Details

Autor(en) / Beteiligte

• Dourou, Dimitra
• Beauchamp, Catherine Simpson
• Yoon, Yohan
• Geornaras, Ifigenia
• Belk, Keith E.
• Smith, Gary C.
• Nychas, George-John E.
• Sofos, John N.

Titel

Attachment and biofilm formation by Escherichia coli O157:H7 at different temperatures, on various food-contact surfaces encountered in beef processing

Ist Teil von

• International journal of food microbiology, 2011-10, Vol.149 (3), p.262-268

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2011

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Escherichia coli O157:H7 attached to beef-contact surfaces found in beef fabrication facilities may serve as a source of cross-contamination. This study evaluated E. coli O157:H7 attachment, survival and growth on food-contact surfaces under simulated beef processing conditions. Stainless steel and high-density polyethylene surfaces (2 × 5 cm) were individually suspended into each of three substrates inoculated (6 log CFU/ml or g) with E. coli O157:H7 (rifampicin-resistant, six-strain composite) and then incubated (168 h) statically at 4 or 15 °C. The three tested soiling substrates included sterile tryptic soy broth (TSB), unsterilized beef fat-lean tissue (1:1 [wt/wt]) homogenate (10% [wt/wt] with sterile distilled water) and unsterilized ground beef. Initial adherence/attachment of E. coli O157:H7 (0.9 to 2.9 log CFU/cm 2) on stainless steel and high-density polyethylene was not affected by the type of food-contact surface but was greater (p < 0.05) through ground beef. Adherent and suspended E. coli O157:H7 counts increased during storage at 15 °C (168 h) by 2.2 to 5.4 log CFU/cm 2 and 1.0 to 2.8 log CFU/ml or g, respectively. At 4 °C (168 h), although pathogen levels decreased slightly in the substrates, numbers of adherent cells remained constant on coupons in ground beef (2.4 to 2.5 log CFU/cm 2) and increased on coupons in TSB and fat-lean tissue homogenate by 0.9 to 1.0 and 1.7 to 2.0 log CFU/cm 2, respectively, suggesting further cell attachment. The results of this study indicate that E. coli O157:H7 attachment to beef-contact surfaces was influenced by the type of soiling substrate and temperature. Notably, attachment occurred not only at a temperature representative of beef fabrication areas during non-production hours (15 °C), but also during cold storage (4 °C) temperatures, thus, rendering the design of more effective sanitation programs necessary. ► Attachment and biofilm formation was evaluated on stainless steel and HDPE surfaces. ► Growth substrates included broth, beef fat-lean tissue homogenate, and ground beef. ► Type of food-contact surface did not affect attachment or biofilm formation. ► Initial adherence/attachment was greater in ground beef than in liquid substrates.