Characterization of serovars recovered from meat products legally and illegally imported into the EU reveals the presence of multiresistant and AmpC-producing isolates.

BACKGROUND

Food products of animal origin brought into the EU from third countries, both legally and illegally, can harbor foodborne pathogens such as . In this study, we examined five isolates recovered either from legally imported chicken meat (n = 3) or from meat products confiscated from air travel passengers arriving in Germany (n = 2). The isolates were serotyped and further characterized by antimicrobial susceptibility testing, PCR-detection and sequencing of genes associated with antimicrobial resistances, and macrorestriction analysis. Transferability of resistance to third-generation cephalosporins was assessed by conjugation experiments and the plasmids tested for their incompatibility groups.

RESULTS

The three isolates from legal imports were identified as . Heidelberg or as non-flagellated. All three isolates were identified as AmpC producers carrying and as non-susceptible to ciprofloxacin. They were additionally resistant to tetracycline and sulfamethoxazole. The -carrying plasmids were transferable by conjugation and belonged to incompatibility groups IncI1 or IncA/C. The two isolates from illegally imported meat belonged to the serovars Infantis or Weltevreden. The former was phenotypically resistant to five classes of antimicrobial agents while the . Weltevreden isolate was fully susceptible to all agents tested.

CONCLUSION

The results of this study demonstrate that meat products imported from third countries, both legally and illegally, can harbor multiresistant . Consequently, these imports could constitute a source for the dissemination of antimicrobial resistant isolates, including those resistant to third-generation cephalosporins and fluoroquinolones.