Highly ciprofloxacin resistant Salmonella enterica serovar Kentucky isolates of human and animal origin in Germany

National Salmonella surveillance in France, England, Wales, Denmark and the USA recorded in recent years about 500 human infections caused by multidrug-resistant Salmonella enterica Serovar ( S .) Kentucky isolates displaying high-level resistance to fluoroquinolones (ciprofloxacin, MIC > or = 4 mg/l), which were referred to clone ST198-X1. To determine whether this clone is also present in German S. Kentucky isolates, the National Reference Laboratory for Salmonella (NRL-Salm) at the Federal Institute for Risk Assessment (BfR) analyzed the trend of S . Kentucky isolates received over the past years. Since 2010 the first submissions of highly ciprofloxacin resistant S. Kentucky isolates, especially from turkey meat products, were recorded. Thirty-two isolates originating from animal, food and non-human sources, and in addition 30 human isolates from the National Reference Centre of Salmonella and other enterics at the Robert Koch Institute (RKI) with MIC values of > or = 8 mg/l to ciprofloxacin were analysed. Molecular biological typing methods showed most of the German S. Kentucky isolates were identical to the clone described by Le Hello et al. (2011) and carried a multidrug resistance encoding region (SGI1). Since WHO considers fluoroquinolones to be drugs of critical importance in human and veterinary medicine, the spread of ST198-X1 S . Kentucky demands special attention. The implementation of mitigation strategies for this highly resistant clone seems to be urgently required.