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Prolonged expression and production of Staphylococcus aureus enterotoxin A in processed pork meat.

Wallin, Nina LU ; Marta, Dora LU ; Borch, Elisabeth and Rådström, Peter LU (2010) In International Journal of Food Microbiology 141. p.69-74
Abstract
The bacteriophage-encoded staphylococcal enterotoxin A (SEA) is the toxin most frequently reported to be involved in staphylococcal food poisoning. In this study, sea expression and SEA formation were studied in four processed pork products: boiled ham, hot-smoked ham, Serrano ham (dry-cured Spanish ham) and black pepper salami. The products were selected because of their differences in intrinsic factors. As a reference, Staphylococcus aureus was cultivated under favorable planktonic growth conditions. Expression was mainly linked to bacterial growth for both meat products and broth cultures. In liquid broth, however, the relative level of sea mRNA peaked in the late exponential phase and then rapidly declined, while in the meat products... (More)
The bacteriophage-encoded staphylococcal enterotoxin A (SEA) is the toxin most frequently reported to be involved in staphylococcal food poisoning. In this study, sea expression and SEA formation were studied in four processed pork products: boiled ham, hot-smoked ham, Serrano ham (dry-cured Spanish ham) and black pepper salami. The products were selected because of their differences in intrinsic factors. As a reference, Staphylococcus aureus was cultivated under favorable planktonic growth conditions. Expression was mainly linked to bacterial growth for both meat products and broth cultures. In liquid broth, however, the relative level of sea mRNA peaked in the late exponential phase and then rapidly declined, while in the meat products allowing immediate growth, i.e. boiled and smoked ham, active sea expression occurred throughout the incubation period of seven days. Lower levels of sea mRNA and SEA were found in smoked ham compared to boiled ham, although viable counts of S. aureus on the two products were similar. Furthermore, the SEA concentration in the boiled ham reached a maximum after three days of incubation and then unpredictably decreased. In the Serrano ham, no increase in cell number was observed until day seven, and sea expression and extracellular SEA could only be detected on days five and seven. Finally, the black pepper salami with low pH and competing microbiota proved to be a difficult environment for the survival of S. aureus. The molecular mechanism behind the behaviour of S. aureus SEA expression is discussed in connection to the life-cycle of the SEA-encoding bacteriophage and the microbial communities in these pork products. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Food Microbiology
volume
141
pages
69 - 74
publisher
Elsevier
external identifiers
  • wos:000281830700008
  • pmid:20406714
  • scopus:77955846855
ISSN
0168-1605
DOI
10.1016/j.ijfoodmicro.2010.03.028
language
English
LU publication?
yes
id
61fd3437-7a64-42e4-b8d9-3bbd02bddf6b (old id 1595025)
date added to LUP
2010-05-06 14:42:09
date last changed
2018-05-29 10:04:04
@article{61fd3437-7a64-42e4-b8d9-3bbd02bddf6b,
  abstract     = {The bacteriophage-encoded staphylococcal enterotoxin A (SEA) is the toxin most frequently reported to be involved in staphylococcal food poisoning. In this study, sea expression and SEA formation were studied in four processed pork products: boiled ham, hot-smoked ham, Serrano ham (dry-cured Spanish ham) and black pepper salami. The products were selected because of their differences in intrinsic factors. As a reference, Staphylococcus aureus was cultivated under favorable planktonic growth conditions. Expression was mainly linked to bacterial growth for both meat products and broth cultures. In liquid broth, however, the relative level of sea mRNA peaked in the late exponential phase and then rapidly declined, while in the meat products allowing immediate growth, i.e. boiled and smoked ham, active sea expression occurred throughout the incubation period of seven days. Lower levels of sea mRNA and SEA were found in smoked ham compared to boiled ham, although viable counts of S. aureus on the two products were similar. Furthermore, the SEA concentration in the boiled ham reached a maximum after three days of incubation and then unpredictably decreased. In the Serrano ham, no increase in cell number was observed until day seven, and sea expression and extracellular SEA could only be detected on days five and seven. Finally, the black pepper salami with low pH and competing microbiota proved to be a difficult environment for the survival of S. aureus. The molecular mechanism behind the behaviour of S. aureus SEA expression is discussed in connection to the life-cycle of the SEA-encoding bacteriophage and the microbial communities in these pork products.},
  author       = {Wallin, Nina and Marta, Dora and Borch, Elisabeth and Rådström, Peter},
  issn         = {0168-1605},
  language     = {eng},
  pages        = {69--74},
  publisher    = {Elsevier},
  series       = {International Journal of Food Microbiology},
  title        = {Prolonged expression and production of Staphylococcus aureus enterotoxin A in processed pork meat.},
  url          = {http://dx.doi.org/10.1016/j.ijfoodmicro.2010.03.028},
  volume       = {141},
  year         = {2010},
}