Auditing and Identifying Contamination Points for Listeria

in Food Plants

Presented by:

Graham Monda

Canadian Recalls

• Mitchell’s Gourmet Foods, Saskatoon: Wieners

• JM Schneider, Kitchener, Ont. sliced luncheon meats

• Golden Valley Farms, Arthur, Ont.: Fletcher’s smoked chicken and smoked turkey breast

• Maple Leaf Foods, Ont. Deli meats, sausage, Canada wide recall

Listeria monocytogenes

• Named for Joseph Lister

• Non-spore forming, Gram-positive rod

• Grows aerobically and anaerobically

• Grows between -0.4 and 50C• Grows at pH 4.4 to 9.6

• Grows at 10% NaCl

• Studies suggest up to 10% of human gastrointestinal tracts may be colonized

Lm is unique

• Grows (slowly) at refrigeration temperatures

• Difficult to inactivate

• RTE contaminated post processing

• Can survive vacuum packaging

• Is ubiquitous

Lm Policy - Canada

(1) RTE foods linked to listeriosis 0/50g

(2) RTE foods, support growth, 0/25g SL>10 days

(3) RTE foods, SL<10days or RTE <100/g foods not supporting growth

CDC Estimated Food-Related Deaths*:

5 Pathogens = 90% of Total

0%

5%

10%

15%

20%

25%

30%

35%

Est. Food-Related Deaths

Salmonella

Listeria

Toxoplasma

Norwalk-likeviruses

Campylobacter

E.coli 0157:H7*Approximately 5,000/year 100/week

What are we dealing with?

• Listeria is the clean plant organism

• To manage Listeria requires change, not only in actions but to our thought process

• This includes, Sanitation Management Training SSOP’S HACCAP

Conduct a Listeria Audit

• Data driven management decisions

• Objective risk assessment

• Identify areas for improvement

• Assess equipment & personnel

• Vehicle for training

• Demonstrate compliance

Purpose of a Listeria Audit

• Evaluate the effectiveness of the environmental sanitation program

• Assist in implementing the QA/QC program– QA - Are we doing the right things? – QC - Are we doing things right?

• Confirm the area’s compliance with procedures

• Identify opportunities for improvement

Stages in a Listeria Audit

Environmental: Floors

DrainsWalls (cracks)

Ceilings, overheadsCat walks

Condensation (bio-aerosols)Wet insulation Standing water

Equipment moving from raw to finished

Sources of Product Contamination

Sources of Product Contamination

Equipment:

Trolleys, forklifts

Cleaning tools

Maintenance tools

Pallets

Sources of Product from raw materials

Raw Materials

Ingredients: MeatsSpices Water BeefSweeteners PorkConcentrates Poultry

Turkey

1) Keep ingredients, raw materials, and products as cool as possible; (below 7 C) during processing, storage, and distribution.

Sources of Product Contamination

Packaging Materials:

Cartons

Cans

Films

Combo’s

Tape

Plastic coverings

Sources of Product Contamination

•Engineering Design– Dead Ends– Cross Connections– Improper Welds– Difficult to Clean Areas– Exposed Insulation – Sandwiched Materials - Niches

Sources of Product Contamination

• Processing Equipment– Smokehouses– Cookers– Coolers– Freezers (Spiral -Blast)– Refrigeration Units– Air handling Units– Seals & Gaskets– Flexible Hosing– Air Baggers

Sources of Product Contamination

• Employees

– Orientation– Operators – Mechanics– Employee traffic

patterns

Sources of Product Contamination

•Employees - GMP’S– Bathroom practices– Washing & sanitizing hands– Footwear

Identify Growth Areas

Limit Microbes Food/Water

Store trash properlyDrains should be properlycleaned and sanitized

Identify Growth Areas

Find the organism’s growth nichesWorn GasketsUnsealed Equipment Areas

Identify Growth Areas

Maintain Air Handling Systems

Identify Growth Areas

Beware of Temporary Repairs!!

