|Title||Survival strategies of Listeria monocytogenes - roles of regulators and transporters|
|Source||Wageningen University. Promotor(en): Frans Rombouts, co-promotor(en): Tjakko Abee; J.A. Wouters. - [S.l.] : S.n. - ISBN 9789058089335 - 152|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||listeria monocytogenes - voedselbewaring - koudeshock - bacteriële eiwitten - osmoregulatie - genetische regulatie - celmembranen - eiwittransport - listeria monocytogenes - food preservation - cold shock - bacterial proteins - osmoregulation - genetic regulation - cell membranes - protein transport|
|Abstract||Outbreaks of the food-borne pathogen Listeria monocytogenes are mainly associated with ready-to-eatfoods. Survival strategies of L. monocytogenes in relation to minimally processed foods were studied.
L.monocytogenespossesses several mechanisms to regulate transcription, e.g. the cold-shock proteins and the alternative sigma factorsB. Studies showed thatsBplays a crucial role in survival and adaptation to acidic conditions, HHP treatment and freezing by inducing the transcription of several genes.
To survive adverse conditions, L. monocytogenes accumulates solutes such as theosmolytesbetaine and carnitine, and (proline-containing) peptides. The transportersBetL,GbuandOpuCmediate betaine and carnitine uptake in the cell, ensuring low-temperature and high-osmolarity growth.OpuB, a fourthtransporter, is not involved in betaine or carnitine accumulation. Strains carrying anopuC oropuBdeletion were impaired in their ability to cause infection in mice.
Understanding the growth and survival of L. monocytogenes and knowledge of virulence factors will contribute to adequate food-safety measures.