1,721,120 research outputs found
Exposure to the agricultural fungicide tebuconazole promotes Aspergillus fumigatus cross-resistance to clinical azoles. [Comini S. is the co-first author; Banche G. is the corresponding author; Cuffini A.M. is the co-corresponding author]
No full textResistance to clinical triazoles in Aspergillus fumigatus is a growing concern for individuals at high risk of Aspergillus infection. Two triazole resistance selection routes are currently being investigated: one occurring in triazole-treated patients in healthcare settings, and the second taking place in the environment due to the widespread use of agricultural triazoles. This study aimed to assess the ability of agricultural azoles to promote cross-resistance to clinical azoles in A. fumigatus. Five A. fumigatus isolates susceptible to clinical azoles were exposed to the triazole 14α-demethylase inhibitor, tebuconazole (TBC), and then antifungal susceptibility tests for voriconazole, itraconazole, posaconazole and isavuconazole were performed. Under TBC selection pressure, all A. fumigatus isolates exhibited resistance to clinical triazoles. However, only two displayed a multiresistant phenotype to clinical azoles. TBC exposure was also associated with delayed conidia formation and progressive absence of conidiation. Noteworthy, no TBC-exposed clones harbored TR34/L98H mutation, as judged by real-time PCR assays. The observation that TBC exposure promotes cross-resistance to clinical triazoles warrants careful and thorough assessment of the human health risk associated with agricultural azoles. The absence of TR34/L98H mutation in cross-resistant A. fumigatus isolates suggests that other cyp51A mutations may be involved in clinical azole cross-resistance
Surface functionalization of chemically treated Ti6Al4V alloy with mentha piperita essential oil
No full textMentha piperita essential oil is a complex mixture of different natural biomolecules with proven
antibacterial activity against Gram-positive and Gram-negative bacteria, fungi and viruses [1] and
it has been widely used in folk medicine for various applications. Despite its increasing use in
phytotherapy, application of peppermint essential oil in medicine is still quite scarce and almost
no research work considers its application in combination with biomaterials. On the other hand,
the possibility to employ the antibacterial properties of this essential oil together with its low
resistance development risk and its low toxicity is a challenging approach for the development of
smart biomaterials for prosthetic applications. The aim of the work is to combine the antibacterial
properties of peppermint essential oil with those of bioactive titanium alloy for applications in which
good osteointegrability and antimicrobial effects are required
Bioactive and antibacterial Ti6Al4V for bone contact applications
No full textSilver is a well-known antibacterial agent with broad spectrum activity and low resistance development . An increasing interest is registered for silver nanoparticles because of their large surface area and multiple mode of action (damage of the cell membrane, induction of ROS and release of silver ions). Despite of a wide research on surface enrichment of titanium surfaces with silver, the identification of an affective technology is a still an open issue. The aim of the present research is the surface modification of Ti6Al4V alloy in order to induce bioactive and antibacterial behaviou
Evaluation of Bartonella henselae by molecular and serological assays in different clinical specimens from patients with suspected cat scratch disease
No full textBackground: Bartonella henselae is the etiological agent of cat scratch disease (CSD), a common
infection that usually occurs in children presenting as a self-limiting lymphadenopathy. In a minority of
cases, including immunocompromised individuals, B. henselae can cause atypical infections. Given
the slow and difficult growth in culture, diagnosis is usually made by epidemiological, clinical,
histological and serological criteria. In this study, a qualitative real-time PCR has been used in order to
evaluate its suitability for diagnosing B. henselae in comparison to serology.
Material/methods: Between march 2011 and may 2016, 139 clinical specimens (lymphonodal
biopsies, blood, exudates) from 129 patients (M/F 52/77; 10 adults/119 children, age 3 months-68
years) with suspected CSD were evaluated at the Microbiology and Virology Unit, Azienda
Ospedaliera Universitaria Città della Salute e della Scienza di Torino, by serological (IgM and IgG) and
molecular assays. Clinical charts were reviewed in all patients.
Results: Overall, 86/129 patients (66.7%) were PCR-negative (non-CSD group; M/F 33/53, age 3
months-37 years) and 43 (33.3%) PCR-positive (CSD group; M/F 19/24, age 7 months-68 years,
including 5 adults and 38 children). Serology was available for 28 CSD patients: 8 (28.57%) IgMpositive,
two of which also IgG-positive; 20 IgM+IgG-negative. CSD was diagnosed in all patients from
CSD group, whereas other infective causes were evidenced in the remaining patients.
