Whats the difference between salmonella and food poisoning


Mar 08 2022

Whats the difference between salmonella and food poisoning


Salmonella is the second most common intestinal infection in the United States. More than 7,000 cases of Salmonella were confirmed in 2009; however, the majority of cases go unreported. The Centers for Disease Control and Prevention estimates that over 1 million people in the U.S. contract Salmonella each year, and that an average of 20,000 hospitalizations and almost 400 deaths occur from Salmonella poisoning, according to a 2011 report.

Salmonella infection usually occurs when a person eats food contaminated with the feces of animals or humans carrying the bacteria. Salmonella outbreaks are commonly associated with eggs, meat and poultry, but these bacteria can also contaminate other foods such as fruits and vegetables. Foods that are most likely to contain Salmonella include raw or undercooked eggs, raw milk, contaminated water, and raw or undercooked meats.

Symptoms of Salmonella infection, or Salmonellosis, range widely, and are sometimes absent altogether. The most common symptoms include diarrhea, abdominal cramps, and fever.

Typical Symptoms of Salmonella infection: Appear 6 to 72 hours after eating contaminated food and last for 3 to 7 days without treatment.

• Diarrhea

• Abdominal Cramps

• Fever of 100 F to 102 F

Additional symptoms:

• Bloody diarrhea

• Vomiting

• Headache

• Body Aches

Escherichia coli (E. coli) are bacteria that live in human and animal intestines. Shiga toxin-producing strains of E. coli, or STECs, are responsible for most food-related E. coli infections. E. coli O157:H7 and other STECs like E. coli O145 and E. coli O121:H19 produce a toxin called Shiga toxin, which causes illness in humans. E. coli bacteria do not make animals such as livestock and deer, which harbor the bacteria in their intestines, ill.

E. coli O157:H7 is most commonly found in cows, although chickens, deer, sheep, and pigs have also been known to carry it. Meat becomes contaminated during slaughter, when infected animal intestines or feces come in contact with the carcass. Ground or mechanically tenderized meats are considered riskier than intact cuts of meat because E. coli bacteria, can be mixed throughout the meat in the grinding process or during tenderization.

Other foods that sometimes become contaminated with E. coli bacteria include unpasteurized milk and cheese, unpasteurized juices, alfalfa and radish sprouts, lettuce, spinach, and water. However, any food is at risk of becoming contaminated with E. coli through cross-contamination. One can also get E. coli bacteria from contact with feces of infected animals or people.

E. coli symptoms change as the infection progresses. Symptoms usually begin two to five days after infection. The initial symptoms include the sudden onset of cramps and abdominal pain, followed by diarrhea within 24 hours. Diarrhea will become increasingly watery, and then noticeably bloody. People with E. coli infection also often feel nauseated and experience headaches. Less common symptoms include fever and chills.

Hemolytic Uremic Syndrome, or HUS, follows around 10 percent of E. coliO157:H7 infections. HUS occurs when Shiga toxins get into the bloodstream and cause the part of the kidney that filters toxins out of the blood to break down, causing kidney injury and sometimes kidney failure. Some HUS patients also suffer damage to the pancreas and central nervous system impairment.

The main difference between E Coli and salmonella is that E. coli is a type of commensal bacteria that commonly lives in the lower intestine of warm-blooded animals whereas Salmonella is a facultative, intracellular pathogen in both warm-blooded and cold-blooded animals. Although most E. coli strains are harmless, some can cause serious food poisoning through food contamination. Salmonella, on the other hand, can cause typhoid fever, and paratyphoid fever through food-borne infection.

E. coli and Salmonella are Gram-negative bacteria of the family Enterobacteriaceae. Generally, they are rod-shaped, non-spore-forming, facultative anaerobes. Their pathogenic species use the faecal-oral contamination route for spreading. 

Key Areas Covered 

1. What is E. coli
     – Definition, Characteristics, Importance
2. What is Salmonella
     – Definition, Characteristics, Importance
3. What are the Similarities Between E. coli and Salmonella
     – Outline of Common Features
4. What is the Difference Between E. coli and Salmonella
     – Comparison of Key Differences  

Key Terms 

Commensal, E. coli, Gram-Negative Bacteria, Intracellular Pathogen, Salmonella, Warm-blooded Animals

Whats the difference between salmonella and food poisoning

E. coli (Escherichia coli) is a Gram-negative bacterium of the family Enterobacteriaceae. Therefore, it is a rod-shaped bacterium that is a facultative anaerobe. Thus, E. coli can switch between aerobic respiration and fermentation according to the presence and absence of oxygen. It is also a type of coliform bacteria. The two main characteristic features of a coliform bacterium include living in the intestine as an ecological resident and the ability to ferment lactic acid, producing gas.

Whats the difference between salmonella and food poisoning

Figure 1: Gram Staining of Gram-Negative E. coli and Gram-Positive Staphylococcus 

Furthermore, E. coli is a commensal that produces beneficial effects such as the production of vitamin K2. It also prevents the colonization of the pathogenic bacteria in the intestine. It is a harmless, normal part of the microbiota of the gut. E. coli is expelled into the environment along with the faecal matter. In rare cases, food contamination can allow some serotypes of E. coli to cause serious food poisoning. 

