A large outbreak of botulism: the hazardous baked potato

In April 1994, the largest outbreak of botulism in the United States since 1978 occurred in El Paso, Texas. Thirty persons were affected; 4 required mechanical ventilation. All ate food from a Greek restaurant. The attack rate among persons who ate a potato-based dip was 86% (19/22) compared with 6% (11/176) among persons who did not eat the dip (relative risk [RR] = 13.8; 95% confidence interval [CI], 7.6-25.1). The attack rate among persons who ate an eggplant-based dip was 67% (6/9) compared with 13% (241189) among persons who did not (RR = 5.2; 95% CI, 2.9-9.5). Botulism toxin type A was detected from patients and in both dips. Toxin formation resulted from holding aluminum foil-wrapped baked potatoes at room temperature, apparently for several days, before they were used in the dips. Consumers should be informed of the potential hazards caused by holding foil-wrapped potatoes at ambient temperatures after cooking.

The detection of a deletion in the type B neurotoxin gene of Clostridium botulinum A(B) strains by a two-step PCR

Differences between the type B neurotoxin gene sequence of Clostridium botulinum type A(B) and Cl. botulinum type B, including a six nucleotide deletion, were recently proposed as a cause of the lack of expression of this gene in the type A toxigenic strains. A polymerase chain reaction (PCR) based on two sets of primers was designed to investigate the absence of the 6-nucleotide sequence in the apparently unexpressed type B toxin gene of 42 strains of Cl. botulinum type A(B). Thirty-five strains were shown to exhibit a deletion in their type B toxin gene; two strains did not have the deletion and actually produced small amounts of type B toxin when tested by the mouse bioassay. This two-step PCR might be useful for the rapid determination of the presence of the six nucleotide deletion and consequently, whether the type B toxin is likely to be produced.

Endogenous antibody production to botulinum toxin in an adult with intestinal colonization botulism and underlying Crohn's disease

A patient with obstruction of the terminal ileum from Crohn's disease developed complete paralysis in week 1 of hospitalization. Features initially suggested Guillain-Barre syndrome, but botulinum toxin was identified in serum and stool specimens from week 1 and type A toxin-producing Clostridium botulinum in stool specimens from weeks 3 to 19, confirming botulism due to intestinal colonization. In week 19, the inflamed small bowel was resected, and C. botulinum disappeared from the stool. In week 31, the patient was able to breath without assistance. Testing for an active immune response with neutralizing antibodies to C. botulinum at week 19 was positive; these antibodies remained at a protective level for >1 year. Intestinal colonization botulism, rare in adults, should be considered for patients with descending paralysis, especially those with a preceding alteration in small bowel function. An active immune response to botulinum toxin with production of protective antibodies has not been demonstrated previously in a patient with botulism and may have contributed to this patient's recovery.

Sensitive assay for measurement of antibodies to Clostridium botulinum neurotoxins A, B, and E: use of hapten-labeled-antibody elution to isolate specific complexes

The measurement of chicken and human antibodies to Clostridium botulinum neurotoxins A, B, and E was accomplished by affinity isolation of complexes containing these antibodies. By this approach, a mixture of toxin with the test antibody, fluoresceinated antibody, and enzyme (Russell's viper venom factor X activator)-labeled antibody is allowed to form a complex in solution phase. This complex is then bound to a matrix containing antifluorescein antibody. All components not bound to the matrix are washed off, and the complex is isolated intact by elution with fluorescein, which competes with the complex for binding to the antifluorescein matrix. The eluted complex is then bound to a matrix which specifically binds the test antibody (anti-chicken immunoglobulin Y [IgY] or anti-human IgG), and the bound complex is measured by using the enzyme label. Using this approach, we were able to measure as little as 1 ng of specific antibody per ml from affinity-isolated, monospecific chicken antibody preparations and to measure antibody specifically from IgY fractions of monospecific chicken antibody preparations. Human antibodies from subjects immunized with pentavalent toxoid preparations were detectable at dilutions as great as 24,300-fold, and undiluted serum from most control subjects showed no measurable antibody. Antibody was also measured in 65 subjects who were receiving preparations of neurotoxin A (BOTOX) for the treatment of spastic disorders. Eighteen of them had toxin-specific antibody reactive with toxin B, and two of them had toxin-specific antibody reactive with toxin A. The two patients having antibody to toxin A were refractory to treatment with this toxin. This approach of isolation of hapten-labeled immune complexes under nondenaturing conditions with hapten is broadly applicable to the specific measurement of antibodies present at very low concentrations in serum.

An outbreak of type A botulism associated with a commercial cheese sauce

BACKGROUND

Although botulism is rare, recognition of a possible case of this illness represents a public health emergency. To prevent more cases, prompt investigation must be done to determine whether illness is linked to commercial product or restaurant. Botulism can masquerade as other illnesses, and seemingly unlikely foods can harbor botulinum toxin.

