Biodiversity of Clostridium botulinum type E strains isolated from fish and fishery products. (1/315)

The genetic biodiversity of Clostridium botulinum type E strains was studied by pulsed-field gel electrophoresis (PFGE) with two macrorestriction enzymes (SmaI-XmaI and XhoI) and by randomly amplified polymorphic DNA (RAPD) analysis with two primers (OPJ 6 and OPJ 13) to characterize 67 Finnish isolates from fresh fish and fishery products, 15 German isolates from farmed fish, and 10 isolates of North American or North Atlantic origin derived mainly from different types of seafood. The effects of fish species, processing, and geographical origin on the epidemiology of the isolates were evaluated. Cluster analysis based on macrorestriction profiles was performed to study the genetic relationships of the isolates. PFGE and RAPD analyses were combined and resulted in the identification of 62 different subtypes among the 92 type E isolates analyzed. High genetic biodiversity among the isolates was observed regardless of their source. Finnish and North American or North Atlantic isolates did not form distinctly discernible clusters, in contrast with the genetically homogeneous group of German isolates. On the other hand, indistinguishable or closely related genetic profiles among epidemiologically unrelated samples were detected. It was concluded that the high genetic variation was probably a result of a lack of strong selection factors that would influence the evolution of type E. The wide genetic biodiversity observed among type E isolates indicates the value of DNA-based typing methods as a tool in contamination studies in the food industry and in investigations of botulism outbreaks.  (+info)

Foodborne botulism associated with home-canned bamboo shoots--Thailand, 1998. (2/315)

On April 13, 1998, the Field Epidemiology Training Program in the Thailand Ministry of Public Health (TMPH) was informed of six persons with sudden onset of cranial nerve palsies suggestive of botulism who were admitted to a provincial hospital in northern Thailand. To determine the cause of the cluster, TMPH initiated an investigation on April 14. This report summarizes the results of the investigation, which indicate that the outbreak was caused by foodborne botulism from home-canned bamboo shoots.  (+info)

In situ detection of the Clostridium botulinum type C1 toxin gene in wetland sediments with a nested PCR assay. (3/315)

A nested PCR was developed for detection of the Clostridium botulinum type C1 toxin gene in sediments collected from wetlands where avian botulism outbreaks had or had not occurred. The C1 toxin gene was detected in 16 of 18 sites, demonstrating both the ubiquitous distribution of C. botulinum type C in wetland sediments and the sensitivity of the detection assay.  (+info)

A predictive model that describes the effect of prolonged heating at 70 to 90 degrees C and subsequent incubation at refrigeration temperatures on growth from spores and toxigenesis by nonproteolytic Clostridium botulinum in the presence of lysozyme. (4/315)

Refrigerated processed foods of extended durability such as cook-chill and sous-vide foods rely on a minimal heat treatment at 70 to 95 degrees C and then storage at a refrigeration temperature for safety and preservation. These foods are not sterile and are intended to have an extended shelf life, often up to 42 days. The principal microbiological hazard in foods of this type is growth of and toxin production by nonproteolytic Clostridium botulinum. Lysozyme has been shown to increase the measured heat resistance of nonproteolytic C. botulinum spores. However, the heat treatment guidelines for prevention of risk of botulism in these products have not taken into consideration the effect of lysozyme, which can be present in many foods. In order to assess the botulism hazard, the effect of heat treatments at 70, 75, 80, 85, and 90 degrees C combined with refrigerated storage for up to 90 days on growth from 10(6) spores of nonproteolytic C. botulinum (types B, E, and F) in an anaerobic meat medium containing 2,400 U of lysozyme per ml (50 microg per ml) was studied. Provided that the storage temperature was no higher than 8 degrees C, the following heat treatments each prevented growth and toxin production during 90 days; 70 degrees C for >/=2,545 min, 75 degrees C for >/=463 min, 80 degrees C for >/=230 min, 85 degrees C for >/=84 min, and 90 degrees C for >/=33.5 min. A factorial experimental design allowed development of a predictive model that described the incubation time required before the first sample showed growth, as a function of heating temperature (70 to 90 degrees C), period of heat treatment (up to 2,545 min), and incubation temperature (5 to 25 degrees C). Predictions from the model provided a valid description of the data used to generate the model and agreed with observations made previously.  (+info)

Clostridium difficile colitis associated with infant botulism: near-fatal case analogous to Hirschsprung's enterocolitis. (5/315)

