Clostridium botulinum blood sausages. Introduction Introduction - PDF document

Introduction • About 900's: � Certain foods caused typical poisoning. � Emperor Leo VI of Byzantium forbade the manufacture of Clostridium botulinum blood sausages. Introduction Introduction 1820 • Kerner collected • 1793: An outbreak caused by blood sausages data on 230 was described in Wildbad, Germany cases of typical poisoning. • Disease became known as "Kerner’s Disease." Introduction Other Findings • van Ermengem isolated an anaerobic 1897 bacterium from cured raw ham that had caused “Kerner’s Disease” in 23 Extract from ham & a culture of m.o. people and killed 3. killed a number of different experimental animals with the same signs as the disease in humans 1

Other Findings Introduction • van Ermengem called the organism Bacillus botulinus after botulus. – Latin for sausage • Later named C. botulinum proved to be fairly resistant Back to Germany Introduction • The C. botulinum strain isolated 1904 by van Ermengem was later Landman investigated botulism designated type B. caused by canned, white beans. • The name of the disease was changed from Kerner’s Disease to botulism. Landman Findings Cont.. How about the US? 1904 • The signs and symptoms were typical • Between 1918-1922: for botulism. � 297 cases and 185 deaths • The antitoxin Landman produced did � mainly in California not cross-react with van Ermengem’s strain. • Landman had discovered C. botulinum type A. 2

Introduction Introduction • 1936: C. botulinum type E was isolated • 1922: C. botulinum type C was isolated � caused paralysis in chickens and cattle � from smoked fish that caused botulism in the US and Russia • 1929: C. botulinum type D was isolated � from cattle that died from paralysis Introduction Introduction • 1960: C. botulinum type F was isolated in • 1951: Wound botulism was described for the Denmark first time. � from liver paste that caused human botulism Introduction Introduction • 1985: Hall et al. found that a strain of C. • 1970: C. botulinum type G was isolated in barati produced type F botulinal toxin. Argentina • 1986: Aureli et al. and McCroskey et al. � from soil isolated strains of C. butyricum that � no reported cases of poisoning with this type produced type E botulinal toxin. in man or animals • 1973–1996: CDC documented 724 cases of verified foodborne botulism in American • 1976: Infant botulism was recognized. adults; mainly associated with home-canned vegetables. 3

Illness & Causative Agent Categories of Human Botulism • Botulism is a serious paralytic 1. Foodborne illness. botulism • It is caused by a nerve toxin that is produced by the bacterium. 2. Infant botulism • It is a rare illness. 3. Wound botulism • It is much feared. 4. Unclassified Categories of Human Botulism Categories of Human Botulism • Foodborne botulism • Infant botulism � This type of food poisoning is � It was first recognized in 1976. caused by the ingestion of foods � This type of poisoning affects containing the potent infants under the age of 12 neurotoxin. months. � The neurotoxin is formed in � It is caused by the ingestion of C. the food during growth of C. botulinum spores. botulinum . Categories of Human Botulism Categories of Human Botulism • Infant botulism � The spores germinate & • Infant botulism multiply, colonizing the � Infant botulism has been intestinal tracts of infants, and reported in 41 states nationwide. produce neurotoxin. � The incidence is 1 case per � The neurotoxin travels through 100,000 live births. the bloodstream to the central � Case fatality rate is below 4%. nervous system and causes flaccid paralysis. 4

Categories of Human Botulism Categories of Human Botulism • Infant botulism • Infant botulism � In California the incidence from 1985 to 1995 was 7.1 cases per � Honey is one vehicle that has 100,000 live births. been associated with infant botulism by a number of � Estimated medical cost/case at laboratory and $85,000 (total cost = $31 million). epidemiological studies. Categories of Human Botulism Categories of Human Botulism • Wound botulism � This illness results from the • Infant botulism pathogen itself infecting a wound. � Foods are not the vehicle of � Honey is now thought to account for no more than transmission. 5% of cases. � The microorganism produces the � California cases may come neurotoxin which is transmitted to from spores on wind-blown other parts of the body via the blood. dust. � Rare form of illness Categories of Human Botulism Recorded Botulism Cases in the US: 1973–1996 • Unclassified Botulism type Range/yr Total (all � Resembles infant botulism, but affects years) adults. Food 8–86 724 � C. botulinum colonizes the intestinal tract of adults and produces the toxin Infant 0-99 1444 in vivo. Wound 0-25 103 � Thought to occur after antibiotic Unclassified Not avail. 39 treatment depleted the indigenous intestinal flora. 5

