds active against human pathogenic bacteria and fungi is an urgent need, and the isatin may represent the suitable scaffold in the design of biologically relevant antimicrobials. A small library of 18 isatin hybrids was synthetized and evaluated for their antimicrobial potential on three reference strains: S. aureus, E. coli, both important human pathogens infamous for causing community- and hospital-acquired severe systemic infections; and C. albicans, responsible for devastating invasive infections, mainly in immunocompromised individuals. The study highlighted two lead compounds, 6k and 6m, endowed with inhibitory activity against S. aureus at very low concentrations (39.12 and 24.83 µg/mL, respectively). [ABSTRACT FROM AUTHOR]

The availability of biomaterials able to counteract bacterial colonization is one of the main requirements of functional implants and medical devices. Herein, we functionalized hydroxyapatite (HA) with tungsten oxide (WO3) nanoparticles in the aim to obtain composite materials with improved biological performance. To this purpose, we used HA, as well as HA functionalized with polyacrilic acid (HAPAA) or poly(ethylenimine) (HAPEI), as supports and polyvinylpyrrolidone (PVP) as stabilizing agent for WO3 nanoparticles. The number of nanoparticles loaded on the substrates was determined through Molecular Plasma-Atomic Emission Spectroscopy and is quite small, so it cannot be detected through X-ray diffraction analysis. It increases from HAPAA, to HA, to HAPEI, in agreement with the different values of zeta potential of the different substrates. HRTEM and STEM images show the dimensions of the nanoparticles are very small, less than 1 nm. In physiological solution HA support displays a greater tungsten cumulative release than HAPEI, despite its smaller loaded amount. Indeed, WO3 nanoparticles-functionalized HA exhibits a remarkable antibacterial activity against the Gram-positive Staphylococcus aureus in absence of cytotoxicity, which could be usefully exploited in the biomedical field. [ABSTRACT FROM AUTHOR]

Background: Alkaloids present in plants of the Amaryllidaceae family are secondary metabolites of high biological interest, possessing a wide range of pharmacological activities. In the search for new plant-derived compounds with antimicrobial activities, two alkaloid extracts obtained from bulbs and leaves of Pancratium illyricum L., a plant of the Amarillydaceae family, were tested for their effect on bacterial and yeast growth. Methods: The broth microdilution susceptibility test was applied to study the effect of plant extracts on the growth of reference bacterial strains and Candida albicans reference and clinical isolates strains. Extracts obtained from the different parts of the plant were tested and compared with the pure components identified in the extracts. Since matrix metalloproteinase enzymes play a role in the dissemination process of Candida albicans, the effect of the bulb extract and pure alkaloids on in vitro collagenase activity was tested. Cell viability test was carried out on human embryo lung fibroblasts (HEL 299). Results: Whilst both extracts did not show any inhibitory activity against neither Gram positive nor Gram negative bacteria, a strong antifungal activity was detected, in particular for the bulb extract. All clinical isolates were susceptible to the growth inhibitory activity of the bulb extract, with endpoint IC50 values ranging from 1.22 to 78 µg/mL. The pure alkaloids lycorine and vittatine, identified as components of the extract, were also assayed for their capacity of inhibiting the yeast growth, and lycorine turned very active, with endpoint IC50 values ranging from 0.89 to 28.5 µg/mL. A potent inhibition of the in vitro collagenase activity was found in the presence of the bulb extract, and this effect was much higher than that exerted by the pure alkaloids. Viability of cell lines tested was not affected by the extract. Conclusions: Taken together, results suggest that the extract of Pancratium illyricum may act as antifungal agent both directly on the yeast growth and by altering the tissue invasion process. [ABSTRACT FROM AUTHOR]

