Book Review

Food Safety: Old Habits, New Perspectives

Food Microbiology: Fundamentals and Frontiers

N Engl J Med 2007; 357:1266-1267September 20, 2007

Article

Food Safety: Old Habits, New Perspectives
By Phyllis Entis. 400 pp. Washington, DC, ASM Press, 2007. $49.95. ISBN: 978-1-55581-417-5

Food Microbiology: Fundamentals and Frontiers
Third edition. Edited by Michael P. Doyle and Larry R. Beuchat. 1038 pp., illustrated. Washington, DC, ASM Press, 2007. $169.95. ISBN: 978-1-55581-407-6

Technological advances, including pasteurization and refrigeration, have contributed to the safety of the food supply. However, the centralization of food processing and the widespread distribution of food can facilitate the spread of foodborne pathogens. The reprocessing and repackaging of foods complicate the logistics of recalling contaminated foods. Public and private infrastructures for carrying out inspections and monitoring and investigating foodborne diseases are essential to the safety of the food supply. The basic science of foodborne microorganisms and their relationship to the food microenvironment underlies current food safety measures. These two books contribute in different ways to the overall objective of improving the safety of food.

The author of Food Safety, Phyllis Entis, uses an engaging journalistic narrative to describe numerous investigations of outbreaks of foodborne diseases. Each story vividly illustrates breakdowns in food safety — lapses in sanitary techniques, the reluctance of the food industry to embrace safer practices in processing, and ineffective regulatory oversight. Using examples such as the fatal outbreak in 2001 of Enterobacter sakazakii that was linked to powdered infant formula, Entis conveys her central message effectively: old habits must be changed as knowledge about food safety evolves. The standard practice at the time of the 2001 outbreak was to allow powdered formula that had been reconstituted to remain at room temperature for up to 8 hours, and because this well-accepted practice was presumed to be safe, there was a delay in finding the link between the outbreak and the contaminated formula.

The emphasis in Food Safety is on errors, oversights, delays, conflicts of interest, and cumbersome policies within the food industry and government that compromise food safety. In language characteristic of the book, Entis attributes an outbreak of Escherichia coli O157:H7 that was associated with reprocessed beef products to both the “feeble performance” of the companies that were implicated and the regulators' “laissez-faire approach to meat safety regulation.” In her narrative of an outbreak of Salmonella enterica that was associated with raw almonds, Entis acknowledges the industry's efforts to improve processing practices and to fund associated research but points out their inability to prevent a second outbreak, stating that “the best of intentions is not always enough.”

A Microbiologist Testing Food Samples as Part of an Outbreak Investigation of Foodborne Salmonellosis.

At times, Entis's conclusions seem polarizing and strongly judgmental of the food industry and regulatory agencies. Although it is critical to identify weaknesses in food-safety systems, a more balanced view would also provide insights into challenges and highlight successful interventions. For example, in the salmonella outbreak that was associated with raw almonds, even though an intensive investigation was undertaken, the source of the contamination remained unclear. In addition, the recall of more than 13 million pounds of raw almonds that had been distributed to approximately 50 commercial customers in the United States and nine other countries was a tremendous challenge. As an example of an improvement in food safety, the beef industry has developed successful strategies for reducing E. coli O157:H7 in live cattle and for preventing contamination of the meat during slaughter.

In the last chapter, Entis offers constructive suggestions, based on systems that were developed in other countries, for consolidating the various agencies that are responsible for inspections. She points out the need to reduce conflicts of interest in agencies whose mandates are both to inspect food products and to support markets for them. Using her background in microbiology and her experience in journalism, Entis writes in an accessible, engaging style with anecdotes and colorful language.

Food Microbiology is an update of a well-regarded reference. Its editors, Michael Doyle and Larry Beuchat, are affiliated with the University of Georgia's Center for Food Safety. They and their contributors assume that readers have a background in microbiology and biochemistry; at times, high-level knowledge is required. The target audience includes students who are working toward advanced degrees, food-safety scientists, and microbiologists who are interested in a biochemically oriented review of foodborne pathogens and food safety issues.

Chapters on meats, vegetables, dairy products, beer, and other types of food emphasize the basic science that serves as the foundation for measures to increase food safety. For example, one chapter is an exploration of the microorganisms that are commonly found on the surface of meat, the biochemistry of meat spoilage, and the biochemical assays for detecting spoilage. In another chapter, the discussion of the role of lactose-producing bacteria and lactose metabolism in the fermentation of dairy products (to produce cheese, for example) is detailed. A variety of methods of preserving food are discussed, including the antimicrobial effect of food additives made from organic acids.

A major part of the book is devoted to foodborne bacterial pathogens. These chapters include information about each organism's reservoirs, infectious dose, associated outbreaks, and resistance to antimicrobial agents; the emphasis in most of these chapters is on pathogenesis and the molecular biochemistry of factors that determine virulence. The detailed review of staphylococcus enterotoxins includes information about the genetic regulation of enterotoxin production and about specific regions within the biochemical structure that induce emesis. The growth and survival of salmonella in various environmental conditions is also discussed in detail. There are some allusions to practical applications. For example, it is noted that the evolutionally conserved invasion genes of the salmonella pathogenicity island enable scientists to detect salmonella in foods using the polymerase chain reaction.

The improvement of viral diagnostic tests has shown that viral foodborne pathogens — mainly noroviruses — accounted for 33% of foodborne outbreaks that were reported to public health authorities in the United States between 1998 and 2002. Despite the importance of these viral pathogens in foodborne outbreaks, disproportionately little space in Food Microbiology is devoted to them. Other sections in the book address mycotoxigenic molds, prions, and foodborne and waterborne parasites.

One chapter in the last section of the book discusses the Hazard Analysis Critical Control Point — a universally recognized approach to the assurance of food safety. Other chapters in this section present an up-to-date literature review of technological advances, including miniaturized and automated kits that are used to identify bacteria and methods of molecular subtyping that are used to match isolates in food items with clinical isolates. On the whole, the book is a comprehensive resource on the microbiologic basis of food spoilage, foodborne pathogens, and food preservation.

I was excited to review these two books because they complement each other — one provides insight into the complex interaction of the industries and regulatory agencies that are involved in food safety, and the other serves as a reference for understanding the microbiologic and molecular bases of the field.

Nkuchia M. M'ikanatha, Dr.P.H., M.P.H.
Pennsylvania Department of Health, Harrisburg, PA 17108
nmikanatha@state.pa.us