OBJECTIVE

To confirm the diagnosis and determine the cause and extent of an outbreak of botulism associated with food served at a delicatessen.

DESIGN

Retrospective cohort study of patrons of the delicatessen; laboratory analysis of food, serum samples, and stool samples; and traceback of implicated food.

SETTING

Community in Georgia.

PARTICIPANTS

Patrons of the delicatessen.

MAIN OUTCOME MEASURES

Botulinum toxin in food, serum, or stool and Clostridium botulinum in food and stools.

RESULTS

8 of 52 patrons (15%) met the case definition for botulism. In 4 of the 8 patrons, and illness other than botulism was initially diagnosed. Five of the 8 were hospitalized, and 1 died. Stool cultures from 4 patrons yielded type AC. botulinum, and two serum samples contained botulinum toxin. All ill persons ate food from the delicatessen on 1 October 1993. Of the 22 persons who ate at the delicatessen that day, all 8 ill persons but none of the 14 well persons ate a potato stuffed with meat and cheese sauce. An open can of cheese sauce contained type A botulinum toxin and yielded C botulinum on culture. Cheese sauce experimentally inoculated with C botulinum spores became toxic after 8 days at a temperature of 22 degrees C (room temperature).

CONCLUSIONS

A commercial, canned cheese caused a botulism outbreak. This product readily becomes toxic when contaminated by C botulinum spores and left at room temperature. Mild botulism caused by unusual vehicles may be misdiagnosed. Botulism should be included in the differential diagnosis of persons with signs or symptoms of acute cranial nerve dysfunction.

Genetic characterization of Clostridium botulinum type A containing silent type B neurotoxin gene sequences

A recent study detected genes encoding type B botulinum neurotoxin in some type A strains of Clostridium botulinum that exhibit no type B toxin activity. In this study, we investigated the presence, structure, linkage, and organization of genes encoding botulinum neurotoxin (BoNT) and other components of the progenitor complex. Sequence analysis showed that the silent BoNT/B gene is highly related to that from authentic proteolytic type B C. botulinum. However, a stop signal and deletions were found within the sequence. A non-toxin nonhemagglutinin gene (NTNH) was mapped immediately upstream of both the BoNT/A and silent BoNT/B genes. Significantly the NTNH gene adjacent to the defective BoNT/B gene was "chimeric, " the 5'- and 3'-regions of the gene had high homology with corresponding regions of the type B NTNH gene, while the 471-amino acid sequence in the central region was identical to NTNH of type A. Hemagglutinin genes HA-33 and HA-II were not found adjacent to the NTNH/A gene, but instead there was an unidentified open reading frame previously reported in strains of C. botulinum types E and F. By contrast HA-II, HA-33, and NTNH genes were located immediately upstream of the silent BoNT/B gene. Pulsed-field gel electrophoretic analysis of chromosomal DNA digests indicated the distance between type A and B gene clusters to be less than 40 kilobases.

Botulism: the present status of the disease

The main form of human botulism throughout the world is the classic foodborne intoxication. Would botulism is very rare, and most of the documented cases have been found in the United States. While infant botulism remains rare throughout the world, it has become the most frequent form of the disease in the United States in recent years. On very rare occasions botulism results from growth and toxin production in humans other than infants. Botulism occurs in animals with much higher frequency. The causative organisms constitute a diverse group of clostridia, resulting in nomenclature problems. Human botulism is largely limited to toxin types A, B, and E, while type C botulism predominates in avian and nonhuman mammalian species. The diagnosis of botulism is made on the basis of the neurologic signs and symptoms that it causes in humans and animals. The diagnosis is confirmed by tests that identify the toxin and toxigenic organisms in patient and food specimens. Treatment includes supportive intensive care and use of therapeutic antitoxin.

Detection of type A, B, and E botulism neurotoxin genes in Clostridium botulinum and other Clostridium species by PCR: evidence of unexpressed type B toxin genes in type A toxigenic organisms

We studied the effectiveness of the PCR in detecting the type A, B, and E botulism neurotoxin genes in 209 strains of Clostridium botulinum and 29 strains of other Clostridium spp. All 79 strains that produced type A toxin, 77 strains that produced type B toxin, and 51 organisms that produced type E toxin (46 C. botulinum and 5 C. butyricum) were PCR positive in reactions with primers targeting sequences specific for their respective toxin genes. The PCR for type A toxin was positive for one type B toxin-producing strain that produced a small amount of type A toxin in addition to a large amount of type B toxin. Surprisingly, the type B toxin gene was detected in addition to the type A toxin gene in 43 type A toxin-producing strains, only 1 of which could be shown by bioassay to produce biologically active type B toxin in culture. The type B gene was also detected in two strains of C. subterminale, which were determined to be nontoxigenic by bioassay. While the PCR was sensitive and specific in detecting the neurotoxin genes, the discovery of unexpressed toxin genes indicates that PCR results may not be adequate for establishing type B neurotoxigenicity.

