A few years ago I came back from a vacation to find my office covered in Shigella–not microscopic foodborne illness-causing bacteria, but giant, stuffed Shigella from www.GiantMicrobes.com (pictured, left).  Soon thereafter, my Shigella were joined by E. coli and Salmonella, which now adorn the Christmas tree in the Marler Clark offices.  

On the Giant Microbes website you can find a variety of microbes, from Athlete’s Foot to Swine Flu and the aforementioned foodborne bacteria.  

The microbes look friendly and cute and make a great stocking-stuffer for anyone on your list.  The same can not be said for the real microbes that inspired their design.  

Here is a brief rundown on a few real microbes that won’t be on anyone’s Christmas list this year:

E. coli

Escherichia coli (E. coli) are members of a large group of bacterial germs that inhabit the intestinal tract of humans and other warm-blooded animals.  

More than 700 serotypes of E. coli have been identified.  The E. coli serotypes responsible for reports of contaminated foods and beverages are those that produce a Shiga toxin (Stx), one of the most potent toxins known to man. 

The best-known and most notorious Stx-producing E. coli is E. coli O157:H7, which is responsible for the majority of human illnesses attributed to E. coli.  Ingestion of as few as fifty E. coli O157:H7 bacteria can result in illness.

Symptoms of E. coli O157:H7 infection typically begin between two and ten days after ingestion of E. coli bacteria and include the sudden onset of abdominal pain and severe cramps, followed within 24 hours by diarrhea, which may become bloody.  Vomiting can also be a symptom.  

Most people who become ill with E. coli infection recover within a week without any long-term problems; however, a small percentage–mostly children–develops post-diarrheal hemolytic uremic syndrome (D+HUS), a syndrome that is defined by three symptoms: hemolytic anemia (destruction of red blood cells), thrombocytopenia (low platelet count), and acute kidney failure.  

Additional Stx-producing E. coli, such as E. coli O121:H19, can also cause hemorrhagic colitis and HUS. 

The Centers for Disease Control and Prevention (CDC) estimates that every year at least 2000 Americans are hospitalized, and about 60 die as a direct result of E. coli infection and its complications.

The CDC has estimated that 85 percent of E. coli O157:H7 infections are foodborne in origin.  In fact, consumption of any food or beverage that becomes contaminated by animal (especially cattle) manure can result in contracting the illness. 

Foods associated with E. coli outbreaks include ground beef, venison, sausages, dried (non-cooked) salami, unpasteurized milk and cheese, unpasteurized apple juice and cider, orange juice, alfalfa and radish sprouts, lettuce, spinach, and water.

Campylobacter

Campylobacter jejuni (pronounced “camp-e-low-back-ter j-june-eye”) is another bacterium that lives in the intestines of humans and other warm-blooded animals.  

The bacterium that was first recognized as a cause of human gastrointestinal illness in 1975, but has since been identified as the most common cause of bacterial foodborne illness in the world.

Campylobacteriosis, the illness caused by the injestion of Campylobacter bacteria, is an infectious disease that causes diarrhea, which is often bloody, abdominal pain, malaise, fever, nausea, and vomiting.  The severity of the illness varies from person to person, but usually people who become ill with campylobacteriosis recover completely within 10 days.

For a small number of people, Campylobacter infection may result in long-term health problems.  Campylobacter infection is the most common cause of Guillain-Barré syndrome, which can occur several weeks after a person’s acute symptoms have subsided, and may result in permanent paralysis.  

Over 10,000 cases of campylobacteriosis are reported to the Centers for Disease Control and Prevention (CDC) each year; however, many more cases go undiagnosed or unreported.  Estimates are that Campylobacter causes more than 2 million illnesses, 13,000 hospitalizations, and over 100 deaths each year in the United States. 

Chicken is the most common food implicated in Campylobacter outbreaks; however, the source is unknown for more than 50 percent of campylobacteriosis infections.  Ingestion of as few as 500 bacteria – an amount that can be found in one drop of chicken juice – has been proven to cause human illness. 

Large outbreaks with more than 1,000 reported cases of campylobacteriosis have been documented, most often from consumption of contaminated milk or unchlorinated water supplies.

Salmonella

Salmonella bacteria also live in the intestines of humans and other warm-blooded animals, and have been found in bird, frog, and reptile populations.  

Salmonellosis, the illness caused by Salmonella, is one of the most commonly diagnosed bacterial foodborne illnesses in the United States.  Overall, it is the second most common bacterial foodborne illness reported behind Campylobacteriois. 

The first strain of Salmonella–Salmonella cholerae suis–was discovered in 1885.  Since that time, the number of serotypes of Salmonella known to cause salmonellosis has increased to over 2,300. 

Salmonella typhi, the strain that causes typhoid fever, is uncommon in the U.S., while Salmonella enterica serotype Typhimurium and Salmonella enterica serotype Enteritidis have been the most frequently reported illnesses since 1993.  Salmonella enterica serotypes Newport, Mississippi and Javiana have been increasingly identified as the source of illness. 

Symptoms of Salmonella infection typically occur within six to 72 hours of ingestion of the bacteria, and include the sudden onset of nausea, abdominal cramping, fever, and bloody diarrhea with mucous.  Vomiting is a less common symptom than diarrhea.  

Only about 3 percent of Salmonella cases are officially reported nationwide, and many milder cases are never diagnosed.  The CDC estimates that 1.4 million cases occur annually, with 600 deaths attributed to salmonellosis every year.  Salmonellosis accounts for 31 percent of all food-related deaths in the U.S. 

Although Salmonella is often associated with poultry and eggs, meat, raw milk, sprouts, other produce, and ready-to-eat foods have all been identified as the source of Salmonella outbrea
ks.

Li
steria

Listeria monocytogenes is found in soil and water. Although there are other types of Listeria, most cases of listeriosis are caused by Listeria monocytogenes.

Although healthy people can consume contaminated foods without becoming ill, it is believed that those at increased risk for infection can become ill with listeriosis after eating food contaminated with just a few bacteria.

Listeriosis is a serious infection caused by Listeria that mostly occurs among elderly or immunocompromised people.  Adults can become infected with listeriosis by eating food contaminated with Listeria and babies can be born with listeriosis if their mothers eat contaminated food during pregnancy.  Infections during pregnancy can cause premature delivery, miscarriage, stillbirth, or serious health problems for the newborn.

The most recent data suggest that about 2,500 illnesses and 500 deaths can be attributed to listeriosis in the United States annually.  Babies whose mothers have listeriosis are often stillborn or are born prematurely.  Neonatal infections are often severe, with a mortality rate of 25-50 percent.

Listeria has been found in a variety of raw foods, such as vegetables, uncooked meats, and unpasteurized (raw) milk or foods made from raw milk.  Listeria is killed by pasteurization and cooking; however, contamination of certain ready-to-eat foods like hot dogs and cold cuts may occur after cooking but before packaging.