Current microbiological status of 'health foods' sold in Canada.

A follow-up survey was conducted across Canada to evaluate the current status of 'health foods' sold in Canada. A total of 1239 sample units of 'health foods' were analysed for a variety of bacteria, including aerobic colony counts (ACC), coliforms, aerobic and anaerobic sporeformers, Escherichia coli and Bacillus cereus. Results presented indicate that 16.8-18.4% of the 'health foods' exceed ACC guidelines, 16.0-17.8% exceeded coliform guidelines, 35.7% exceeded aerobic sporeformer guidelines, 81.4% exceeded anaerobic sporeformer guidelines, and 9% exceeded B. cereus guidelines. Some ACC were further identified and found to be opportunistic pathogens, including the genera Bacillus, Enterococcus, and Staphylococcus. It was concluded that more extensive surveillance of this industry by health officials is needed.

Comparison of bacterial counts obtained from naturally contaminated foods by means of Stomacher and blender.

Four Regional Health Protection Branch laboratories each compared aerobic colony counts obtained after "stomaching" and blending, for a minimum of 10 samples in each of the seven food groups: dry pastas; chocolate and cocoa powders; frozen entrees (macaroni and cheese, chow mein, chop suey, fried rice, seafood casseroles, and Salisbury steak); nonfat dry milk; shrimp and crabmeats; spices; and breakfast sausages. Overall, counts obtained after using the Stomacher were equivalent to or higher than counts obtained after using the blender in 73% of the comparisons (alpha = 0.05). Where differences existed, counts obtained after using the Stomacher tended to be higher than counts obtained after using the blender from milk powder and lower from sausage. Aerobic colony counts from these foods are not unacceptably biased when obtained by Stomacher.

Collaborative study of the MPN, Anderson-Baird-Parker direct plating, and hydrophobic grid-membrane filter methods for the enumeration of Escherichia coli biotype I in foods.

Five Health Protection Branch laboratories compared two membrane filter methods (the Anderson-Baird-Parker direct plating, and a hydrophobic grid-membrane filter method) against the most probable number procedure (MPN) for enumerating Escherichia coli biotype I in foods. Results were available in 24 h by both membrane filter methods, compared with 10-14 days by the MPN procedure. For ground beef, Parmesan cheese, and cut green beans, the hydrophobic grid method generally gave the highest recovery, although the two membrane filter methods were not significantly different. Both these methods gave significantly higher recoveries than the MPN procedure, and for most foods, either method would be preferable. Further work is required before either membrane filter method can be recommended for bean and alfalfa sprouts, which may contain very high levels of Klebsiella spp.

Detection of Salmonella in Refrigerated Preenrichment and Enrichment Broth Cultures.

Refrigeration (4 C) of non-selective and selective enrichment broth cultures for 72 h did not markedly affect detection of Salmonella in 160 contaminated high and low moisture foods. Detection in refrigerated preenrichment (non-selective) broth cultures of poultry and high and low moisture foods was 90, 95 and 100%, respectively; homologous results for refrigerated selective enrichment broth cultures were 90, 100 and 100%. All but one of the 22 negative results were obtained with poultry and two of the six laboratories participating in poultry analysis contributed 19 of the 21 negative results. Refrigeration of broth cultures provides greater operational flexibility by increasing the number of days on which analyses can be initiated without engendering work outside a normal work week.

ICMSF methods studies. X. An international comparative study of four media for the enumeration of Staphylococcus aureus in foods.

An international comparative study, undertaken by six laboratories to assess the performance of four selective media commonly used for the enumeration of Staphylococcus aureus in foods, revealed that Baird-Parker agar performed most satisfactorily. There was no significant difference among milk salt, tellurite polymyxin egg yolk, and kalium rhodanid - actidione - natriumazid - eigelb - pyruvat (KRANEP) agars. The type of food examined appeared to influence the performance of the media, but no specific patterns could be determined. Cultures yielding 3+ and 4+ coagulase reactions are most likely to possess thermostable nuclease activity, and are therefore most likely to be S. aureus.

Microbiological Standards for Cheese: Survey and Viewpoint of the Canadian Health Protection Branch.

The Health Protection Branch, Health and Welfare Canada is considering proposals for microbiological standards for cheese. These proposals are based on a 2-year study (1974-1976) carried out by the Branch. The proposed standards per gram are: total coliforms m = 500, M = 1500, fecal coliforms m = 100, M = 500, and Staphylococcus aureus m = 100, M = 1000, for cheeses made from pasteurized milk; total coliforms m = 5000, M = 50,000, fecal coliforms m = 500, M = 1000, and S. aureus m = 1,000, M = 10,000 for cheeses made from heat treated or unpasteurized milk. The type of standard proposed will be based on a three-class acceptance plan as developed by the International Commission on Microbiological Specifications for Foods. Use of this plan in interpretation of the analytical results allows for the normal variation between analytical samples.