Wound botulism in a patient with a tooth abscess: case report and review

We describe a case of wound botulism associated with a tooth abscess in a 5-year-old boy. We reviewed the literature and reports to the Centers for Disease Control and Prevention (Atlanta) of laboratory-confirmed cases of wound botulism. From 1943 through 1990, 47 cases were reported. Type A botulinus toxin was identified in 32 cases, type B in 13, types A and B in 1, and an unknown type in 1. Botulism was associated with wounds from trauma, use of injectable drugs, and surgery. Sinusitis after use of intranasal cocaine has also been associated with botulism. Treatment for wound botulism includes prompt debridement of the wound for eliminating anaerobic conditions, intensive care, and treatment with antitoxin.

A massive outbreak of type E botulism associated with traditional salted fish in Cairo

In April 1991, 91 hospitalized patients in Cairo were reported to the Egyptian Ministry of Health with botulism intoxication. To define the spectrum of illness and identify a food vehicle, 45 patients were interviewed and a case-control investigation was conducted among families of 5 hospitalized patients. Clinical specimens and specimens of implicated food were tested for toxin and cultured for Clostridium botulinum. Hospitalized patients had symptoms consistent with botulism; 18 (20%) of 91 reported patients died. Illness was associated with eating faseikh (uneviscerated, salted mullet fish; lower 95% confidence limit of odds ratio = 6.6, P < .001). All 5 case-families purchased faseikh from one shop. Very high levels of type E botulinal toxin were detected in faseikh reported to be purchased from the implicated shop; C. botulinum type E was isolated from cultures of clinical specimens and from the faseikh. This is the first documented outbreak of botulism in Egypt and the largest type E outbreak ever reported.

Clinical and laboratory comparison of botulism from toxin types A, B, and E in the United States, 1975-1988

Cases of adult botulism (n = 309) were studied to identify clinical differences between toxin types and to evaluate the sensitivity of diagnostic laboratory testing. Patients with illness from type E toxin had the shortest incubation periods. Sporadic case-patients were more severely ill: 85% required intubation compared with only 42% in multiperson outbreaks. Of patients with type A botulism, 67% required intubation compared with 52% with type B and 39% with type E. Toxin testing was positive for 40%-44% of serum and stool specimens obtained within 3 days of toxin ingestion and for 15%-23% of specimens obtained thereafter, while 37% of stool specimens obtained > 3 days after toxin ingestion were positive by culture. Patients with type A botulism have more severe illness. In general, specimens obtained early are more likely to be positive by toxin assay, and stool cultures are more sensitive than toxin detection for specimens obtained later in the illness.

Type F botulism due to neurotoxigenic Clostridium baratii from an unknown source in an adult

Type F botulism was confirmed in a 54-year-old male with signs compatible with botulism who reported to the emergency unit of a hospital. Botulinal neurotoxin was detected in the patient's serum and fecal specimens, and a neurotoxigenic organism whose physiologic characteristics correspond to those of Clostridium baratii was isolated. The toxin produced by the isolate was neutralized by type F botulinal antitoxin and cross-neutralized with lower efficiency by type E antitoxin. The patient's food history was not suggestive of botulism, and it seems likely that the illness was due to colonization of the gut.

Clostridium perfringens food poisoning: use of serotyping in an outbreak setting

An outbreak of Clostridium perfringens food poisoning occurred among attendees of a firehouse luncheon. The predominant symptoms of diarrhea (100%) and abdominal pain (81%) among case-patients, the mean incubation period (13.4 h), and the mean duration of illness (21.2 h) were all characteristic of C. perfringens enteritis. Roast beef, although not epidemiologically implicated, was the most likely vehicle of transmission. Fecal specimens from case-patients contained a median C. perfringens spore count of greater than 10(6) and yielded isolates that were heat sensitive and predominantly nonhemolytic, produced C. perfringens enterotoxin A, and, in the majority of specimens (four of five), were identical in serotype. Food samples were negative. This outbreak demonstrates that following enumeration of C. perfringens from a suitable number of fecal specimens from case-patients, serotyping of the isolates may be helpful in implicating C. perfringens as the cause of foodborne illness. This is especially true when implicated food items test negative or are no longer available for testing.

Multilocus enzyme electrophoresis of Clostridium argentinense (Clostridium botulinum toxin type G) and phenotypically similar asaccharolytic clostridia

Twenty-three strains of Clostridium argentinense, C. subterminale, C. hastiforme, and other phenotypically similar asaccharolytic clostridia recently placed in seven DNA hybridization groups were compared by multilocus enzyme electrophoresis. The three nontoxigenic strains of C. argentinense were most closely related to the toxigenic strains of this species. All nine toxigenic strains of C. argentinense belonging to a single DNA hybridization group had identical enzyme types on the basis of nine enzymes. All other strains except for two derived from the type strain of C. subterminale were differentiable. Overall, there was excellent agreement between DNA relatedness and multilocus enzyme electrophoresis results.

