Azithromycin resistance in Escherichia coli and Salmonella from food-producing animals and meat in Europe.

Objectives: To characterize the genetic basis of azithromycin resistance in Escherichia coli and Salmonella collected within the EU harmonized antimicrobial resistance (AMR) surveillance programme in 2014-18 and the Danish AMR surveillance programme in 2016-19.

Methods: WGS data of 1007 E. coli [165 azithromycin resistant (MIC > 16 mg/L)] and 269 Salmonella [29 azithromycin resistant (MIC > 16 mg/L)] were screened for acquired macrolide resistance genes and mutations in rplDV, 23S rRNA and acrB genes using ResFinder v4.

Multiplex PCR for detection of plasmid-mediated colistin resistance determinants, and for surveillance purposes.

Background and aimPlasmid-mediated colistin resistance mechanisms have been identified worldwide in the past years. A multiplex polymerase chain reaction (PCR) protocol for detection of all currently known transferable colistin resistance genes ( to , and variants) in was developed for surveillance or research purposes. We designed four new primer pairs to amplify , , and gene products and used the originally described primers for to obtain a stepwise separation of ca 200 bp between amplicons.

International collaborative study on the occurrence of plasmid-mediated quinolone resistance in Salmonella enterica and Escherichia coli isolated from animals, humans, food and the environment in 13 European countries.

Objectives: This study was initiated to collect retrospective information on the occurrence of plasmid-mediated quinolone resistance (PMQR) in Salmonella enterica and Escherichia coli isolates in Europe and to identify the responsible genes.

Methods: Databases of national reference laboratories containing MIC values for Salmonella and E. coli isolated between 1994 and 2009 in animals, humans, food and the environment from 13 European countries were screened for isolates exhibiting a defined quinolone resistance phenotype, i.