Listeria monocytogenes has been found to withstand harsh environmental
conditions including desiccation. The pathogen is also known to form biofilm when in
co-culture with other bacteria found in food products. This study investigated the
desiccation survival of L. monocytogenes in mixed biofilms with Pseudomonas
fluorescens, Serratia liquefaciens and Shewanella putrefaciens. To this end, mono- or
binary species biofilms were formed and desiccated (43% relative humidity, 21 days at
15°C) on stainless steel coupons and the double Weibull model was fitted to the resulting survivor curves.
The presence of the competitor Gram-negative food spoilage bacteria with the
exception of Sh. putrefaciens suppressed (p<0.05) L. monocytogenes during biofilm
formation (100% relative humidity, 15°C and 48 h) and subsequently decreased (P<0.05) the desiccation survival in L. monocytogenes without affecting the resistance of
individual cells. Microscopic approaches revealed different biofilm forming capabilities
in the mono- and binary bacterial combinations.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:NSHD.ca#10222/15810 |
| Date | 28 November 2012 |
| Creators | Daneshvar Alavi, Hessam Edin |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
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