Genetic confirmation of identities of neurotoxigenic Clostridium baratii and Clostridium butyricum implicated as agents of infant botulism

Two unusual neurotoxigenic clostridia isolated from fecal specimens from patients with type F and type E infant botulism were phenotypically identical to the existing species Clostridium baratii and C. butyricum, respectively. DNA hybridization experiments confirmed that one strain was C. baratii and that the other was C. butyricum. These species therefore do contain neurotoxigenic strains and are possible causes of infant botulism.

Food-borne botulism in Alaska, 1947-1985: epidemiology and clinical findings

We reviewed records of all food-borne outbreaks of botulism in Alaska from 1947 through 1985. Fifty-nine confirmed or suspected outbreaks with 156 cases were reported. All outbreaks occurred in Alaska Natives and were associated with eating traditional Alaska Native foods. Forty-four (75%) of the outbreaks were laboratory confirmed and involved 133 persons. The overall annual incidence of confirmed or suspected botulism was 8.6 cases per 100,000 population. Seventeen persons died, an overall case-fatality rate of 11%. Type E toxin accounted for 32 (73%) laboratory-confirmed outbreaks; type A, six (14%); and type B, five (11%). Forty-one cases demonstrated botulinal toxin in one or more specimens (serum, gastric contents, or stool). Of the 41 botulinal toxin-positive persons, 38 (93%) had at least three of the commonly recognized pentad of signs or symptoms--nausea and vomiting, dysphagia, diplopia, dilated and fixed pupils, or dry mouth and throat--and 20 (49%) required respiratory assistance.

Laboratory findings in four cases of adult botulism suggest colonization of the intestinal tract

There was laboratory evidence of intestinal colonization in four cases of adult botulism confirmed by the Centers for Disease Control. No performed toxin was detected in available foods, but Clostridium botulinum was isolated from foods in two instances. Botulinal toxin was detected in the sera of all four patients, in one case at 47 days after ingestion of suspected food. C. botulinum was demonstrated in the stool of all four patients and persisted for 119 days after the onset of illness in one patient. Two patients had surgical alterations of the gastrointestinal tract, which may have promoted the colonization. The apparent lack of ingestion of performed toxin in these cases and the persistence of botulinal toxin or C. botulinum, or both, for long periods in three of the patients suggest that colonization of the intestinal tract occurred.

Examination of feces and serum for diagnosis of infant botulism in 336 patients

In the 12-year period 1975 to 1987, feces from 336 infants were examined for botulinal neurotoxin and Clostridium botulinum. All the infants had illnesses which prompted their physicians to consider infant botulism in the diagnosis. Stool specimens from 113 of the infants yielded organisms that produced botulinal neurotoxins assumed to be responsible for the illness. The types of botulinal toxin in the confirmed cases were distributed as follows: 38 A, 69 B, 2 atypical B, 1 E, 1 F, 1 A + B, and 1 B + F. The type A and B toxins in a single infant were produced by two different strains of organism, and the type B and F toxins in another infant were produced by a single strain. The physiological characteristics of all the isolated toxigenic organisms except two were consistent with those of group I (proteolytic) C. botulinum. The toxigenic isolate from the infant with type E botulism was identified as C. butyricum, and that from the infant with type F botulism was identified as C. barati. Toxin of the same type as produced by the isolated organisms was identified in feces of 98 of 111 culture-positive infants. Botulinal toxin was identified in the serum of 9 of 67 culture-positive infants (8 of 22 infants with type A organisms; 1 of 43 infants with type B organisms; neither of 2 infants with A + B or atypical type B organisms). Botulinal toxin was not detected in feces (206 infants) or in serum (114 infants) of the culture-negative infants. The culture-positive infants had clinical features and a course of illness consistent with those of infant botulism. Most of the culture-negative infants probably had illnesses other than botulism, but specimens might have been obtained late in some infants' illnesses, when the organism had disappeared.

Infant botulism. Three cases in a small town

Through Dec 31, 1985, there have been six cases of infant botulism reported in Colorado. Three of these infants have lived in the same town of 800 people in western Colorado. Two of these three infants developed infant botulism within a six-month period in late 1981. The infants lived approximately 400 m apart; they had used the same crib at the time each developed botulism. A specimen from the crib yielded Clostridium botulinum, as did four soil samples from the town and house-dust samples from the home of a relative of the second infant. The third infant developed infant botulism in September 1984. This infant had not shared the crib. In this case, all seven samples of soil from various locations in the town yielded C botulinum, as did a sample of house dust from the home of this infant. The occurrence of these three cases in such a small town seems unlikely to be only coincidental. Investigations and reports of other such clusters may provide insight into modes of transmission of infant botulism.

