results of listeria sampling in crawfish processing plants

RESULTS OFLISTERIA SAMPLING

INCRAWFISH PROCESSING

PLANTS

Project Approach

Study 10 RTE seafood processing plants in the U.S. - 4 smoked fish (2 East Coast & 2 West Coast)

- 4 crab (Chesapeake) & 2 crawfish (Louisiana) Year 1 (2001) – Track and evaluate Listeria

contamination patterns in each plant using molecular DNA subtyping techniques

Year 2 (2002) - Implement and evaluate intervention strategies & their effectiveness

Year 3 (2003) – Conduct industry workshops to facilitate industry use of effective Lm controls

Summary of Sampling Results

L. monocytogenes and other Listeria species

were found on live crawfish

Assume there are Listeria on every

uncooked crawfish entering your facility

Standard industry cooking process destroys

Listeria Achieve an internal temperature of 180ºF

Based on destroying pathogens

Summary of Sampling Results

Primary risk of Listeria on processing surfaces

and final product is through in-plant cross-

contamination

L. monocytogenes in finished product is a serious

health risk to the consumer

Discovery of Lm in your final product puts

your business at risk to regulatory actions

Sampling Overview

Sampling Goal - determine potential sources of Listeria and

its spread through the process Two crawfish plants participated Two seasons – weekly sampling

2001 & 2002 Listeria control strategies training were given between

seasons As the study progressed in the two plants, sampling

locations were added

Sampling Sites

Divided into 5 groups Raw Product samples Raw/In-Process areas Cooked/In-Process areas Food Contact Surfaces Finished Product samples

Sampling Sites Crawfish product samples (raw &

finished) were collected Surfaces were sampled by wiping with a

moist collection sponge Non-food contact

doors, drains, sinks, sealer, underneath tables Food contact

colanders, tables, trays, scale, hands

Industry Production Notes

Production for 2001>>2002 for both plants ~ 4 – 5 times greater

2001 harvest ~ 90% from ponds

2002 ~ 30%-50% from wild harvest

Microbiology data & results

Different numbers & colors mean different Lm (pathogens) ribotypes

L.ssp means Listeria (non-pathogens) other than monocytogenes

Raw & Finished product had six lots tested at each sampling week

“-” means no Listeria were found

Plant C1-Raw Product

Confirms presence of Listeria on live crawfish Raw crawfish are source of Listeria Multiple ribotypes (strains) of Lm and other

Listeria species 2002 season larger incidence of Listeria

4 – 5 times greater production

C1-Raw/In-Process

Shows presence of Listeria and potential growth Potential of cross-contamination from raw, live crawfish:

Live crawfish falling on floor Employees – handling raw, then cooked crawfish

Handling raw crawfish, then area surfaces Travel between live collection/handling area and

cook room Leaving raw crawfish containers in cook room/floor

C1-Cooked/In-Process

Further confirmation of kill step during cooking Potential cross-contamination from raw

process area Drains – single largest area of incidence

Difficult to control & remove Listeria once it is introduced A mostly wet, moist environment

Favorable condition for Listeria growth

Drain-to-Drain

Potential methods of contamination Back-up/overloading of drains

All rooms same connected system Via floors, travel between rooms

Employees, equipment Control or stop employee travel between

rooms Control equipment movement between

peeling and packing rooms

C1-Non-food Contact Surfaces

Doors Example of potential cross-contamination

Employee movement between rooms Live/raw crawfish to hands to doors Contaminated equipment or clothing to hands to

doors Packing Room door

Control employee movement Peeling Room into Packing Room Packing Room into Peeling Room

C1-Food Contact Surfaces& Finished Product Samples

End of Process, Highest Consequence Control at beginning, decrease risk at end No incidence of Listeria

Confirms cooking process kills Listeria Achieve internal temperature of 180ºF

Maintain control of product, equipment and employee sanitation and cross-contamination

Plant C2-Raw Product & Raw/In-Process Areas

Again, confirms presence of multiple Listeria on live crawfish

Greater incidence of Listeria in 2002 Listeria harborage in drains, similar to C1

No Lm found though No incidence found on employee hands

C2-Cooked/In-Process &Non-food Contact Surfaces

Potential cross-contamination from raw, live crawfish Drains & Doors

Listeria in peeling room, not in packing room drains – does includes Lm

Mostly continuous wet, moist environment Favorable condition for Listeria growth

Listeria found on packing room door Similar to plant C1

C2-Food Contact Surfaces

Repeated incidence of Listeria found Contamination of processing equipment

Possibly trays on floor Listeria found in peeling room drain

Trays back onto table Contamination of table

Similar risk if product gets onto floor then table

C2-Finished Product Samples

Single incidence of Listeria confirms importance of preventing cross-contamination

Listeria on food product surfaces provides high risk of contamination of finished product Tables, trays, colanders

Need to control cross-contamination throughout process to prevent Listeria in packaged tail meat

Overall Conclusions Live crawfish are a source of Listeria

monocytogenes and other bacteria Proper crawfish cooking process kills Listeria Facilities can still possess Listeria

Drains were the main location of contamination Cross-contamination of food processing

surfaces and equipment can lead to Listeria in your finished product

Overall Conclusions

Preventing cross-contamination is Critical Live crawfish to plant surfaces Live product to cooked product Contamination of surfaces between cook, peeling,

and packing rooms Equipment to product

Food Safety, Product Quality, Good Business

Acknowledgements Johnathan Walker for collecting plant

samples Martin Wiedmann’s Laboratory at Cornell

for microbiological testing and analysis USDA Food Safety Initiative for project

funding