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A serious global problem with the increasing resistance of microorganisms to currently used antimicrobials has opened up the promotional research in the identification of new, more effective drugs with a broad spectrum of antimicrobial activities. Plant essential oils, due to the large biological and structural diversity of their components, are known to have many potential benefits. This study aimed to evaluate the antimicrobial and anti-adhesion activity of fifteen essential oils and their compounds against two bacterial and two yeast species responsible for food spoilage and infectious diseases. Antimicrobial activity was determined by testing the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) and the minimum fungicidal concentration (MFC) of essential oils and compounds. The essential oils of Cinnamomum zeylanicum and Eugenia caryophyllus showed the highest antimicrobial activity with MICs ranging from 0.078 to 1.25 mg/mL, and 0.039 to 1.25 mg/mL, respectively. On the other hand, essential oils of Eucalypti aetheroleum and Salvia officinalis had significantly weaker antimicrobial properties than the others. Further, MICs were used to assess the inhibition of adhesion of bacteria Salmonella Typhimurium ATCC 25923 and Staphylococcus aureus ATCC 14208, and yeasts Candida albicans ATCC 10231 and Saccharomyces cerevisiae ATCC 9763 in a microtiter plate using the crystal violet staining method. Based on the percentage of adhesion inhibition, yeast S. cerevisiae ATCC 9763 showed a high level of antimicrobial resistance. E. caryophyllus had the strongest effect with inhibition up to 73%. Consistent with the antimicrobial susceptibility results, the most active anti-adhesion compounds were carvacrol and thymol. Considering the role of biofilm in food spoilage and clinical diseases, inhibition of the initial phase of biofilm formation by natural antimicrobial agents may be an alternative to commonly used synthetic ones.

Purpose: One area of science that will increasingly influence our society is biotechnology. An increasing number of modern biotechnological applications have provoked consideration of the ethical and social issues; therefore, it is important that the public is well-informed about them. Formal education in upper-secondary schools should help students to become biotechnologically literate citizens. There is little published research data on Slovenian high-school students' knowledge about and attitudes towards biotechnology, as well a lack of curriculum evaluation data. Methodology: This study combines two research approaches. The first part is content analysis of current upper-secondary education programmes in Slovenia, in which all curricula were reviewed about 15 selected biotechnological topics. The second part of the research focused on assessing students' knowledge of traditional and modern biotechnology and exploring their attitudes towards modern biotechnological methods and their products. The sample included 1163 students aged 17-18 from three different types of schools located in 12 different regions of Slovenia. A questionnaire to measure knowledge and attitudes was designed. Results: The research results revealed that selected biotechnological concepts appeared most frequently in the curricula of bio-technical gymnasia. These students also showed the 30 highest level of knowledge and the most positive attitudes. Furthermore, a clear correlation between students' knowledge of and attitudes towards modern biotechnology was found. On the other hand, no significant differences in attitudes to the statements, which dealt with ethics, were found among the students 35 involved in the research. Conclusion: Biotechnology teaching in upper-secondary education in Slovenia is obviously very diverse and dependent on the programme.

Since formal education is guided through food-related curricula, there is a concern regarding to which extent food safety elements are supported in the current educational objectives presented in syllabi. The aim of this study was to analyze the existing food safety elements in the syllabi at the elementary (for students between 6 and 14 y of age) and upper-secondary level (food-related programs) of formal education (for students between 15 and 18 y of age). Analysis was done through predefined criteria, evaluating the educational objectives listed in available syllabi approved by the national government. The results revealed the elementary level as a good prestage for education at the next level concerning food safety elements. At the upper-secondary level, the acquisition of knowledge and development of skills related to food safety elements of interest are well supported. However, based on frequent errors made by professional food handlers reported in the literature, the role of food handlers and their food safety awareness should receive more attention in the syllabi. To support this and to overcome a lack of educational objectives identified, several actions are suggested. Based on methodological recommendations for the teacher in the syllabi, the importance of qualified teachers was once again confirmed. Vocational schools are and will remain an indispensable pillar in the education of future professional food handlers; however, teachers with sufficient knowledge and a positive attitude toward food safety seems to be, besides quality curricula, one of the important factors in achieving the proper attitudes of people required to implement food safety.

Healthy diet and development of proper dietary habits in adolescence combined with sufficient physical activity are recognized as the key factors of a long-term health. This study was conducted to gain an insight into the dietary habits, the frequency of meal intake and physical activity of the young population by applying a survey. Surveyed participants were Hungarian nationality students who attended elementary and high schools in the province of Vojvodina, Serbia. The total number of participants was 525 (42.5% males and 57.5% females) most of which were from the rural area. To address the nutritional status and risk for overweight among the young population, body mass index (BMI) of the participants was determined. The majority of participants had normal range nutritional status (70.48%) followed by overweight (19.81%) and obese (7.62%). Overweight and obese nutritional statuses were more common among male participants. Increasing number of participants with overweight nutritional status was noticed in the 7th grade of elementary school (25.81%). Insufficient physical activity and irregularities in meals intake were also noticed within the studied population which is an indicator of potential obesity development in adulthood.