Two cases of type E infant botulism caused by neurotoxigenic Clostridium butyricum in Italy

The first two confirmed cases of type E infant botulism occurred in two 16-week-old girls in Rome, Italy. The original diagnosis for the first patient was intestinal blockage due to an ileocecal invagination, which was treated surgically. Postoperatively, the patient became unresponsive and required ventilatory assistance. A diagnosis of infant botulism was then made. The second infant presented to the same hospital 7 1/2 months later with profound weakness, hypotonicity, mydriasis, and areflexia. This case was recognized as possible botulism at admission. Both cases were confirmed by detection and identification of type E botulinal toxin in stool specimens and in enrichment cultures of those specimens. The toxigenic organisms isolated were quite different from Clostridium botulinum type E. The apparent causative organism in each case resembles Clostridium butyricum but produces a neurotoxin that is indistinguishable from type E botulinal toxin by its effects on mice and by its neutralization with type E botulinal antitoxin.

Characterization of an organism that produces type E botulinal toxin but which resembles Clostridium butyricum from the feces of an infant with type E botulism

The apparent causative organism from the only reported case of type E infant botulism was isolated and characterized. Except for its ability to produce type E botulinal toxin, this organism (strain 5262) would be unquestionably identified as Clostridium butyricum. This is the second time an organism resembling a defined Clostridium species other than a member of the C. botulinum group has been implicated in infant botulism.

Isolation of an organism resembling Clostridium barati which produces type F botulinal toxin from an infant with botulism

All reported cases of infant botulism except one have been caused by proteolytic strains (group I) of Clostridium botulinum, toxin types A or B. We describe the cultural and biochemical characteristics of the causative organism of this singular case of infant botulism, caused by type F botulinal toxin. Although this organism produces type F botulinal toxin, it is quite different from proteolytic (group I) C. botulinum, being more closely related to Clostridium barati.

Type A botulism from sauteed onions. Clinical and epidemiologic observations

Twenty-eight persons were hospitalized in Illinois with neurologic signs and symptoms compatible with botulism in October 1983. Twelve patients required ventilatory support, and 20 patients were treated with trivalent ABE antitoxin; one patient died while still in the hospital six months after onset of illness. Type A toxin and/or type A Clostridium botulinum were subsequently identified in specimens from 18 patients. Case-control studies implicated sauteed onions made from fresh raw onions and served on a patty-melt sandwich in a local restaurant as the vehicle of transmission. Although the original sauteed onions were not available for toxin testing, type A toxin was detected in washings from a wrapper in which a patty-melt sandwich was taken home by one of the ill persons. Also, type A C botulinum was cultured from five of 75 raw onions taken from the restaurant. This outbreak implicated an unusual vehicle for botulinal toxin that was initially not suspected and demonstrates the importance of considering all theoretically possible food items as potential vehicles for toxin until epidemiologic and laboratory data have been collected and analyzed.

Isolation and enumeration of Clostridium botulinum by direct inoculation of infant fecal specimens on egg yolk agar and Clostridium botulinum isolation media

Direct plating of stool specimens on selective (Clostridium botulinum isolation) and nonselective (egg yolk agar) media was evaluated as an aid in confirming infant botulism. C. botulinum was isolated from 13 of 14 culture-positive specimens with C. botulinum isolation and from 8 of 14 egg yolk agar. No lipase reaction was seen on plates of 31 culture-negative specimens.

Evaluation of fluorescent-antibody tests as a means of confirming infant botulism

Fluorescent-antibody techniques were evaluated for confirming infant botulism. Seventy-seven stool specimens from suspected cases were examined. All 34 specimens containing viable Clostridium botulinum at time of study gave positive results (29 on direct smears and 34 on enrichments). Two false-positive reactions were observed.

Enzyme-linked immunosorbent assay for detection of Clostridium botulinum type A and type B toxins in stool samples of infants with botulism

An enzyme-linked immunosorbent assay (ELISA) for Clostridium botulinum type A and type B toxins was assessed for diagnostic accuracy in cases of infant botulism. This test was positive in all 22 cases confirmed by the conventional tests, which included the mouse lethality assay and stool culture. Stool specimens from five cases were positive by culture, but the mouse lethality bioassay was either negative or toxicity was judged nonspecific since it could not be neutralized by specific antitoxin. The positive ELISA results in these specimens suggested that this assay may be more reliable, in some cases, than the mouse bioassay. Of the 21 fecal specimens from suspected foodborne cases, 2 contained botulinal toxin demonstrable by the mouse assay and the ELISA. With regard to specificity, 35 fecal specimens from infants and 19 from suspected foodborne cases which were negative in the bioassay for botulinal toxins A and B were also negative in the ELISA. Only two fecal specimens with negative bioassay gave positive ELISA readings, providing a specificity rate of 96%. These results suggest that the ELISA may serve as a useful screening test to detect C. botulinum toxin in clinical specimens.

