Search results for "Staphylococci"

FRAGMENTS OF BETA-THYMOSIN FROM THE SEA-URCHIN PARACENTROTUS LIVIDUS AS NOVEL ANTIMICROBIAL PEPTIDES AGAINST STAPHYLOCOCCAL BIOFILMS

2012

With the aim to face the threat of pathogen biofilms intrinsically resistant to conventional antibiotics, we focused on coelomocytes, the immune mediators in echinoderms, as source of novel antimicrobial peptides (AMPs). The proteic fraction <5kDa from coelomocytes cytosol of the sea-urchin Paracentrotus lividus (5-CC) was tested against a group of Gram positive and Gram negative pathogen reference strains. The 5-CC of P. lividus resulted active against all tested strains at concentrations ranging from 15.8 to 253.7 mg/mL. The ability to prevent staphylococcal biofilm formation was evaluated against the biofilm of clinical strain S.epidermidis 1457 using live/dead staining in combination wi…

Evolution of indigenous starter microorganisms and physicochemical parameters in spontaneously fermented beef, horse, wild boar and pork salamis prod…

2020

Abstract The present work was carried out to evaluate the microbiological and physicochemical composition of salamis produced with the meat of beef, horse, wild boar and pork. Salami productions occurred under controlled laboratory conditions to exclude butchery environmental contaminations, without the addition of nitrate and nitrite. All trials were monitored during the ripening (13 °C and 90% relative humidity) extended until 45 d. The evolution of physicochemical parameters showed that beef and pork salamis were characterized by a higher content of branched chain fatty acids (FA) and rumenic acid than horse and wild boar salamis, whereas the last two productions showed higher values of …

The Influence of Microbiome Dysbiosis and Bacterial Biofilms on Epidermal Barrier Function in Atopic Dermatitis—An Update

2021

Atopic dermatitis (AD) is a common inflammatory dermatosis affecting up to 30% of children and 10% of adults worldwide. AD is primarily driven by an epidermal barrier defect which triggers immune dysregulation within the skin. According to recent research such phenomena are closely related to the microbial dysbiosis of the skin. There is growing evidence that cutaneous microbiota and bacterial biofilms negatively affect skin barrier function, contributing to the onset and exacerbation of AD. This review summarizes the latest data on the mechanisms leading to microbiome dysbiosis and biofilm formation in AD, and the influence of these phenomena on skin barrier function.

Consensus document on controversial issues for the treatment of hospital-associated pneumonia

2010

Background: Hospital-associated pneumonia (HAP) remains an important cause of morbidity and mortality despite advances in antimicrobial therapy. Many aspects of the treatment of HAP caused by multi-resistant Gram-positive microorganisms have been extensively studied, but controversial issues remain. Controversial issues: The aim of this GISIG (Gruppo Italiano di Studio sulle Infezioni Gravi) working group – a panel of multidisciplinary experts – was to define recommendations for some controversial issues using an evidence-based and analytical approach. The controversial issues were: (1) Is combination antibiotic therapy or monotherapy more effective in the treatment of HAP? (2) What role do…

The influence of inadequate empirical antimicrobial treatment on patients with bloodstream infections in an intensive care unit

2003

Objective To determine the occurrence of inadequate antimicrobial therapy among critically ill patients with bacteremia and the factors associated with it, to identify the microorganisms that received inadequate antimicrobial treatment, and to determine the relationship between inadequate treatment and patients outcome. Methods From June 1995 to January 1999 we collected data on all clinically significant ICU-bacteremias in our teaching hospital. Clinical and microbiological characteristics were recorded and the adequacy of empirical antimicrobial treatment in each case was determined. We defined inappropriate empirical antimicrobial treatment as applying to infection that was not being eff…

ANTIMICROBIAL AND ANTISTAPHYLOCOCCAL BIOFILM ACTIVITY FROM THE SEA URCHIN PARACENTROTUS LIVIDUS

2009

Aims: Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system. Methods and Results: We tested the activity of the 5-kDa peptide fraction of the cytosol from coelomocytes (5-CC) against a group of Gram-positive, Gram-negative bacteria and fungi. We determined minimal inhibitory concentrations (MICs) ranging from 253.7 to 15.8 mg ml(-1). We observed an inhibitory activity and antibiofilm properties of 5-CC against staphylococcal biofilms of reference strains Staphylococcus epidermidis DSM 3269 an…

PRELIMINARY COMPARISON FOR GENES INVOLVED IN BIOFILMS IN COAGULASE-NEGATIVE STAPHYLOCOCCI (CONS) AND S. AUREUS STRAINS ISOLATED FROM MILK SAMPLES OF …

2013

Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa…

2014

The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…

Phenotypic and genotypic evaluation of slime production by conventional and molecular microbiological techniques.

2009

Twenty-nine staphylococcal isolates from different clinical samples were tested for slime production: phenotypic characterization was carried out using Christensen test (tube test) and Congo red agar plate test (CRA plate test), while the presence and expression of icaA and icaD genes were evaluated by real-time PCR. In 79.3% of studied strains there was a concordance between slime production and presence of icaA and icaD genes, and between lack of slime production and absence of both or only one of the tested genes. In four of five strains where positive phenotype was not associated with the presence of ica genes, gene co-expression (evaluated by mRNA determination) was lacking, while in o…

Immune mediators of sea-cucumber Holothuria tubulosa (Echinodermata) as source of novel antimicrobial and anti-staphylococcal biofilm agents

2013

The present study aims to investigate coelomocytes, immune mediators cells in the echinoderm Holothuria tubulosa, as an unusual source of antimicrobial and antibiofilm agents. The activity of the 5kDa peptide fraction of the cytosol from H. tubulosa coelomocytes (5-HCC) was tested against a reference group of Gram-negative and Gram-positive human pathogens. Minimal inhibitory concentrations (MICs) ranging from 125 to 500 mg/ml were determined against tested strains. The observed biological activity of 5-HCC could be due to two novel peptides, identified by capillary RP-HPLC/nESI-MS/MS, which present the common chemical-physical characteristics of antimicrobial peptides. Such peptides were c…