At the time of manufacture, 76% of 74 sets of raw beef patties collected in 42 federally inspected establishments had aerobic plate counts of 1,000,000 or fewer/g; 84% contained 100 or fewer coliforms/g; 92% contained 100 or fewer Escherichia coli/g; and 85% contained 100 or fewer Staphylococcus aureusig (geometric means of 10 patties/set). Salmonellae were isolated from only three (0.4%) of 735 beef patties.

FISHBEIN, MORRIS (Food and Drug Administration, Washington, D.C.), AND BERNARD F. SURKIEWICZ. Comparison of the recovery of Escherichia coli from frozen foods and nutmeats by confirmatory incubation in EC medium at 44.5 and 45.5 C. Appl. Microbiol. 12:127-131. 1964.-The productivity of confirmatory EC broth for the isolation of fecal Escherichia coli was determined at 44.5 and 45.5 C. A variety of frozen precooked foods and an assortment of nutmeats were examined after primary incubation in Lauryl Sulfate Tryptose (LST) broth. In 85.3% of the cases, the parallel tubes of EC broth incubated for 24 hr at 44.5 and 45.5 C gave rise to identical E. coli responses of positive, false positive, and negative. The remaining 14.7% of the reactions represent the qualitative difference between the two temperatures. The EC test at 45.5 C was more specific for E. coli, since twoto threefold fewer false positives were produced at this temperature than at 44.5 C. However, fecal E. coli recoveries were slightly higher (4%Vc) at the lower temperature. Incubating the EC tubes from the interval of 24 to 48 hr gave rise to an additional 4.3% of E. coli recovery, but this was accompanied by an excessive production of false positives (75.9%), representing a 3.5-fold decrease in specificity. It is recommended that, in the confirmatory use of EC broth in the examination of frozen foods and nutmeats for the recovery of fecal E. coli, the test be made at 45.5 C in a water bath and limited to 24 hr of incubation only, to insure optimal specificity. During the study, a "fixed" productivity ratio was noted; E. coli+/LST+ equaled approximately one-fourth or 25%. The significance of this ratio is discussed.

At the time of manufacture, 78% of 69 sets of packaged frankfurters collected from 40 firms had aerobic plate counts of 10,000 or fewer/g and 90% had 20,000 or fewer/g (geometric means of 10 units/set), 91% were coliform-negative, and 93% were Staphylococcus aureus-negative. Only one of 690 packaged frankfurter units was Escherichia coli-positive, and all units were salmonellae-negative.

SURKIEWICZ, BERNARD F. (Food and Drug Administration, Washington, D.C.). Bacteriological survey of the frozen prepared foods industry. I. Frozen cream-type pies. Appl. Microbiol. 14:21-26. 1966.-During Food and Drug Administration inspections of 12 imitation cream pie producers, 453 finished product samples and 350 line samples were collected and analyzed bacteriologically. Sanitary conditions in the plants varied from good to poor and, in general, were reflected in the bacteriological results. The survey revealed that, in the great majority of cases, frozen imitation-cream pies produced in plants operating under good conditions of sanitation had the following bacteriological content: (i) a most probable number (MPN) of fewer than three Escherichia coli cells per gram (i.e., absent from all tubes in the methodology employed), (ii) an average MPN of fewer than 50 coliforms per gram (10 or more pies), (iii) the absence of coagulase-positive staphylococci in 0.1-g portions, and (iv) an aerobic plate count of fewer than 25,000 per gram (geometric mean of 10 or more pies).

No abstract