Fluorescent-antibody reagents for the identification of Clostridium botulinum

Fluorescent-antibody reagents were prepared against vegetative cells of representative strains of each physiological group and toxin type of Clostridium botulinum known to have caused botulism in humans. A fluorescent-antibody reagent was also prepared for C. botulinum type G, which has been isolated from autopsy specimens but which has not clearly been implicated in botulism. These fluorescent-antibody reagents were evaluated against 200 strains of C. botulinum and 64 strains of other clostridia. Each reagent reacted with at least a 2+ intensity with all of the strains in its same toxin type and physiological group. Ninety-seven percent of the strains gave at least a 3+ reaction with the homologous group or toxin type reagent. Some cross-reactions occurred with reagents against different toxin type strains within a physiological group; there was less cross-reaction between physiological groups and very little reactivity of C. botulinum reagents with nontoxigenic organisms. Absorption of cross-reacting antibodies was not successful. Certain reagents could be used for presumptive laboratory identification of C. botulinum strains causing botulism, especially in infants. The type G reagent provided a good means of identifying C. botulinum type G, which lacks the lipase marker and whose toxigenicity may be more difficult to demonstrate in mixed cultures. There was a serological relationship between C. botulinum type G and some strains of Clostridium subterminale. This relationship provided evidence of differences between strains of C. botulinum type G isolated in two different countries.

Laboratory diagnosis in a large outbreak of type A botulism: confirmation of the value of coproexamination

Coproexamination is a vital component of the laboratory evaluation of botulism and is an essential part of the investigation of suspected botulism cases. In April 1978, type A botulism developed in 34 persons who had eaten at a restaurant in a town in New Mexico. Pretreatment serum specimens, along with stool specimens for toxin assay and culture for Clostridium botulinum, were obtained. At least one specimen (serum or stool) was available for each patient. Of 30 serum specimens, 16 (53%) were toxin positive; seven (32%) of 22 stools were toxin positive; and C. botulinum type A was cultured from 19 (79%) of 24 stool specimens. Overall laboratory confirmation was available for 26 cases (76%). Serum and stool toxin detection was related both to the time elapsed between symptom onset and specimen collection and to the severity of illness, with shorter times and severe illness associated with higher rates of toxin detection. Recovery of C. botulinum type A did not vary appreciably according to these factors. In 18 cases, both serum and stool specimens were available; the proportion of suspected cases that could be laboratory-proven increased by 46% when patients' feces, and not just their sera, were subjected to botulism testing procedures.

Atypical toxin variant of Clostridium botulinum type B associated with infant botulism

An atypical toxin variant of Clostridium botulinum (strain 657) was isolated from the feces of a 6-week-old female infant whose symptoms and clinical history were consistent with infant botulism. Toxin detected in the feces and the toxin produced by isolates from the feces and from two rectal swabs could be neutralized by type B botulinal antitoxin only at very high ratios of of antitoxin to toxin in the neutralization mixture. One international unit of type B antitoxin neutralized only about 10 lethal doses of 657 toxin as compared with approximately 10,000 lethal doses of conventional type B toxin from the Beans strain. Antitoxin prepared against 657 toxin was 10 times more effective against the conventional toxin than against the homologous toxin. Toxoid-antitoxin-binding studies indicate that both 657 toxin and type B toxin are heterogeneous and that both toxins may contain the same molecular variants, but that the proportions of the variants are different in each.

Restaurant-associated type A botulism: transmission by potato salad

In the period November 13-18, 1978, seven cases of type A botulism occurred in persons who had eaten in a restaurant in Colorado. The outbreak was recognized when two persons who had independently eaten at the restaurant were hospitalized with an illness compatible with botulism. Surveillance efforts identified five additional cases. Potato salad made at the restaurant and available for service during an 11-day period was epidemiologically incriminated as the vehicle of botulinal toxin transmission (p less than 0.00001). Laboratory studies showed that Clostridium botulinum spores on the surface of potatoes could survive baking in the manner used by the restaurant and that botulinal toxin could be produced in potatoes contaminated with C. botulinum spores.

Selective medium for isolation of Clostridium botulinum from human feces

A selective medium, Clostridium botulinum isolation (CBI) agar, was developed for the isolation of C. botulinum from human feces. This medium contains cycloserine (250 microgram/ml), sulfamethoxazole (76 microgram/ml), and trimethoprim (4 microgram/ml) as selective inhibitory agents. Qualitative tests indicated complete recovery of C. botulinum types A, B, F, and G on CBI medium. It was more difficult to recognize type G colonies on the medium because of their lack of lipase activity. Except for a few species of Clostridium, the growth of other obligate anaerobes and of the facultative anaerobes tested on CBI medium was suppressed. Quantitative studies of C. botulinum on the selective medium yielded counts comparable to those obtained on egg yolk agar control plates. Isolation of C. botulinum types A, B, and F from seeded fecal specimens was easily achieved with CBI medium. The use of CBI agar should aid the rapid isolation of C. botulinum from fecal specimens associated with foodborne and infant botulism.

