What Is Alfalfa Sprouts

One of my favourite sandwiches from a local eatery features alfalfa sprouts, but I've heard some cautionary tales about their safety. This class has led me to consider the type of bacteria that may be growing in the sprouts and become informed about the risks of consuming them raw.

A study in 2008 which tested the bacterial DNA purified from 4 retail samples of alfalfa sprouts from different producers in various regions of the United States found that most bacteria are Enterobacteriaceae, a large family of gram negative bacteria, including Salmonella, Escherichia coli (E. coli), and Shigella as well as Listeria (a gram positive bacterium) (1). Understanding the bacteria in alfalfa sprouts and other fresh produce such as salad is important as they are typically eaten raw and therefore entire bacteria communities that are introduced in the growing process are consumed with them.

The main source of contamination is likely the seeds themselves, which may harbour bugs within the germ or be contaminated by bird or rodent feces during harvesting, storage or transportation (2). Typically sprouts are grown in soil free conditions; however, a source of bacteria in field productions could be water tanks and irrigation hoses, as well as irrigation water and run-off from lakes, rivers, or livestock pastures (1). Indoor growing facilities can provide a breeding ground for bacteria through improper equipment sanitation and poor hygiene of