A novel series of 3-(3-phenyl-isoxazol-5-yl) or 3-[(3-phenyl-isoxazol-5-yl)amino] substituted 4(3H)-quinazolinone derivatives was synthesized. The compounds were tested for their antineoplastic activity in vitro against Raji (human... more
A novel series of 3-(3-phenyl-isoxazol-5-yl) or 3-[(3-phenyl-isoxazol-5-yl)amino] substituted 4(3H)-quinazolinone derivatives was synthesized. The compounds were tested for their antineoplastic activity in vitro against Raji (human Burkitt limphoma). K-562 (human chronic myelogeneous leukemia) and U937 (human histiocytic limphoma) cell lines. The most active quinazolinones showed IC50 values in the range 16-30 microM.
Research Interests:
Schillaci, D., Raimondi, MV, Cusimano, MG, La Giglia, M., Piraino, C., SCiurba, N., et al. (2011). Antibiofilm activity of a novel pyrrolomycin against staphylococcal biofilms of veterinary interest. In Eurobiofilm 2011 Second European... more
Schillaci, D., Raimondi, MV, Cusimano, MG, La Giglia, M., Piraino, C., SCiurba, N., et al. (2011). Antibiofilm activity of a novel pyrrolomycin against staphylococcal biofilms of veterinary interest. In Eurobiofilm 2011 Second European Congress on Microbial Biofilm-Basic and ...
Research Interests:
Research Interests:
By reacting methylaminopyrazoles with hexane-2,5-dione in 1,4-dioxane in the presence of p-toluensulfonic acid, new derivatives containing the policyclic sistem... more
By reacting methylaminopyrazoles with hexane-2,5-dione in 1,4-dioxane in the presence of p-toluensulfonic acid, new derivatives containing the policyclic sistem 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3'.4':2,3]azepino[4,5-f]azocine were obtained. The new synthesized compounds were tested preliminarly at 10 microM against five human cancer cell lines showing a range of inhibition of 20-62% against the most susceptible cell lines K562 and HCT116
Research Interests:
Grifola frondosa (Dicks.) Gray (Meripilaceae) is a big size, perennial, infrequent lignicolous basidiomycetes, traditionally known as Maitake. Brown or grayish overlapped caps, with a wavy margin, characterize the sporophore. In the wild,... more
Grifola frondosa (Dicks.) Gray (Meripilaceae) is a big size, perennial, infrequent lignicolous basidiomycetes, traditionally known as Maitake. Brown or grayish overlapped caps, with a wavy margin, characterize the sporophore. In the wild, it is usually found at the base of living oak trees but it is also cultivated. G. frondosa is mainly distributed in Japan, Asia, Eastern America, and Europe. In Italy, is infrequent but widely distributed in all regions. Field investigation carried out in autumn 2016 in Sicily (southern Italy) permitted to observe an unusual white G. frondosa growing at the base of a living tree of Quercus pubescens Willd. s.l. Once harvested, the mushroom sample was cleaned of debris with a knife, cut into pieces and placed in plastic bags for freezing, then transported to the laboratory and preserved at -80 \ub0C. Finally the frozen mushroom was lyophilized.The morphological studies were carried out under the microscope using KOH 3% and ammoniacal Congo Red and performed in a combination with DNA sequence analyses of the Internal Trancribed Spacer (ITS) region. The chemical and nutritional composition (ashes, water, proteins, fats, carbohydrates, vitamins, nitrogen, and organic and inorganic substances) was evaluated according to standard methodologies. The antibacterial activity against four Gram-positive and Gramnegative bacteria strains: Staphylococcus aureus ATTC 25923, S. epidermidis ATTC 12228, Pseudomonas aeruginosa ATCC 15442, and Escherichia coli ATCC 25922 was also evaluated. The minimal inhibitory concentration (MIC) of G. frondosa extracts was determinated by a micro-method by diluiting in a range from 50% to 0,6% v/v. Tryptic soy broth (TSB, Sigma) was used as media. As a result of morphological analysis the white G. frondosa showed basidiospores of slightly narrowed shape than the typical Maitake (5 - 7 x 3.2 \u2013 4 \u3bcm). Besides, sterigmata are long up to 6 \u3bcm, sturdy, with the base of diameter up to 1.5 \u3bcm. These microscopical features are not reported in Ryvarden while Bernicchia illustrated for the typical Maitake sterigmata \u201cthin and very divaricate\u201d. Clamp connections are present but rare in the contest. Cystidia and cystidioles are absent. The identity of the white G.frondosa