In the search for novel antibacterial agents against multidrug-resistant bacteria, an alkaloid extract obtained from whole plants of Crinum angustum Steud., containing six different groups of alkaloids, was analysed by using gas chromatography/mass spectrometry, and its in vitro activity against American Type Culture Collection bacterial strains and clinical isolates was evaluated. The antimicrobial activity of the extract was tested against nine standard strains of microorganisms and two drug-resistant clinical isolates, methicillin-resistant Staphylococcus aureus and carbapenemase-producing Klebsiella pneumoniae. The extract exhibited a significant activity against six of the examined strains of microorganisms. Antibacterial activity was more pronounced on Gram-positive bacteria than on Gram-negative bacteria, and IC50 values ranged from 156 to 625 μg/mL. Mycostatic activity against Candida albicans was also found, with an IC50 of 78 μg/mL after 48 h of incubation. Promising results were also obtained from tests carried out on both clinical isolates investigated. [ABSTRACT FROM AUTHOR]

Advances in nanotechnology have opened up new horizons in nanomedicine through the synthesis of new composite nanomaterials able to tackle the growing drug resistance in bacterial strains. Among these, nanosilver antimicrobials sow promise for use in the treatment of bacterial infections. The use of polydopamine (PDA) as a biocompatible carrier for nanosilver is appealing; however, the synthesis and functionalization steps used to obtain Ag-PDA nanoparticles (NPs) are complex and require time-consuming cleanup processes. Post-synthesis treatment can also hinder the stability and applicability of the material, and dry, offline characterization is time-consuming and unrepresentative of real conditions. The optimization of Ag-PDA preparation and purification together with well-defined characterization are fundamental goals for the safe development of these new nanomaterials. In this paper, we show the use of field-flow fractionation with multi-angle light scattering and spectrophotometric detection to improve the synthesis and quality control of the production of Ag-PDA NPs. An ad hoc method was able to monitor particle growth in a TLC-like fashion; characterize the species obtained; and provide purified, isolated Ag-PDA nanoparticles, which proved to be biologically active as antibacterial agents, while achieving a short analysis time and being based on the use of green, cost-effective carriers such as water. [ABSTRACT FROM AUTHOR]

Microbial infections occurring during bone surgical treatment, the cause of osteomyelitis and implant failures, are still an open challenge in orthopedics. Conventional therapies are often ineffective and associated with serious side effects due to the amount of drugs administered by systemic routes. In this study, a medicated osteoinductive and bioresorbable bone graft was designed and investigated for its ability to control antibiotic drug release in situ. This represents an ideal solution for the eradication or prevention of infection, while simultaneously repairing bone defects. Vancomycin hydrochloride and gentamicin sulfate, here considered for testing, were loaded into a previously developed and largely investigated hybrid bone-mimetic scaffold made of collagen fibers biomineralized with magnesium doped-hydroxyapatite (MgHA/Coll), which in the last ten years has widely demonstrated its effective potential in bone tissue regeneration. Here, we have explored whether it can be used as a controlled local delivery system for antibiotic drugs. An easy loading method was selected in order to be reproducible, quickly, in the operating room. The maintenance of the antibacterial efficiency of the released drugs and the biosafety of medicated scaffolds were assessed with microbiological and in vitro tests, which demonstrated that the MgHA/Coll scaffolds were safe and effective as a local delivery system for an extended duration therapy—promising results for the prevention of bone defect-related infections in orthopedic surgeries. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) "fermentates" confer a beneficial effect on intestinal function. However, the ability of new fermentations to improve LAB broth activity in preventing pathogen-induced intestinal inflammation and barrier dysfunction has not yet been studied. The objective of this study was to determine if broths of LAB fermented with Eruca sativa or Barbarea verna seed extracts prevent gut barrier dysfunction and interleukin-8 (CXCL8) release in vitro in human intestinal Caco-2 cells infected with enterohemorrhagic Escherichia coli (EHEC) O157:H7. LAB broths were assayed for their effects on EHEC growth and on Caco-2 viability; thereafter, their biological properties were analysed in a co-culture system consisting of EHEC and Caco-2 cells. Caco-2 cells infected with EHEC significantly increased CXCL8 release, and decreased Trans-Epithelial Electrical Resistance (TEER), a barrier-integrity marker. Notably, when Caco-2 cells were treated with LAB broth enriched with E. sativa seed extract and thereafter infected, both CXCL8 expression and epithelial dysfunction reduced compared to in untreated cells. These results underline the beneficial effect of broths from LAB fermented with E. sativa seed extracts in gut barrier and inflammation after EHEC infection and reveal that these LAB broths can be used as functional bioactive compounds to regulate intestinal function. [ABSTRACT FROM AUTHOR]

