salmonella interventions€for€beef - meat science

John N. SofosCatie A. Simpson, K. E. Belk, J. A. Scanga, and G. C. Smith

[email protected]

SALMONELLAINTERVENTIONS FOR BEEF

mailto:[email protected]

23 June 2006JNS 2

PATHOGEN SOURCESPATHOGEN SOURCES

SOURCES OF MICROBIAL CONTAMINATION

Food

People

Equipment

Pests

EnvironmentFeces, Soil,Water, Dust

Facilities

Animals

23 June 2006JNS 3

PATHOGEN RELATIONSHIPS

Diarrheagenic Escherichia coli vs. Salmonella ?Correlations/Interactions/Associations ?Presence/absence/levels relationships ?No available indicators or indicesSalmonella and E. coli O157:H7: fecalNo trends evidentData collected with one do not necessarily

reflect or predict the behavior of anotherCertain interventions may affect them similarlyData may be indicative of overall picture

6.1 7.2

1.1

28.8

0

17.7

0

10

20

30

40

50

SA EC CA

Prev

alen

ce (%

)

Lairage

Hide at salughter

SALMONELLA vs. OTHER PATHOGENS

No trends or associations evident

Small et al. 2002. J. Food Prot. 65:931936

23 June 2006JNS 5

SALMONELLA CONTAMINATIONDISTRIBUTION/SOURCES/PREVALENCE

Field and Feedlot:Numerous environmental sources:

Cattle pensFeedWaterFecesHidesAny site, object or material

exposed to animal feces

23 June 2006JNS 6


Variation in incidence and prevalence:Cattle ageFinishing programTime on feedAnimal sexAnimal healthAnimal body siteAnimal groupFeces vs. hideTransportation effectsLairage sourcesSeasonal variationRegional or geographic variation

510

18

21.6

54.6

24.3

34.8

0

20

40

60

Hide Feces Hide Feces

Prev

alnc

e (%

)

FeedyardPlant

Steer Heifer


Animal sex variation: No clear trend

Barham et al. 2002. J.Food Prot. 65:280283

2.2 3.30

4.40

10

22.2

0

8.8

0

20

40

60

SA EC CA

Prev

alen

ce (%

) RumpFlankBRISKET


Animal body site variation (hides)

Reid et al. 2002. FoodControl 13:411415

0

20

40

60

80

100

1 2 3 4

Pre

vale

nce

(%)

Pen fecesFecesHidesRumenOral

Animal Group


Animal group and animal site variation (Australia)

Fegan et al. 2002. J. FoodProt. 68:11471153

9887.6

95 99

77.9

49.5 45.7

26.7

0

20

40

60

80

100

April May July August

Prev

alen

ce (%

)

Plant A/SouthPlant B/North


Hide seasonal and geographic variation

RiveraBetancourt et al. 2004. J. Food Prot. 67:296302

0

20

40

60

80

100

April May July August

Prev

alen

ce (%

)

SalmonellaE.coli O157:H7L. monocytogenes

SALMONELLA vs. OTHER PATHOGENSSeasonal variation on hides

RiveraBetancourt et al. 2004.J. Food Prot. 67:296302

52

91.8

23.30 0.8

25.3 26.850.3

020406080

100

Fenc

e/H

oldi

ngPe

ns Hid

es

Car

cass

at

Pre

evis

.

Car

cass

Pos

tIn

terv

.

Pre

vale

nce

(%) Plant A South

Plant B North


Regional/Geographic variation

RiveraBetancourt et al. 2004.J. Food Prot. 67:296302

0

20

40

60

80

100

Fed Adult Fed Adult

Prev

alen

ce (%

)RectalHideVehicleKnock boxCarcass

Pretransit Posttransit


Animal age and transportation stress effects:

Beach et al. 2002a. J.Food Prot. 65:16871693

1

35

8

22

55

10

24

5

0

20

40

60

80

Feedyard Plant Feedyard Plant

Prev

alen

ce (%

)