was confirmed by analysis of ITS sequence. The results of nutritional composition analysis (Table 1) showed that the white G. frondosa is richer in nutritional elements than the cultivated brown Maitake analyzed by Stamets. In particular the white Maitake possess a very high content of Ca, Fe, K, Na, and Cu. As regards vitamins only the value of vitamin D2 is similar to the value reported by other authors. The other vitamin contents are lower. The cold extract of G.frondosa has been showed to be effective in inhibiting the growth of S. epidermidis 12228 and P. aeruginosa 15442 at the maximum screening concentration of 50% v/v. In our opinion the white Maitake is a promising and potential new medicinal mushroom. Further investigations are currently in progress to evaluate potential application as cultivated and medicinal mushroom
Research Interests:
Several new 3‐(indazol‐3‐yl)‐quinazolin‐4(3H)‐one and 3‐(indazol‐3‐yl)‐benzotriazin‐4(3H)‐one derivatives 5 and 6 were synthesized and tested for their in vitro antiproliferative activity against Raji, K562, and K562‐R cell lines. The... more
Several new 3‐(indazol‐3‐yl)‐quinazolin‐4(3H)‐one and 3‐(indazol‐3‐yl)‐benzotriazin‐4(3H)‐one derivatives 5 and 6 were synthesized and tested for their in vitro antiproliferative activity against Raji, K562, and K562‐R cell lines. The pharmacological screening showed that some 2, 6, or 7‐substituted quinazolinones 5 posses a significant antiproliferative activity, with a percentage growth inhibition ranging from 44.8% to 100% at 50 μM, which was higher than that showed by the unsubstituted derivative 5a previously synthesized. For the most active compounds 5d, 5f, and 5g the IC50 were recorded.
Research Interests:
Research Interests:
A class of 36 new 2-(6-phenylimidazo[2,-1-b][1,3,4]thiadiazol-2-yl)-1H-indoles was efficiently synthesized and evaluated for their anti-biofilm properties against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC... more
A class of 36 new 2-(6-phenylimidazo[2,-1-b][1,3,4]thiadiazol-2-yl)-1H-indoles was efficiently synthesized and evaluated for their anti-biofilm properties against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923, S. aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228, and the Gram-negative strains Pseudomonas aeruginosa ATCC 15442 and Escherichia coli ATCC 25922. Many of these new compounds, were able to inhibit biofilm formation of the tested staphylococcal strains showing BIC50 lower than 10 μg/ml. In particular, derivatives 9c and 9h showed remarkable anti-biofilm activity against S. aureus ATCC 25923 with BIC50 values of 0.5 and 0.8 μg/ml, respectively, whereas compound 9aa was the most potent against S. aureus ATCC 6538, with a BIC50 of 0.3 μg/ml. Remarkably, these compounds showed effects in the early stages of the biofilm formation without affecting the mature biofilm of the same strains and the viability of the planktonic form. Their ability in counteracting a virulence factor (biofilm formation) without interfering with the bacterial growth in the free life form make them novel valuable anti-virulence agents.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Mastitis in small ruminant farms are quite spread in Sicily. Coagulase-negative staphylococci (CoNS) are frequently isolated from milk of animals with sub-clinical mastitis. They are less pathogenic but can cause persistent infections... more
Mastitis in small ruminant farms are quite spread in Sicily. Coagulase-negative staphylococci (CoNS) are frequently isolated from milk of animals with sub-clinical mastitis. They are less pathogenic but can cause persistent infections with increased somatic cell count (SCC) in milk and consequentially reduction of milk quality. It is possible that the bacteria organized in biofilm communities can be responsible for the persistency of infection. Sicilian sheep flocks interested in clinical and sub-clinical mastitis were selected to isolate bacteria strains from milk samples. We started a comparison of S.aureus and CoNS isolates for the presence of bac and ica genes and the evaluation of their capability in biofilm formation. The Bacteria were isolated from bulk milk samples. The isolated colonies were typed by API Staph strip ( BioMerieux). PCR was performed with primers for ica and bap genes. The analysis for biofilm formation was performed by safranin method in microtiter plates. T...