Extensive documentation is available on plant essential oils as a potential source of antimicrobials, including natural drugs against Candida spp. Yeasts of the genus Candida are responsible for various clinical manifestations, from mucocutaneous overgrowth to bloodstream infections, whose incidence and mortality rates are increasing because of the expanding population of immunocompromised patients. In the last decade, although C. albicans is still regarded as the most common species, epidemiological data reveal that the global distribution of Candida spp. has changed, and non-albicans species of Candida are being increasingly isolated worldwide. The present study aimed to review the anti-Candida activity of essential oils collected from 100 species of the Lamiaceae family growing in the Mediterranean area and the Middle East. An overview is given on the most promising essential oils and constituents inhibiting Candida spp. growth, with a particular focus for those natural products able to reduce the expression of virulence factors, such as yeast-hyphal transition and biofilm formation. Based on current knowledge on members of the Lamiaceae family, future recommendations to strengthen the value of these essential oils as antimicrobial agents include pathogen selection, with an extension towards the new emerging Candida spp. and toxicological screening, as it cannot be taken for granted that plant-derived products are void of potential toxic and/or carcinogenic properties. [ABSTRACT FROM AUTHOR]

At present, there is no vaccine or effective standard treatment for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection (or coronavirus disease-19 (COVID-19)), which frequently leads to lethal pulmonary inflammatory responses. COVID-19 pathology is characterized by extreme inflammation and amplified immune response with activation of a cytokine storm. A subsequent progression to acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) can take place, which is often followed by death. The causes of these strong inflammatory responses in SARS-CoV-2 infection are still unknown. As uncontrolled pulmonary inflammation is likely the main cause of death in SARS-CoV-2 infection, anti-inflammatory therapeutic interventions are particularly important. Fenretinide N-(4-hydroxyphenyl) retinamide is a bioactive molecule characterized by poly-pharmacological properties and a low toxicity profile. Fenretinide is endowed with antitumor, anti-inflammatory, antiviral, and immunomodulating properties other than efficacy in obesity/diabetic pathologies. Its anti-inflammatory and antiviral activities, in particular, could likely have utility in multimodal therapies for the treatment of ALI/ARDS in COVID-19 patients. Moreover, fenretinide administration by pulmonary delivery systems could further increase its therapeutic value by carrying high drug concentrations to the lungs and triggering a rapid onset of activity. This is particularly important in SARS-CoV-2 infection, where only a narrow time window exists for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Non-Escherichia coli Enterobacterales (NECE) can colonize the human gut and may present virulence determinants and phenotypes that represent severe heath concerns. Most information is available for virulent NECE strains, isolated from patients with an ongoing infection, while the commensal NECE population of healthy subjects is understudied. In this study, 32 NECE strains were isolated from the feces of 20 healthy adults. 16S rRNA gene sequencing and mass spectrometry attributed the isolates to Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Enterobacter kobei, Citrobacter freundii, Citrobacter amalonaticus, Cronobacter sp., and Hafnia alvei, Morganella morganii, and Serratia liquefaciens. Multiplex PCR revealed that K. pneumoniae harbored virulence genes for adhesins (mrkD, ycfM, and kpn) and enterobactin (entB) and, in one case, also for yersiniabactin (ybtS, irp1, irp2, and fyuA). Virulence genes were less numerous in the other NECE species. Biofilm formation was spread across all the species, while curli and cellulose were mainly produced by Citrobacter and Enterobacter. Among the most common antibiotics, amoxicillin-clavulanic acid was the sole against which resistance was observed, only Klebsiella strains being susceptible. The NECE inhabiting the intestine of healthy subjects have traits that may pose a health threat, taking into account the possibility of horizontal gene transfer. [ABSTRACT FROM AUTHOR]

Abstract: Human bocavirus DNA was detected by means of a quantitative, real-time polymerase chain reaction at low levels in the 5.51% of sera obtained from healthy blood donors, suggesting that viral detection in blood is not necessarily associated with disease status. [Copyright &y& Elsevier]

