Durban - Leafy vegetables such as lettuce and spinach are among the fresh produce found to be contaminated with the highest levels of microbes.
A study that is under way into food safety has also reported for the first time the presence of the norovirus of swine origin on fruit – in this case, strawberries.
Funded by the Water Research Commission, the research is led by the departments of plant science and food sciences at the University of Pretoria, and the department of microbiology at the University of KwaZulu-Natal.
Some of the results are given in the latest edition of the commission’s Water Wheel magazine, and reveal that E coli levels in irrigation-water sources often exceed 1 000 colony-forming units to 100ml, the allowable maximum set by the World Health Organisation and the Department of Health.
“Genotyping of hepatitis A virus and sapovirus strains isolated from irrigation water samples showed they were of human origin. This indicates that human faeces were the most likely source of contamination.
“This poses a clear health risk to consumers.”
The study also found microbial levels on crop surfaces often exceeded the microbiological guidelines of the Department of Health for ready-to-eat fresh fruit and vegetables.
“Researchers found a strong correlation between irrigation-water sources and pathogen presence on fresh produce. In addition, the E coli isolates from irrigation-water sources were often found to be resistant to multiple antibiotics by up to 42 percent,” notes the article, compiled by academics at the University of Pretoria.
Independent on Saturday