This study aimed to evaluate the potential of the bacterium Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes to adhere to stainless steel discs with differing degrees of surface roughness (Ra = 25.20–961.90 nm). Stainless steel is a material commonly used in the food industry for processing equipment, which is regularly exposed to cleaning procedures. The investigation included the commercial disinfectants hydrogen peroxide/peracetic acid and sodium hypochlorite which were evaluated for their antibacterial and anti-adhesion activity. The adhesion was assessed by the standard plate count method, while the broth microdilution method CLSI M07-A10 was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the disinfectants. Based on the MIC values, both disinfectants exerted significant inhibitory effects with MIC values for hydrogen peroxide/peracetic acid and sodium hypochlorite of 250 µg ml−1 and 500 µg ml−1, respectively. Whereas the MBC values were equal to the MIC for all bacteria except for E. coli with values 2-fold higher than the MIC. Obtained results also revealed that all tested bacteria were able to adhere to stainless steel surfaces, although differences were found for strains and surface roughness. The lowest adhesion rate of each strain was recorded on the roughest stainless steel disc at a Ra of 961.90 nm. Further, at a concentration of 1 MIC, the disinfectant sodium hypochlorite reduced initial bacterial adhesion to stainless steel surfaces to a significantly greater extent than the disinfectant hydrogen peroxide/peracetic acid. These findings are consistent with the results obtained by Scanning Electron Microscopy (SEM) analysis, which indicates the great applicability of the tested disinfectants for the control of bacterial adhesion in the food industry. [ABSTRACT FROM AUTHOR]

The effect of functional additives (carob flour and sugar beet fiber) on empirical rheological dough performance and bread quality was examined. Also the microbiological quality of bread was investigated during 16 days of storage. The study included 5 samples: control (CON), with preservative calcium propionate (CONP), with carob flour (CON-CAR), with sugar beet fiber (CON-SBF) and with a combination of carob flour and sugar beet fibers (CON-SBF-CAR). Samples with functional additives had a higher water holding capacity (2-10%) and extended dough development time due to the presence of dietary fiber. Dough resistance of these samples was significantly increased, especially in CON-CAR, in which the time of final fermentation is remarkably prolonged (20% in comparison to CON). The addition of the functional ingredients (due to hydration properties of dietary fiber) improved texture and sensory characteristics of bread. In sample CON-SBF crumb firmness was significantly reduced (by 70%) while elasticity was increased by 25% compared to CON. Positive effect of addition of sugar beet fiber was proved by improving the elasticity of the crumb and finer crumb structure (sample CON-SBF) in comparison with the addition of carob flour (sample CON-CAR). In bread sample with carob flour there was no microbiological contamination for 16 days of examination, which confirms the fact that carob flour can be used as a natural preservative.

The yeast Saccharomyces cerevisiae is a two-sided coin; it has a beneficial, biotechnological value with a strong connotation of reliable safety, but also a negative, potentially pathogenic nature on the other hand. This review is discussing the methodological approaches that were used for unraveling putative virulence traits that should separate pathogenic and non-pathogenic strains. These methods can be sorted in four main groups regarding physiology/morphology, genetics, proteomics and host-pathogen interactions. They can be used to enrich the knowledge regarding e.g. invasive growth, rapid molecular identification, cell-wall adhesions and virulence of yeast pathogens, respectively. Most of these methods have been adapted mainly to the leading yeast pathogen Candida albicans or bacterial pathogens. S. cerevisiae, on the other hand, can act as a weak opportunistic pathogen in certain conditions and its pathogenicity is not comparable to the pathogenicity of C. albicans, therefore it is welcomed that new, modified methods are introduced. New approaches already showed a strong induction of invasive growth under nutrient starvation and at temperatures typical for human fever (37-39°C), revealing the potential of S. cerevisiae strains to cause a disease in humans. A repressive effect on the other hand was observed in the presence of salts, anoxia and some preservatives, which implies the importance of food safety measures. The role of cell-wall proteins, which are involved in the adhesion to plastic material like catheters and other cell wall components that bind to the epithelial surface in the host, should be subjected to more detailed studies. The mechanisms for antimycotic resistance and rapid molecular identification techniques that would identify potentially pathogenic strains should be the focus of research, as well.

Impact of three fungicides against B. cinerea (iprodione, pyrimethanil and f ludioxonil plus cyprodinil) on the population of Saccharomyces cerevisiae strains during the spontaneous alcoholic fermentation was studied. With regard to the use of fungicides in the vineyard at two stages of the grapevine growth we followed four different spontaneous fermentations: control, iprodione, pyrimethanil and f ludioxonil plus cyprodinil. The fungicide residues in the grapes were determined by GC/MS system and the fermentations were followed by changes in yeast, sugar, and ethanol concentrations using colony counting and HPLC. The karyotype analysis of 473 isolates was done by pulsed-field gel electrophoresis. The fungicide residues in the grapes at the harvest were below the maximum residue limits. Isolates of S. cerevisiae were classified into 15 karyotype groups. The duration of the processes and the populations of the karyotypes differed between the fermentations. The iprodione and control fermentations lasted 36 days with the prevalence of karyotype A while the fludioxonil plus cyprodinil fermentation lasted 50 days and karyotype D led the process. In the pyrimethanil fermentation, none of the karyotypes prevailed in the must and the fermentation lasted much longer than others did (68 days). The results showed that the fungicide residues have an influence on the fermentation kinetics and selection of S. cerevisiae strains during the spontaneous alcoholic fermentation and therefore should be considered as an important factor that may indirectly influence the formation of fermentation aroma in the wine produced by such process.

