Food safety has become a worldwide concern that affects international trade and
relations due to its impact on human health and economics, especially in recent years
when the number and complexity of food safety issues has increased substantially.
This is evidenced by the large number of new, emerging, reemerging, or evolving
pathogenic microorganisms (e.g., Escherichia coli O157:H7 and other Shiga toxin–
producing E. coli serotypes, Salmonella serotypes Enteritidis and Typhimurium DT
104, Campylobacter jejuni/coli, Yersinia enterocolitica, Listeria monocytogenes, and
Enterobacter sakazakii, parasitic agents such a Cryptosporidium and Cyclospora,
Noroviruses) which have become food safety concerns after the 1970s, 1980s, and
even 1990s. Another alarming development is the increasing number of types of foods
being involved in outbreaks, including products not usually associated with confirmed
foodborne illness episodes in the past (e.g., fruit juices, lettuce, spinach, other produce,
mayonnaise, various berries, saut´eed onions, clam chowder, ice cream). Simultaneously,
controlling bacterial pathogens, which are the most important food safety
concern relative to number of deaths and economic losses, has become more complicated
as accumulating evidence indicates development of resistance to antibiotics
and potential adaptation and cross-resistance or cross-protection to traditional food
preservation barriers, such as acidity, thermal processing, cold temperature storage,
dry or low-water-activity environments, and chemical additives. In addition, evidence
indicates the existence of pathogenic strains with enhanced ability for survival in their
hosts, lower infectious doses, and increased virulence.