THE OCCURRENCE AND GROWTH OF STAPHYLOCOCCI ON PACKED BACON, WITH SPECIAL REFERENCE TO STAPHYLOCOCCUS AUREUS

Abstract

Staphylococcus aureus occurs and survives in bacon curing brines and may be found on shop sliced and on vacuum packed bacon. Under anaerobic conditions it competes with the indigenous flora of the bacon: its growth is favoured by low numbers of other organisms and by high storage temperatures. Packs of bacon for sale should carry the instruction to keep in a cool place.

The ‘Vacuum Pack’ Method of Packaging Foods in Relation to the Formation of the Botulinum and Staphylococcal Toxins

“…This may be particularly pertinent to the production of toxin by Cl. botulinurn type E, for this organism can elaborate toxin a t refrigeration temperatures (Ohye & Scott, 1957). This seems to have applied in the fatal cases referred to.…”

Production of Enterotoxin‐B in Cured Meats

“…When the other curing factors were in low concentration, a suboptimum enterotoxin production is possibly due to variations in meat composition and competition from other bacteria. The poor ability of staphylococci to compete with other bacteria has been etsablished (Casman et al, 1963 ;DiGiancinto et al, 1966 ;Eddy et al, 1962;Kao et al, 1966;McCoy et al, 1966;Miller et al, 1955 ;Peterson et al, 1962 ;Troller et al, 1963). McCoy et al (1966) have also demonstrated an inhibition of enterotoxin-A production by food bacteria independent of an apparent effect on bacterial growth.…”

The fate of a toxigenic strain ofStaphylococcus aureusin vacuum-packaged bacon

“…Thus suggests that it may not be simply a question of numbers as suggested by Eddy & Ingram (1962), but rather types of organisms which exercise the inhibitory effect.…”

“…This has already been established, especially when bacon is stored at temperatures exceeding about 250 C. (Eddy & Ingram, 1962;Ingram, 1960). It was suggested by Eddy & Ingram (1962) that the principle obstacle to the multiplication of staphylococci is the preponderance of the normal microflora and they 571 posed the question, 'why does this flora inhibit staphylococci?'. Sufficient evidence is available to show that certain genera, species and groups of bacteria exercise an inhibitory effect on staphylococci.…”