Search results for "bacterial"
showing 10 items of 3246 documents
Chemical composition of the essential oil of Elaeoselinum asclepium (L.) Bertol subsp. meoides (Desf.) Fiori (Umbelliferae) collected wild in Central…
2020
In the present study, the chemical composition of the essential oils from flowers and leaves of Elaeoselinum asclepium(L.) Bertol subsp. meoides(Desf.) Fiori collected in Central Sicily was evaluated by GC and GC-MS. The main volatile components of the flowers were alpha-phellandrene (42.5%), terpinolene (15.7%), p-cymene (11.6%) and beta-phellandrene (10.2%), whereas the ones of the leaves were p-cymene (44.0%), alpha-pinene (13.2%), alpha-phellandrene (11.0%), beta-phellandrene (10.2%) and beta-pinene (9.2%). Furthermore, the antibacterial and antifungal activities against some microorganisms infesting historical art craft were determined. The essential oil from leaves (EL) showed to be p…
Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation
2020
Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 a…
MODIFICATION OF HYDROPHOBIC SURFACE WITH POLYASPARTAMIDE-BASED POLYCATIONS FOR BIOMEDICAL APPLICATION
2013
A convenient way for the achievement of polymer-based solid materials for specific biomedical applications is grafting the appropriate macromolecules onto the surfaces in order to confer them specific properties. To date many approaches have been used to covalently modify polymeric surfaces, and among them chemoselective coupling reactions, usually referred as “click” reactions, gained much attention thanks to simple procedure with high reaction rate under mild reaction conditions (at normal temperature and pressure) [1]. In particular, radical-initiated thiol-yne “photo-click” chemistry has been demonstrated as an effective way to functionalize efficiently surfaces. This method gives also …
An extended catalogue of ncRNAs in Streptomyces coelicolor reporting abundant tmRNA, RNase-P RNA and RNA fragments derived from pre-ribosomal RNA lea…
2022
Streptomyces coelicolor is a model organism for studying streptomycetes. This genus possesses relevant medical and economical roles, because it produces many biologically active metabolites of pharmaceutical interest, including the majority of commercialized antibiotics. In this bioinformatic study, the transcriptome of S. coelicolor has been analyzed to identify novel RNA species and quantify the expression of both annotated and novel transcripts in solid and liquid growth medium cultures at different times. The major characteristics disclosed in this study are: (i) the diffuse antisense transcription; (ii) the great abundance of transfer-messenger RNAs (tmRNA); (iii) the abundance of rnpB…
Double copies of blaKPC-3::Tn4401a on an IncX3 plasmid in Klebsiella pneumoniae successful clone ST512 from Italy
2015
ABSTRACT A carbapenem-resistant sequence type 512 (ST512) Klebsiella pneumoniae carbapenemase 3 (KPC-3)-producing K. pneumoniae strain showing a novel variant plasmid content was isolated in Palermo, Italy, in 2014. ST512 is a worldwide successful clone associated with the spread of bla KPC genes located on the IncFIIk pKpQIL plasmid. In our ST512 strain, the bla KPC-3 gene was unusually located on an IncX3 plasmid, whose complete sequence was determined. Two copies of bla KPC-3 ::Tn 4401a caused by intramolecular transposition events were detected in the plasmid.
Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli
2005
Type 1 fimbriae ofEscherichia colifacilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation oflrhAresults in an increased expression of structural components of type 1 fimbriae.In vitro, LrhA bound to the promoter regions of the twofimrecombinases (FimB and FimE) that catalyse the inversion of thefimApromoter, and to the invertible element itself. TranslationallacZfusions with these genes and quantification offimEtranscript le…
Modelling the effect of ethanol on growth rate of food spoilage moulds
2005
The effect of ethanol (E) on the radial growth rate (mu) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium digitatum, Rhizopus oryzae and Trichoderma harzianum) was assessed in Potato Dextrose Agar (PDA) medium at a(w) 0.99, 25 degrees C. In order to model this effect, the Monod type equation described previously by Houtsma et al. (Houtsma, P.C., Kusters, B.J.M., de Wit, J.C., Rombouts, F.M., Zwietering, M.H., 1994. Modelling growth rates of Listeria monocytogenes as a function of lactate concentration. Int…
Antibacterial activity and cytotoxicity of selected Egyptian medicinal plants.
2011
Medicinal plants have been used as a source of remedies since ancient times in Egypt. The present study was designed to investigate the antibacterial activity and the cytotoxicity of the organic extracts from 16 selected medicinal plants of Egypt. The study was also extended to the isolation of the antiproliferative compound jaeschkeanadiol p-hydroxybenzoate (FH-25) from Ferula hermonis. The microbroth dilution was used to determine the minimal inhibitory concentration (MIC) of the samples against twelve bacterial strains belonging to four species, Providencia stuartii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli, while a resazurin assay was used to assess the cytoto…
CHARACTERIZATION OF ATYPICAL CLAVIBACTER MICHIGANENSIS subsp. MICHIGANENSIS POPULATIONS IN GREENHOUSE TOMATOES IN ITALY
2012
The quarantine bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) is the agent of tomato bacterial canker (TBC), one of the most destructive bacterial diseases of this crop, that causes severe economic losses worldwide. During a recent outbreak of TBC in Sicily (insular Italy), it was impossible to amplify the pat-1 gene by PCR with CMM5/CMM6 primers from affected greenhouse-grown plants from three farms, although Cmm-like colonies were consistently isolated. Microlog metabolic profile, 16S rDNA sequencing and the positive amplification of other Cmm DNA targets supported the identification of the strains as Cmm, suggesting the occurrence of a population lacking the virulence gen…
Characterizing the bacterial fish pathogen Flavobacterium columnare, and some factors affecting its pathogenicity
2010
Flavobacterium columnare is a bacterial pathogen of fresh water fish causing lethal columnaris disease worldwide. At Finnish fish farms, columnaris disease has occurred since the early 1980s, and is a serious problem in salmonid farming in Finland. Currently, the only effective treatment is with antibiotics. Factors related to the pathogenicity of F. columnare, transmission of columnaris disease and the immunity of salmonids to columnaris infections are poorly known. F. columnare strains isolated from Finnish fish farms were characterized geno- and phenotypically, virulence and transmission experiments were conducted, and the efficacy of two immunostimulants against columnaris infections in…