82 research outputs found

    Comparative Susceptibility Study Against Pathogens Using Fermented Cranberry Juice and Antibiotics.

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    In the present study, unfermented and fermented cranberry juice in combination with the Antibiotics vancomycin and tigecycline were tested for their antimicrobial activity. Cranberry juice was fermented with a recently isolated potentially probiotic Lactobacillus paracasei K5. The tested strains selected for this purpose were Enterococcus faecalis, E. faecium, Enterobacter cloacae and Staphylococcus aureus. The methods followed were the determination of zones inhibition, Minimum Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration Index (FICI). Tigecycline together with fermented juice exhibited larger Zones of Inhibition (ZOI) in strains of E. faecium (65 ± 4.8 mm) compared to the respective ZOI with tigecycline and unfermented juice (no zone). The same outcome was also obtained with E. cloacae. Vancomycin together with fermented juice exhibited larger ZOI in strains of E. faecium (28 ± 2.2 mm) compared to the respective ZOI with vancomycin and unfermented juice (24 ± 2.3 mm). The lowest MIC values were recorded when tigecycline was combined with fermented cranberry juice against S. aureus strains, followed by the same combination of juice and antibiotic against E. cloacae strains. FICI revealed synergistic effects between fermented juice and tigecycline against a strain of E. faecium (A2020) and a strain of E. faecalis (A1940). Such effects were also observed in the case of fermented juice in combination with vancomycin against a strain of S. aureus (S18), as well as between fermented juice and tigecycline against E. cloacae (E1005 and E1007) strains. The results indicate that the antibacterial activity of juice fermented with the potentially probiotic L. paracasei K5 may be due to synergistic effects between some end fermentation products and the antibiotic agents examined

    EFFECT OF THERMAL PROCESSING ON ANTIBACTERIAL ACTIVITY OF MULTIFLORAL HONEYS

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    In this study, the effects of thermal processing in the antibacterial activity of four multifloral honeys were determined. The thermal treatments were carried out at 30, 40, 50, 60, 70 and 80C, and the following characteristics were determined: total phenols and antibacterial activity of three gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Listeria monocytogenes) and three gram-negative bacteria (Escherichia coli, Salmonella typhimurium and Pseudomonas aeruginosa). The results showed that the behavior of total phenols in relation to temperature depended on the floral sources of honey. The honeys presented curves of either linear or quadratic responses of the antibacterial activity in relation to the thermal process, depending on the honey's floral sources and the kind of bacterium to inhibit. The results suggest that the honey's antibacterial activities and behavior with the temperature are different depending on the honey's floral sources and the kind of bacteria that they inhibit.Fundacao para a Ciencia e a Tecnologiainfo:eu-repo/semantics/publishedVersio

    Implementation of food safety management systems along with other management tools (HAZOP, FMEA, Ishikawa, Pareto). the case study of Listeria monocytogenes and correlation with microbiological criteria

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    The food industry’s failure in planning and designing of and in implementing a Food Safety Management System and its foundation elements leads, in most instances, to compromised food safety and subsequent foodborne illness outbreaks. This phenomenon was noticed, worldwide, for all food processors, but with a much higher incidence in the medium-and small-sized food processing plants. Our study focuses on the importance of Food Safety Management System (FSMS), Critical Control Points Hazard Analysis (HACCP) and the Prerequisite Programs (PRPs) as the foundation of HACCP, in preventing foodborne outbreaks. For emphasis, we make use of the example of organizational food safety culture failures and the lack of managerial engagement which resulted in a multi-state listeriosis outbreak in USA. Moreover, we correlate this with microbiological criteria. Implementation of food safety management systems (ISO 22000:2018) along with incorporation of management tools such as HAZOP, FMEA, Ishikawa and Pareto have proved to be proactive in the maintenance of a positive food safety culture and prevention of cross-contamination and fraud. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/)

