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Table 1 Description of Critical Sampling Location (CSLs), samples, periodicity, microbiological parameters, methodologies, results interpretation and references

From: Insights in agricultural practices and management systems linked to microbiological contamination of lettuce in conventional production systems in Southern Brazil

CSL

Description

Samples

Time

Microbiological parameters

Methodology

Interpretation of the results*

References

1

Manure

3 samples

T0

E. coli

ISO 21528-2:2004

10³ cfu/g

MAPA/ IN n°46. (2011)

    

E. coli O157:H7

ISO 16654:2001

A/25g

ND

    

Salmonella spp.

ISO 6579:2002

A/25g

MAPA/ IN n°46. (2011)

2

Manured soil

3 samples → 3 x 3 pooled

T0

E. coli

ISO 21528-2:2004

10³ cfu/g

MAPA/ IN n°46. (2011)

    

E. coli O157:H7

ISO 16654:2001

A/25g

ND

    

Salmonella spp.

ISO 6579:2002

A/25g

MAPA/ IN n°46. (2011)

3

Soil

3 samples → 3 x 3 pooled

T1

E. coli

ISO 21528-2:2004

10³ cfu/g

MAPA/ IN n°46. (2011)

   

T2

E. coli O157:H7

ISO 16654:2001

A/25g

ND

   

T3

Salmonella spp.

ISO 6579:2002

A/25g

MAPA/ IN n°46. (2011)

4

Seedlings in soil

1 sample → 1 x 3 pooled

T0

E. coli

ISO 21528-2:2004

10² cfu/g

RDC n°12 (2001)

    

E. coli O157:H7

ISO 16654:2001

A/25g

ND

    

Salmonella spp.

ISO 6579:2002

A/25g

RDC n°12 (2001)

5

Seedling

1 sample

T0

E. coli

ISO 21528-2:2004

10² cfu/g

RDC n°12 (2001)

6

Lettuce

3 samples → 3 x 3 pooled

T1

E. coli

ISO 21528-2:2004

10² cfu/g

RDC n°12 (2001)

   

T2

E. coli O157:H7

ISO 16654:2001

A/25g

ND

   

T3

Salmonella spp.

ISO 6579:2002

A/25g

RDC n°12 (2001)

7

Lettuce after washing

3 samples → 3 x 3 pooled

T3

E. coli

ISO 21528-2:2004

10² cfu/g

RDC n°12 (2001)

    

E. coli O157:H7

ISO 16654:2001

A/25g

ND

    

Salmonella spp.

ISO 6579:2002

A/25g

RDC n°12 (2001)

8

Rinse water

100 ml

T3

E. coli

20 TH APHA (1998)

2 x102 MPN/100ml

CONAMA. n°357 de 2005

    

E. coli O157:H7

ISO 16654:2001

A/25ml

ND

    

Salmonella spp.

ISO 6579:2002

A/25ml

ND

9

Irrigation water source

100 ml

T0 T1

E. coli

20 TH APHA (1998)

2 x102 MPN/100ml

CONAMA. n°357 de 2005

   

T2

E. coli O157:H7

ISO 16654:2001

A/25ml

ND

   

T3

Salmonella spp.

ISO 6579:2002

A/25ml

ND

10

Irrigation water from tap

100 ml

T0 T1

E. coli

20 TH APHA (1998)

2 x102 MPN/100ml

CONAMA. n°357 de 2005

   

T2

E. coli O157:H7

ISO 16654:2001

A/25ml

ND

   

T3

Salmonella spp.

ISO 6579:2002

A/25ml

ND

11

Swab of farmers’ hands

3 x 25 cm²

T3

E. coli

ISO 21528-2:2004 and AOAC (1998)

≤ 0.7 log cfu/25 cm² (below detection)

Jacxsens. et al. (2010)

12

Swab of transport boxes of lettuce

3 x 50 cm²

T3

E. coli

ISO 21528-2:2004

≤ 0.7 log cfu/25 cm² (below detection)

Jacxsens. et al. (2010)

  1. A: absent; ND: not defined by official regulation.
  2. T0: At planting. T1: Two weeks before harvest. T2: One week before harvest. T3: At harvest.