If you love moist biltong, read this

A study conducted by the University of Pretoria (UP) on the prevalence of food-borne Listeria monocytogenes in beef and beef production reveals concerns regarding the levels of the listeriosis-causing pathogen across the beef production system.

The study was conducted by UP’s team of experts at some abattoirs and retailers in Gauteng, Mpumalanga and the North West.  

The research by the faculty of veterinary science and the Agricultural Research Council-Onderstepoort Veterinary Institute (ARC-OVI) showed that, among other findings, 4.6% of chilled carcasses sampled at seven abattoirs in one of the provinces were contaminated with Listeria monocytogenes.  

This meant that contaminated carcasses had the potential to enter the food chain as beef and beef products sold at retail outlets in the province.  

Listeria monocytogenes is a food-borne pathogen that causes listeriosis, a life-threatening disease that could cause miscarriage and stillbirth among pregnant women. 

Most human cases are associated with the consumption of ready-to-eat foods, and the risk of illness increases with the number of cells ingested. The pathogen is able to survive and multiply at the refrigerated temperatures at which foods are stored to prevent spoilage. 

Talking to eNCA, Dr Rebone Moerane, head of UP’s department of production animal studies, who was part of the research team along with Prof Abiodun Adesiyun, Dr Nomakorinte Gcebe of the ARC-OVI and four postgraduate students, said they wanted to see through the value chain the prevalence of listeriosis.  

“Where are the risk factors in terms of this bacteria, our results so far are indicating some serious challenges with regard to abattoirs and highly at retailers. That’s where we really need to take action and interventions,” said Moerane. 

“Because of potential contamination during slaughter, carcasses can become contaminated, leading to contaminated meat and meat products. A wide variety of foods – including beef, pork, poultry and milk-based products – have been reported to harbour the pathogen and cause listeriosis among consumers.”

The study was funded by Red Meat Research and Development South Africa after the 2017 and 2018 outbreak of listeriosis in the country, which led to 1,060 confirmed cases and about 216 deaths. It was conducted at three levels of beef production:

• samples of faeces, feeds, silage and water were collected from cattle farms;
• carcass swabs were taken from abattoirs, as were samples of faeces and effluents; and
• samples of raw beef and beef products (including ready-to-eat items) were collected from retail outlets of all sizes. 

The study also set out to determine the prevalence and factors associated with the pathogen in cattle, silage, feeds and water on farms in the three provinces, in slaughtered cattle and carcasses at processing plants, and the prevalence and factors associated with the contamination of beef and beef products at retail outlets. 

Some of the serotypes of Listeria monocytogenes detected by the team belong to serogroups known to have the potential to cause human listeriosis.  

The researchers found that the risk of exposure of cattle to listeriosis on farms is minimal. However, the detection of 4.6% of chilled carcasses sampled at Gauteng abattoirs being contaminated with Listeria monocytogenes was troubling, as are the findings at retail outlets.  

The team recommended that the government, in collaboration with industry partners, implement stringent food safety measures at abattoirs and processing plants to reduce contamination and lower the possibility of another listeriosis outbreak.  

It also recommended a follow-up study of moist biltong to determine its ability to support the growth of the pathogen and assess the risk posed to consumers. 

“The unfortunate part in the country is that the meat legislation is fragmented because if you look at the meat in terms of abattoirs, it is veterinary services under the department of agriculture who are responsible for ensuring there is monitoring and abattoirs are following the right processes in the production of the meat,” said Moerane.  

With the results of the study, the department of agriculture and the red meat industry were implementing measures to ensure that abattoirs properly clean the facilities to ensure they reduce the risks, he said. 

“Our biggest concern is more at the retailer level. What is happening there we don’t have a clue. Are municipalities implementing the right measures in doing proper inspection and surveillance monitoring? That is of concern.”

TimesLIVE