    COVID-19 on the spectrum: a scoping review of hygienic standards

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    The emergence of COVID-19 in Wuhan, China, rapidly escalated into a worldwide public health crisis. Despite numerous clinical treatment endeavors, initial defenses against the virus primarily relied on hygiene practices like mask-wearing, meticulous hand hygiene (using soap or antiseptic solutions), and maintaining social distancing. Even with the subsequent advent of vaccines and the commencement of mass vaccination campaigns, these hygiene measures persistently remain in effect, aiming to curb virus transmission until the achievement of herd immunity. In this scoping review, we delve into the effectiveness of these measures and the diverse transmission pathways, focusing on the intricate interplay within the food network. Furthermore, we explore the virus's pathophysiology, considering its survival on droplets of varying sizes, each endowed with distinct aerodynamic attributes that influence disease dispersion dynamics. While respiratory transmission remains the predominant route, the potential for oral-fecal transmission should not be disregarded, given the protracted presence of viral RNA in patients' feces after the infection period. Addressing concerns about food as a potential viral vector, uncertainties shroud the virus's survivability and potential to contaminate consumers indirectly. Hence, a meticulous and comprehensive hygienic strategy remains paramount in our collective efforts to combat this pandemic

    Bioactive compounds and antibacterial activities in crystallized honey liquefied with ultrasound

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    The effect of ultrasound on the crystal size, phenols, flavonoids, Maillard products and antibacterial activity of crystallized honeys was studied. Three multifloral honeys (M), one monofloral (MO) and one honeydew (HD) honey were used. Ultrasound was performed at 42 kHz for different times (0, 5, 10 and 15 min). The antibacterial activities were tested against Salmonella typhimurium, Bacillus subtilis, Pseudomonas aeruginosa, Listeria mono cytogenes, Staphylococcus aureus and Escherichia coli. In all honeys, the parameters analyzed had significant dif ferences ((P < 0.05)). After 15 min of ultrasound the HD had increments of 44 mg of gallic acid/100 g of honey in phenols, and some M showed increase in flavonoids (5.64 mg of quercitin /100 g of honey) and improvement in inhibition against Salmonella typhimurium was 13.1%. In some honeys the correlation between phenols or fla vonoids and antibacterial activity were significant ((P < 0.05)). No correlation was found between Maillard products and antibacterial activity. The ultrasound treatment effect on the crystal size, phenols, flavonoid, Maillard products, and antibacterial activity of crystallized honeys were different in each honey.info:eu-repo/semantics/publishedVersio

    Fermentative Foods: Microbiology, Biochemistry, Potential Human Health Benefits and Public Health Issues

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    Fermented foods identify cultures and civilizations. History, climate and the particulars of local production of raw materials have urged humanity to exploit various pathways of fermentation to produce a wide variety of traditional edible products which represent adaptations to specific conditions. Nowadays, industrial-scale production has flooded the markets with ferments. According to recent estimates, the current size of the global market of fermented foods is in the vicinity of USD 30 billion, with increasing trends. Modern challenges include tailor-made fermented foods for people with special dietary needs, such as patients suffering from Crohn&rsquo;s disease or other ailments. Another major challenge concerns the safety of artisan fermented products, an issue that could be tackled with the aid of molecular biology and concerns not only the presence of pathogens but also the foodborne microbial resistance. The basis of all these is, of course, the microbiome, an aggregation of different species of bacteria and yeasts that thrives on the carbohydrates of the raw materials. In this review, the microbiology of fermented foods is discussed with a special reference to groups of products and to specific products indicative of the diversity that a fermentation process can take. Their impact is also discussed with emphasis on health and oral health status. From Hippocrates until modern approaches to disease therapy, diet was thought to be of the most important factors for health stability of the human natural microbiome. After all, to quote Pasteur, &ldquo;Gentlemen, the microbes will have the last word for human health.&rdquo; In that sense, it is the microbiomes of fermented foods that will acquire a leading role in future nutrition and therapeutics

    Effectiveness of Bacteriocin-Producing Lactic Acid Bacteria and Bifidobacterium Isolated from Honeycombs against Spoilage Microorganisms and Pathogens Isolated from Fruits and Vegetables

