The science side has been initiated by microbiologists working at Michigan State University. Working with the local farming community, a study has discovered that when dairy cattle come under elevated levels of stress, as might arise from hot weather or the energy loss stemming from milk production, such cattle are far more likely to shed high levels of Shiga toxin-producing Escherichia coli.
E. coli consists of a diverse group of bacteria. Pathogenic E. coli strains are categorized into pathotypes. Once such type is Shiga toxin-producing E. coli (or enterohemorrhagic E. coli). This pathotype is a common cause of foodborne outbreaks. This organism produces a dangerous toxin. Food or water can be contaminated with the bacterium, and farm cattle are a prominent source (at least according to social media, there are many tweets currently trending on the subject of farms and E. coli.)
These organisms present a major health concern, inducing bloody diarrhea, leading to hemolytic-uremic syndrome, a disease characterized by hemolytic anemia, in 10 percent of cases. This carries a risk of mortality.
The reference to “shedding,” with the dairy cattle, refers to the process of expelling bacteria from the body (by any orifice, although feces is the most common route.) The variations in shedding according to cattle stress came through observations and tests on over 1,000 cattle from six dairy farms and five feedlots in Michigan.
The new research consists of a systematic review of prevention practices, designed to lower the incidence rate. This includes proposing new cattle management strategies, such as the isolation of high-risk cows.
The next wave of the research will look at how many different types of Shiga-producing E. coli are often in the typical farm, how they are shed, and how quickly a cow, free from the organism, becomes re-contaminated and how this occurs.
The research has been published in the journal Applied and Environmental Microbiology. The research paper is titled “Factors associated with Shiga toxin-producing Escherichia coli shedding in dairy and beef cattle.”
In related news, the Society for Applied Microbiology (SfAM Microbiology @SfAMtweets) has indicated, via Twiter: “”From farm to fork” – Bernhard Merget aims to develop a risk assessment on the dangers of verocytogenic E coli in fresh produce.” This adds to the highlighted research paper.
