Related Experiment Videos
[Poisoning by enterotoxin from Staphylococcus aureus associated with mocha pastry. Microbiology and epidemiology]
E F Escartín1, J Saldaña-Lozano, A Montiel-Falcón
1Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, México. efescart@sunserver.uaq.mx
Abstract:
A brief description of a foodborne outbreak due to S. aureus enterotoxin associated with the consumption of mocha cake in the city of Guadalajara is presented. The cake was prepared in a bakery and affected nearly 100 persons. S. aureus was isolated from the nose and skin of one of the pastry cooks. A S. aureus strain isolated from the cake involved in the outbreak was not only unable to grow in the mocha cream, but it actually decreased in numbers by 2 log after 72 h of storage at 30 degrees C. The pH of mocha cream ranged from 6.2 to 6.6, and water activity from 0.833 to 0.859, with a media of 0.841. In preparing mocha cake at the shop, one half of the dough used to be sprayed with a sucrose solution in water (20% w/v); mocha cream was spread on the other half of the dough before overlapping the two halves. When mocha cake was prepared in this manner, and stored at 30 degrees C, S. aureus increased in number by more than 4 log after 48 h. S. aureus did not grow in the cake stored at 4-7 degrees C. Contributory factors in this outbreak were an increase of water activity in the interphase of the mocha and the cake dough, storage of the cake in an unrefrigerated area, and an unusually high ambient temperature (28-32 degrees C) at that time.
Insights
A S. aureus enterotoxin outbreak linked to mocha cake sickened 100 people. Improper storage and increased water activity allowed bacterial growth, highlighting critical food safety concerns.
Area of Science:
- Food safety
- Microbiology
- Public health
Context:
- A foodborne outbreak of S. aureus enterotoxin poisoning occurred in Guadalajara, affecting nearly 100 individuals.
- The outbreak was associated with the consumption of mocha cake prepared in a local bakery.
- S. aureus was identified on a pastry cook and in the implicated cake.
Purpose:
- To investigate a foodborne outbreak caused by S. aureus enterotoxin.
- To identify the contributing factors to bacterial growth in mocha cake.
- To understand the conditions favoring S. aureus proliferation in a food product.
Summary:
- S. aureus showed limited growth in mocha cream alone at 30°C but significant proliferation (>4 log increase) when incorporated into mocha cake and stored at 30°C.
- The cake's preparation method, involving sucrose solution and overlapping dough halves, increased water activity at the interface, creating a favorable environment for S. aureus.
- Storage at unrefrigerated temperatures (30°C) with high ambient temperatures (28-32°C) were critical factors, while storage at 4-7°C inhibited growth.
Impact:
- Identified critical control points in mocha cake preparation and storage to prevent S. aureus contamination.
- Emphasizes the importance of temperature control and water activity management in food safety for bakery products.
- Provides insights into the conditions that promote S. aureus enterotoxin production in complex food matrices.