Common polysaccharide antigens from the cell envelope of Clostridium perfringens type A

Soluble antigens were obtained by extracting five serotype strains of Clostridium perfringens type A with water at 100 degrees C. The type-specific polysaccharides were precipitated with ethanol, and the common antigens were recovered from the ethanol supernatants by concentration, dialysis, and lyophilization. Refluxing the water-extracted cell residues with 1% acetic acid followed by concentration, dialysis, and lyophilization gave additional common antigen fractions. A comprehensive, side-by-side comparison of the antigen fractions, the ethanol precipitate, the ethanol supernatant, and the acetic acid supernatant, revealed that common antigens were recovered in all three fractions, and that three distinct entities were responsible for the formation of the observed common immunoprecipitin lines; whereas many fractions possessed all three immunoprecipitin lines, others contained only one or two. The serological homology observed between the various antigen fractions was apparently a consequence of N-acetylglucosamine- and N-acetylmannosamine-containing polymers. The common antigens were presumably associated with the cell envelope and may be the type of markers sought previously by others for the serological identification of C. perfringens.

Susceptibility of Clostridium botulinum to thirteen antimicrobial agents

A total of 224 strains of Clostridium botulinum (including isolates from 14 patients with infant botulism and 4 with wound botulism) and 15 strains of C. sporogenes were tested by agar dilution for susceptibility to tetracycline, metronidazole, erythromycin, penicillin, rifampin, chloramphenicol, clindamycin, cephalothin, cefoxitin, vancomycin, sulfamethoxazole-trimethoprim, nalidixic acid, and gentamicin. At least 90% of the C. botulinum strains tested (except for nonproteolytic strains of toxin type F with penicillin) were susceptible to all drugs except sulfamethoxazole-trimethoprim, nalidixic acid, and gentamicin. Minimal inhibitory concentrations for strains from patients with infant and wound botulism were similar to those for other C. botulinum strains.

Production of phenylacetic and hydroxyphenylacetic acids by clostridium botulinum type G

Phenylacetic and hydroxyphenylacetic acids were present as major acids in spent growth medium from Clostridium botulinum type G. These aromatic acids were identified by gas-liquid chromatography and mass spectrometry.

Laboratory procedures for cases of suspected infant botulism

The recent development and evaluation of procedures for examination of fecal specimens for botulinal toxin and Clostridium botulinum have provided the means by which infant botulism can be recognized. The toxicity for mice of fecal extracts containing botulinal toxin can be neutralized with specific botulinal antitoxin. The presence of C. botulinum in the feces is detected by demonstrating the presence of botulinal toxin in enrichment culture supernatant by means of toxicity tests in mice. C. botulinum is isolated by streaking enrichment cultures on egg yolk agar and picking typical lipase-positive colonies. The experience of both the Center for Disease Control (CDC) Botulism Laboratory and other laboratories has been that botulinal toxin and C. botulinum are rarely, if ever, found in the feces of humans (infants or older people) not afflicted with botulism. Results of the examination in the CDC laboratory of specimens from 24 babies with infant botulism are given.

Type C botulism in American Foxhounds

Diffuse lower motor neuron dysfunction developed in a group of American Foxhounds while they were hunting. Of 19 dogs, 10 became weak and 9 became quadriplegic. Three of the quadriplegic dogs died before treatment could be instituted. The remaining quadriplegic dogs recovered after being given supportive treatment, with (4 dogs) or without (2 dogs) trivalent (types A, B, E) botulinal antitoxin. The 10 dogs that were weak recovered without treatment. A markedly decreased amplitude of evoked potentials and increased chronaxy were found by electromyographic examination of 2 of the quadriplegic dogs. A toxic substance that was neutralized by type C botulinal antitoxin in mouse inoculation tests was in the serum and feces of the most severly affected dog presented alive and in a fecal extract of another affected dog. In the one dog necropsied, neither gross nor histologic lesions were found in the central or peripheral nervous systems or in the skeletal musculature. The history, clinical signs, electromyographic findings, toxin neutralization tests in mice, and absence of histologic abnormalities in the neuromuscular system provided evidence for the diagnosis of C botulism.