Here, we describe the most promising small synthetic organic compounds that act as potent Sortase A inhibitors and cater the potential to be developed as antivirulence drugs. Sortase A is a polypeptide of 206 amino acids, which catalyzes... more
Here, we describe the most promising small synthetic organic compounds that act as potent Sortase A inhibitors and cater the potential to be developed as antivirulence drugs. Sortase A is a polypeptide of 206 amino acids, which catalyzes two sequential reactions: (i) thioesterification and (ii) transpeptidation. Sortase A is involved in the process of bacterial adhesion by anchoring LPXTG-containing proteins to lipid II. Sortase A inhibitors do not affect bacterial growth, but they restrain the virulence of pathogenic bacterial strains, thereby preventing infections caused by Staphylococcus aureus or other Gram-positive bacteria. The efficacy of the most promising inhibitors needs to be comprehensively evaluated in in vivo models of infection, in order to select compounds eligible for the treatment of bacterial infections in humans.
Research Interests: Microbiology, Chemistry, Organic Chemistry, Medicinal Chemistry, Enzyme Inhibitors, and 15 moreMedicine, Humans, Nitriles, Animals, Staphylococcus aureus, Thiones, Rhodanine, Cysteine endopeptidases, Protein Conformation, Thiazoles, Bacterial Adhesion, Adamantane, Sortase, Pharmacology and pharmaceutical sciences, and Staphylococcal infections
Research Interests: Microbiology, Chemistry, Biofilms, Medical Microbiology, Biology, and 15 moreMedicine, Humans, Biofilm, Gram Positive, Bacteria, Staphylococcus aureus, Antimicrobial, Staphylococcus epidermidis, Gram Positive Bacteria, Anti-Bacterial Agents, Antimicrobial agents, Microbial Sensitivity Tests, Thiazoles, Pharmacology and pharmaceutical sciences, and Minimum Inhibitory Concentration
Research Interests: Chemistry, Food Science, Complementary and Alternative Medicine, Medicine, Cell line, and 15 moreHumans, Fruit, Citrus, High Performance Liquid Chromatography, High Pressure Liquid Chromatography, Default, Flavanone, Fitoterapia, Flavonoid, Cell Proliferation, Citrus Sinensis, Antiproliferative Activity, Fruit Juice, Chronic myelogenous leukemia, and flavanones
Summary A number of new 4-diazopyrazole derivatives were prepared by the reaction of 1- R -3-methyl-5(R 1 -substituted)benzamidopyrazoles with a sevenfold excess of nitrous acid in acetic medium. The compounds were tested for activity... more
Summary A number of new 4-diazopyrazole derivatives were prepared by the reaction of 1- R -3-methyl-5(R 1 -substituted)benzamidopyrazoles with a sevenfold excess of nitrous acid in acetic medium. The compounds were tested for activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Listeria monocytogenes, Candida albicans, Candida tropicalis and Paecilomyces varioti . The highest microbial susceptibility was shown by Gram-positive bacteria, with minimum inhibitory concentrations (MIC) in the range 0.5–12.5 μg/mL. For S aureus the R 1 substituents were screened utilizing the Topliss operational scheme. The 4-nitro group was found to be the best substituent. We also tested the compounds 41,o,p , found to be the most active in the test against S aureus ATCC 25923, on ten clinical S aureus strains, five of which were sensitive and five resistant to methicillin. The above compounds were active in the range 2–8 μg/mL against methicillin-resistant S aureus strains. An X-ray analysis of compounds 4i and 4q is reported.
Research Interests:
Several triazenoindazoles and triazenopyrazoles were prepared transforming the appropriate aminoindazoles and aminopyrazoles in the corresponding diazonium salts which were reacted with dimethylamine, diethylamine and pyrrolidine. All the... more
Several triazenoindazoles and triazenopyrazoles were prepared transforming the appropriate aminoindazoles and aminopyrazoles in the corresponding diazonium salts which were reacted with dimethylamine, diethylamine and pyrrolidine. All the triazenes were tested for their antiproliferative activity against K562, HL60, L1210 and MCF7 cell lines. The biological data showed that the benzocondensation plays a positive role on the antiproliferative activity. The (1)H-NMR spectra showed that the rotational barrier around the N(2)-N(3) bond in the triazene group can be influenced both by the position of this group in the indazole nucleus and by the substitution pattern in the benzene moiety.
