Contamination Pathways can Be Traced along the Poultry Processing Chain by Whole Genome Sequencing of Listeria innocua

Microorganisms, vol. 8, pp. 414

Abstract

Foodborne infection with Listeria causes potentially life-threatening disease listeriosis. Listeria monocytogenes is widely recognized as the only species of public health concern, and the closely related species Listeria innocua is commonly used by the food industry as an indicator to identify environmental conditions that allow for presence, growth, and persistence of Listeria spp. in general. In our study, we analyze the occurrence of Listeria spp. in a farm-to-fork approach in a poultry production chain in Egypt and identify bacterial entry gates and transmission systems. Prevalence of Listeria innocua at the three production stages (farm, slaughterhouse, food products) ranged from 11% to 28%. The pathogenic species Listeria monocytogenes was not detected, and Listeria innocua strains under study did not show genetic virulence determinants. However, the close genetic relatedness of Listeria innocua isolates (maximum 63 SNP differences) indicated cross-contamination between all stages from farm to final food product. Based on these results, chicken can be seen as a natural source of Listeria. Last but not least, sanitary measures during production should be reassessed to prevent bacterial contamination from entering the food chain and to consequently prevent human listeriosis infections. For this purpose, surveillance must not be restricted to pathogenic species.

Authors 8

1. Mayada Gwida

   Mansoura University

   Affiliation as printed

   Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

2. Stefanie Lüth corresponding

   Federal Institute for Risk Assessment · Freie Universität Berlin

   Affiliation as printed

   Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany

   Institute for Biology, Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany

3. Maged R. El-Ashker

   Mansoura University

   Affiliation as printed

   Department of Internal Medicine, Infectious and Fish Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

4. Amira Ibrahim Zakaria

   Mansoura University

   Affiliation as printed

   Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

5. Fatma A. El-Gohary

   Mansoura University

   Affiliation as printed

   Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

6. Mona Elsayed

   Mansoura University

   Affiliation as printed

   Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt

7. Sylvia Kleta

   Federal Institute for Risk Assessment

   Affiliation as printed

   Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany

8. Sascha Al Dahouk Aachen

   Federal Institute for Risk Assessment · Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany

   RWTH Aachen University Hospital, Pauwelsstraße 30, 52074 Aachen, Germany