Introduction

Escherichia coli (E. coli) bacteria normally live in human and animal intestines. Most E. coli are harmless and are an important part of a healthy human intestinal function. However, some E. coli are pathogenic, meaning they can cause illness.

Pathogenic E. coli cause disease by making a toxin called Shiga toxin. The type of E. coli that make these toxins are called Shiga toxin-producing E. coli, or STEC for short.

STEC cause human illnesses, which can range from mild diarrhea to very severe and life-threatening conditions, including death.

The STEC strain most frequently associated with human illness in North America is serotype O157:H7. However, several other E. coli serotypes (O26, O45, O103, O111, O121, and O145) are also commonly associated with severe illness in humans.

In 2017, Public Health Ontario reported 129 cases of foodborne illnesses and one death caused by STEC in the province of Ontario.

What you can do on-farm to reduce the presence of STECs in meat

Research results have shown that the dirtier the hide, the greater the potential for carcass contamination and the higher the risk to human health. More particularly, if hides are contaminated with fecal material at the time of slaughter, there is a greater risk of the meat becoming contaminated with pathogenic bacteria such as STECs during dressing.

Farmers can assist abattoir operators in reducing the risk of contamination on the meat from slaughtered animals by making sure that only clean cattle intended for slaughter are shipped from the farm.

This can be a difficult task, since cattle cleanliness is particularly affected by diet, housing, cattle health, weather conditions and the cost of bedding materials.

In addition, evidence suggests visible and bacterial cleanliness declines with increasing transport time and distance. It is advisable for farmers to:

  • keep cattle clean, hides free of manure tag, and house them with sufficient clean bedding
  • modify the diet, or withdraw food for a short time before transport, to reduce fecal soiling, or feed a straw diet for 1-2 days prior to transport
  • use a reputable hauler for cattle that will avoid mixing animals and arrive at the farm with clean, disinfected and well-ventilated trailers that have fresh bedding in them

It is in both the producers' and the abattoir operators' interest to make sure that cattle are clean when presented for slaughter since inspectors will verify compliance with the following section of Ontario Regulation 31/05:

68. (3) If the condition of a food animal would likely cause contamination during the dressing of its carcass, the operator of a slaughter plant shall ensure that the animal is not presented for slaughter.

The operator may need to:

  • retain dirty animals
  • alter the order of slaughter
  • and/or take additional time during dressing to decrease the risk that contaminants from the hide get onto the carcass

All these measures can result in delay and extra costs for both producers and abattoir operators.

Cleanliness of animals presented for slaughter contributes to the production of safe meat, minimizes the risk to human health, improves the shelf life of the meat, increases consumer confidence, and protects industry's reputation and investment.

Microbial control interventions on carcasses

Abattoirs must always use hygienic slaughter and dressing practices so that contamination is kept off the carcasses.

However, even the highest standards of abattoir hygiene cannot guarantee the absence of contamination of the carcass or cross-contamination of nearby carcasses during dressing. Bacteria are often unintentionally transferred from the fecal material, gastrointestinal tract, hide and plant equipment to the surface of the carcass during processing.

Microbial control interventions are being applied to carcasses both during and at the end of dressing to help control any cross-contamination that might have occurred on the kill floor.

Applying microbial control interventions effectively reduces or inactivates bacterial contamination and improves meat safety.

Commonly used microbial control interventions include:

  • organic acid rinses
  • hot water rinses
  • steam pasteurization
  • steam vacuuming
  • dry aging

Each abattoir selects the microbial control intervention that works best for their operation. Below are some of the pros and cons of each type of intervention.

Organic acid rinses are highly effective, can be installed directly into an existing water line for ease of application, and have minimal health and safety concerns for workers.

Hot water and steam, although effective, can be a hazard to workers and increases the likelihood of excessive condensation on the kill floor.

Dry aging requires carcasses to be kept in a cooler that is less than 4°C in temperature and less than 90 per cent relative humidity for at least six days. To prevent cross-contamination and allow sufficient air circulation, cooler storage rails must be placed far enough from refrigeration equipment, walls, columns and other fixed parts. Sides of beef should be placed in the cooler so that there is no contact between them for efficient air circulation. For some operations, limited cooler space prevents this as a viable option for microbial control.

Organic acid rinses on meat

Organic acid rinses are safe for use as microbial control interventions on meat. They are commonplace in the food industry, have been used for many years, and are mandated at federally registered meat processing facilities. Health Canada has expressed no objection to the use of various acid washes as antimicrobial food processing aids to treat the surface of a carcass.

The organic acid wash is applied to the carcass prior to the chill step. During chilling, the acid rapidly dissipates from the carcass. If applied correctly, little evidence of its use should be present.

The acid, as a processing aid, is not considered to be an ingredient, and is therefore not required to be declared on labels under federal regulations.

Organic certification

Lactic acid and citric acid rinses for application to carcasses meet the requirements of the Canadian General Standards Board (CAN/CGSB-32.311-2015) Organic Production Systems - Permitted Substances List as food additives.

The use of these highly effective microbial control interventions will allow your product to remain organic in nature while protecting the public from harmful bacteria.