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

Multidrug resistant (MDR) Salmonella (S.) isolates constitute a growing threat to human health as they are an increasing source for human infections and outbreaks (Alcaine et al., 2007). Food producing animals are one of the main reservoirs for non-typhoid MDR Salmonella. These pathogens are mainly transmitted by the consumption of contaminated food products (Cray et al.,2000; Pires et al., 2009). Multidrug resistance to clinically important antimicrobials, in particular to fluoroquinolones like ciprofloxacin (CIP), may disable therapies for patients with systemic course of disease or risk disposal (Anonymous, 2007). The occurrence of S. Kentucky in humans was only rarely observed in the EU and has been normally linked to foreign travel (Weill et al., 2006; Collard et al., 2007). According to the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC) in 2009 S. Kentucky was for the first time reported among the ten most frequent serovars causing human salmonellosis (EFSA and ECDC, 2011). In recent years national surveillance systems in France, England, Wales, Denmark and the USA registered an increased occurrence of MDR S. Kentucky displaying high-Level resistance to fluoroquinolones (CIP, MIC > or = 4 mg/l). These isolates were ascribed to clone ST198-X1, which caused between 2000 and 2008 in the countries mentioned above around 500 human infections and was presumably transferred by poultry (Le Hello et al., 2011). To determine whether this clone is also present in Germany in non-human sources, the National Reference Laboratory for Salmonella (NRL-Salm) at the Federal Institute for Risk Assessment (BfR) analysed the trend of S. Kentucky isolates received over the past years. Human isolates collected within the same period were also included in the study for comparison purposes.