1,721,072 research outputs found
Editorial for the Special Issue: Colistin Resistance—The Need for a One Health Approach
Full text linkColistin is an “old” antimicrobial belonging to the class of polymyxins, initially discovered in 1947 [...
Beeswax: A minireview of its antimicrobial activity and its application in medicine
No full textBeeswax is the substance that forms the structure of a honeycomb; the bees secrete wax to build the honeycombs where to store honey. Thanks to its rich hydrophobic protective properties, the beeswax is in fact present within cosmetics and body products. Also, beeswax is used in the food industry: as a film to wrap cheese for maturing or as a food additive (E901) to give shine to the products. Exactly as the honey which it contains, beeswax is also characterized by several therapeutic properties of great interest to us; it is thought to be particularly effective in healing bruises, inflammation and burns. Recently, the interest of researchers has moved even on antimicrobial properties of beeswax although there are still few studies in the literature focused only on the action of beeswax. The few studies showed an antimicrobic effectiveness of beeswax against overall Staphylococcus aureus, Salmonella enterica, Candida albicans and Aspergillus niger; these inhibitory effects are enhanced synergistically with other natural products such as honey or olive oil. This minireview aims to be a collection of major scientific works that have considered the antimicrobial activity of beeswax alone or in combination with other natural products in recent years
Qualitative and quantitative evaluation of biogenic amines in vitro production by bacteria isolated from ewes' milk cheeses
Full text linkStudying the production of biogenic amines (BA) by cheese microbiota is important, because high BA concentrations in food represent a health risk for consumers. Qualitative screening with differential media and HPLC quantification were used to investigate the production of 8 BA (2-phenylethylamine, cadaverine, histamine, putrescine, spermidine, spermine, tryptamine, and tyramine) by 72 isolates from curd and cheese samples manufactured with raw and pasteurised ewes' milk. Enterobacteriaceae showed good putrescine and cadaverine production, both for number of positive isolates and for concentrations produced (average: 341 and 785 micrograms/ml, respectively). Among Enterobacteriaceae data are provided on BA formation by Pantoea conspicua, previously not isolated from food samples. All enterococci formed tyramine, often in high amounts (average: 1608 micrograms/ml), and many produced notable 2-phenylethylamine, putrescine, and cadaverine concentrations (average: 184, 121, and 146 micrograms/ml, respectively). BA formation by lactobacilli was overall extremely limited, with the notable exception of high tyramine concentrations produced by 1 Lactobacillus paracasei (800 micrograms/ml) and 2 Lactobacillus curvatus (> 1700 micrograms/ml), all isolated from pasteurised milk samples. Thus, undesired and technologically useful microorganisms both play a role in BA accumulation in cheeses
Sub-inhibitory concentration of essential oils induces antibiotic resistance in Staphylococcus aureus
No full textFourteen Staphylococcus aureus wild strains were stressed with sub-inhibitory concentration of five essential oils: Leptospermum scoparium (manuka), Origanum majorana (marjoram), Origanum vulgare (oregano), Satureja montana (winter savoury) and Thymus vulgaris (thyme). Antibiotics susceptibility profiles of the strains were determined by agar disk diffusion method before and after EOs treatment. The following antibiotics were employed: amoxicillin-clavulanic acid, amikacin, ampicillin, amoxicillin, aztreonam, ceftazidime, cephalothin, ciprofloxacin, colistin, cefotaxime, doxycycline, enrofloxacin, erythromycin, gentamicin, cephalexin, neomycin, piperacillin, rifampin, streptomycin, trimethoprim-sulphamethoxazole, tetracycline and tobramycin. Before EOs treatment, strains were susceptible to all antibiotics except for aztreonam and colistin. After exposure to sub-inhibitory EOs concentration of manuka, marjoram and oregano, several modifications in antibiotics susceptibility profiles were detected. Conversely, few modifications were induced by winter savoury and thyme EOs. Moreover, occurrence of resistances seems uncorrelated with drug classes as low concentration of EO could induce phenotypic changes in susceptible bacteria leading to antibiotic resistance phenomena
