Antimicrobial resistance in bacteria is a global health threat to human and veterinary medicine, with a rapid emergence and expansion worldwide.1,4 Wildlife species can play an important role as reservoirs for these organisms3, posing a hazard to humans and domestic animals regarding direct or environmental transmission of antimicrobial resistant bacteria or resistance determinants2. Up to now, a total of 117 rectal/cloacal and faecal swabs were collected from different sea fish, sea birds and marine mammals of the North and Baltic Sea of Schleswig-Holstein, Germany. The collected swabs were incubated in Mossel bouillon and the suspensions were then streaked on antibiotic containing MacConkey agar plates. Tested antibiotics include ampicillin (30 mg/L), cephalothin (30 mg/L), chloramphenicol (10 mg/L), ciprofloxacin (1 mg/L), colistin (2 mg/L), gentamicin (10 mg/L), sulfamethoxazole (512 mg/L), and tetracycline (15 mg/L). Preliminary results show a high occurrence of antibiotic resistant Enterobacteriaceae. Of 101 incubated swabs 85 (84%) originated bacterial growth on one or more antibiotic containing MacConkey agar plates (data as of March 21st, 2018). These high resistance results were unexpected, and confirmation studies are undergoing as well as the characterization of the isolates via PCR or MALDI-TOF. Up to now, 53 isolates were identified as E. coli. Further investigations will look into their antimicrobial resistance profiles and virulence factors. Besides evaluating the occurrence of antimicrobial resistant E. coli in different levels of the marine food chain, we will possibly elucidate differences regarding antimicrobial resistance prevalence and profiles according to different aquatic systems (North and Baltic Sea).
The authors would like to thank Martin Altemüller, NABU Waterfowl Reserve Wallnau, Nils Kobarg and Uwe Schwippert, Förderverein Integrierte Station Geltinger Birk, Thomas Diedrichsen, Sönke Lorenzen, Andreas Milde and Eckhardt Kasten, Stranding network of Schleswig-Holstein, Thomas Lang and his colleagues, Thünen Institute of Fisheries Ecology, Abbo van Neer, Jan Lakemeyer, Katharina Gonnsen, ITAW, for their support in collecting faecal and rectal swabs and Iris Oltrogge, LMQS, for her excellent technical assistance.
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