Salmonella and E.coli both are a type of bacteria. However, they are entirely different from each other. If you are experiencing symptoms like food poisoning or diarrhea, you might be wondering if these two are interchangeable bacteria. Following is the detailed explanation of the source, incubation period, symptoms as well as transmission of these bacteria.

Table of Contents

Differences between Salmonella and E. Coli


Salmonella is part of a group of bacteria that includes 2500 types of bacteria. In fact, it has evolved from E.coli 100 million years ago. Salmonella is most commonly found in raw poultry, eggs, and beef. It is also found on unwashed fruit and vegetables that have been in contact with dirt or fecal matter.

It is one of the most common causes of foodborne illness. The symptoms include fever, diarrhea, abdominal cramps, fever, and headache. These symptoms usually last anywhere between 4 – 7 days. Contamination occurs when these foods are not cooked properly. Salmonella is transferred when these foods come into contact with an animal or human feces.

Usually, it does not require hospitalization and should clear out on its own. However, it can get more severe in the case of elderly, infants, and also people with chronic conditions. It is generally treated with antibiotics. It can, however, lead to a condition called Reiter’s syndrome. This condition is associated with joint pain, painful urination, as well as irritation in your eyes. If it worsens, there could be long-term complications.

Furthermore, salmonella is highly contagious. It can be transferred by direct contact such as saliva, fecal/oral spread, and kissing or indirect contact such as using contaminated shared eating utensils.


E. coli or Escherichia coli are part of the healthy gut bacteria found in your intestines. They are mostly harmless and help maintain your stomach’s ecosystem. However, it has some pathogenic strains as well. These strains can make you unwell and also cause diarrhea. It takes about 2 to 10 days for the symptoms to show after infection.

E.coli is also transmitted via contaminated food. Food that has been improperly handled or in some way come in contact with an animal or human feces. A common symptom of E.coli infection is a bloody stool. In worse cases, it can sometimes cause kidney failure and even death. However, these complications are more likely for children, elderly or adults with weak immune systems.

Not all E. coli are the same. There are stains that cause food poisoning. It is either transferred from animals as it may have existed in the GI tract of the animal or via surface contamination. One of the common strands called E. coli 0157 can cause complications like hemolytic uremic syndrome.

Depending on the strain and the infection type, E. coli may or may not be contagious. Some strains that are responsible for causing gastrointestinal problems can be transmitted. This usually happens by the oral or fecal route. It can also spread indirectly by contaminated food or water.

How to Keep Yourself Safe?

  • Wash fruits and vegetables properly before consuming
  • Wash hands before eating or handling food as these bacteria can transfer via handshakes.
  • Make sure your meat is cooked thoroughly. Take special care especially when cooking chicken.
  • Make sure that clean drinking water flowing through your taps.
  • Avoid unpasteurized milk and juices
  • Ensure proper refrigeration of food within two hours of cooking.
  • Avoid public pools as these bacteria can spread through contaminated water.

When Should You Go to the Hospital?

Both these types of bacteria cause diarrhea. So when you are vomiting too much or if you feel like you can barely keep any food down, you should go to the hospital. Similarly, in the event of bloody stools, you should seek medical attention at once. People who already suffer from other medical conditions or diabetes should not wait around for their symptoms to get worse.

As children, elderly, and people with compromised immunities are likely to experience complicated symptoms, they should be taken for a check-up as soon as an infection is suspected.

Additional Facts

  • The probability of contaminations of salmonella and E.coli will double every 30 mins that your food is left out without refrigeration.
  • Typically, it takes about 3-4 days for diarrhea to begin after the ingestion of these bacteria.


(Last Updated on June 17, 2020 by Sadrish Dabadi)

Nina Howell is a Rewenable Energy researcher and consultant based out of Houston, Texas Area. She earned her Master's Degree in Energy and Earth Resources from Austin Jackson School of Geosciences in 2010, and a Bachelor's Degree in Environmental Science from State University of New York College of Environmental Science and Forestry in 2008. Nina has been working in the energy sector since 2011. She worked as an Energy Supply Analyst from 2011 to 2017 in Bounce Energy and then as a Research and Energy Consultant at GE Renewable Energy from March 2017 to February 2020 . Nina is a mom of 2 beautiful children who are joy to her life. She strongly believes in eco-friendly living and is vocal about renewable energy, environmental issues, water crisis, and sustainable living.