What is Salmonella 

Salmonella is a pathogenic bacterium in the family Enterobacteriaceae. It is a rod-shaped, Gram-negative bacterium and a facultative anaerobe. Along with E. coli, Salmonella is a type of campylobacteria that occurs in the gut of the infected individuals. In addition to these, the common symptoms of campylobacter bacteria infections include diarrhoea, stomach pain or cramps, flu-like symptoms, nausea, and vomiting. Generally, campylobacter bacteria appear in 1-10 days of infection, and the symptoms last for less than 10 days.

Whats the difference between salmonella and food poisoning

Figure 2: Salmonella Typhimurium – Gram Staining

Moreover, there are two species of Salmonella. They are Salmonella enterica and Salmonella bongori. The former infects warm-blooded animals while the latter infects cold-blooded animals, particularly reptiles. Moreover, nontyphoidal Salmonella can be invasive and cause paratyphoid fever, which requires immediate treatment with antibiotics. In contrast, typhoid subtypes of Salmonella cause typhoid and paratyphoid fever. Most importantly, typhoid fever can generate life-threatening conditions such as hypovolemic shock and septic shock as the typhoid form invades the bloodstream and the septic form invades organs and secretes endotoxins. 

Similarities Between E. coli and Salmonella  

  • E. coli and  Salmonella are two types of bacteria that belong to the family Enterobacteriaceae.  
  • Both are rod-shaped, non-spore-forming, Gram-Negative bacteria.  
  • Moreover, they are facultative anaerobes that can switch between fermentation and aerobic respiration according to the absence or presence of oxygen.    
  • They mainly live in the intestine of animals.  Both can also cause diseases in animals. Therefore,  they are campylobacter bacteria that appear 1-10 days of infection.  
  • Both types of bacteria are present in faeces and later contaminate food and water. 

Difference Between E. coli and Salmonella 

Definition

E. coli refers to a bacterium commonly found in the intestines of humans and other animals; some strains can cause severe food poisoning, while Salmonella refers to a bacterium that occurs mainly in the gut, especially a serotype causing food poisoning. 

Type of the Host

E. coli commonly lives in the lower intestine of warm-blooded animals, while Salmonella lives in both warm-blooded and cold-blooded animals.  

Size

E. coli is about 2.0 μm long and 0.25–1.0 μm in diameter, while Salmonella is about 2 to 5 μm long and 0.7 and 1.5 μm in diameter. 

Coliform or Non-Coliform

Moreover, E. coli is a type of coliform bacteria, while Salmonella is a type of non-coliform bacteria. 

Mode of Living

E. coli is a type of commensal bacteria, while Salmonella is an intracellular pathogen. 

Effect on the Host

While E. coli is typically harmless and produces vitamin K2, Salmonella is pathogenic. 

Type of Diseases Caused 

Some E. coli strains can cause serious food poisoning through food contamination, while Salmonella can cause typhoid fever and paratyphoid fever through food-borne infection. 

Appearance of Symptoms 

The symptoms of E. coli appear in 2-10 days after infection, while the symptoms of Salmonella appear 6-72 days after infection.  

Conclusion

E. coli is a type of Gram-negative, rod-shaped bacteria that live in the intestine of animals. Therefore, it is a facultative anaerobe and produces vitamin K2. It is a commensal, usually harmless to the host. However, some strains can cause food poisoning. Salmonella is also a type of Gram-negative, rod-shaped bacteria that belong to the same family. However, it is an intracellular pathogen that causes typhoid and paratyphoid fever. Hence, the main difference E Coli and Salmonella is their mode of living. 

References:

1. Felson, Sabrina. “E. Coli Bacteria Infection: Symptoms, Treatment, Causes & Prevention.” WebMD, WebMD, 15 Dec. 2018, Available Here.
2. “Campylobacter, E.Coli and Salmonella.” HealthEd, Available Here.

Image Courtesy:

1. “Gram stain 01” By Y tambe – Y tambe’s file (CC BY-SA 3.0) via Commons Wikimedia    
2. “Salmonella Typhimurium Gram” By Y tambe – Own work (CC BY-SA 3.0) via Commons Wikimedia   

Whats the difference between salmonella and food poisoning

Is salmonella the same as food poisoning?

Salmonella is one of the most common forms of food poisoning. Over a million people in the U.S. alone get salmonella every year and 26,500 are hospitalized. There are about 420 deaths due to salmonella every year in the U.S.

What are 3 symptoms if you get salmonella?

Most people with Salmonella infection have diarrhea, fever, and stomach cramps. Symptoms usually begin six hours to six days after infection and last four to seven days.

Is food poisoning always salmonella?

Food poisoning is an illness caused by eating contaminated food. It's not usually serious and most people get better within a few days without treatment. In most cases of food poisoning, the food is contaminated by bacteria, such as salmonella or Escherichia coli (E. coli), or a virus, such as the norovirus.

Can salmonella go away on its own?

Illness from these bacteria is officially called salmonellosis. It can cause an upset stomach, diarrhea, fever, and pain and cramping in your belly. Most people get better on their own at home within 4 to 7 days.