Cultural and physiological characteristics of Clostridium botulinum type G and the susceptibility of certain animals to its toxin

Strain 89 of Clostridium botulinum type G, isolated by Gimenez and Ciccarelli in 1969, was characterized culturally, biochemically, and toxigenically. It was motile, hemolytic asaccharolytic, weakly proteolytic, lipase and lecithinase negative, and it produced acetic, isobutyric, butyric, and isovaleric acids in peptone-yeast extract-glucose broth. No spores were seen in smears from solid or liquid media. Very low levels of toxin were produced in regular broth cultures, but dialysis cultures yielded 30,000 mouse 50% mean lethal doses (LD50 per kg, orally and subcutaneously, respectively; and for guinea pigs, 10,000 to 20,000 and 100 mouse LD50 per kig, intragastrically and intraperitoneally, respectively.

Coproexamination for botulinal toxin and clostridium botulinum. A new procedure for laboratory diagnosis of botulism

Stool or serum specimens or both from 318 persons pertaining to 165 botulism investigations over a three-year period were examined. Botulinal toxin was detected in stools of 19 of 56 patients and in sera of 20 of 60 patients with clinical botulism; it was not detected in specimens from 246 persons with an illness other than botulism or well contacts of patients. Clostridium botulinum was identified in stools of 36 of 60 clinical botulism patients and in four of 27 asymptomatic contacts of patients with botulism victims, but not in stools of 65 persons not associated with confirmed botulism. When stool and serum samples were examined, confirmatory evidence was obtained for 72.9% of the botulism cases. Detection of botulinal toxin or C botulinum in the stool of a persons should be considered evidence supporting the clinical diagnosis of botulism.

Type A and type B botulism in the North: first reported cases due to toxin other than type E in Alaskan Inuit

Botulism outbreaks shown to be due to type A and type B toxin occurred in Alaska, a region previously known for only type E botulism. The outbreak due to type A toxin involved three people, two of whom died. The outbreak due to type B toxin involved nine people, none of whom died. Both outbreaks were in Inuit villages, and native foods were incriminated. The occurrence of these outbreaks strongly suggests that Clostridium botulinum, types A and B are indigenous to Alaska. The outbreaks underscore the need for initial treatment of patients with antitoxin that is trivalent (ABE), even in Arctic regions.

Laboratory diagnosis of botulism complicated by pyridostigmine treatment of the patient. A method for selectively removing interfering substances from clinical specimens

In August 1974, a case of botulism occurred; home-canned potatoes and peas containing Clostridium botulinum, type A, were strongly incriminated as the vehicle of transmission. C. botulinum, type A, was isolated from a stool specimen of the patient, but the mouse neutralization test for botulinal toxin could not be completed because the stool extract contained a highly toxic, heat-stable substance that rapidly killed mice. Historical and laboratory evidence indicated that the substance was pyridostigmine bromide, a low-molecular-weight drug with which the patient had been treated after her disease was misdiagnosed as myasthenia gravis. A generally applicable method employing dialysis by which toxic SUBSTANCED of low molecular weigth could be selectively removed from specimens without diminishing the potency of botulinal toxin contained in them was developed. Dialysis rendered a pyridostigmine solution, a stool extract from the patient with botulism, and a stool extract from a person taking pyridostigmine virtually nontoxic to mice. Dialysis did not significantly alter the toxicity to mice of crude botulinal toxin; it selectively eliminated all or almost all pyridostigmine toxicity from a pyridostigmine-botulinal toxin mixture without altering the toxicity of the botulinal toxin.

Toxoid of Clostridium botulinum type F: purification and immunogenicity studies

Toxin from Clostridium botulinum type F was recovered from dialysis cultures and partially purifed by: (i) ammonium sulfate and ethanol precipitation; (ii) O-(diethylaminoethyl)-cellulose chromatography; or (iii) diethylaminoethyl-cellulose chromatography followed by O-(carboxymethyl)-cellulose chromatography. Toxin purities as reflected by specific activity were 1.83 X 10(6), 9.8 X 10(6), and 2.0 X 10(7) mouse 50% lethal doses (LD50)/mg of N, respectively, for toxins purified by the three methods. The toxins were converted to toxoids by incubation at 35 C in the presence of 0.3 to 0.45% formalin for 21 to 35 days. Toxoids were immunogenic in guinea pigs, as demonstrated by serum antitoxin response and the immunized animals' resistance to challenge by type F botulinal toxin. The immune response to type F toxoids was lower when toxoids of serotypes A, B, C, D, and E were combined with the type F toxoid than when the type F toxoid only was administered. The toxoid prepared from the most highly purified toxin (method [iii]) conferred the highest immunity in guinea pigs at a given dose level. A relation between serum antitoxin level and resistance to challenge was observed. At least 50% of the groups of guinea pigs with 0.015 antitoxin units or more per ml survived challenge by 10(5) mouse LD50 of type F botulinal toxin. A dose of 3.75 mug of N of the most highly purified type F toxoid in combination with the other five serotypes of botulinal toxoid invoked an immune response in guinea pigs comparable to that considered adequate for the other toxoids.