Microbiological Condition of Retail Beef Steaks: A Canadian Survey

The second national baseline microbiological survey of beef steaks offered for retail in Canada was conducted in 2015. A total of 621 steaks of four types (cross rib, CR; inside round, IR; striploin, SL; top sirloin, TS) collected from 135 retail stores in five cities across Canada were tested. Swab samples each from swabbing the entire upper surface of each steak were processed for enumeration of seven groups of indicator organisms: total aerobes (AER), psychrotrophs (PSY), lactic acid bacteria (LAB), pseudomonads (PSE), Brochothrix thermosphacta (BRO), coliforms (COL) and Escherichia coli (ECO). The overall mean values (log CFU/100 cm2) were 5.17±1.29, 4.92±1.36, 4.79±1.42, 3.26±1.49, 2.34±1.88, and 0.80±1.05 for AER, PSY, LAB, PSE, BRO, and COL, respectively. ECO were not recovered from 87.3% of the steaks and when there was recovery, the numbers were mostly ≤ 1 log CFU/100 cm2. Strong correlation was found between the log numbers of AER and PSY, of AER and LAB, and of PSY and LAB, while the correlation between the log numbers of COL and ECO was weak. The numbers of COL and ECO from different groups of steak types or from different cities were not substantially different. Of the four types of steaks, IR had the lowest median values for AER, PSY, LAB, PSE and BRO, followed by CR. The microbiological condition of retail beef steaks in this survey was on par with that in the previous one, with very low numbers of generic E. coli being recovered from very few steaks and the indicators for microbial quality being at numbers much lower than the upper limit for shelf life of beef.