Research Interests: Chemistry, Organic Chemistry, Magnetic Resonance Spectroscopy, Comparative Study, Medicine, and 13 moreCell Division, Cell line, Humans, Stereochemistry, European, Pyrazoles, Structure activity Relationship, Antineoplastic Agents, Biological Data, Minimum inhibitory concentration, Molecular Structure, Pyrrolidine, and Pharmacology and pharmaceutical sciences
Research Interests:
Research Interests: Complementary and Alternative Medicine, Plant Biology, Biology, Ethnopharmacology, Leukemia, and 15 moreMedicine, Cell Division, Cell line, In Vitro, Humans, Mice, Animals, Antimicrobial activity, Endemic species, Antimicrobial, Apiaceae, Acetone, Antineoplastic Agents, Chronic myelogenous leukemia, and Pharmacology and pharmaceutical sciences
For Abstract see ChemInform Abstract in Full Text.
Research Interests:
Research Interests:
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Research Interests:
Research Interests:
Several new 4-diazopyrazole derivatives 6a-g and 9a-c were obtained by the reaction of 1-(R-substituted-phenyl)-3-(1,3-dimethyl-1H-pyrazol-5-yl)ureas 5a-g and N-(1,3-dimethyl-1H-pyrazol-5-yl)-2-(R-substituted-phenyl)acetamides 8a-c... more
Several new 4-diazopyrazole derivatives 6a-g and 9a-c were obtained by the reaction of 1-(R-substituted-phenyl)-3-(1,3-dimethyl-1H-pyrazol-5-yl)ureas 5a-g and N-(1,3-dimethyl-1H-pyrazol-5-yl)-2-(R-substituted-phenyl)acetamides 8a-c respectively with a sevenfold excess of nitrous acid in acetic acid solution. The compounds were assayed for their activity against the Staphylococcus aureus reference strains ATCC 25923, ATCC 29213 and ATCC 6538, as well as six veterinary strains. The best anti-staphylococcal profile was showed by [(R-substituted-phenyl)acetyl](4-diazonio-1,3-dimethyl-1H-pyrazol-5-yl)azanides 9a,c. Compound 9c was also able at 3.1 μg mL(-1) to inhibit of 45.7% the biofilm formation of the strains S. aureus ATCC 29213.
Research Interests:
Research Interests:
Research Interests:
To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At... more
To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At concentrations ranging from 217.3 microg ml(-1) (25% v/v) to 6.8 microg ml(-1) (0.75% v/v), the essential oil of Boswellia papyrifera showed considerable activity against both Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213 biofilms. The anti-microbial efficacy of this oil against S. epidermidis RP62A biofilms was also tested using live/dead staining in combination with fluorescence microscopy, and we observed that the essential oil of B. papyrifera showed an evident anti-biofilm effect and a prevention of adhesion at sub-MIC concentrations. Boswellia rivae essential oil was very active against preformed C. albicans ATCC 10231 biofilms and inhibited the formation of C. albicans biofilms at a sub-MIC concentration. Essential oils of Boswellia spp. could effectively inhibit the growth of biofilms of medical relevance. Boswellia spp. essential oils represent an interesting source of anti-microbial agents in the development of new strategies to prevent and treat biofilms.