MinMax

Hide Feces


Transportation stress effects


618.2 18

9.5

43.4

4.5 5.5

86.9

0

20

40

60

80

100


Prev

alen

ce (%

) FeedyardPlant

Salmonella EHEC

SALMONELLA vs. E. COLI O157:H7Transportation stress effects: Conflicting results


23 June 2006JNS 16


170Gates418Stunning box

55Crush05Funnel walls05Corner: lairage pens and race010Water trough

4010Pen floor00Pen walls05Corner: unloading area/lairage pens50Unloading rump

O157SalmonellaLairage site

Lairage sources

Small et al. 2002. J.Food Prot. 65:931936

23 June 2006JNS 17


Beach et al. 2002a. J. Food Prot. 65:16871693

Additional sources of contaminationSlaughter plant environment and humans

Knock boxes:Facility A: 64.3 % positiveFacility B: 83.3 % positive

Aprons: 26 % positive for E. coli O157Knives: 29 % positive for E. coli O157

Tutenel et al. 2003. J. Food Prot. 66:15641469

0

20

40Sl

augh

ter

Floo

rD

rain

s

Lock

erR

oom

Dra

in

Prod

uct

Con

tact

Surf

ace

Bris

ket

Saw

Split

ting

Saw

Pre

vale

nce

(%) Before operation

During operation


Slaughter plant and human sources of contamination

RiveraBetancourt et al. 2004. J. Food Prot. 67:296302

0

20

40

60

80

100

A B C D E

Prev

alen

ce (%

)FecalHideCarcass

Plant


Plant variation

Ransom et al. 2002. J.Food Prot. 65:621626

0

20

40

60

80

100


Prev

alen

ce (%

)

Day 1Day 2Day 3Day 4

EHEC Salmonella


Slaughter day variation


2.5

8.5

3.630.80.6

0

20

40

Brisket Flank Rump

Pre

vale

nce

(%)

Preevisceration

Postevisceration


Sofos et al. 1999. J. Food Prot. 62:467473

Carcass site variation

23 June 2006JNS 22


0

10

20

30

40

50

60

70

Sponge Excision Gauze Hair Clip Rinse

E. coli O157:H7Salmonella

Perc

ent P

ositi

ve S

ampl

es

Ransom et al. 2002. J.Food Prot. 65:621626Hide sampling method variation

23 June 2006JNS 23


Fegan et al. 2002. J. Food Prot. 68:11471153

ND<0.1ND9.2ND<3ND4.8ND933

ND0.31ND<3ND<3ND<0.18ND<32

ND3.6ND43<0.060.46

ND931

Chilledcarcass

Prechillcarcass

OralRumenHideFecesGroup

Counts (MPN/g or cm2) of SalmonellaLive animal to carcass (Australia)

23 June 2006JNS 24

FECALSCANNER

Visible Contamination: “Zero Tolerance”Ground Beef: “Adulterant”E. coli O157:H7Pathogen Reduction/HACCP Rule (1996):

SSOPHACCPMicrobiological Criteria:

Performance Criteria: E. coliPathogen Reduction Standard: Salmonella

Beef HACCP Revision (2002)Listeria Control in RTE Products Rule (2003)Directives and Guidances

USA REGULATIONS FOR PATHOGENCONTROL

23 June 2006JNS 25

STRATEGY FOR PATHOGEN CONTROLPreharvest or Field Control

Minimize sources and levelsMinimize access or transfer

Postharvest or Processing Factory ControlMinimize or reduce contaminationInactivate contaminationInhibit or retard growth

Foodservice controlInhibit growthInactivate contaminationPrevent crosscontamination

Education

23 June 2006JNS 26

PATHOGEN CONTROL IN THE FIELD

Reasons for preharvest pathogen controlReduce pathogen sources and levelsWater contaminationProduce contaminationAnimaltohuman transmission

Ideal preharvest interventions:Animal friendlyEnvironmentally compatibleEffective against various pathogensPractical to applyCost effective

23 June 2006JNS 27

PATHOGEN CONTROL IN THE FIELD

Interventions explored:Diet manipulationFeed additives/supplementsAntibioticsBacteriophagesVaccines/ImmunizationCompetitive exclusion/Prebiotics/ProbioticsManagement practices

23 June 2006JNS 28

PATHOGEN CONTROL IN THE FIELDManagement Practices:Pathogens may be ubiquitousPotential:

Clean feedPest controlPen conditionPen densityManure controlTransportation stressingChlorination/Ozonation/UV lightDust controlScreens/filters for solidsCombined efforts needed for control

23 June 2006JNS 29

PATHOGEN CONTROL IN THE FIELDDifficulties in preharvest pathogen control

Limited scientific informationUnknown reservoirsNumerous complicating variablesAsymptomatic animalsSporadic or low sheddingLow pathogen cell numbersLarge numbers of total contaminationInadequate detection methodologyUbiquitous presence of some pathogensEconomic issuesLack of proven interventions

23 June 2006JNS 30

INTERVENTIONS TO REDUCECARCASS CONTAMINATION

PreEviscerationWashing

PreEviscerationWashing

ThermalPasteurization

ThermalPasteurization

OrganicAcidRinsing

OrganicAcidRinsing

Sequential Hurdles

AnimalCleaning

Chemicaldehairing

Knifetrimming andSteamVacuumingKnifetrimming andSteamVacuuming

CarcasswashingCarcasswashing

23 June 2006JNS 31

Around TailheadAround Tailhead

Whole HideWhole Hide

CATTLE HIDE WASHING

0

2

4

6

8

10

12

Untreated Water 0.5% CPC 1.0% CPC

E. coli O15:H7Salmonella TyphimrumListeria monocytogenesHosingHosing “Beauty Parlor”“Beauty Parlor”

5660Chlorine

Salmonella Positive (%)Treatment

5250Lactic acid

4036Double wash7258Single wash

PosttreatmentPretreatment

N=90; Mies et al. (J. Food Prot. 2004. 67:579582)

23 June 2006JNS 32

CATTLE HIDE WASHING

1.30.040.60.01Chlorine

Mean Log Reduction(%)Treatment0.7Control1.32Lactic acid3.345.16

5.270Ethanol

4.863.842.42Acetic acid

Inoculated: 6.1 Log Salmonella; Mies et al. (J. Food Prot. 2004. 67:579582)

23 June 2006JNS 33

Preharvest

Postprocessing

SLAUGHTER INTERVENTIONS

23 June 2006JNS 34

CATTLE CHEMICAL DEHAIRING

Graves Delmore et al. (1996)

1.10.7 0.9

7.7

4.84.4

E.coli Salmonella L. monocytogenesMicroorganism

0

1

2

3

4

5

6

7

8 Inoculated DehairedBa

cter

ial C

ount

s(lo

g C

FU/c

m²)

Hide samples

23 June 2006JNS 35

KNIFETRIMMING, STEAMVACUUMING,SPRAYWASHING

KnifeTrimming

Steamvacuuming

Carcass sprayingwashing

23 June 2006JNS 36

CARCASS DECONTAMINATION

Percent Positive

Treatments Listeria Salmonella E. coliO157:H7

Control 44 30 0.7

Trimmed (T) 25 8 2.1

Washed (W) 27 9 0.7

T + W 13 1.4 1.4Reagan et al. 1996. J. Food Prot. 69:751756

Commercial Beef Decontamination in 6 Plants

23 June 2006JNS 37


ThermalHot water (>74oC)Pressurized steam

*

Control

Trim/Wash

No Trim/Hot WaterRinse (77°C, 2.5 sec)

N = 96 carcasses per treatment

abcdeP < 0.05

Trim/Hot Water Rinse(77°C, 2.5 sec)

No Trim/Hot WaterRinse (77°C, 8 sec)

Trim/Hot Water Rinse(77°C, 8 sec)

1.9a

0.3d

0.5c

0.3de

0.6b

0.1e

0 0.5 1 1.5 2

TCC (log CFU/cm²)

±0.5

±0.4

±0.5

±0.4

±0.6

±0.1


4.83.53.62.91.45.698.92.71.71.61.305.693.3

0.70.200.20.15.787.81512963InitialoC

Salmonella Reduction(log CFU/cm2)Following SteamPasteurization of Prerigor Beef for VariousTimes (sec)

Retzlaff et al. 2004. J. Food Prot. 67:16301633

23 June 2006JNS 38


Chemical; Organic Acid RinsingLactic or Acetic (1.55%; 55oC)