Microbial biodiversity can also be reflected in final product composition. The work described in this paper investigates the differences in the amino acid composition of 14 Malvasia musts/wines fermented with local and commercial starter yeasts, comparing all to the spontaneous fermentations of must of the same origin. We tried to ascertain whether the changes were dependent upon different initiations of fermentations. A comparative study of free and total amino acid evolution was prepared. The total concentration of 15 amino acids studied was 1975 mg/l, and the concentration of fraee amino acids was 1061 mg/l. Spontaneous and induced fermentations showed different fermentation rates. Three to nine days were needed to reduce sugar by 50%. Although the proline is regarded as non-assailable amino acid, decreases in concentration were observed. Lysine was the only amino acid where the concentration increased. The minimal uptakes of amino acids occurred during spontaneous fermentations, whereas the maximal uptakes were observed in the fermentations inoculated with local starters.

The aim of the study was to identify consumers' food safety knowledge, practices, and hygiene status in the observed home kitchens. The results provide the starting point for evaluating progress or regression in this area compared to the past statewide study. Food safety knowledge was analyzed among 380 consumers with an online questionnaire. Additionally, 16 consumers were observed during their preparation of specified foods. The hygiene conditions in the kitchens were microbiologically examined using contact agar plates, while the cleaning adequacy was determined by measuring the ATP bioluminescence. A lack of knowledge on certain topics regarding food safety was established; the consumers aged from 36 to 55 in general and women demonstrated the highest level of knowledge. In some cases, the observed consumers did not take proper action when preparing the food. Increased total bacteria, coliform bacteria, and Escherichia coli counts were detected in 12.7% of the consumers' kitchens observed here. Eighty-three (74.1%) out of 112 surfaces examined with either hygiene test sheets or ATP swabs met the standards and were adequately or acceptably cleaned. The kitchen surfaces exceeded the recommended limits for 25% of consumers. Statistical differences in RLU and TCC levels on surfaces between older and younger consumers were not observed, although all (25%) inadequately cleaned kitchens belonged to older consumers. The greatest emphasis has to be put on the cleaning of home kitchens and personal hygiene. Even though consumers have some knowledge on food safety, they often fail to put that knowledge into daily practice. [ABSTRACT FROM AUTHOR]

There is a wide range of factors affecting bacterial adhesion and biofilm formation. However, in both food processing and medical settings, it is very hard to obtain suitably controlled conditions so that the factors that reduce surface colonisation and biofouling can be studied. The aim of this study was to evaluate the effect of glucose concentration, temperature and stainless steel (SS) surface roughness on biofouling by four common pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and L. monocytogenes). Among the tested variables, the untreated SS surface (3C) was shown to be fouled more than 3D polished, brushed or electropolished SS surfaces. Although an array of parameters influenced biofouling, the most promising control measure was the influence of low temperature (4 °C) that reduced biofouling even in the case of the psychrophilic Listeria monocytogenes. The study findings could significantly contribute to the prevention of SS surface contamination and consequential biofouling by food and healthcare associated pathogens. [ABSTRACT FROM AUTHOR]

Candidemia and other forms of invasive fungal infections caused by Candida glabrata and to a lesser extent Saccharomyces cerevisiae are a serious health problem, especially if their steadily rising resistance to the limited range of antifungal drugs is taken into consideration. Various drug combinations are an attractive solution to the resistance problem, and some drug combinations are already common in the clinical environment due to the nature of diseases or therapies. We tested a few of the common antifungal-immunomodulatory drug combinations and evaluated their effect on selected strains of C. glabrata and S. cerevisiae. The combinations were performed using the checkerboard microdilution assay and interpreted using the Loewe additivity model and a model based on the Bliss independence criterion. A synergistic interaction was confirmed between calcineurin inhibitors (Fk506 and cyclosporine A) and antifungals (fluconazole, itraconazole, and amphotericin B). A new antagonistic interaction between mycophenolic acid (MPA) and azole antifungals was discovered in non-resistant strains. A possible mechanism that explains this is induction of the Cdr1 efflux pump by MPA in C. glabrata ATCC 2001. The Pdr1 regulatory cascade plays a role in overall resistance to fluconazole, but it is not essential for the antagonistic interaction. This was confirmed by the Cgpdr1Δ mutant still displaying the antagonistic interaction between the drugs, although at lower concentrations of fluconazole. This antagonism calls into question the use of simultaneous therapy with MPA and azoles in the clinical environment. [ABSTRACT FROM AUTHOR]