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

Anja Müller,Corinna Kehrenberg,Nils Th Grabowski,Wiebke Jansen

doi:10.1186/s13099-018-0268-3

Anja Müller, Corinna Kehrenberg + Show 2 more

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https://doi.org/10.1186/s13099-018-0268-3

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Abstract

BackgroundFood products of animal origin brought into the EU from third countries, both legally and illegally, can harbor foodborne pathogens such as Salmonella enterica. In this study, we examined five S. enterica 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.ResultsThe three isolates from legal imports were identified as S. Heidelberg or as non-flagellated. All three isolates were identified as AmpC producers carrying blaCMY-2 and as non-susceptible to ciprofloxacin. They were additionally resistant to tetracycline and sulfamethoxazole. The blaCMY-2-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 S. Weltevreden isolate was fully susceptible to all agents tested.ConclusionThe results of this study demonstrate that meat products imported from third countries, both legally and illegally, can harbor multiresistant Salmonella enterica. Consequently, these imports could constitute a source for the dissemination of antimicrobial resistant isolates, including those resistant to third-generation cephalosporins and fluoroquinolones.

Highlights

Food products of animal origin brought into the European Union (EU) from third countries, both legally and illegally, can harbor foodborne pathogens such as Salmonella enterica
For 2016, the European Food and Safety Authority (EFSA) reported over 94,000 confirmed cases of human salmonellosis in the European Union (EU) and S. enterica was identified as the bacterial agent responsible for the most foodborne outbreaks [1]
They were collected in the years 2014 and 2015, in the course of a previous study (Project “ZooGloW”) investigating meat and meat products imported into the European Union both legally and illegally

Summary

Introduction

Food products of animal origin brought into the EU from third countries, both legally and illegally, can harbor foodborne pathogens such as Salmonella enterica. Salmonella (S.) enterica is one of the most common bacterial pathogens causing foodborne infections and, constitutes a major healthcare concern worldwide. Poultry meat constitutes an important source of Salmonella enterica and infections in humans are often linked to the consumption of improperly cooked poultry meat or a cross-contamination of other foodstuffs [1]. Previous reports of salmonellosis outbreaks involving multiple countries have raised concerns about the role of international food and animal trade in the spread of Salmonella serovars, especially considering the comparatively high rates of Salmonella detection in some parts of the world [6]. Imported meat products have been implicated as a possible source for S. enterica isolates resistant to clinically relevant antimicrobials [7, 8]

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