Background: The use of beneficial bacteria like spp. is a potential innovative approach to fight antibiotic-resistant pathogens. is one of the most concerning multi drug-resistant (MDR) pathogens, and its ability to colonize the human gut is considered to be the main reason for recurrent infections in critically ill patients.
View Article and Find Full Text PDF: Vancomycin-intermediate (VISA) emerges typically in the healthcare-associated methicillin-resistant and more rarely in community-acquired (CA-MRSA). VISA is a serious concern for public health due to its association with persistent infections, the failure of vancomycin treatment, and poor clinical outcomes. Currently, the burden of VISA is somewhat high, even though vancomycin is the mainstay treatment for severe MRSA infections.
View Article and Find Full Text PDFBackground: Methicillin-resistant (MRSA) with intermediate resistance to Vancomycin (VISA) is reported worldwide. These strains frequently emerge among hospital-associated (HA)-MRSA and rarely within community-acquired (CA)-MRSA. Here, the genomic and transcriptomic adaptations distinguishing VISA daptomycin resistant (DAP-R) CA-MRSA, which emerged in a hospitalized patient under glycopeptide treatment, were explored.
View Article and Find Full Text PDFThe treatment of multidrug-resistant Gram-negative infections is based on colistin. As result, COL-resistance (COL-R) can develop and spread. In , a crucial step is to understand COL-R onset and stability, still far to be elucidated.
View Article and Find Full Text PDFThe use of natural compounds with biocidal activity to fight the growth of bacteria responsible for foodborne illness is one of the main research challenges in the food sector. This study reports the preparation and physicochemical characterization of chitosan nanoparticles loaded with (Th-CNPs) and (Or-CNPs) essential oils. The nanosystems were obtained by ionotropic gelation technique with high encapsulation efficiency (80-83%) and loading capacity (26-27%).
View Article and Find Full Text PDFMethicillin-susceptible (MSSA) and methicillin-resistant (MRSA) is a pathogen commonly found in bone and joint infections, including septic arthritis. virulence and the frailty of affected patients can cause several complications; a prompt and specific antibiotic treatment can positively affect the outcome of patients. We carried out an in-depth genomic characterization by Illumina whole genome sequencing and bioinformatics of two biofilm-producing M1 and M2 ST398 MSSA causing septic knee arthritis not-responding to antimicrobial therapy.
View Article and Find Full Text PDFDaptomycin (DAP) is one of the last-resort treatments for heterogeneous vancomycin-intermediate (hVISA) and vancomycin-intermediate (VISA) infections. DAP resistance (DAP-R) is multifactorial and mainly related to cell-envelope modifications caused by single-nucleotide polymorphisms and/or modulation mechanisms of transcription emerging as result of a self-defense process in response to DAP exposure. Nevertheless, the role of these adaptations remains unclear.
View Article and Find Full Text PDFMultidrug-Resistant (MDR) and Extensively Drug Resistant (XDR) () represent a serious cause of healthcare-associated infections worldwide. Currently, the available treatment options are very restricted and colistin-based therapies are last-line treatments of these infections, even though colistin resistant (COL) have rarely been isolated yet. In bacteria, small non-coding RNAs (sRNAs) have been implicated in regulatory pathways of different biological functions, however, no knowledge exists about the sRNA role on the biological adaptation in COL .
View Article and Find Full Text PDFThe goal of our work was to titer the IgG, IgM and IgA in Pentaglobin® (a preparation enriched in IgM), targeting specific surface antigens of Gram-positive and Gram-negative bacteria as well as a C. albicans strain. Lipopolysaccharides from Gram-negative bacteria, peptidoglycan and lipoteichoic acid from the other microorganisms were extracted and used in several ELISA assays in order to determine the titration of immunoglobulins in Pentaglobin® directed towards the aforementioned surface antigens.
View Article and Find Full Text PDFCalix[4]arene derivative (1), bearing four α-l-C-fucosyl units linked via a flexible spacer, and a monomeric analogous (2) bearing a single moiety of fucose, were synthesized. Compounds 1 and 2 were assayed for antibiofilm activity against Pseudomonas aeruginosa (Gram-) and Staphylococcus epidermidis (Gram+). The macrocyclic compound 1 showed very high percentage of biofilm inhibition against two different bacterial strains while compound 2, which does not possess a macrocyclic structure, showed only moderate biofilm inhibition against P.
View Article and Find Full Text PDFEven though colistin-based treatment represents the antimicrobial-regimen backbone for the management of multidrug-resistant Gram-negative infections, colistin resistance is still rare, at least as a full resistance, in (). We investigated the genomics and transcriptomics of two clinical Extensively Drug Resistance (XDR) colistin-susceptible/resistant (COL-S/R) strain-pairs in which COL-resistance was developed after exposure to colistin therapy. The molecular characterization of the strains showed that all strains belonged to PFGE-A, ST-281, OXA-23 producers, Global Clone-II, and were resistant to imipenem, meropenem, ampicillin/sulbactam, ciprofloxacin, gentamicin, amikacin, trimethoprim/sulfamethoxazole, and susceptible to tigecycline, in agreement with NGS-acquired resistome.
View Article and Find Full Text PDFThe aim of this work is the encapsulation of essential oils (EOs) in polymeric nanocapsules (NCs), in order to enhance their antimicrobial activity against food-borne pathogens. Thymus capitatus and Origanum vulgare EOs were selected for their different chemical composition, carvacrol (73%) and thymol (44%) being the major constituent, respectively. Polymeric poly(ɛ-caprolactone) (PCL) nanocapsules loaded with EOs were prepared by a nanoprecipitation method.