Insects, arachnids and centipedes venom: A powerful weapon against bacteria. A literature review
No full textCurrently, new antimicrobial molecules extracted or obtained by natural sources, could be a valide alternative to traditional antibiotics. Most of these molecules are represented by antimicrobial peptides (AMPs), which are essential compounds of insect, arachnids and centipedes venom. AMPs, due to their strong effectiveness, low resistance rates and peculiar mode of action, seem to have all the suitable features to be a powerful weapon against several bacteria, especially considering the increasing antibiotic-resistance phenomena. The present literature review focuses on the antibacterial activity of bee, wasp, ant, scorpion, spider and scolopendra crude venom and of their main biological active compounds. After a brief overview of each animal and venom use in folkloristic medicine, this review reports, in a comprehensive table, the results obtained by the most relevant and recent researches carried out on the antibacterial activity of different venom and their AMPs. For each considered study, the table summarizes data concerning minimal inhibitory concentration values, minimal bactericidal concentration values, the methods employed, scientific name and common names and provenience of animal species from which the crude venom and its respective compounds were obtained
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
Serological and molecular survey of Anaplasma phagocytophilum in Italian hunting dogs.
No full textThe presence of Anaplasma phagocytophilum, a tick-transmitted zoonotic pathogen, has been reported in Italy in humans and several animal species, including dogs, but data concerning its prevalence in the Italian canine population are lacking. The aim of this study was to determine the prevalence of A. phagocytophilum infection in hunting dogs which live in geographic areas of central Italy where the infection had been previously detected in wild animals. Sera from 215 hunting dogs were tested by indirect immunofluorescence antibody test (IFAT) to detect antibodies to A. phagocytophilum. Bufy coat samples from the same 215 animals were submitted to a polymerase chain reaction (PCR) assay specific for the A. phagocytophilum 16S rRNA gene. Thirty-two (14.8%) dogs proved to be seropositive with antibody titres from 1:40-1:2,560. The highest seroprevalence was observed in dogs 6-10-year-old. Two seropositive (0.9%) animals were also PCR positive. Sequencing of PCR products revealed gene sequences of A. phagocytophilum in both cases. These results confirm the presence of A. phagocytophilum in the Italian areas studied; thus, the zoonotic potential of this agent should be considered particularly for people, as hunters, at risk of exposure to tick bites
Is Leptospira able to survive in raw milk? Study on the inactivation at different storage times and temperatures
No full textThe consumption of raw milk is currently increasing due to several beneficial aspects, such as nutritional qualities, taste and health benefits. However, some Authors highlight the potential risk associated with raw milk consumption. While the absence of some pathogen microorganisms is set by the regional regulation DGR 381/2007, for other microorganisms, such as Leptospira, no recommendations are provided. Leptospira is not ascribed among classical milk pathogens, however, it can potentially be present in raw milk. The aim of this study was to evaluate the survival in raw milk of 6 serovars of Leptospira after storage at different temperatures (4°C +/- 2°C, 20°C +/- 2°C and 30°C +/- 2°C) for different incubation times (20 minutes, 45 minutes, 1 hour and 1 hour and 30 minutes), in order to determine the potential risk for consumers. Moreover, the immediate effect of bovine, goat and donkey raw milk on tested Leptospira serovars was visually evaluated. After incubation, all samples were subcultured in EMJH and incubated aerobically at 30 °C for 3 months. All inoculated media were weekly examined by dark-field microscope in order to assess Leptospira survival. Extemporary observation of strains’ behavior in milk allowed to detect an almost immediate motility loss and no leptospires were detected by microscopic observations carried out weekly during the trial period. According to our results, it could be possible to exclude raw milk as a source of Leptospira infection for consumers
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
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