VanA-type human (n ‫؍‬ 69), animal (n ‫؍‬ 49), and food (n ‫؍‬ 36) glycopeptide-resistant enterococci (GRE) from different geographic areas were investigated to study their possible reservoirs and transmission routes. Pulsed-field gel electrophoresis (PFGE) revealed two small genetically related clusters, M39 (n ‫؍‬ 4) and M49 (n ‫؍‬ 13), representing Enterococcus faecium isolates from animal and human feces and from clinical and fecal human samples. Multilocus sequence typing showed that both belonged to the epidemic lineage of CC17. purK allele analysis of 28 selected isolates revealed that type 1 was prevalent in human strains (8/11) and types 6 and 3 (14/15) were prevalent in poultry (animals and meat). One hundred and five of the 154 VanA GRE isolates, encompassing different species, origins, and PFGE types, were examined for Tn1546 type and location (plasmid or chromosome) and the incidence of virulence determinants. Hybridization of S1-and I-CeuI-digested total DNA revealed a plasmid location in 98% of the isolates. Human intestinal and animal E. faecium isolates bore large (>150 kb) vanA plasmids. Results of PCR-restriction fragment length polymorphism and sequencing showed the presence of prototype Tn1546 in 80% of strains and the G-to-T mutation at position 8234 in three human intestinal and two pork E. faecium isolates. There were no significant associations (P > 0.5) between Tn1546 type and GRE source or enterococcal species. Virulence determinants were detected in all reservoirs but were significantly more frequent (P < 0.02) among clinical strains. Multiple determinants were found in clinical and meat Enterococcus faecalis isolates. The presence of indistinguishable vanA elements (mostly plasmid borne) and virulence determinants in different species and PFGE-diverse populations in the presence of host-specific purK housekeeping genes suggested that all GRE might be potential reservoirs of resistance determinants and virulence traits transferable to human-adapted clusters.

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BackgroundSafety assessment of genetically modified organisms is currently often performed by comparative evaluation. However, natural variation of plant characteristics between commercial varieties is usually not considered explicitly in the statistical computations underlying the assessment.ResultsStatistical methods are described for the assessment of the difference between a genetically modified (GM) plant variety and a conventional non-GM counterpart, and for the assessment of the equivalence between the GM variety and a group of reference plant varieties which have a history of safe use. It is proposed to present the results of both difference and equivalence testing for all relevant plant characteristics simultaneously in one or a few graphs, as an aid for further interpretation in safety assessment. A procedure is suggested to derive equivalence limits from the observed results for the reference plant varieties using a specific implementation of the linear mixed model. Three different equivalence tests are defined to classify any result in one of four equivalence classes. The performance of the proposed methods is investigated by a simulation study, and the methods are illustrated on compositional data from a field study on maize grain.ConclusionsA clear distinction of practical relevance is shown between difference and equivalence testing. The proposed tests are shown to have appropriate performance characteristics by simulation, and the proposed simultaneous graphical representation of results was found to be helpful for the interpretation of results from a practical field trial data set.

EFSA carries out the risk assessment of genetically modified organisms (GMOs) submitted under Regulation (EC) 1829/2003 and Regulation (EU) 503/2013. Dietary exposure is an essential element of the risk assessment on genetically modified (GM) foods. Dietary exposure estimations should cover average and high consumers across all the different age classes and special population groups and identify and consider particular consumer groups with expected higher exposure. This EFSA statement provides guidance on how human dietary exposure to newly expressed proteins in GM foods should be estimated using a deterministic model that makes use of the available information. Summary statistics of consumption of foods containing, consisting of and produced from crops relevant for the assessment of GMO applications are available in the EFSA website together with different factors to convert the reported consumption of processed foods into raw primary commodities. Guidance is also provided on how concentration data of newly expressed proteins, typically determined in raw primary commodities, should be used (materials to be analysed, growth stage, descriptive statistics to be used, etc.). An overview of the different uncertainties linked to the dietary exposure estimations is provided, informing on the strengths and limitations of the assessment. The document also describes the information applicants need to provide on human dietary exposure to allow EFSA doing an appropriate evaluation of the assessment provided as part of the application dossiers.

Genetically modified organisms (GMOs) and derived food and feed products are subject to a risk analysis and regulatory approval before they can enter the market in the European Union (EU). In this risk analysis process, the role of the European Food Safety Authority (EFSA), which was created in 2002 in response to multiple food crises, is to independently assess and provide scientific advice to risk managers on any possible risks that the use of GMOs may pose to human and animal health and the environment. EFSA's scientific advice is elaborated by its GMO Panel with the scientific support of several working groups and EFSA's GMO Unit. This review presents EFSA's scientific activities and highlights its achievements on the risk assessment of GMOs for the first 10 years of its existence. Since 2002, EFSA has issued 69 scientific opinions on genetically modified (GM) plant market registration applications, of which 62 for import and processing for food and feed uses, six for cultivation and one for the use of pollen (as or in food), and 19 scientific opinions on applications for marketing products made with GM microorganisms. Several guidelines for the risk assessment of GM plants, GM microorganisms and GM animals, as well as on specific issues such as post-market environmental monitoring (PMEM) were elaborated. EFSA also provided scientific advice upon request of the European Commission on safeguard clause and emergency measures invoked by EU Member States, annual PMEM reports, the potential risks of new biotechnology-based plant breeding techniques, evaluations of previously assessed GMOs in the light of new scientific publications, and the use of antibiotic resistance marker genes in GM plants. Future challenges relevant to the risk assessment of GMOs are discussed. EFSA's risk assessments of GMO applications ensure that data are analysed and presented in a way that facilitates scientifically sound decisions that protect human and animal health and the environment.

