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This review summarizes the current knowledge on the contribution of metals to the development of oxidative stress in fish. Metals are important inducers of oxidative stress in aquatic organisms, promoting formation of reactive oxygen species through two mechanisms. Redox active metals generate reactive oxygen species through redox cycling, while metals without redox potential impair antioxidant defences, especially that of thiol-containing antioxidants and enzymes. Elevated levels of reactive oxygen species lead to oxidative damage including lipid peroxidation, protein and DNA oxidation, and enzyme inactivation. Antioxidant defences include the enzyme system and low molecular weight antioxidants. Metal-binding proteins, such as ferritin, ceruloplasmin and metallothioneins, have special functions in the detoxification of toxic metals and also play a role in the metabolism and homeostasis of essential metals. Recent studies of metallothioneins as biomarkers indicate that quantitative analysis of mRNA expression of metallothionein genes can be appropriate in cases with elevated levels of metals and no evidence of oxidative damage in fish tissue. Components of the antioxidant defence are used as biochemical markers of oxidative stress. These markers may be manifested differently in the field than in results found in laboratory studies. A complex approach should be taken in field studies of metal contamination of the aquatic environment.

Spoilage fungi are ubiquitous contaminants of cereals, pre- and post-harvest. These fungi can produce a wide range of secondary metabolites under ecological conditions which are conducive for growth. However, some of these secondary metabolites are toxic and have a significant impact if they enter the production and animal food chains. Prevention of mycotoxin contamination of feed and food raw materials is now considered more important than subsequent cure. The key ecological determinants pre- and post-harvest are water availability and temperature (climate). Accurate information is therefore needed on the impact of an association between these key factors, and it is necessary to understand which are marginal and which critical for germination and toxin production. There have only been a few studies where attempts have been made to integrate the available information on these factors in relation to different raw materials for feed and food processing, especially cereals. This review will examine the available information on the main climatic factors, i.e., water availability and temperature affecting mycotoxin production such as, aflatoxins, ochratoxins, fumonisins, zearalenone, deoxynivalenol and citrinin. This information is crucial for accurately focusing and monitoring key critical control points in the feed and food chain to optimise prevention strategies.

The antifungal activity of organic acids greatly improves the shelf life of bread and bakery products. However, little is known about the effect of lactic acid fermentation on fungal contamination in rice cakes. Here, we show that lactic acid fermentation in rice dough can greatly retard the growth of three fungal species when present in rice cakes, namely Cladosporium sp. YS1, Neurospora sp. YS3, and Penicillium crustosum YS2. The antifungal activity of the lactic acid bacteria against these fungi was much better than that of 0.3% calcium propionate. We found that organic acids including lactic and acetic acid, which are byproducts of lactic fermentation or can be artificially added, were the main antifungal substances. We also found that some Leuconostoc citreum and Weissella confusa strains could be good starter species for rice dough fermentation. These results imply that these lactic acid bacteria can be applicable to improve the preservation of rice cakes.

Amazingly, despite the 24,143 papers on mycobacteria, indexed in the Web of Science database during the last six years, published by 67,008 authors from 13,128 organizations located in 166 countries or territories, internationally accepted legal directives on how to control the public health risk associated with environmental mycobacteria have yet to be developed. Mycobacteria are human and animal pathogens, causing not only tuberculosis and leprosy, but mycobacterioses of skin, soft tissues and lung. Due to their cell wall composition and their adaptability mycobacteria can survive in different habitats for years. Their immunomodulatory ability has been recognised for more than 50 years and hundreds of papers published during the last two decades have demonstrated that small chemical products derived from mycobacterial cells participate in inflammatory pathways involved the pathogenesis of important human diseases like Crohn's disease, asthma, type 1 diabetes mellitus, psoriasis, arthrosis, Blau syndrom, sarcoidosis, autism etc. Mycobacteria can influence inflammatory pathways not only as live organisms, but also by means of components derived from dead cells. Pasteurisation or cooking does not affect this ability. Hence, how many mycobacterial cells are ingested, what factors play a role concurrently, and how long the harmful effect persists become important questions. This paper presents only a short review based on selected papers about mycobacteria in water, soil, plants and air with the aim of attracting attention to this significant global problem and of making the first steps towards protection of people. Selected bibliographic references of published data from 2007 to 2012 are presented in easy-to-navigate tables.

