Our data underscore the diversity of ESBL genes in Salmonella enterica isolated from animals, food products and human patients.

This is the first study among a large collection of Dutch companion animals and horses characterizing ESBL/AmpC-producing isolates. A similarity in resistance genes and E. coli STs among these isolates and isolates from Dutch poultry and humans may suggest exchange of resistance between different reservoirs.

No abstract

Multiple events of mobilization, transposition and replicon fusion generate the complexity observed in qnr-positive isolates that are emerging worldwide. Despite the fact that the occurrence of qnr genes in bacteria from animals is scarcely reported, these genes are associated with genetic elements and located on plasmids that are recurrent in animal isolates.

VetCAST is the EUCAST sub-committee for Veterinary Antimicrobial Susceptibility Testing. Its remit is to define clinical breakpoints (CBPs) for antimicrobial drugs (AMDs) used in veterinary medicine in Europe. This position paper outlines the procedures and reviews scientific options to solve challenges for the determination of specific CBPs for animal species, drug substances and disease conditions. VetCAST will adopt EUCAST approaches: the initial step will be data assessment; then procedures for decisions on the CBP; and finally the release of recommendations for CBP implementation. The principal challenges anticipated by VetCAST are those associated with the differing modalities of AMD administration, including mass medication, specific long-acting product formulations or local administration. Specific challenges comprise mastitis treatment in dairy cattle, the range of species and within species breed considerations and several other variable factors not relevant to human medicine. Each CBP will be based on consideration of: (i) an epidemiological cut-off value (ECOFF) – the highest MIC that defines the upper end of the wild-type MIC distribution; (ii) a PK/PD breakpoint obtained from pre-clinical pharmacokinetic data [this PK/PD break-point is the highest possible MIC for which a given percentage of animals in the target population achieves a critical value for the selected PK/PD index (fAUC/MIC or fT > MIC)] and (iii) when possible, a clinical cut-off, that is the relationship between MIC and clinical cure. For the latter, VetCAST acknowledges the paucity of such data in veterinary medicine. When a CBP cannot be established, VetCAST will recommend use of ECOFF as surrogate. For decision steps, VetCAST will follow EUCAST procedures involving transparency, consensus and independence. VetCAST will ensure freely available dissemination of information, concerning standards, guidelines, ECOFF, PK/PD breakpoints, CBPs and other relevant information for AST implementation. Finally, after establishing a CBP, VetCAST will promulgate expert comments and/or recommendations associated with CBPs to facilitate their sound implementation in a clinical setting.

Our 'One Health' approach provides an integrated evaluation of the molecular relatedness of ESBL/AmpC-EC from numerous sources. The analysis showed distinguishable ESBL/AmpC-EC transmission cycles in different hosts and failed to demonstrate a close epidemiological linkage of ESBL/AmpC genes and plasmid replicon types between livestock farms and people in the general population.

This study shows the occurrence and dissemination of PMQR genes in Salmonella and E. coli in Europe with a defined quinolone resistance phenotype. We also report the first detection of qnrD in Salmonella collected in Europe.

Please cite this article as: Cavaco, L.M., Hasman, H., Aarestrup, F.M., on behalf of the MRSA collaborating group (MRSA-CG), Zinc resistance of Staphylococcus aureus of animal origin is strongly associated with methicillin resistance, Veterinary Microbiology (2010Microbiology ( ), doi:10.1016Microbiology ( /j.vetmic.2011 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The test population consisted of 476 porcine MRSA isolates from ten European 30 countries, 18 porcine MRSA isolates from Canada and seven MRSA from China, 92 31 MRSA and 60 methicillin-susceptible S. aureus (MSSA) isolates from veal calves in the 32Netherlands and 88 porcine MSSA isolates from four European countries. Most porcine 33 MRSA (n=454) and all bovine MRSA belonged to clonal complex (CC) 398 whereas 37 34 of the pig MRSA from Europe and the seven Chinese isolates belonged to other CCs 35 and 3 isolates were not classified into a CC. 36All isolates were tested for susceptibility to zinc chloride and copper sulphate using 37 agar dilution and tested by PCR for the czrC gene encoding zinc resistance. 38Phenotypic zinc resistance (MIC>2mM) was observed in 74% (n=324) and 42% (n=39) 39 of European MRSA CC398 from pigs and veal calves respectively, and in 44% of the 40 Canadian isolates (n=8), but not among the Chinese isolates. Almost all (99%) zinc-41 resistant MRSA carried czrC. Of the 37 European non-CC398 MRSA, 62% were 42 resistant to zinc, but only 46% of them carried czrC,. The MICs of the MSSA isolates to 43 zinc chloride ranged from 1 to 4 mM and none carried czrC. The MICs of copper 44 sulphate were neither associated with methicillin resistance nor with the detection of 45 czrC. 46This study showed that zinc resistance and the czrC gene is widespread among 47 CC398 MRSA isolates. This suggests that the use of zinc in feed might have 48 contributed to the emergence of MRSA. 49 50