Please use this identifier to cite or link to this item: http://hdl.handle.net/10773/16743
Title: Evaluation of resistance development and viability recovery by toxigenic and non-toxigenic Staphylococcus aureus strains after repeated cycles of high hydrostatic pressure
Author: Baptista, Inês
Queirós, Rui P.
Cunha, Ângela
Rocha, Sílvia M.
Saraiva, Jorge A.
Almeida, Adelaide
Keywords: High hydrostatic pressure (HPP)
Staphylococcus aureus
Enterotoxins
Resistance
Viability growth recovery
Issue Date: 2015
Publisher: Elsevier
Abstract: In this work, the development of resistance and the recovery of growth after several consecutive cycles of high hydrostatic pressure (HPP) were for the first time evaluated in different strains of Staphylococcus aureus. Three strains of this important and highly resilient to HPP foodborne pathogen were used: a nonenterotoxigenic ATCC 6538 strain, treated with 600 MPa for 30 min at 20 C, and the toxigenic strains 2153 MA (with enterotoxin A) and 2065 MA (with the enterotoxins A, G and I), treated with 600 MPa for 15 min at 20 C. After the first treatment, surviving colonies were used to produce new bacterial cultures. This procedure was repeated nine times more for each bacterium or until total inactivation occurred. The inactivation profile of non-enterotoxic strain and the two enterotoxic strains did not change after consecutive cycles, but the toxic strain with three enterotoxins was completely inactivated after the fourth cycle. The three strains did not recover their viability after 14 days. The results indicate that HPP effectively inactivates non-toxigenic and toxigenic strains of S. aureus after a single treatment. The surviving bacteria did not develop resistance after 10 cycles of pressurization and did not recover their viability after 14 days of incubation.
Peer review: yes
URI: http://hdl.handle.net/10773/16743
DOI: 10.1016/j.fm.2014.09.016
ISSN: 0740-0020
Appears in Collections:CESAM - Artigos

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