Clostridium botulinum and botulism

1. Clostridium botulinum and botulism

2. Introduction • About 900's: • Certain foods caused typical poisoning. • Emperor Leo VI of Byzantium forbade the manufacture of blood sausages.

3. Introduction • 1793: An outbreak caused by blood sausages was described in Wildbad, Germany

4. 1897 Introduction • van Ermengem isolated an anaerobic bacterium from cured raw ham that had caused “Kerner’s Disease” in 23 people and killed 3.

5. Other Findings killed a number of different experimental animals with the same signs as the disease in humans Extract from ham & a culture of m.o.

6. Another outbreak • Caused by canned white beans • The signs and symptoms were typical of botulism • The toxin did not cross-react: type A • Subsequently more toxin types found

7. How about the US? • Between 1918-1922: • 297 cases and 185 deaths • mainly in California • Prompted the cannery program that still exists today

8. Introduction • 1936: C. botulinum type E was isolated • from smoked fish that caused botulism in the US and Russia

9. Introduction • 1951: Wound botulism was described for the first time.

10. Categories of Human Botulism • Foodborne botulism • Infant botulism • Wound botulism • Adult infectious botulism

11. Categories of Human Botulism • Infant botulism • It was first recognized in 1976. • This type of poisoning affects infants under the age of 12 month. • It is caused by the ingestion of C. botulinum spores.

12. Categories of Human Botulism • Infant botulism • The spores colonize the intestinal tracts of infants, germinate, multiply, and produce neurotoxin. • The neurotoxin travels through the bloodstream to the central nervous system and causes flaccid paralysis.

13. Categories of Human Botulism • Wound botulism • This illness results from the pathogen itself infecting a wound. • Foods are not the vehicle of transmission. • The microorganism produces the neurotoxin which is transmitted to other parts of the body via the blood. • Seen in intravenous drug users

14. Categories of Human Botulism • Adult infectious botulism • This type of botulism resembles infant botulism, however, it affects adults. • C. botulinum colonizes the intestinal tract of adults and produces the toxin in vivo. • It has been thought to occur after antibiotic treatment depleted the indigenous intestinal flora.

15. Recorded Botulism Cases in California and in the US: 2002-2007 http://ww2.cdph.ca.gov/data/statistics/Pages/CD_Tables.aspx http://www.cdc.gov/nationalsurveillance/botulism_surveillance.html

16. Classification of C. botulinum • There are seven types of C. botulinum • A, B, C, D, E, F, and G • based on the serological specificity of the neurotoxin produced • Types A, B, E, and, very rarely, F are associated with human botulism (foodborne, wound and infant types). • Types C and D affect animals. • Type G has not been linked to illness up to this date.

17. Characteristics of C. botulinum • pH values for growth • Types A and proteolytic B pH 4.6-8.5 • Minimum pH for E is: • 6.2 at 5°C, and • 5.4 at 30°C

18. Implicated Foods in Botulism • Any food that can support the growth of this pathogen or allow the germination of its spores and eventually toxin production can be associated with this illness. • Low acid foods (pH>4.6) • Home canned or preserved low acid vegetables • Garlic in soybean oil • Foil-wrapped baked potato • Commercial carrot juice held at ambient temperature

19. Implicated Foods in Botulism • North American Indian specialties • fish and fish eggs • seal flippers • Other implicated foods include luncheon meats, ham, sausage, smoked and salted fish, and lobster.

20. Illness & Causative Agent • Botulism is a serious paralytic illness. • It is caused by a nerve toxin that is produced by the bacterium. • It is a rare illness. • It is much feared.

21. Nature of Illness • Intoxication • Onset is about 18 – 36 hrs after ingestion of the food containing the neurotoxin. • Symptoms vary from a mild to severe illness.

22. Clinical Symptoms • Symptoms include: • neurological signs • blurred or double vision • difficulty in speaking or swallowing • fatigue • lack of muscle coordination, and • difficulties in breathing

23. Toxigenic Dose • Few nanograms of C. botulinum neurotoxin can cause illness. • The neurotoxin produced is probably the most toxic compound made by a biological system. • About 1 oz. of this toxin can kill 200 million people. • Fortunately, the incidence of the illness is low.

24. Mechanism of Toxin Neurotoxin 0 binds to neurons 0 internalized 0 prevents release of acetyl choline (neurotrasmitter)

25. C. botulinum Outbreak • In 1994, in Oklahoma, a 47-year old man was hospitalized for symptoms of progressive dizziness, blurred vision, slurred speech difficulty swallowing, and nausea. • Twenty-four hours earlier the patient had eaten some home canned green beans and beef and potato stew. • Green beans tested negative, but stew was positive

26. C. botulinum Outbreak • Apparently, • the stew was cooked, • covered tight, • left out for four days at room temperature, and • then eaten without reheating

27. Other recent cases: October 2004 • Refrigerated clam chowder that was stored in the consumer’s home at room temperature • Consumer tasted it, spit it out because it tasted bad • She put it out for her chickens • The next morning the chickens were dead

28. Other recent cases: June 2006 • A truck driver picked up a load of pasteurized refrigerated carrot juice in the Bakersfield area • He kept a case of it, and left one bottle in the cab of his truck where he was sleeping • He subsequently drank it and developed botulism signs and symptoms • Other bottles from the case that had been refrigerated were negative

29. Prevention • Assurance of destruction or inhibition of C. botulinum. • Keep susceptible foods out of the temperature danger zone (4.4 – 60°C or 40 – 140°F). • Botulinum toxin is destroyed by heating at 80°C for 30 min or boiling for a few minutes. Thus re-heating foods properly can be a controlling factor.

30. Antitoxin • Produced in horses by injecting them with gradually increasing levels of toxin type A • To make a bivalent antitoxin, the horse is then injected with toxin type B, starting with extremely low levels • Plasma is subjected to purification steps such as enzyme treatment and ammonium sulfate precipitation • Time required is a matter of months

31. Antitoxin • Distributed by CDC • In California, local health jurisdictions can contact the DCDC duty officer for release of antitoxin (see flow chart) • HHS awarded contract to Cangene Corp. of Canada for 200,000 doses of heptavalent botulism antitoxin to be delivered to SNS starting in 2007 as part of Project Bioshield

32. Assumption: Active toxin will kill mouse Detection of Toxin • Toxin can be detected and typed by mouse inoculation. Number of tests depends on how many mice the lab has available. • An ELISA method has been developed for detection of toxin. Used by LRN labs

33. Detection of Toxin • Department of Defense, USDA, and Food and Drug Lab Branch use ECL (electrochemiluminescence) with which they can do 400-500 samples per day • CDC has developed a TRF (Time-resolved fluorescence) test that is also high capacity (based on 96-well plate).