View Article and Find Full Text PDFBackground: The aims of this study were to identify the source and the transmission pathway for a Staphylococcal Scalded Skin Syndrome (SSSS) outbreak in a maternity setting in Italy over 2 months, during 2014; to implement appropriate control measures in order to prevent the epidemic spread within the maternity ward; and to identify the Methicillin-Resistant Staphylococcus aureus (MRSA) epidemic clone.
Methods: Epidemiological and microbiological investigations, based on phenotyping and genotyping methods, were performed. All neonates involved in the outbreak underwent clinical and microbiological investigations to detect the cause of illness.
The emergence of glycopeptide reduced susceptibility and resistance in Staphylococcus aureus strains is a growing clinical problem that poses significant clinical challenges in treatment. Its development is a complex and novel process involving many subtle physiological changes in the micro-organism. Daptomycin is the first cyclic lipopeptide approved for clinical use.
View Article and Find Full Text PDFDevelopment of in vivo daptomycin resistance (DAP-R) among Staphylococcus aureus clinical isolates, in association with clinical treatment failures, has become a major therapeutic problem. This issue is especially relevant to methicillin-resistant S. aureus (MRSA) strains in the context of invasive endovascular infections.
View Article and Find Full Text PDFThe mechanisms leading to reduced susceptibility to daptomycin (DAP) are multifactorial and have not been fully elucidated. We analysed, by sequencing and expression studies, the role of the major molecular targets (cell-envelope charge genes, dltA, mprF, cls2; cell-wall turnover and autolysis genes, sceD, atl) involved in the emergence of DAP resistance in three series of isogenic clinical methicillin-resistant Staphylococcus aureus (MRSA) in which DAP resistance emerged after a heterogeneous glycopeptide-intermediate S. aureus (hGISA) step under teicoplanin and DAP therapy.
View Article and Find Full Text PDFGlycopeptides are still the gold standard to treat MRSA (Methicillin Resistant Staphylococcus aureus) infections, but their widespread use has led to vancomycin-reduced susceptibility [heterogeneous Vancomycin-Intermediate-Staphylococcus aureus (hVISA) and Vancomycin-Intermediate-Staphylococcus aureus (VISA)], in which different genetic loci (regulatory, autolytic, cell-wall turnover and cell-envelope positive charge genes) are involved. In addition, reduced susceptibility to vancomycin can influence the development of resistance to daptomycin. Although the phenotypic and molecular changes of hVISA/VISA have been the focus of different papers, the molecular mechanisms responsible for these different phenotypes and for the vancomycin and daptomycin cross-resistance are not clearly understood.
View Article and Find Full Text PDFS. aureus represents a critical cofactor in atopic dermatitis (AD). In this paper, the prevalence of S.
View Article and Find Full Text PDFThe prevalence and molecular characterisation of heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) strains were determined in a large group of Italian strains isolated between 2005 and mid 2007. Amongst the 1284 strains isolated from documented infections in hospitalised patients (bloodstream infection, pneumonia, and skin and skin-structure infections), 139 S. aureus with vancomycin minimum inhibitory concentrations (MICs) between 1 mg/L and 2 mg/L were screened for the presence of hVISA using three different methods and were confirmed by population analysis profile (PAP).
View Article and Find Full Text PDFThe purpose of our study was to evaluate the anti-staphylococcal biofilm activity of tigecycline, compared with a group of recently developed or commonly used antimicrobials such as linezolid, daptomycin, levofloxacin, tobramycin and rifampin, all possessing putative antibiofilm properties, on a sample of multi-drug-resistant methicillin-resistant Staphylococcus aureus grown as a planktonic and mature biofilm. We determined conventional minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for the planktonic forms, MICs of adherent cells and finally, minimum biofilm eradication concentrations (MBECs). No drug was able to inhibit adherent bacteria at the same concentration necessary for eradicating a mature biofilm; the latter concentrations varied from three to seven times higher than the ones inhibiting adhesion.
View Article and Find Full Text PDFThe aim of this study was to ascertain the incidence and clinical significance of metallo-beta-lactamases among Enterobacter strains isolated from patients with nosocomial infections. We prospectively collected data on patients with Enterobacter infection during a 13-month period. All of the strains were investigated for antibiotic susceptibility, the presence and expression of metallo-beta-lactamases, and clonality.
View Article and Find Full Text PDFBackground: Apoptosis is a critical biological phenomenon, executed under the guidance of the Apoptotic Machinery (AM), which allows the physiologic elimination of terminally differentiated, senescent or diseased cells. Because of its relevance to BioMedicine, we have sought to obtain a detailed characterization of AM Omics in Homo sapiens, namely its Genomics and Evolution, Transcriptomics, Proteomics, Interactomics, Oncogenomics, and Pharmacogenomics.
Methods: This project exploited the methodology commonly used in Computational Biology (i.
Recent articles have described an increasing number of infections due to Panton-Valentine leukocidin PVL-positive community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) worldwide. We report a case of necrotizing pneumonia successfully treated with levofloxacin in Italy, sustained by a PVL-positive CA-MRSA, belonging to ST88 and carrying a staphylococcal chromosomal cassette mec type V. Further molecular characterization of isolates revealed that they were PVL positive, belonged to the agr IV allele, possessed a capsular type 8, and had an almost complete pathotype composed of leukocidins and numerous adhesins.
View Article and Find Full Text PDFFEMS Immunol Med Microbiol
October 2007
We investigated the correlation between biofilm production and the accessory-gene-regulator (agr) in 29 strains isolated from catheter-associated infections compared to a control group (30 isolates). All strains were tested for their ability to produce biofilm in a static system, and their agr genotype was determined. ScaI-restriction fragment length polymorphism for agr-typing showed that strong biofilm-producing strains belong to agr-type II.
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