The Response to Oxidative Stress in Listeria monocytogenes Is Temperature Dependent

Publikationen als Autor:in / Herausgeber:in der Vetmeduni

Wagner, Martin; Stessl, Beatrix

Abstrakt

The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood company) and sample types (floor, wall, drain, boxes, food products and water machine). Isolates were exposed to two oxidizing agents: 13.8 mM cumene hydroperoxide (CHP) and 100 mM hydrogen peroxide (H2O2) at 10 degrees C and 37 degrees C. Temperature affected the oxidative stress response as cells treated at 10 degrees C survived better than those treated at 37 degrees C. H2O2 at 37 degrees C was the condition tested resulting in poorest L. monocytogenes survival. Strains belonging to STs of Lineage I (ST5, ST6, ST87, ST1) were more resistant to oxidative stress than those of Lineage II (ST7, ST9, ST199 and ST321), with the exception of ST7 that showed tolerance to H2O2 at 10 degrees C. Isolates of each ST5 and ST9 from different food industry origins showed differences in oxidative stress response. The gene expression of two relevant virulence (hly) and stress (clpC) genes was studied in representative isolates in the stressful conditions. hly and clpC were upregulated during oxidative stress at low temperature. Our results indicate that conditions prevalent in food industries may allow L. monocytogenes to develop survival strategies: these include activating molecular mechanisms based on cross protection that can promote virulence, possibly increasing the risk of virulent strains persisting in food processing plants.

Dokumententyp

Originalarbeit

Open Access Type

Gold

WoS ID

WOS:000533510400096

Projekt

Protection of consumers by microbial risk mitigation through combating segregation of expertise