Research Interests:
Research Interests:
The present study was carried out to assess the antibacterial, antifungal and antibiofilm properties of polypeptide-rich extracts isolated from green leaves and rhizomes of Mediterranean seagrass Posidonia oceanica (L. Delile)... more
The present study was carried out to assess the antibacterial, antifungal and antibiofilm properties of polypeptide-rich extracts isolated from green leaves and rhizomes of Mediterranean seagrass Posidonia oceanica (L. Delile) (Posidoniaceae). The seagrass was collected, washed with freshwater, grinded with liquid nitrogen in order to obtain fine powders that were exposed to extraction by acetic acid and antiproteases. The crude extracts isolated from leaves and rhizomes of P. oceanica were subjected to microbiological assays to evaluate the antibacterial, antifungal and antibiofilm activity of polypeptide fraction against two reference bacterial strains Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 15442, and the fungus Candida albicans ATCC 10231. The antimicrobial and antifungal activity of the extracts were evaluated starting from 50% v/v concentration of each sample and the results are expressed in terms of Minimum inhibitory concentration (MIC), with the values detailed in percentage v/v and in concentration \uf06dg/ml of protein content. The most interesting result has been deduced from rhizomes that showed a MIC of 12.5% v/v, corresponding to 3.37 \uf06dg/ml of protein content, against three selected pathogens compared to the sample from the leaves that revealed a MIC of 25% v/v, corresponding to a protein concentration of 4.25 \uf06dg/ml. The crude extracts isolated from P. oceanica were also active to combat the biofilm formation at sub-MIC concentration. The inhibition was evident with crude extracts from rhizomes in S. aureus ATCC 25923 at IC50 of 0.54 \uf06dg/ml, compared to a value of IC50 of 0.74\uf06dg/ml with the extracts from leaves. Moreover, the polypeptide fraction of leaves of P. oceanica was also able to inhibit the biofilm formation in C. albicans ATCC 10231 at IC50 = 0.58 \uf06dg/ml. Peptide fractions displaying antimicrobial activity were further investigated by by High-Pressure Liquid Chromatography/nano-Electrospray Ionization tandem Mass Spectrometry (RP-HPLC/nESI-MS/MS) and database search. Database search allowed the characterization of fourteen peptides, one of them is related to a Viridiplantae-derived protein, whereas the others are attributable to bacterial proteins present in the investigated database. Moreover, most of identified peptides showed similarities with already described antimicrobial peptides (AMPs) from bacteria, animals and plants
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) is the major pest of palm trees in the Mediterranean area. Damages are caused mainly by the endophytophagous larvae that consume the palm tender... more
The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier, Coleoptera, Curculionidae) is the major pest of palm trees in the Mediterranean area. Damages are caused mainly by the endophytophagous larvae that consume the palm tender soft tissues making galleries and producing a wet \u201cfrass\u201d with a characteristic fermented odour. The culturable bacterial community associated to the frass produced by RPW larvae inside Phoenix canariensis trees is mainly composed of facultative anaerobe gamma-proteobacteria that have their closest phylogenetic relatives in the gut microbiome of other endophytophagous and xilophagous coleopteran as bark beetles and other plant biomass-degrading insects (leaf-cutter ants). In RPW-bored galleries, these enterobacteria together with lactic acid bacteria, could be responsible for the synthesis of organic volatiles such as ethyl esters that are attractants for adults that deposit their eggs on the palm. The hypothesis that the frass-associated bacteria might be inoculated by the RPW larvae in order to obtain benefits for the insect (i.e. attraction of adults, plant polymers degradation, protection against fungal invasion, etc.) is under investigation. To this aim we started to characterize the bacterial community of the RPW larval gut by culture-based and culture-independent methods. Bacterial and DNA isolation was carried out from RPW larval guts after sterilization and dissection. About 107 CFU/gut were detected on Nutrient Agar plates and the phylogenetic analysis of 48 isolates is in progress. Cellulosolytic and hemicellulosolytic proteobacteria and actinobacteria were isolated from gut enrichment cultures on carboxymethyl cellulose and sterile filter paper but no cellulolytic activity was detected in the frass-associated bacterial community. Total gut DNA was used in 16S rRNA gene analysis by denaturing gradient gel electrophoresis and for the construction of a ribosomal gene library that is under screening
Research Interests:
Research Interests:
Sortase A (SrtA) is a membrane enzyme responsible for the covalent anchoring of surface proteins on the cell wall of Gram-positive bacteria. [...]
Research Interests:
Research Interests:
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly... more
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly with infectious agents and/or modulate immunoreactions. In invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system, AMPs represent the major humoral defense system against infection, showing a diverse spectrum of action mechanisms, most of them related to plasma membrane disturbance and lethal alteration of microbial integrity. Here, we summarize the knowledge of AMPs in echinoderms as Strongylocins identified in the sea urchins, Strongylocentrotus droebachiensis and Strongylocentrotus purpuratus, focusing attention on peptides that exhibit an antibiofilm activity, as Paracentrin 1 from Paracentrotus lividus and Holoturoidin 1 and 2 from sea cucumber Holothuria tubulosa. Future studies on AMPs should be aimed at revealing how echinoderms use these AMPs in the immune response against microbial pathogens.