We present the first five reported cases of Clostridium difficile-associated diarrhea (CDAD) in children with infant botulism caused by Clostridium botulinum. We compare two fulminant cases of colitis in children with colonic stasis, the first caused by infant botulism and the second caused by Hirschsprung's disease. In both children, colitis was accompanied by hypovolemia, hypotension, profuse ascites, pulmonary effusion, restrictive pulmonary disease, and femoral-caval thrombosis. Laboratory findings included pronounced leukocytosis, hypoalbuminemia, hyponatremia, coagulopathy, and, when examined in the child with infant botulism, detection of C. difficile toxin in ascites. CDAD recurred in both children, even though difficile cytotoxin was undetectable in stool after prolonged initial therapy. Four children who had both infant botulism and milder CDAD also are described. Colonic stasis, whether acquired, as in infant botulism, or congenital, as in Hirschsprung's disease, may contribute to the susceptibility to and the severity of CDAD.  (+info)

Quantification of Clostridium botulinum toxin gene expression by competitive reverse transcription-PCR. (6/315)

Clostridium botulinum produces a characteristic botulinum neurotoxin which can cause an often fatal neuroparalytic condition known as botulism. Although food-borne botulism is rare, critical screening by food companies is necessary to ensure that food products are safe. At present, the food industry assesses the risks of botulinum neurotoxin production by challenge testing to check any new food products and to check the efficacy of new storage regimes. Challenge testing involves artificial introduction of defined strains of microorganisms into food, and microbial growth and possible toxin production are then monitored. Botulinum toxin is normally analyzed by using the mouse bioassay. However, the mouse bioassay is expensive, slow, and politically sensitive because of animal rights issues. In this paper we describe adaptation of a new assay, competitive reverse transcription-PCR (RT-PCR), to monitor botulinum neurotoxin production. This method accurately measures the level of toxin-encoding mRNA in C. botulinum cells. Measurement of mRNA should provide a good indication of gene expression as mRNA is turned over rapidly in bacterial cells. In addition, the method is rapid, specific, and sensitive. The competitive RT-PCR method was developed to examine C. botulinum E VH toxin gene expression and was used to investigate the level of toxin production by C. botulinum E VH when the organism was grown in two different types of broth. The results which we obtained with the competitive RT-PCR method demonstrated that this method is more rapid and more sensitive than the mouse bioassay.  (+info)

Type C botulism in dairy cattle from feed contaminated with a dead cat. (7/315)

Four hundred twenty-seven of 441 adult Holstein dairy cattle from a 1,200-cow dairy died over a 1-week period during early spring 1998. Affected animals were from 4 late lactation pens, one of which included the bull string. Signs included weakness, recumbency, watery diarrhea, and death. Eighty animals from the 4 pens were dead approximately 8 hours after the first ill cows were noted. Affected cows would collapse on stimulation and extend all 4 limbs with moderate rigidity. Several lacked lingual tonus and had abdominal breathing patterns. The animals had been fed a load of total mixed ration that included a rotten bale of oat hay containing a dead cat. No common toxicants were identified, and pathologic examination revealed no consistent lesions. Testing of tissue from the cat carcass found in the feed sample using mouse protection bioassay identified the presence of type C botulinum toxin. Samples of feed, tissue from affected animals, cat tissue from feed, milk, and serum were also tested using an enzyme-linked immunosorbent assay (ELISA) specific for type C botulinum. Two samples of rumen contents were tested and found to be positive for botulism by ELISA, and 1 of 3 liver samples had a weak positive finding. No botulinum toxin was found in milk or sera using the ELISA.  (+info)

Control of bacterial spores. (8/315)

Bacterial spores are much more resistant than their vegetative counterparts. The most dangerous spore-former is Clostridium botulinum which produces a potent neurotoxin that can prove fatal. The most common food poisoning from a spore-former is caused by C. perfringens. Other food poisoning spore-formers include Bacillus cereus, B. subtilis and B. licheniformis. There are a number of non-pathogenic spore-formers including butyric and thermophilic anaerobes that cause significant economic losses to food producers. Some unusual spoilage complaints have been reported, for example, B. sporothermodurans in UHT milk, Alicyclobacillus acidoterrestris in apple and orange juice and Desulfotomaculum nigrificans in hot vending machines. Control of spore-formers requires an understanding of both the resistance and outgrowth characteristics of the spores.  (+info)

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