Fundamental Food Microbiology, Third Edition - Fuad Fathir

420 FUNDAMENTAL FOOD MICROBIOLOGY
frequently, or if the incidence results in death or severe consequences, the samples
are generally tested for other suspected pathogens along with the common foodborne
pathogens. Most of the new foodborne pathogens were discovered this way. In the
U.S., the association of Yer. enterocolitica, Cam. jejuni, Lis. monocytogenes, and
Esc. coli O157:H7 in foodborne outbreaks has been confirmed this way. In the future,
other pathogens will be recognized as “new” pathogens in the same way. This is
probably true for several pathogens, such as Aeromonas hydrophila, Plesiomonas
shigelloides, and other opportunistic pathogens, as well as Hel. pyloris, Myc. paratuberculosis,
and several enteric viruses, which have been suspected from circumstantial
evidence to be foodborne pathogens but have not yet been directly confirmed.
One of the major reasons for testing available food samples for new pathogens,
other than those tested routinely, is our current expanded knowledge about the
characteristics of many pathogens. Much information is available about different
pathogens with respect to their physiological, biochemical, immunological, and
genetic characteristics, as well as their pathogenicity, habitat, and mode of disease
transmission. Recent knowledge on entire genome sequences of several pathogens
and advances in molecular biology techniques have greatly aided these studies. This
information has helped develop new, effective, and specific methods to isolate and
identify foodborne pathogens from samples. Many of the identification techniques
are specific, rapid, and less involved, even in the presence of large numbers of
associated bacteria. This aids in testing, economically and effectively, a large number
of samples in a relatively short span of time for many pathogens, which includes
those routinely tested and those that are probably suspected. Availability of readyto-use
kits from commercial sources has advanced this approach.
B. Improvement in Regulatory Actions
In recent years, at least in most developed countries, the local, state, and federal
regulatory agencies have been highly active in reporting a foodborne outbreak and
taking quick actions to identify the etiological agents. 4 The number of reported
outbreaks has increased in the U.S. from an average of 240 per year in the 1960s
to an average of 530 per year in the 1980s. This increase is due, in large part, to an
increase in reporting. Once a new foodborne pathogen is identified, its frequency of
occurrence in foods, mode of transmission in foods, and growth and survival in
foods under conditions of processing, storage, and handling at different stages from
production to consumption are determined. After this information becomes available,
regulatory agencies develop effective methods to either prevent or reduce its presence
in the food ready for consumption. This is accomplished by developing proper
methods of sanitation during processing and handling of foods and preservation. For
some pathogens, methods to reduce their presence in raw foods or even in live
animals (such as for Esc. coli O157:H7) are being studied. Finally, some improved
efforts have been and are being made by regulatory agencies to educate consumers
(especially at home) and food handlers (especially at food service facilities) about
the means by which one can reduce the incidence of contamination (such as for
Salmonella from uncooked chicken) due to cross-contamination and improper cooking
or cooling of foods. Public education will need increased focus in order to reduce