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    Screening natural products for bacteriocin-producing bacteria may be the equilibrium point between the consumer demand for mild processing and the industry&rsquo;s need for hazard control. Raw unprocessed honeycombs filled with oregano honey from the alpine mountainous territory of Epirus, Greece were screened for bacteriocinogenic lactic acid bacteria and Bifidobacterium spp., with inhibitory action towards some pathogens and spoilage microorganisms isolated from fresh fruits and vegetables (number and type of strains: three E. coli, two L. monocytogenes, two Salmonella spp., two B.cereus, two Erwinia spp., one Xanthomonas spp., L. innocua (ATCC 33090TM) and E. coli 0157:H7 (ATCC 69373)). Among the 101 collected isolates (73 Lactobacillus, 8 Lactococcus, 8 Leuconostoc and 12 Bifidobacterium species) from the oregano honeycombs (an original finding since there are no other reports on the microbial biodiversity of the flora of the oregano honey), 49 strains of lactic acid bacteria (LAB) and Bifidobacterium spp. were selected and tested for their bacteriocin-producing capacity (34 Lactobacillus, 6 Lactococcus, 5 Leuconostoc and 4 Bifidobacterium). The antibacterial activity exerted by the tested LAB and Bifidobacterium strains was not of the same potency. Our results suggest that the main molecules involved in the antimicrobial activity are probably bacteriocin-like substances (a conclusion based on reduced antibacterial activity after the proteolytic treatment of the cell-free supernatant of the cultures) and this antimicrobial activity is specific for the producing strains as well as for the target strains. The spoilage bacteria as well as the reference microorganisms showed increased resistance to the bacteriocin-like substances in comparison to the wild-type pathogens

    Plant-Derived Compounds: A Promising Tool for Dental Caries Prevention

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    There is a growing shift from the use of conventional pharmaceutical oral care products to the use of herbal extracts and traditional remedies in dental caries prevention. This is attributed to the potential environmental and health implications of contemporary oral products. This comprehensive review aims at the analysis of plant-derived compounds as preventive modalities in dental caries research. It focuses on data collected from 2019 until recently, trying to emphasize current trends in this topic. The research findings suggest that several plant-derived compounds, either aqueous or ethanolic, exhibit notable antibacterial effects against Streptococcus mutans and other bacteria related to dental caries, with some extracts demonstrating an efficacy comparable to that of chlorhexidine. Furthermore, in vivo studies using plant-derived compounds incorporated in food derivatives, such as lollipops, have shown promising results by significantly reducing Streptococcus mutans in high-risk caries children. In vitro studies on plant-derived compounds have revealed bactericidal and bacteriostatic activity against S. mutans, suggesting their potential use as dental caries preventive agents. Medicinal plants, plant-derived phytochemicals, essential oils, and other food compounds have exhibited promising antimicrobial activity against oral pathogens, either by their anti-adhesion activity, the inhibition of extracellular microbial enzymes, or their direct action on microbial species and acid production. However, further research is needed to assess their antimicrobial activity and to evaluate the cytotoxicity and safety profiles of these plant-derived compounds before their widespread clinical use can be recommended

    Biodiversity and Microbial Resistance of Lactobacilli Isolated From the Traditional Greek Cheese Kopanisti.

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    Kopanisti is a Greek artisan cheese produced from raw milk in the island of Mykonos, Greece. The milk is left to rest for 12-24 h and then the rennet is added. After its formation the curd is left to drain for 2-3 days and is ready either for consumption (as tyrovolia fresh cheese), or with the addition of extra salt, the curd is left to ripen through further fermentation and surface development of Penicillium fungi, aprocess leading to the production of the traditional Greek cheese Kopanisti. From 120 samples of kopanisti, 574 javax.xml.bind.JAXBElement@2077a29b strains were isolated, distributed in 17 species (16 of them isolated from tyrovolia as well). Strains from 15 species were found resistant or multiresistant against 15 antimicrobial agents, representing all categories of antibiotics. Analysis revealed that the resistance was moderated during ripening of the curd from tyrovolia to Kopanisti. Resistance against penicillin G, ampicillin/sulbactam, clindamycin, chloramphenicol, streptomycin, trimethoprim, metronidazole, vancomycin, teichoplanin, and quinupristin/dalvopristin was significantly enhanced, while the resistance against ampicillin, erythromycin, oxytetracycline, gentamycin, and fucidic acid was significantly reduced. These changes during ripening suggest that resistance to antimicrobials is a dynamic process subjected to environmental factors. The biodiversity of isolated javax.xml.bind.JAXBElement@1dccd3b5 strains is impressive and explains the exquisite sensorial characteristics of the cheese. However, the extent of the resistance is alarming
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