Conclusions: Real-time-PCR allows for a timely CSD diagnosis, especially in subjects in which
serology does not evidence the occurrence of an antibody response. A rapid and accurate diagnosis
of CSD may prevent unnecessary diagnostic procedures and allows for an appropriate clinical and
therapeutic management, including antibiotic treatment
New Generation of Osteoinductive and Antimicrobial Polycaprolactone-Based Scaffolds in Bone Tissue Engineering: A Review
Full text linkWith respect to other fields, bone tissue engineering has significantly expanded in recent years, leading not only to relevant advances in biomedical applications but also to innovative perspectives. Polycaprolactone (PCL), produced in the beginning of the 1930s, is a biocompatible and biodegradable polymer. Due to its mechanical and physicochemical features, as well as being easily shapeable, PCL-based constructs can be produced with different shapes and degradation kinetics. Moreover, due to various development processes, PCL can be made as 3D scaffolds or fibres for bone tissue regeneration applications. This outstanding biopolymer is versatile because it can be modified by adding agents with antimicrobial properties, not only antibiotics/antifungals, but also metal ions or natural compounds. In addition, to ameliorate its osteoproliferative features, it can be blended with calcium phosphates. This review is an overview of the current state of our recent investigation into PCL modifications designed to impair microbial adhesive capability and, in parallel, to allow eukaryotic cell viability and integration, in comparison with previous reviews and excellent research papers. Our recent results demonstrated that the developed 3D constructs had a high interconnected porosity, and the addition of biphasic calcium phosphate improved human cell attachment and proliferation. The incorporation of alternative antimicrobials—for instance, silver and essential oils—at tuneable concentrations counteracted microbial growth and biofilm formation, without affecting eukaryotic cells’ viability. Notably, this challenging research area needs the multidisciplinary work of material scientists, biologists, and orthopaedic surgeons to determine the most suitable modifications on biomaterials to design favourable 3D scaffolds based on PCL for the targeted healing of damaged bone tissue
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Evaluation of a diagnostic algorithm for rapid identification of Gram-negative species and detection of extended-spectrum β-lactamase and carbapenemase directly from blood cultures
Full text linkAbstract
Objectives
To evaluate a rapid diagnostic algorithm based on MALDI-TOF MS, lateral flow immunoassays (LFIAs) and molecular testing performed directly from positive blood cultures (BCs) for Gram-negative species identification and detection of CTX-M extended-spectrum β-lactamases and main carbapenemases.
Methods
Non-duplicate BCs positive to Gram-negative bacteria at microscope examination were subjected to species identification by direct MALDI-TOF MS following recovery of bacterial pellet by Rapid MBT Sepsityper® kit. Subsequently, NG-Test® CARBA 5 and NG-Test® CTX-M MULTI LFIAs were performed according to identified microbial species. Eazyplex® SuperBug CRE molecular assay was performed in cases of NG-Test® CARBA 5 negative results in patients with documented carbapenemase-producers carriage. Results of rapid diagnostic workflow were compared with those obtained by conventional diagnostic routine.
Results
Overall, the direct MALDI-TOF MS protocol allowed reliable identification to the species level of 92.1% of the 2133 monomicrobial BCs. Rate of matched identification was significantly higher for Enterobacterales (97.3%) in comparison to non-fermenting Gram-negative species (80.2%), obligate anaerobic bacteria (42.1%) and fastidious Gram-negative species (41.5%). The overall sensitivity of NG-Test® CARBA 5 and NG-Test® CTX-M MULTI was 92.2% and 91.6%, respectively. Integration of Easyplex® SuperBug CRE allowed the detection of blaKPC mutants associated with ceftazidime/avibactam resistance, reaching 100% sensitivity in carbapenemase detection. Both LFIAs and molecular testing showed no false-positive results.
Conclusions
Algorithms based on MALDI-TOF MS, LFIAs and molecular testing may represent a cost-effective tool to timely identify Gram-negative species and detect resistance markers directly from BCs. According to local epidemiology, these results may allow antimicrobial stewardship interventions including prompt use of new approved drugs.
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Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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