The development of infections still represents a severe problem in orthopedic field. In this work, we developed an anti-microbial and radiopaque calcium phosphate bone cement with a long-lasting inhibitory activity thanks to the addition of gentamicin sulphate-loaded solid lipid microparticles obtained by spray congealing. Cements containing gentamicin both added into cement powder and loaded into microparticles were prepared and characterized and their properties were compared. The results of structural, morphological, mechanical and in vitro characterizations indicate that inclusion of gentamicin into microparticles is a good approach in order to obtain materials able to display a strong inhibition towards the growth of Gram-negative, as well as Gram-positive bacteria and to enhance the viability of osteoblast-like cells. All the compositions have an excellent activity also against clinical isolates, including multi drug resistant phenotypes. In particular, cements containing gentamicin-loaded microparticles display a strong and long-term inhibitory activity. Suitable modification of the liquid/powder ratio provided injectable formulation, whereas addition of BaSO 4 produced radiopacity. All the formulations display good injectability and cohesion, and no evidence of demixing. Image 1 [ABSTRACT FROM AUTHOR]

Snail mucus is an attractive natural substance, which is increasingly used in cosmetic creams and syrups thanks to its emollient, moisturizing, protective and reparative properties. The aim of the present study was to explore the physicochemical properties of chitosan-based films added with snail mucus extracted from Helix Aspersa Muller. To this aim, chitosan films at different content of snail mucus were fabricated by simple solvent casting technique. The results of X-ray diffraction analyses, tensile mechanical tests, Infrared spectroscopy and thermogravimetry demonstrated that snail mucus addition strongly modifies the properties of chitosan films. In particular, it acted like a plasticizer enhancing films extensibility up to ten times and strongly improving their water barrier and bioadhesion properties, with a trend depending on Snail mucus content. Furthermore, it provides the films with antibacterial properties and enhanced cytocompatibility, yielding materials with tailored properties for specific requirements. Unlabelled Image • Snail mucus addition confers functional properties to chitosan films. • Composite films can be stretched up more than ten times with respect to chitosan films. • Bioadhesion and water vapor barrier properties are highly enhanced. • Obtained films are natural materials with antibacterial activity. [ABSTRACT FROM AUTHOR]

The development of new biomaterials able to favor bone formation and to inhibit bone abnormal resorption is mandatory to face the increasing number of age-related musculo-skeletal disorders. Moreover, the increasing antibiotic resistance of clinically important bacteria, which is among the main causes of implant failure, requires new antimicrobial systems. In this study, we prepared multifunctional materials consisting of hydroxyapatite-zoledronate composite crystals decorated with Ag Nanoparticles (AgNPs). Zoledronate, a potent bisphosphonate widely applied for the treatment of pathologies associated to abnormal bone loss, was incorporated into hydroxyapatite up to about 8 wt%. Loading of poly(ethylenimine) – stabilized AgNPs onto the crystals was promoted by zoledronate functionalization and provoked a significant variation of the values of zeta potential. The results of in vitro tests demonstrate that the multifunctional materials combine the beneficial actions of zoledronate and AgNPs. In fact, they improve osteoblast differentiation and activity, whereas they inhibit osteoclastogenesis and osteoclast differentiation, and significantly hinder the growth of multi-drug resistant Gram positive and Gram negative bacteria. As a consequence, they can be exploited both as antiresorptive agents and as antimicrobial materials able to prevent the development of bone-associated infections. [ABSTRACT FROM AUTHOR]

Abstract: An accurate tool for viral typing is important for management of patients with human papillomavirus (HPV) infection and to monitor HPV vaccine efficacy. This study evaluated the performance of the HPV sign® Genotyping Test by analyzing 87 archival cervical specimens and compared results with historical data by INNO-LiPA HPV Genotyping Extra assay. There was a substantial concordance for HPV detection in clinical samples (k 0.66), with an overall agreement rate of 85.1%. The genotyping overall agreement, considering one by one the HPV infection detected, was 95.7%. The HPV sign test showed, however, lower sensitivity than INNO-LiPA for HPV 31, 53, and 66. On the other hand, The HPV16 sensitivity was higher for HPV sign (90.0%, confidence interval [CI] 0.79–1.01) than for INNO-LiPA (83.3%, CI 0.70–0.97). Furthermore, HPV sign allowed identifying the presence of HPV16 intratype variants. In conclusion, HPV sign is a promising method for HPV genotyping and has revealed advantages in detecting a broad spectrum of HPV types and variants. [Copyright &y& Elsevier]

