Food-borne Illnesses Table: Bacterial Agents

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Incubation Period

Signs and Symptoms

Duration of Illness

Associated Foods

Laboratory Testing


Bacillus anthracis

2 days to weeks

Nausea, vomiting, malaise, bloody diarrhea, acute abdominal pain.


Insufficiently cooked, contaminated meat.


Penicillin is first choice for naturally acquired gastrointestinal anthrax. Ciprofloxacin is second option.

Bacillus cereus  (diarrheal toxin)

10–16 hours

Abdominal cramps, watery diarrhea, nausea.

24–48 hours

Meats, stews, gravies, vanilla sauce.

Testing not necessary, self-limiting (consider testing food and stool for toxin in outbreaks).

Supportive care, self limiting.

Bacillus cereus (pre-formed enterotoxin)

1-6 hrs

Sudden onset of severe nausea and vomiting. Diarrhea may be present.

24 hrs

Improperly refrigerated cooked and fried rice, meats.

Normally a clinical diagnosis. Clinical laboratories do not routinely identify this organism. If indicated, send stool and food specimens to reference laboratory for culture and toxin identification.

Supportive care.

Brucella abortus,
B. melitensis,
and B. suis

7-21 days

Fever, chills, sweating, weakness, headache, muscle and joint pain, diarrhea, bloody stools during acute phase.


Raw milk, goat cheese made from unpasteurized milk, contaminated meats.

Blood culture and positive serology.

Acute: Rifampin and Doxycycline daily for ³6 weeks. Infections with complications require combination therapy with Rifampin, tetracycline and an aminoglycoside.

Campylobacter jejuni

2-5 days

Diarrhea, cramps, fever, and vomiting; diarrhea may be bloody.

2-10 days

Raw and undercooked poultry, unpasteurized milk, contaminated water.

Routine stool culture; Campylobacter requires special media and incubation at 42oC to grow.

Supportive care. For severe cases, antibiotics such as erythromycin and quinolones may be indicated early in the diarrheal disease. Guillain-Barre Syndrome can be a sequelae.

Clostridium botulinum - children and adults (pre-formed toxin)

12-72 hrs

Vomiting, diarrhea, blurred vision, diplopia, dysphagia, and descending muscle weakness.

Variable (from days to months).
Can be complicated by respiratory failure and death.

Home-canned foods with a low acid content, improperly canned commercial foods, home-canned or fermented fish, herb-infused oils, baked potatoes in aluminum foil, cheese sauce, bottled garlic, foods held warm for extended periods of time (e.g.. in a warm oven).

Stool, serum, and food can be tested for toxin. Stool and food can also be cultured for the organism. These tests can be performed at some State Health Department Laboratories and CDC.

Supportive care. Botulinum antitoxin is helpful if given early in the course of the illness. Call 404-639-2206 or 404-639–3753 workdays, 404-639-2888 weekends and evenings.

Clostridium botulinum - infants

3-30 days

In infants <12 months, lethargy, weakness, poor feeding, constipation, hypotonia, poor head control, poor gag and suck.


Honey, home-canned vegetables and fruits.

Stool, serum, and food can be tested for toxin. Stool and food can also be cultured for the organism. These tests can be performed at some State Health Department laboratories and CDC.

Supportive care. Botulism immune globulin can be obtained from the Infant Botulism Prevention Program, Health and Human Services, California (510-540-2646). Botulinum antitoxin is generally not recommended for infants.

Clostridium perfringens toxin

8-16 hrs

Watery diarrhea, nausea, abdominal cramps; fever is rare.

24-48 hrs

Meats, poultry, gravy, dried or precooked foods.

Stools can be tested for enterotoxin and cultured for organism. Because Clostridium perfringens can normally be found in stool, quantitative cultures must be done.

Supportive care. Antibiotics not indicated.

Enterohemorrhagic E. coli   (EHEC) including E. coli 0157:H7 and other Shiga toxin-producing E. coli (STEC)

1-8 days

Severe diarrhea that is often bloody, abdominal pain and vomiting. Usually, little or no fever is present. More common in children <4 years.

5-10 days.

Undercooked beef, unpasteurized milk and juice, raw fruits and vegetables (e.g.. sprouts), salami, salad dressing, and contaminated water.

Stool culture; E. coli O157:H7 requires special media to grow. If E. coli O157:H7 is suspected, specific testing must be requested. Shiga toxin testing may be done using commercial kits; positive isolates should be forwarded to public health laboratories for confirmation and serotyping.

Supportive care, monitor renal function, hemoglobin, and platelets closely. Studies indicate that antibiotics may be harmful. E. coli O157:H7 infection is also associated with hemolytic uremic syndrome, which can cause lifelong complications.

Enterotoxigenic E. coli (ETEC)

1-3 days

Watery diarrhea, abdominal cramps, some vomiting.

3->7 days

Water or food contaminated with human feces.

Stool culture. ETEC requires special laboratory techniques for identification. If suspected, must request specific testing.

Supportive care. Antibiotics are rarely needed except in severe cases. Recommended antibiotics include TMP-SMX and quinolones.