to allow cultivation of hemp varieties with a ⌬ 9 -THC content below 0.3%. By 1998 hemp was reintroducedThe objective was to study the genetic structure and degree of in practically all of Europe (Bó csa and Karus, 1998), variability of hemp (Cannabis sativa L.) varieties. Six varieties of hemp were analyzed by random amplified polymorphic DNA though in some countries significant resources are still (RAPD) analysis, using 10 plants per variety. The varieties were a being employed to prevent hemp diffusion regardless dioecious landrace, a dioecious selection from it, a cross-bred cultivar, of its ⌬ 9 -THC content (Linacre and Thorpe, 1998). a monoecious variety, a drug strain, and an inbred female line. The Because of the continuous variation of most morphogenetic complexity of each cultivar was investigated by determining logical and biochemical traits within the Cannabis genus, the number of bands produced by the primers used, the number of it would be useful to identify groups on the basis of fixed and polymorphic loci, the average allele frequency, and the their use or origin. A nonbiosystematic classification heterozygosity. A good correlation was found between these paramedistinguishes wild populations from fiber landraces, culters and the genetic origin and breeding strategy of each variety. The tivars, drug strains, and ornamentals (de Meijer, 1995). average polymorphism over all varieties and loci was 97.1%; the single Hemp cultivars are characterized by different degrees cultivar polymorphism ranged from 31.1 to 85.5%. Heterozygosity ranged from 0.05 (inbred female line) to 0.26 (cross-bred Fibranova). of genetic variability because of commercial value, re-The average heterozygosity calculated over all 102 loci and all plants productive biology (dioecious or monoecious), end use, studied was 0.29. The Fst (Wright's fixation index) value calculated and different criteria employed in breeding. for all loci was 0.48, and only 33.3% of the scored loci had higher Dioecious cultivars (e.g., Italian fiber varieties) are values and can be considered informative for cultivar identification. obligate outbred, and the method used to multiply them A Fisher's test based on allele frequencies suggested complete differ-(open-field pollination) approaches a random-mating entiation among all varieties, with the exception of the Italian dioecondition. This is also true for monoecious cultivars, cious varieties Carmagnola and CS, for which no discriminating alleles which are composed of about 50 to 70% monoecious were found. The correlations among the molecular data and the geplants and 30 to 50% female plants, with a small number netic structure of the different cultivars and the consequences in of male plants. The original monoecious trait occurred relation to variety discrimination in hemp are discussed.spontaneously in material from central Russia (de Meijer, 1995) and the presence of male plants in a monoecious stand must be limited to avoid reversion to the Istituto Sperimentale per le Colture Industriali, Via di C...

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The RD2 region of the internalization-associated gene prtF1, which encodes the fibronectin-binding repeat domain type 2 of protein F1, plays a crucial role in the entry of group A streptococci (GAS) into epithelial cells. A molecular study of the variability of the RD2 region was carried out with 77 independent Italian GAS, 66 erythromycin resistant (ER) and 11 erythromycin susceptible (ES), which had previously been investigated for the association between erythromycin resistance and ability to enter human respiratory cells. The amplicons obtained from PCR analysis of the RD2 region were consistent with a number of RD2 repeats ranging from one to five, more frequently four (n ‫؍‬ 30), three (n ‫؍‬ 27), and one (n ‫؍‬ 18). A new method to type cell-invasive GAS (RD2 typing) was developed by combining PCR analysis of the RD2 region and restriction analysis of PCR products with endonucleases HaeIII, DdeI, and HinfI. Overall, 10 RD2 types (a to j) were distinguished (all detected among the 66 ER isolates, four detected among the 11 ES isolates). Comparison and correlation of RD2 typing data with the genotype and phenotype of macrolide resistance and with data from PCR M typing and SmaI macrorestriction analysis allowed us to identify 41 different clones (31 among the 66 ER isolates and 10 among the 11 ES isolates). Three major clones accounted for 40% of the isolates (47% of ER strains). Some ES isolates appeared to be related to ER isolates with identical combinations of RD2 type and emm type. While simultaneous use of different typing methods is essential for a thorough investigation of GAS epidemiology, RD2 typing may be especially helpful in typing cell-invasive GAS.