Abstract: Objectives. : Cervical intraepithelial neoplasias (CIN) associated with high-risk (HR) human papillomavirus infection, in addition to HR-HPV typing need other viral marker testing to distinguish a subset of lesions with clinical relevant infections. This study has evaluated the significance of viral markers, such as viral load, physical status and E2/E6 ratio, to stratify HPV16 infected women at a single point in time for grade of cervical lesions. Methods. : One hundred sixty-six cytological specimens were selected from women with low (n =72) and high (n =94) grade squamous intraepithelial lesions (SIL), and positive to HPV16. All the 72 LSIL were CINI, 83 of the 94 HSIL were CINII/III and 11 SCC (Squamous Cervical Carcinoma). Cytological specimens were analysed by two different SYBR Green Real-time PCR assays (RT-PCR). Specific primers for both E2 and E6 viral genes and GAPDH cellular gene were designed to determine viral load, physical status and E2/E6 ratio. Results. : The viral load was significantly higher in HSIL than in LSIL. In CINI episomal DNA was prevalent (72.2%), mixed forms (episomal and integrated) were 27.8%, suggestive of an early integration of viral DNA into cellular genome, no pure integrated forms were detected. However in CINII/III mixed DNA forms were prevalent (73.5%). In SCC pure integrated DNA was prevalent (81.8%) in absence of episomal forms. E2/E6 ratio decreased significantly from CINI to CINII/III and SCC with a linear trend. The logistic regression analysis showed that viral load higher than 1.38×106 genome copies per 300 ng of total DNA associated with E2/E6 ratio lower than 0.90 was highly significant in differentiating CINII/III versus CINI, while the only E2/E6 value lower than 0.17 was significant in differentiating SCC from CINI. Conclusions. : Viral load higher than 1.38×106 genome copies per 300 ng of total DNA and E2/E6 ratio values allow HPV16 infected women with high grade cervical intraepithelial lesions to be recognized. [Copyright &y& Elsevier]

[Display omitted] Gelatin-based films enriched with snail slime are proposed as novel biodegradable and naturally bioadhesive patches for cutaneous drug delivery. Films (thickness range 163–248 μm) were stretchable and they adhered firmly onto the wetted skin, especially those with high amount (70% V/V) of snail slime extract. Fluconazole was selected as model drug and added to films containing the highest amount of snail slime. The presence of Fluconazole (4.53 ± 0.07% w/w) did not modify significantly the mechanical properties, the swelling degree and the bioadhesive performances of the films. Structural investigations demonstrated that the crystalline form III of the drug changed to the amorphous one, forming an amorphous solid dispersion. Moreover, snail slime prevented the drug recrystallization over time. In vitro permeation studies showed that film exhibited a cumulative drug concentration (over 60% in 24 h) similar to that of the control solution containing 20% w/V of ethanol. Fluconazole-loaded gelatin films proved to be effective towards clinical isolates of Candida spp. indicating that the drug maintained its remarkable antifungal activity once formulated into gelatin and snail slime-based films. In conclusion, snail slime, thanks to its peculiar composition, has proved to be responsible of optimal skin adhesion, film flexibility and of the formation of a supersaturating drug delivery system able to increase skin permeation. [ABSTRACT FROM AUTHOR]

In response to the critical issue of chronic wound management, this research explores the development of a multiple-layer biomaterial loaded with LTX-109 a novel broad-spectrum topical antimicrobial peptide currently investigated for the treatment of bacterial skin infections. The novel patch is conceived to load and preserve the function of LTX-109, release it on site in a progressive manner, and therefore make available a device for simultaneous wounds disinfection and tissues healing. Chitosan, tannic acid and glycerol along with the solvent casting process are selected for the development of a multilayer structure in which each single layer is designed by choosing a specific composition and stability to tune its behavior and function. On the top, a protective layer to protect the wound from external contaminations, in the middle a medicated layer loaded with LTX-109 and at the bottom a multifunctional layer to modulate the release of LTX-109. Extensive characterizations show that the patch meets the essential requirements for creating an effective wound healing environment, such as absorption of exudate, maintenance of good oxygen and moisture permeability, biodegradability, biocompatibility, and sustained release of LTX-109 with fully retained antibacterial activity as demonstrated by MIC values obtained against reference bacteria., (© 2024 The Author(s). Macromolecular Bioscience published by Wiley‐VCH GmbH.)