Research Interests:
Research Interests:
Rhynchophorus ferrugineus (Coleoptera: Curculionidae) known as the Red Palm Weevil (RPW) is becoming more and more of a problem in Italy, and especially in Sicily, where it is well adapted. The infestations are mainly in the urban areas,... more
Rhynchophorus ferrugineus (Coleoptera: Curculionidae) known as the Red Palm Weevil (RPW) is becoming more and more of a problem in Italy, and especially in Sicily, where it is well adapted. The infestations are mainly in the urban areas, and for that reason, chemical control is not advisable. Data from literature show that entomopathogenic nematodes (EPN) particularly Steirnenema carpocapsae, have a quite successfully control of RPW. However, results coming from the laboratories are often in contrast with each other and no data are available on precise doses and S. carpocapsae seems not be able to reproduce itself in the host. The effect of EPN on the RPW immune system is totally unknown. Different dosages of S. carpocapsae and varying durations of exposure were assessed. Larval mortality showed a positive linear correlation with both nematode dosage and the duration of exposure. Median Lethal Dose (DL50) and the Median Lethal Time (TL50) were calculated for older larvae. The number...
Research Interests:
Staphylococcus aureus is a common pathogen responsible for several diseases in animals and for recurrent mastitis in milk producing animals, probably related to its capability to form biofilm. Antimicrobial therapy failures are often... more
Staphylococcus aureus is a common pathogen responsible for several diseases in animals and for recurrent mastitis in milk producing animals, probably related to its capability to form biofilm. Antimicrobial therapy failures are often related to these bacterial communities. To the aim of searching alternative antimicrobial therapy against biofilm we focused on antimicrobial system of marine invertebrates. Their fitness in the marine environment, suggests that their innate immune system is very strong. The presence of antimicrobial and anti-biofilm activity in the 5kDa peptide fraction of the effector cells of Paracentrotus lividus has been reported on reference strains of Staphylococcus spp. The same analysis were performed on isolates of S. aureus isolated from animals and dairy products. In the staphylococcal isolates PCRs for mec A and toxin productions genes and for genes involved in biofilm formation (ica) locus, (bap) gene, and Sas C genes were performed. The ability of staphyl...
Research Interests:
Research Interests:
Research Interests:
To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At... more
To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At concentrations ranging from 217.3 microg ml(-1) (25% v/v) to 6.8 microg ml(-1) (0.75% v/v), the essential oil of Boswellia papyrifera showed considerable activity against both Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213 biofilms. The anti-microbial efficacy of this oil against S. epidermidis RP62A biofilms was also tested using live/dead staining in combination with fluorescence microscopy, and we observed that the essential oil of B. papyrifera showed an evident anti-biofilm effect and a prevention of adhesion at sub-MIC concentrations. Boswellia rivae essential oil was very active against preformed C. albicans ATCC 10231 biofilms and inhibited the formation of C. albicans biofilms at a sub-MIC concentration. Essential oils of Boswellia spp. could effectively inhibit the growth of biofilms of medical relevance. Boswellia spp. essential oils represent an interesting source of anti-microbial agents in the development of new strategies to prevent and treat biofilms.
Research Interests:
The defense system of freshwater crayfish Procambarus clarkii as a diversified source of bioactive molecules with antimicrobial properties was studied. Antimicrobial activity of two polypeptide-enriched extracts obtained from hemocytes... more
The defense system of freshwater crayfish Procambarus clarkii as a diversified source of bioactive molecules with antimicrobial properties was studied. Antimicrobial activity of two polypeptide-enriched extracts obtained from hemocytes and hemolymph of P. clarkii were assessed against Gram positive (Staphylococcus aureus, Enterococcus faecalis) and Gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and toward the yeast Candida albicans. The two peptide fractions showed interesting MIC values (ranging from 11 to 700 μg/mL) against all tested pathogens. Polypeptide-enriched extracts were further investigated using a high-resolution mass spectrometry and database search and 14 novel peptides were identified. Some peptides and their derivatives were chemically synthesized and tested in vitro against the bacterial and yeast pathogens. The analysis identified a synthetic derivative peptide, which showed an interesting antifungal (MIC and MFC equal to 31.2 μg/mL and 62.5 μg/...