Listeria monocytogenes

9-48 hrs for gastrointestinal symptoms,
2-6 weeks for invasive disease

Fever, muscle aches, and nausea or diarrhea. Pregnant women may have mild flu-like illness, and infection can lead to premature delivery or stillbirth. Elderly or immunocompromized patients may have bacteremia or meningitis.


Fresh soft cheeses, unpasteurized milk, inadequately pasteurized milk, ready-to-eat deli meats, hot dogs.

Blood or cerebrospinal fluid cultures. Asymptomatic fecal carriage occurs; therefore, stool culture usually not helpful. Antibody to listerolysin O may be helpful to identify outbreak retrospectively.

Supportive care and antibiotics; Intravenous ampicillin, penicillin, or TMP-SMX are recommended for invasive disease.

Listeria monocytogenes  

At birth and infancy

Infants infected from mother at risk for sepsis or meningitis.

As above.

As above.

As above.

As above.

Salmonella  spp.

1-3 days

Diarrhea, fever, abdominal cramps, vomiting. S. typhi and S. paratyphi produce typhoid with insidious onset characterized by fever, headache, constipation, malaise, chills, and myalgia; diarrhea is uncommon, and vomiting is not usually severe.

4-7 days.

Contaminated eggs, poultry, unpasteurized milk or juice, cheese, contaminated raw fruits and vegetables (alfalfa sprouts, melons). S. typhi epidemics are often related to fecal contamination of water supplies or street vended foods.

Routine stool cultures.

Supportive care. Other than for S. typhi, antibiotics are not indicated unless there is extra-intestinal spread, or the risk of extra-intestinal spread, of the infection. Consider ampicillin, gentamicin, TMP-SMX, or quinolones if indicated. A vaccine exists for S. typhi.

Shigella  spp.

24-48 hrs

Abdominal cramps, fever, and diarrhea. Stools may contain blood and mucus.

4-7 days

Food or water contaminated with fecal material. Usually person-to-person spread, fecal oral transmission. Ready-to-eat foods touched by infected food workers, raw vegetables, egg salads.

Routine stool cultures.

Supportive care. TMP-SMX recommended in the US if organism is susceptible; nalidixic acid or other quinolones may be indicated if organism is resistant, especially in developing countries.

Staphylococcus aureus (pre-formed enterotoxin)

1-6 hrs

Sudden onset of severe nausea and vomiting. Abdominal cramps. Diarrhea and fever may be present.

24-48 hrs

Unrefrigerated or improperly refrigerated meats, potato and egg salads, cream pastries.

Normally a clinical diagnosis. Stool, vomitus, and food can be tested for toxin and cultured if indicated.

Supportive care.

Vibrio cholerae (toxin)

24-72 hrs

Profuse watery diarrhea and vomiting, which can lead to severe dehydration and death within hours.

3-7 days. Causes life-threatening dehydration.

Contaminated water, fish, shellfish, street-vended food.

Stool culture; Vibrio cholerae requires special media to grow. If V. cholerae is suspected, must request specific testing.

Supportive care with aggressive oral and intravenous rehydration. In cases of confirmed cholera, tetracycline or Doxycycline is recommended for adults, and TMP-SMX for children (<8 years).

Vibrio parahaemolyticus

2-48 hrs

Watery diarrhea, abdominal cramps, nausea, vomiting.

2-5 days

Undercooked or raw seafood including fish, shellfish.

Stool cultures. Vibrio parahaemolyticus requires special media to grow. If V. parahaemolyticus is suspected, must request specific testing.

Supportive care. Antibiotics are recommended in severe cases: tetracycline, Doxycycline, gentamicin, and cefotaxime.

Vibrio vulnificus

1-7 days

Vomiting, diarrhea, abdominal pain, bacteremia, and wound infections. More common in the immuno-compromised, or in patients with chronic liver disease (presenting with bullous skin lesions).

2-8 days; can be fatal in patients with liver disease and the immuno-compromised

Undercooked or raw shellfish, especially oysters, other contaminated seafood, and open wounds exposed to sea water.

Stool, wound, or blood cultures. Vibrio vulnificus requires special media to grow. If V. vulnificus is suspected, must request specific testing.

Supportive care and antibiotics; tetracycline, Doxycycline, and ceftazidime are recommended.

Yersinia enterocolytica and Y. pseudotuberculosis

24-48 hrs

Appendicitis-like symptoms (diarrhea and vomiting, fever, and abdominal pain) occur primarily in older children and young adults. May have a scarlitiniform rash with Y. pseudotuberculosis.

1-3 weeks

Undercooked pork, unpasteurized milk, contaminated water. Infection has occurred in infants whose caregivers handled chitterlings, tofu.

Stool, vomitus or blood culture. Yersinia requires special media to grow. If suspected, must request specific testing. Serology is available in research and reference laboratories.

Supportive care, usually self-limiting. If septicemia or other invasive disease occurs, antibiotic therapy with gentamicin or cefotaxime (Doxycycline and ciprofloxacin also effective).


Incubation Period

Signs and Symptoms

Duration of Illness

Associated Foods

Laboratory Testing