C. botulinum Toxins Classification of C. botulinum • There are seven types of C. • C. botulinum produces botulinum eight toxins (A, B, C 1 , � A, B, C, D, E, F, and G C 2 , D, E, F and G). � based on the serological • All are neurotoxins specificity of the neurotoxin except C 2 . produced Classification of C. botulinum C. botulinum Toxins • Some strains produce pairs of • Types A, B, E, and, very rarely, F toxins are associated with human botulism • These are designated subtypes (foodborne, wound and infant � The capital letter identifies the types). type of toxin in greater amount • Types C and D affect animals. � The lower case letter identifies • Type G has not been linked to the type of toxin produced in illness up to this date. lesser amount C. botulinum Toxins Distribution of Serotypes in Human Botulism in the US • An example: Type Cases (%) Deaths (%) � strain isolated from a case of A 38 52 infant botulism was classified as B 38 12 subtype E 9.7 10 F 0 0 Unknown 13 0 6

C. botulinum Groups C. botulinum groups • C. botulinum strains are divided into • Another classification of C. botulinum four groups. strains is based on physiological � group I*: proteolytic and produce differences. neurotoxins type A, B, and F. � growth temperature � group II*: nonproteolytic and � pH produce neurotoxins type B, E, and F. � water activity *the most commonly involved in human � sodium chloride concentration illness. C. botulinum Groups Characteristics of C. botulinum • C. botulinum strains are divided into • Gram positive four groups. • Sporeformer � group III: variably nonproteolytic or • Anaerobic proteolytic and produce neurotoxins type C and D. • Rods � group IV: proteolytic and produce • Produce a potent neurotoxin type G. neurotoxin [A. Dowsett/Science Photo Library] Characteristics of C. botulinum Characteristics of C. botulinum • pH values for growth • Limiting water activity � Types A and proteolytic B (Gp I), � Type A 0.95 pH 4.6 -8.5 � Minimum pH for E (Gp II) is: � Type B 0.94 � 6.2 at 5°C, and � 5.4 at 30°C � Type E 0.97 7

Characteristics of C. botulinum Characteristics of C. botulinum • Growth temperature • Limiting salt concentration for � Type A and proteolytic B (Gp I) growth 10–50°C � 10.7–12% NaCl � E and non-proteolytic B and F (Gp II) 3.3–45°C � Non-proteolytic most sensitive � Spores are highly resistant to freezing Characteristics of C. botulinum Characteristics of C. botulinum • Heat resistance defined • Redox potential � Decimal reduction time (D value; � Optimum growth occurs at Eh of ! 350 mV 90% kill) � Time required to reduce the microbial population by 1 log � E is the least anaerobic, cycle. 0–100 mV Characteristics of C. botulinum Characteristics of C. botulinum • Heat resistance • Heat resistance � 121.1°C (250°F) / 3 min to � 121.1°C (250°F): DRT = 0.20– achieve 10 12 -fold reduction 0.21 min for the most resistant (A (standard for low acid canned and proteolytic B) foods), “bot cook” � 0.3–0.6 min causes 10 6 -fold reduction and is standard for canned, cured meats 8

Characteristics of C. botulinum Mechanism of Toxin • Radiation resistance To cause 10 12 fold reduction Neurotoxin 0 binds to neurons 0 � 47 – 54 kGy for type A spores internalized 0 � 10 – 11 kGy for type B spores � 7 – 9 kGy for type E spores prevents release of acetyl choline � 12 kGy for type F spores (neurotrasmitter) � 48 kGy is the accepted dose for sterilization of food spores Clinical Symptoms Nature of Food Botulism • Intoxication • Symptoms include: • Onset is about 18 – 36 hrs after � nausea and vomiting ingestion of the food containing the neurotoxin. • Symptoms vary from a mild to severe illness. Clinical Symptoms Nature of Illness • Symptoms include: • Other symptoms include: � neurological signs � gastrointestinal problems � blurred or double vision � cramps � difficulty in speaking or swallowing � abdominal pain � fatigue � diarrhea, or � lack of muscle coordination, and � constipation � difficulties in breathing 9