The Problem with

High Pressure - Aerosols

Aerosols

Low pressureLow pressure High pressureHigh pressure

Effects of Water Pressure - Aerosols

0102030405060708090

100

after15min

after30min

after45min

after60min

HighpressureLowpressure

Air samplingCounts of micro-organisms in filter on a vacuum system

A high pressure system still leaves more airborne contamination after 45 mins than low pressure after 15 mins

Conclusion

•High Pressure

Not Recommended

Where Listeria is

an Issue

Sanitary Design ofProcessing Equipment

Transmission of Microbes

Brushes shouldbe properlystored

By Brushes/Hoses/Tools:

Transmission of Microbes

By People:

> walking > moving carts> using tools

Moving from a ‘raw’ to‘finished’ area withouthandwashing, cleaningequipment, etc.

Transmission of Microbes

By Vehicles:

Could this Hi-Lo move microbes around?

What is happening here?

Transmission of Microbes

Condensation is a real threat!

Condensation

Exposed product

Outside Factors

Black Mold enteringfrom leak in column

All cracks/gaps should be sealed

Not just open doors, but anyopenings that facilitate insect or rodent and ultimately microbial movement.

“Bulls Eye” Approach to Control

Direct Product Contact• Filling or

packaging equipment

• Conveyors • Chilling solutions• Slicers, dicers,

shredders, blenders (after heating, before packaging)

• Collators• Racks• Hand tools • apparel • Spiral/blast freezers• Bins, tubs, or

baskets

Secondary Level of Concern, Indirect Product Contamination

• Equipment framework and other equipment in the area

• Floors• Drains• Walls and ceilings,

especially if cracked

• Overhead structures, catwalks

• Condensate• Insulation in walls or

around pipes• Walkways• Cleaning tools• Maintenance tools

Tertiary Level; Recontamination of

Processing Area

• Traffic in the processing and packaging areas• people• equipment such as trolleys and

forklifts

• Unscheduled equipment maintenance

Niches, the Dark Holes of Lm Control

• Hollow conveyor rollers

• Slicers, dicers• On/off switches• Rubber seals around

doors• Damp insulation

• Fibrous or porous conveyor belts

• Conveyor scrapers, especially if in poor condition

• Open bearings in equipment

More Niches

• Hollow implements, including box cutters

• Trash cans and other ancillary items

• Standing water in production areas

• Cleaning tools, including mops and sponges

• In-line air filters for compressed air

• Wet, rusting or hollow framework

• Motor housings• Walls/crevices of

spiral freezers;• Ice makers

Lm Control in Niches

•Good control involves identifying the source or niche of the Listeria contamination and eliminating it.

Some Conditions That Have Caused Problems

• Moving or significantly modifying a packaging line

• Installing used equipment brought from storage or another plant

• Equipment breakdown

More “Red Flag” Situations

• Construction or major modifications in an RTE area.

• A new employee, unfamiliar with the operation and L. monocytogenes controls

in the RTE product area.

Keep in Mind………….

• Initially most equipment is of a sanitary design; however, over time it has been welded, repaired, re-positioned to the extent that the sanitary design has now been lost...

LISTERIAEnvironmental survey reported at the AMI List. workshop

• Drains & Trenches 355 samples 133 + 37%• Floors 269 samples 79 + 29%• Condensate 265 samples 19 + 7.0%• Walls & Ceilings 114 samples 6 + 5.0%• Exhaust Hoods 23 samples 5 + 22 %• Brine system 24 samples 2 + 8.0%• Cleaning Aids 86 samples 21 + 24%• Wash Areas 17 samples 4 + 24%• Potable water 25 samples 1 + 4.0%• Compressed air 25 samples 1 + 4.0%• Product contact surfaces 740 samples 152 + 20%• Others 333 samples 50 + 21%• TOTALS 2276 473* 21%

• ** 60% monocytogenes• 40% Other Listeria (All areas Post Processing)

Top Ten

1. Drains, Floors.2. Cleaning equipment.3. Exhaust hoods.4. Condensation.5. Wash areas.

Top Ten

6. Unsanitary welds and niches.7. Tools.8. Staff, operators, maintenance.9. Gaskets.10. Aerosols, high pressure

cleaning.