Research Interests:
Many infections such as otitis media, sinusitis, cholesteatoma, tonsillitis and adenoiditis are caused by biofilm forming mucosal pathogens (P. aeruginosa, S. aureus, S. peneomoniae, H. influenzae and M. catarrhalis). Moreover, the role... more
Many infections such as otitis media, sinusitis, cholesteatoma, tonsillitis and adenoiditis are caused by biofilm forming mucosal pathogens (P. aeruginosa, S. aureus, S. peneomoniae, H. influenzae and M. catarrhalis). Moreover, the role of biofilms in the chronic otolaryngologic infections has been recognized for otitis media, tonsillitis and rhinosinusitis. Finally, bacterial biofilms of S. aureus, S. epidermis and E. faecalis are the leading cause of medical device-related infections. Pathogens growing as biofilms are intrinsically resistant to conventional antibiotics and therefore the discovery of new compounds able to act against biofilm aggregated micro organisms is an urgent task. Previously, we reported the study on the antibiofilm activity of 4-diazopyrazole derivatives of type 1 against S. aureus ATCC 29213, methycillin-resistant S. aureus ATCC 43866 and methycillin-resistant S. epidermis RP626 preformed biofilms. The compounds were active at the maximum tested concentrati...
Research Interests:
Research Interests:
Recent studies suggest an inverse relationship between the intake of Citrus fruits and the incidence of cardiovascular diseases, stroke and different cancer types. Protective effects shown could be ascribed to the flavonoid content of... more
Recent studies suggest an inverse relationship between the intake of Citrus fruits and the incidence of cardiovascular diseases, stroke and different cancer types. Protective effects shown could be ascribed to the flavonoid content of Citrus fruits. A reversed-phase highperformance liquid chromatographic method was developed to determine the content of flavanone glycosides, which are the main flavonoids present in Citrus fruits. Fresh squeezed juices of six different grapefruit cultivars (Citrus paradisi Macf.) were analysed. In all grapefruit juices tested, we found total flavanone glycoside contents in the range from 33.93 to 44.97 mg/100 ml of juice; naringin was the main flavanone component (16.37-26.14 mg/100 ml of juice). To evaluate pharmacological activity and, in particular, inhibitory effects in vitro on proliferation and growth of cancer cells, the six freshly squeezed grapefruit juices were tested against K562 (human chronic myelogenous leukemia), NCI-H460 (human lung ca...
Research Interests:
Research Interests:
Staphylococcus aureus, due to its wide arsenal of virulence factors, is a very versatile pathogen responsible for a wide variety of infectious diseases. The virulence factors include the cell-wall associated proteins that have a direct... more
Staphylococcus aureus, due to its wide arsenal of virulence factors, is a very versatile pathogen responsible for a wide variety of infectious diseases. The virulence factors include the cell-wall associated proteins that have a direct role in the first stage of pathogenesis. The Sortase A (SrtA) transpeptidase is responsible for covalent anchoring to the cell wall of various surface proteins and it is considered a good target to design new antivirulence agents. In this study, we report the identification of an inhibitor of SrtA afforded from the random screening of a small molecular library of around 150 synthetic compounds, through a high throughput assay by using the standard Dabcyl-QALPETGEE-Edans fluorescence resonance energy transfer (FRET)-peptide substrate for measurement of enzyme activity. Such hit compound showed an IC50 value of 80\ub5M. A group of derivatives of the hit compound has been obtained and evaluated for their activity as SrtA inhibitors. The efficacy of the most interesting SrtA inhibitors needs to be evaluated by in vivo models of infection, but we used a simple methodology in vitro, such as inhibition of biofilm formation, for a preliminary assessment of antivirulence properties of some of these novel inhibitors of SrtA. An interesting correlation between inhibition of SrtA and interference with the formation of staphylococcal biofilms has been observed in many cases especially at a concentration equal or more than IC50 determined as SrtA inhibitors