Publikationsdatenbank

Prevalence of Yersinia enterocolitica in retail seafood and the isolate specific cold response in transcriptional, proteomic, and membrane physiological changes (2020)

Art

Hochschulschrift

Autor

Li, Chenyang (WE 8)

Quelle

Berlin: Mensch und Buch Verlag Berlin, 2020 — V, 83 Seiten

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/28203

Kontakt

Institut für Lebensmittelsicherheit und -hygiene

Königsweg 69
14163 Berlin
+49 30 838 62551 / 52790
lebensmittelhygiene@vetmed.fu-berlin.de / fleischhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The first part of the thesis determined the prevalence of Y. enterocolitica in seafood. The presumptive Y. enterocolitica isolates were analyzed by biotyping, serotyping and antimicrobial susceptibility testing. The total prevalence of Y. enterocolitica in seafood samples was 2.7% (6/220). All isolates belonged to biotype 1A and three isolates were identified as serotype O:8, one isolate as O:5,27, while two samples did not belong to the investigated serotypes. Most isolates contained the virulence-associated genes ail, inv and ystB and the isolates were resistant to cephalothin (83.3%), amoxicillin (83.3%) and ampicillin (50.0%). The results indicate that seafood might be a potential source of infection by Y. enterocolitica. Since Y. enterocolitica (as psychrotrophic bacterium) is able to multiply at low temperatures, information about the underlying mechanisms is needed. However, information about Y. enterocolitica cold response is still scarce. In this study, strain specific growth profiles at 4°C were found and the cold response was investigated by combining phenotypic, gene expressional and proteomic approaches. The expressional changes of the cold-response genes showed that the ability to survive under cold stress depends on the transient induction and effective repression of cold-shock genes and the resumption of gene expression in other non-cold shock genes. Global proteomic analysis with label free quantification was firstly used in Y. enterocolitica cold response to indicate general cold response and resistance mechanism. Additionally, the isolate specific differences at transcriptional levels in motility- and fluidity- related genes contribute to our understanding of cold response regulated by motility and fluidity in Y. enterocolitica. By combining different approaches, cold response was described systematically, providing a better understanding of the physiological processes of Y. enterocolitica in response to cold stress.