A collection of 250 enterococci isolated from various food-stuffs were used to investigate seven virulence determinants and the microbial susceptibility of eight antibiotics. Species-specific PCR revealed the presence of E. faecalis (127 isolates), E. faecium (77 isolates), E. casseliflavus (21 isolates), E. mundtii (19 isolates) and E. durans (6 isolates). Multiplex PCR for virulence factors showed that out of the 250 isolates tested, 221 carried one or more virulence-encoding genes. Beta-haemolytic activity was also evident in enterococcal species other than E. faecalis and E. faecium. Species other than E. faecalis and E. faecium isolated from food may also be virulent. Antimicrobial susceptibility was tested using the disk diffusion method. It showed that out of 250 isolates, 114 were resistant to cephalothin and 94 to ofloxacin. Lower antibiotic resistance was seen with ampicillin, chloramphenicol, gentamicin and teicoplanin. None of the isolates was found to be resistant to vancomycin. The results of this study show that food can play an important role in the spread of virulent enterococci through the food chain.

The gastric stomach of humans is a barrier to food-borne pathogens, but Escherichia coli can survive at pH 2.0 if it is grown under mildly acidic conditions. Cattle are a natural reservoir for pathogenic E. coli, and cattle fed mostly grain had lower colonic pH and more acid-resistant E. coli than cattle fed only hay. On the basis of numbers and survival after acid shock, cattle that were fed grain had 10(6)-fold more acid-resistant E. coli than cattle fed hay, but a brief period of hay feeding decreased the acid-resistant count substantially

Furan and its derivatives were identified in a small number of heat-treated foods back in the 60's and 70's. In May 2004, US Food and Drug Administration published a report on the occurrence of parent furan in a number of thermally treated foods. Since furan has been classified as possibly carcinogenic to human by IARC, a great concern has been addressed to the analysis of this substance naturally-occurring in food. This paper gives a short overview on the mechanistic pathways of the parent furan formation in food by degradation of amino acids and/or reducing sugars, and oxidation of ascorbic acid and polyunsaturated acids which can be induced by thermal or irradiation treatments; further, it deals with the metabolism and toxicology of furan as well as with the comparison of the methods of furan determination.

The aim of this paper was to review the status of bovine tuberculosis (BTB) in Ethiopia in relation with the existing animal husbandry systems and abattoir meat inspection surveillances. Ethiopia is one of the African countries where tuberculosis is widespread in both humans and cattle. The disease is considered as one of the major livestock diseases that results in high morbidity and mortality, although the current status on the actual prevalence rate of BTB at a national level is yet unknown. Detection of BTB is based mainly on tuberculin skin testing, abattoir meat inspection and very rarely on bacteriological techniques. The prevalence rates vary from 3.4% (small farms) to 50% (intensive dairy farms) and from 3.5% to 5.2% in slaughterhouses. Control measures, economic impacts and zoonotic aspect of the disease are also briefly reviewed.

Quantitative risk assessment of Bacillus cereus using data from pasteurised milk produced in Slovakia was performed. Monte Carlo simulations were used for probability calculation of B. cereus density at the time of pasteurised milk consumption for several different scenarios. The results of the general case exposure assessment indicated that almost 14% of cartons can contain 104 CFU/ml of B. cereus at the time of pasteurised milk consumption. Despite the absence of a generally applicable dose-response relationship that limits a full risk assessment, the probability of intoxication per serving and the estimated number of cases in the population were calculated for the general exposure assessment scenario using an exponential dose-response model based on Slovak data. The mean number of annual cases provided by the risk assessment model for pasteurised milk produced in Slovakia was 0.054/100 000 population. In comparison, the overall reporting rate of the outbreaks in the EU in which B. cereus toxins were the causative agent was 0.02/100 000 population in 2010. Our assessment is in accordance with a generally accepted fact that reporting data for alimentary intoxication are underestimated, mostly due to the short duration of the illness.