Guess That Bacterium!

Salmonella, a potentially dangerous bacterium, is often associated with raw eggs.
Courtesy: Bill Marler, www.marlerblog.com

      Food poisoning is an unconvenient part of life. Though foods can be prepared with the proper guidelines, bacteria and viruses can sometimes evade these safeguards and cause illness upon ingestion. In the case that infections spread through a population, it is the Center for Disease Control and Prevention (CDC) that conducts investigations to identify the sources of foodborne illness.

      For potentially serious outbreaks, whole genome sequencing has recently been adopted to identify causative pathogens. Whole genome sequencing allows for the elucidation of all DNA sequences within an organism, and this method has been a useful tool for distinguishing organisms within a species. Recently, the CDC has embarked on a project to identify several strains of Listeria involved in outbreaks this year. This work will be carried out with whole exome sequencing, and this venture is exciting because Listeria strains responsible for these cases may be detected more accurately. The probability that two bacterial strains will be 100% genetically identical is extremely low; therefore, this testing option may distinguish pathogenic bacteria and viruses more effectively.

       If this project is successful, the CDC will have a robust protocol for identifying the sources of illness within the population. In addition to recognizing bacterial and viral agents efficiently, whole genome sequencing can illuminate the diversity that exists between strains and the mechanisms by which this diversity arose (e.g. genetic mutations). Though this prospect is a step forward in understanding the genetic landscape of pathogens, we should still enjoy that next burger safely!