Short communication Prevalence of antibiotic-resistant enterobacteriaceae isolated from chicken and pork meat purchased at the slaughterhouse and at retail in Bavaria, Germany Karin Schwaiger a, ⁎, Sabine Huther a , Christina Hölzel a , Peter Kämpf b , Johann Bauer a a Chair of Animal Hygiene, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising-Weihenstephan, Germany b Bavarian Health and Food Safety Authority (LGL) Oberschleißheim, Veterinärstraße 2, 85764 Oberschleißheim, Germany abstract article info Article history: Received 13 July 2011 Received in revised form 9 November 2011 Accepted 11 December 2011 Available online 19 December 2011 Keywords: Chicken meat Pork meat Escherichia coli Coliforms Salmonella Antibiotic resistance The purpose of this study was to investigate chicken and pork meat sampled at the slaughterhouse and at retail for differences in the presence of antibiotic resistant Gram-negative bacteria. For this aim, Escherichia coli (n = 677), Enterobacter spp. (n = 167), Citrobacter spp. (n = 83), Serratia spp. (n = 116), Klebsiella spp. (n = 125), and Salmonella spp. (n = 89) were isolated from 500 chicken and 500 pork samples purchased at the slaughterhouse and at retail (in the same amounts) in Germany. Salmonella were present in 17% of the chicken, and in 0.4% of the pork meat samples. There was a clear shift in the spectrum of coliforms from slaughterhouse to retail: Enterobacter, Citrobacter and Klebsiella were the most frequently detected coliforms (other than E. coli) from slaughterhouse samples, whereas the prevalence of Serratia spp. was up to eight times higher in retail samples. The prevalence of E. coli was higher in slaughterhouse samples, where- as the prevalence of other coliforms and Salmonella spp. was higher in retail samples. E. coli strains were often resistant to penicillins, streptomycin, spectinomycin, doxycycline and sulfamethoxazole/trimethoprim. Resistance rates of the other coliforms were generally low. Resistant and multi-resistant isolates were signif- icantly more common in chicken meat. Compared to samples from the slaughterhouse, the prevalence of resistant bacteria tended to be higher in retail samples, probably due to good conditions for resistant bacteria on the matrix meat and/or due to secondary contamination with resistant strains. Therefore, stringent hygiene measures should be observed to reduce the risk of transmission of resistant bacteria from food to humans. © 2011 Elsevier B.V. All rights reserved. 1. Introduction The spread of antibiotic-resistant bacteria is an emerging world- wide problem that increasingly threatens the successful treatment of infectious diseases (Anderson, 2003). Excessive and incorrect use of antimicrobials in human and veterinary medicine, as well as their metaphylactic 1 application in livestock are considered to be key aspects of this current situation (Phillips et al., 2004). Pork and poul- try cover more than 80% of the per capita consumption of meat in Germany (ZMP, 2003). Moreover, about 80% of all antibiotics used in the livestock sector are applied to these two animal species (Schwarz and Chalsus-Dancla, 2001). Due to contamination, resistant bacteria can get to the meat, for example via smear infections with fecal bacteria, polluted spray water or due to poor production hygiene (Schlegelova et al., 2004). It is known that multi-resistant, obligate or facultative pathogenic bacteria occur in meat, and this has emerged as an important health concern (LeJeune and Christie, 2004; Miko et al., 2005). However, apart from the fact that data from Germany are rare, the comparison of results of different studies is often hampered by different methods. This is especially the problem when comparing multi-resistance (Hölzel et al., 2010). Using exactly the same method- ologies for all samples, the results are well comparable in the present study. Above all, it is not known where the entry of resistant bacteria is actually higher — directly at slaughter or subsequently along the pro- duction chain. Any knowledge about that might provide valuable information to reduce the sources of contamination with resistant bacteria during food processing and thus to minimize the risk for the consumer. Therefore, pork and chicken meat was sampled and International Journal of Food Microbiology 154 (2012) 206–211 ⁎ Corresponding author. Tel.: +49 81 61/71 33 14; fax: +49 81 61/71 45 16. E-mail addresses: Karin.Schwaiger@wzw.tum.de (K. Schwaiger), SabineHuther@web.de (S. Huther), Christina.Hoelzel@wzw.tum.de (C. Hölzel), peter.kaempf@lgl.bayern.de (P. Kämpf), Johann.Bauer@wzw.tum.de (J. Bauer). 1 Metaphylaxis is the timely mass medication of a group of animals to eliminate or minimize an expected outbreak of disease (Blood et al., 2007). 0168-1605/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ijfoodmicro.2011.12.014 Contents lists available at SciVerse ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro