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Colistin is considered to be an antimicrobial of last-resort for the treatment of multidrug-resistant Gram-negative bacterial infections. The recent global dissemination of mobilized colistin resistance (mcr) genes is an urgent public health threat. An accurate estimate of the global prevalence of mcr genes, their reservoirs and the potential pathways for human transmission are required to implement control and prevention strategies, yet such data are lacking. Publications from four English (PubMed, Scopus, the Cochrane Database of Systematic Reviews and Web of Science) and two Chinese (CNKI and WANFANG) databases published between 18 November 2015 and 30 December 2018 were identified. In this systematic review and meta-analysis, the prevalence of mcr genes in bacteria isolated from humans, animals, the environment and food products were investigated. A total of 974 publications were identified. 202 observational studies were included in the systematic review and 71 in the meta-analysis. mcr genes were reported from 47 countries across six continents and the overall average prevalence was 4.7% (0.1–9.3%). China reported the highest number of mcr-positive strains. Pathogenic Escherichia coli (54%), isolated from animals (52%) and harboring an IncI2 plasmid (34%) were the bacteria with highest prevalence of mcr genes. The estimated prevalence of mcr-1 pathogenic E. coli was higher in food-animals than in humans and food products, which suggests a role for foodborne transmission. This study provides a comprehensive assessment of prevalence of the mcr gene by source, organism, genotype and type of plasmid.

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Nowadays luminescent semiconductor quantum dots (QDs) are widely applied in different areas due to their unique optical properties. QDs can be used as photoluminescent labels with excellent possibilities for high-throughput detection and diagnostics. For most of such applications QDs must be coupled to biomolecules, which often represents a fundamental challenge. Although QDs have a lot of advantages over organic dyes, most of the techniques that have been developed for QD functionalization and bioconjugation, are more complicated than the corresponding techniques for organic fluorescent dyes. Here, the importance of choosing a suitable bioconjugation strategy in different applications, such as imaging and assays is described. The main goal of this review is to give a structured and detailed overview and comparison of the most widely used conjugation strategies in function of the active groups (carboxyl, amine, thiol, epoxy, hydroxyl and aldehyde groups) present on QD surface.

Toxin expression is of utmost importance for the food-borne pathogen B. cereus, both in food poisoning and non-gastrointestinal host infections as well as in interbacterial competition. Therefore it is no surprise that the toxin gene expression is tightly regulated by various internal and environmental signals. An overview of the current knowledge regarding emetic and diarrheal toxin transcription and expression is presented in this review. The food safety aspects and management tools such as temperature control, food preservatives and modified atmosphere packaging are discussed specifically for B. cereus emetic and diarrheal toxin production.

(word count = 400)In January 2011, a workshop was organized by the EU FP7 Veg-i-Trade project to capture opinions of stakeholders on food safety issues in the global fresh produce supply chain. Food safety experts from various stakeholder types in the farm-to-fork chain were represented: farmer related organizations (n=6), fresh produce processing and trading companies (n=17), retail (n=3), consumer organizations (n=2), competent authorities (n=7) and lastly research institutes and universities (n=19). The experts were grouped in nine discussion groups per type of stakeholder and asked to rank food safety issues via a scoring approach according to perceived importance from their stakeholder type point of view. Also information sources for opinion making, appropriate food safety control measures and perceived contextual factors increasingly challenging governance of food safety in fresh produce were ranked according to perceived importance. Although some differences were noted between opinions of the different stakeholders, there was in general an agreement on the main priorities in food safety of fresh produce. Bacterial pathogens were overall considered to be the most important food safety issue for fresh produce, followed by foodborne viruses, pesticide residues and mycotoxins. Alert systems such as the European Commission"s Rapid Alert System for Food and Feed (RASFF) were considered as the most important source of information of food safety issues, followed by reports of international organizations (e.g. WHO, EFSA), legislative documents (e.g. EU legislation), national reports (e.g. on monitoring hazards, foodborne outbreaks) and exchange of information between people (informal contacts).Concerning the control measures, the application of good agricultural practices (GAP) was identified to be the most important control measure to assure the safety of fresh produce, followed by the application of good hygienic practices (GHP) and the certification of food safety management systems (FSMS). Increasing international trade and globalization were overall expected to have a large impact on food safety in fresh produce. Other contextual 3 factors perceived to be important were the food safety policies by governments and the (lack of) food safety knowledge by consumers and other stakeholders of the fresh produce supply chain. Although the various stakeholder groups may conceive issues differently from their proper position in the fresh produce supply chain, no deep disagreements emerged. This type of workshop enhances interaction and communication between stakeholders and contributes to a better understanding of each other"s concerns, constraints and motivating interests to deal with the food safety of the increasingly complex and globalized fresh produce supply chain. Key wordsdiscussion group, fresh produce, food safety issue, control measures, contextual factors, information source 4 IntroductionFresh produce is an important part of a healthy diet. Its consumption is known to have a protective health effe...

With an average annual production of 6.9 M tonnes and 2.5 M tonnes of maize and wheat respectively, Serbia is one of the main grain producers and exporters in Europe. Cereals are also the major staple food in Serbian diet. In view of the high cereal consumption, for human and animal nutrition, the presence of mycotoxins entails a high public health risk of chronic exposure to mycotoxins. This study provides an overview of the incidence of predominant mycotoxins, mainly in cereal and dairy products, in Serbia, in the 2004–2016, using data reported in the scientific literature. The study demonstrated that the total prevalence of aflatoxins was 62.9% (n = 12,517) with 26.2% of the samples exceeding the EU limits during this period. Results obtained for T-2/HT-2 (n = 523), deoxynivalenol (n = 2907), fumonisins (n = 998), zearalenone (n = 689) and ochratoxin A (n = 740) indicated the prevalence of 45.5%, 42.9%, 63.3%, 39.3% and 28.1%, respectively. For these mycotoxins, the EU limits were less frequently exceeded. Comprehensive collection and analysis of all accessible information reviewed in this paper showed moderate incidence and prevalence of mycotoxins in Serbia, with an exception of the 2012 drought year and the 2014 flood year.

Dried fruits, vegetables, herbs, and spices are produced in and sourced from many countries worldwide, but they have been increasingly reported to be involved in outbreaks and alerts due to the presence of foodborne pathogens such as Salmonella. These dried products are mainly produced by solar drying and conventional air drying, but a wide range of drying technologies are available. From a technological point of view the general trend is to optimize and standardize the drying process to ensure high-quality products to be offered. Drying technologies are mainly evaluated for their performance to reduce water activity at low energy cost while maintaining good sensorial quality of the dried product. However, as low water activity foods are increasingly recognized to support microbial survival and dried products are often consumed as they are, or are used as ingredients in many ready-to-eat foods, there is increasing attention to the microbiological quality and safety aspects of these products. This review presents traditional and emerging technologies to dry fruits, vegetables, herbs, and spices and discusses their potential to inactivate bacteria and viruses throughout the drying process. Overall, the microbial inactivation effect of the presented technologies has not yet been thoroughly assessed, even for traditional methods like solar drying, conventional air drying, or freeze-drying. Emerging technologies such as dielectric (assisted) drying and low-pressure superheated steam drying have been shown to reduce microbial populations; however, the number of studies is still low. Very few studies have focused on viral inactivation during drying processes.