Food Biochemistry and Food Processing

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Table 31.3.

Comparison of Nucleic Acid–Based Detection Methods for

L. monocytogenes

Enrichment

Total

Number of

Medium in which

Method of

Gene

Culture

Detection

Cells

Pathogens Were

Detection

Detected

Time (hrs)

Time (hrs)

Detected

Detected

References

PCR

Commercial kit

a

48

58–60

2–8 cfu/25 g

Salmon

(Wan et al. 2003)

inlAB

None

Not available

10

5 cfu/mL

Pure culture

(Jung et al. 2003)

inlAB

16

24

10 cfu/25 g

Frankfurter

(Jung et al. 2003)

Competitive PCR

hlyA

None

5

10

3 cfu/0.5 mL

Milk

(Choi and Hong 2003)

hlyA

15 h

20

1 cfu/0.5 mL

Milk

(Choi and Hong 2003)

PCR with DNA

Commercial

16 h

24

2-10 cells/g

Milk and various

(Ingianni et al. 2001)

probe

probe

meat products

FRET-PCR

hlyA

None

2.5

500 cfu/mL

Pure culture

(Koo and Jaykus 2003)

hlyA

None

2.5

10

3 –10

4

cfu/mL

Skim milk

(Koo and Jaykus 2003)

Real-time PCR

Commercial kit

24

30

10

2 –10

3

cfu/mL

Pure culture

(Bhagwat 2003)

Commercial kit

None

8

10

8 –10

10

cfu/25 g

Cabbage

(Hough et al. 2002)

Multiplex PCR

23S rRNA

None

4

10

3 –10

5

genome

Pure culture

(Dunbar et al. 2003)

with

copies

microsphere sorting

DNA microarray

iap, hly,

None

N/A

b

N/A

Pure cultures

(Volokhov et al. 2002)

inlB, plcA, plcB, clpE

RT-PCR

iap

1

54

10–15 cfu/mL

Pure culture

(Klein and Juneja 1997)

iap

2

55

3 cfu/g

Ground beef

(Klein and Juneja 1997)

aThe gene amplified is not mentioned for the kit.bN/A, not addressed in paper.