Clofazimine (CLZ) is an antibiotic with a promising behavior against Gram-positive bacteria; however, the drug is completely insoluble in water and accumulates in fat tissues. We explored nanocarriers, labeled and not labeled with rhodamine, consisting of negatively charged sulfobutylether-β-cyclodextrins for CLZ loading. A new oligomeric carrier was obtained cross-linking βCyD with epichlorohydrin followed by sulfonation in a strongly alkaline aqueous medium. The oligomeric carrier has a MW of 53 kDa and forms small nanoparticles of a few tens of nm. With aqueous solutions containing a 25 mg/mL oligomeric carrier, we loaded up to 0.5 mg/mL of drug. The oligomers exhibited a 10-fold better loading capacity compared to monomers and formed nanoparticles with a size in the 20-60 nm range after drug loading. Circular dichroism confirmed encapsulation of the CLZ in the nanocarriers. All carriers with or without CLZ are not cytotoxic up to 1 μM, while CLZ alone is highly cytotoxic at the same concentration. The drug has IC 50 values below 100 nM against S. epidermidis. The same holds true also for clinical isolates of S. epidermidis, some displaying MDR. So, the selectivity index significantly increased for CLZ/carrier systems compared to the drug alone. Taken all together, our results open new avenues for the clinical application of this antibiotic.

Herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) cause several clinically relevant syndromes in both adults and neonates. Despite the availability of efficient anti-HSV agents, the search for new therapeutic approaches is highly encouraged due to the increasing drug resistance of virus strains. Medicinal plants represent a source of potential bioactive compounds. In this context we evaluated the anti-herpetic activity of Hemidesmus indicus (L.) R. Br., a plant widely used in traditional Indian medicine. The hydroalcoholic extract prepared from roots was characterized by NMR and HPLC analysis and assayed in vitro by CPE reduction and virus infectivity assays to define its anti-viral effect. The extract's mechanism of action was investigated by virucidal and time-of-addition assays and by in vitro α-glucosidase inhibitory assay. The extract exhibited a remarkable anti-herpetic activity at 100 mg/mL, at non-cytotoxic concentration, through multiple mechanisms: it reduced the infectivity of viral particles released from infected cells possibly through its anti-ER α-glucosidase inhibitory activity and it inhibited the beginning stage of HSV infection acting as a virucide agent and/or preventing virus attachment to the host cell surface.

The development of biomaterials able to act against a wide range of bacteria, including antibiotic resistant bacteria, is of great importance since bacterial colonization is one of the main causes of implant failure. In this work, we explored the possibility to functionalize hydroxyapatite (HA) nanocrystals with some monocyclic N-thio-substituted β-lactams. To this aim, a series of non-polar azetidinones have been synthesized and characterized. The amount of azetidinones loaded on HA could be properly controlled on changing the polarity of the loading solution and it can reach values up to 17 wt%. Data on cumulative release in aqueous solution show different trends which can be related to the lipophilicity of the molecules and can be modulated by suitable groups on the azetidinone. The examined β-lactams-HA composites display good antibacterial activity against reference Gram-positive and Gram-negative bacteria. However, the results of citotoxicity and antibacterial tests indicate that HA loaded with 4-acetoxy-1-(methylthio)-azetidin-2-one displays the best performance. In fact, this material strongly inhibited the bacterial growth of both methicillin resistant and methicillin susceptible clinical isolates of S. aureus from surgical bone biopsies, showing to be a very good candidate as a new functional biomaterial with enhanced antibacterial activity.

