ORIGINAL ARTICLE Outbreak of Cronobacter turicensis in European brown hares (Lepus europaeus) Annika Posautz 1 , Michael P. Szostak 1 , Adriana Cabal Rosel 2 , Franz Allerberger 2 , Anna St € oger 2 , Gerhard Rab 3,4 , Andrea T. Feßler 5,6 , Joachim Spergser 1 , Anna K€ ubber-Heiss 1 , Stefan Schwarz 5,6 , Stephen J. Forsythe 7 , Werner Ruppitsch 2 and Igor Loncaric 1 1 University of Veterinary Medicine, Vienna, Austria 2 Austrian Agency for Health and Food Safety, Vienna, Austria 3 Institute of Hydraulic Engineering and Water Resources Management, University of Technology Vienna, Austria 4 Institute for Land and Water Management Research, Federal Agency for Water Management, Petzenkirchen, Austria 5 Freie Universit€ at Berlin, Berlin, Germany 6 Department of Veterinary Medicine, Veterinary Centre for Resistance Research (TZR), Freie Universit€ at Berlin, Berlin, Germany 7 Foodmicrobe.com, Keyworth, Nottingham, UK Significance and Impact of the Study: The present study demonstrates that C. turicensis could be associ- ated with epidemiologically related typhlocolitis cases occurring in European brown hares in Austria. Due to the potential of this bacterium to inflict severe disease in humans, the risk of a spill over should be kept in mind, especially for those people in direct contact with hares, like hunters, farmers or veteri- narians. This also highlights the importance to investigate the role of wild animals as reservoirs of potentially pathogenic C. turicensis strains carrying mcr-like genes. Keywords antimicrobial resistance, colistin resistance, Cronobacter, European brown hare. Correspondence Annika Posautz, Research Institut of Willife Ecology, vetmeduni Vienna, Savoyenstr.1, 1160 Vienna, Austria. E-mail: annika.posautz@vetmeduni.ac.at 2022/0019: received 13 January 2022, revised 21 February 2022 and accepted 24 February 2022 doi:10.1111/lam.13685 Abstract This is the first report of acute deaths in five European brown hares (Lepus europaeus) attributed to mucoid and necrotizing typhlocolitis caused by genetically different Cronobacter (C.) turicensis strains in northeastern Austria. As this opportunistic pathogen is mainly known for causing disease in immunocompromised humans and neonates, this previously unrecognized potential for a spill over from a wildlife reservoir to humans warrants further attention. Introduction Cronobacter species are largely known as ubiquitous, opportunistic food-borne pathogens found in several types of food products, such as infant milk formula, wheat-based infant food, mincemeat, herbal tea and other dried food (Hochel et al. 2012; Yan and Fanning 2015; Forsythe 2018). They have also been isolated from soil, water, rats and insects (Gakuya et al. 2001; Kuzina et al. 2001; Hu et al. 2019). The genus Cronobacter belongs to the family Enterobacteriaceae and comprises currently seven species C. condimenti, C. dublinensis, C. malonaticus, C. muytjensii, C. sakazakii, C. turicensis and C. universalis (Iversen et al. 2008; Forsythe 2018). Of these, C. sakazakii and C. malonaticus have been the spe- cies implicated in most human clinical Cronobacter infec- tions (Iversen et al. 2008) causing severe symptomatology, like septicaemia, necrotizing enteritis and meningitis. The most severe life-threatening cases occur in neonates under 4 weeks of age (FAO/WHO 2008); however, immuno- compromised adults can also be infected (Tsai et al. 2013). In contrast to humans, clinical infections caused by members of the Cronobacter genus in animals have, to the authors’ knowledge, never been reported. Letters in Applied Microbiology 74, 1008--1015 © 2022 The Society for Applied Microbiology 1008 Letters in Applied Microbiology ISSN 0266-8254 Downloaded from https://academic.oup.com/lambio/article/74/6/1008/6989190 by guest on 19 January 2023