*

E. coli O157 Reductions (log CFU)Treatments Carcass site variationTrimming 3.2 3.3Water (W) 2.0 3.0W/Lactic acid (2%; 55oC) 3.0 4.2W/Acetic acid (2%; 55oC) 2.4 3.0

Hardin et al. 1995. J. Food Prot. 58:368374

Salmonella Reductions (log CFU)Treatments Carcass site variationTrimming 2.9 3.9Water (W) 2.2 –2.5W/Lactic acid (2%; 55oC) 3.4 –5.0W/Acetic acid (2%; 55oC) 3.2 –5.1

23 June 2006JNS 39

MULTIPLE INTERVENTIONSSequential application of:

Animal cleaningChemical dehairingKnifetrimmingSteamvacuumingPreevisceration washingFinal carcass washingChemical and/or thermalCarcass chilling

Combinations of treatments:Warm acid solutionsSteam and vacuum

PEW PEW PEW PEW PEWAAR AAR AAR AAR AAR

FW FW FW FWHWR AAR HW R

0.0

0.7

0.1 0.2

0.6 0.5

1.0

0.5

1.3

1.7

1.2

2.2

1.8

2.3

2.9 2.8

0.0

0.5

1.0

1.5

2.0

2.5

3.0

5.4 7.9 (log CFU/cm²)2.8 3.7 (log CFU/cm²)

Initial Contamination:

Decontamination Treatments


23 June 2006JNS 40

CARCASS DECONTAMINATIONContamination concerns following slaughter:

ChillingFabricationPostfabrication

New and additional contaminationCrosscontaminationSpreading and redistributionMicrobial growthSanitation and hygieneTemperature/TimePotential decontaminationProcessing / Packaging

23 June 2006JNS 41

7.9

25.7

19.1

15.6

7.9

0.7 0.9 0 0.9 0.8

Carcass Subprimals Subprimals Retail Retail0

5

10

15

20

25

30

% P

ositi

ve

Salmonella L. monocytogenes

Cuts (48h)

Packing Plant Retail Store(n=126)

Cuts (0h)(n=222)

(n=444)(n=576)(n=288)

Kain et al. (1996)

MEAT RECONTAMINATION (6 Plants)

23 June 2006JNS 42

0

2

4

6

8

10

0 2 4 6 8 10 12 14 16

Control

Hot Water (75°C, 30 s)

Lactic Acid (2%; 55°C, 30 s)

Hot Water –Lactic Acid

Lactic Acid –Hot Water

Log

CFU

/cm

2

Log

CFU

/cm

2

Storage daysStorage days

Salmonella in Beef

0

2

4

6

8

10

0 2 4 6 8 10 12 14 16

E. coli O157:H7 in Beef

Geornaras et al. (2006)

Storage days

10°C

POSTFABRICATIONDECONTAMINATION

23 June 2006JNS 43


Ideal carcass or meat decontamination:Environment friendlyPlant personnel friendlyConsumer friendlyNo residuesAchieve objectiveEffective against multiple pathogensPractical to applyMaintain product shelflifeDo not mask spoilageCost effective

23 June 2006JNS 44

CARCASS DECONTAMINATIONSUMMARY

Decontamination interventions are useful:Reduce carcass contamination (13 logs)Reduce pathogen prevalenceAssist plants meet regulatory/industry criteria

However, they should be:Evaluated for potential unpredictable risksOptimized for maximum benefits with no risks

Consider potential long term effects of interactingsublethal interventions on the microbial ecology ofplants and raw and readytoeat products

23 June 2006JNS 45

Select treatments, intensity and sequence tomaximize control and minimize selection

Alternate, or use simultaneouslyValidate technologies in the fieldMinimize variationsResearch new technologiesNot readytoeat until processed or cookedPotential benefits:

Reduce probability of illness when productintentionally or unintentionally undercooked

Reduce potential crosscontamination

PATHOGEN CONTROL STRATEGY

23 June 2006JNS 46

FOOD SAFETY RESPONSIBILITIES

Integrated approachFarmtoTableProducer, packer, processor,

distributor, retailer, foodservice and consumer

salmonella interventions€for€beef - meat science

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