The aim of this study was to determine the in vitro antimicrobial activity of crude extracts of three plants from Ayurveda tradition (Tinospora cordifolia, Alstonia scholaris, Crataeva nurvala) against reference microbial strains and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase-producing Klebsiella pneumoniae. IC50 values were obtained by micro-dilution methods meeting the requirements of the NCCLS standard. The cytotoxicity of the extracts was also investigated on a mammalian cell line. Extracts displayed a variable degree of antimicrobial activity and did not interfere with mammalian cell proliferation. T. cordifolia and A. scholaris exhibited a higher inhibitory activity against clinical isolates of MRSA and carbapenemase-producing K. pneumoniae compared with reference strains, while C. nurvala exhibited a different behaviour. An antifungal activity towards Candida albicans was observed for A. scholaris extract. Results indicate that constituents from T. cordifolia and A. scholaris may be a potential source of new therapeutic strategies for infectious diseases.

Coliphage MS2 is used in place of pathogens in many studies and is considered one of the indicators of pathogenetic viruses in wastewater. We developed a quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay to quantify MS2 coliphages in treated wastewater samples. The format used was SYBR Green. The assay included an internal control to disclose the presence of PCR-product inhibitors. The method had a wide dynamic range (8 logs) with a correlation coefficient of 0.999 and is capable of detecting as few as 4x10(2) genome equivalents/100 ml of wastewater sample. The method was validated by using artificially contaminated water samples. The validated method was then applied to naturally contaminated samples collected in a wastewater treatment plant and the results were compared with those obtained by a plaque assay. In comparison with the plaque assay the PCR-method yielded viral counts about 1.5 orders of magnitude higher. The entire detection method, including sample processing and real-time PCR amplification, was completed within 4 hours, making it a rapid single-day method.

Background: Peptide nucleic acid (PNA) molecules are known to bind complementary nucleic acid sequences with a much stronger affinity and with more stable binding than DNA or RNA molecules. We chose parvovirus B19, which is diagnosed by detection of nucleic acids by in situ hybridization assay (ISH) and/or PCR, as an experimental model to develop an ISH assay that uses biotinylated PNA probes to detect viral genome in clinical specimens., Methods: We first optimized the PNA-ISH assay on B19-infected and mock-infected UT-7/EpoS1 cells and then tested the assay on archival B19 specimens and on consecutive specimens. All data were compared with data obtained with a standardized DNA-based ISH assay and confirmed by a PCR-ELISA., Results: PNA-ISH detected B19 genome in a higher number of B19-infected UT-7/EpoS1 cells and with a more defined localization of viral nucleic acids than the standardized DNA-ISH assay. Moreover, PNA-ISH was able to detect B19 genome in all positive archival samples, whereas DNA-ISH failed in 5 samples. PNA-ISH detected more positive samples than DNA-ISH when consecutive specimens were analyzed, and a close agreement was found with PCR-ELISA results., Conclusions: The PNA-ISH assay had sensitivity and specificity comparable to a PCR assay and was more practical and quicker to perform than standard hybridization assays. The assay may be a suitable diagnostic test for the detection of viral nucleic acids in clinical specimens.

Parvovirus B19 is a frequent contaminant of human blood and plasma derivatives and iatrogenic transmission of B19 infection has been shown to occur through the administration of contaminated products. Manufacturing procedures, generally used for removal or inactivation of enveloped viruses (HIV, HCV and HBV) are not always effective in the elimination of B19 virus. A certain risk of contamination remains for some plasma derivatives due to the high-titer viral load in the starting blood donations and the extreme heat resistance and small size of the virus. This review provides an update on the different approaches currently available to detect, remove or inactivate B19 virus in order to enhance the safety margins of plasma products. Nucleic acid amplification techniques are the methods of choice for the detection of viruses, due to their high specificity and sensitivity. NAT assays are beneficial tools for the identification of contaminated mini-pools or plasma pools and the quantification of B19 contamination. They may also be valuable for testing the removal of B19 virus during manufacturing: since the virus may not be completely inactivated or removed by chemical or physical treatments, residual B19 contamination should always be checked. Solvent-detergent treatments fail to destroy B19 capsids because of the absence of a lipid-envelope, and heat treatments (pasteurization and dry-heat methods) cannot guarantee a complete viral inactivation because of the variable heat sensitivity of the virus.