Food Biochemistry and Food Processing

31

Emerging Bacterial Foodborne

Pathogens and Methods of Detection

R. L. T. Churchill, H. Lee, and J. C. Hall*

705

Introduction

Factors Affecting the Emergence of New Pathogens

Common Foodborne Pathogens

Campylobacter jejuni

Salmonellaspp.

Escherichia coliO157:H7

Yersinia enterocolitica

Listeria monocytogenes

Clostridium perfringens

Staphylococcus aureus

Methods to Detect Foodborne Pathogens

Culture-Dependent Enrichment Methods

Automated Methods for Detection of Pathogens

(Non-Nucleic Acid-Based)

Nucleic Acid–Based Methods of Pathogen Detection

Polymerase Chain Reaction (PCR)

DNA Microarrays

Nucleic Acid Sequence–Based Amplification

(NASBA)

Pathogen Subtyping and Verification Methods

RFLP—Restriction Fragment Length

Polymorphism

AFLP—Amplified Fragment Length Polymorphism

RAPD—Randomly Amplified Polymorphic DNA

Ribotyping

Pulsed-Field Gel Electrophoresis

FISH—Fluorescence In Situ Hybridization

Immunoassay-Based Methods

Types of Antibodies Used in Detection of Pathogens

Enzyme-Linked Immunosorbent Assay (ELISA)

Fluorescently Labeled Immunoassays

Immunomagnetic Assays

Surface Plasmon Resonance (SPR)

Latex Agglutination Assays

Conclusions

Glossary

References

INTRODUCTION

Bacterial foodborne pathogens are bacteria that con-
taminate food and cause illnesses in humans when
that food is ingested (Tauxe 2002). In 1999, the esti-
mated number of foodborne illnesses in the United
States was 76 million, that is, one in four people be-
came ill, with approximately 325,000 hospitaliza-
tions in the year and 5000 deaths (Mead et al. 1999).
Despite efforts made to prevent food contamination,
new pathogens often emerge as a result of changing
demography, food consumption habits, food technol-
ogy, commerce, changes in water sources and en-
vironmental factors (Gugnani 1999), and microbial
adaptation (Altekruse et al. 1997). Some of these
bacterial foodborne pathogens are listed in Table
31.1.
There is no accepted general definition of an
“emerging foodborne pathogen,” but disease-causing
organisms are considered to be emerging if they
have one or more of the following properties. First,
the microorganism has not been previously recog-
nized, or it has not been known to cause problems in
food. Second, the microorganism was known to be
pathogenic, but has significantly increased in inci-
dence over the past decades (Schlundt 2001). Third,
*Corresponding author. it may be a pathogen that is predicted to increase in

Food Biochemistry and Food Processing

Edited by Y. H. Hui

Copyright © 2006 by Blackwell Publishing