Viable Clostridium botulinum spores not detected in the household dust of major Canadian cities

Clostridium botulinum causes infant botulism by colonising the intestines and producing botulinum neurotoxin in situ. Previous reports have linked infant botulism cases to C. botulinum spores in household dust, yet the baseline incidence of C. botulinum spores in residential households is currently unknown. Vacuum cleaner dust from 963 households in 13 major Canadian cities was tested for C. botulinum using a novel real-time PCR assay directed against all known subtypes of the botulinum neurotoxin gene. None of the samples tested positive for C. botulinum. Analysis of a random subset of samples by MALDI Biotyper revealed that the most common anaerobic bacterial isolates were of the genus Clostridium and the most common species recovered overall was Clostridium perfringens. Dust that was spiked with C. botulinum spores of each toxin type successfully produced positive real-time PCR reactions. These control experiments indicate that this is a viable method for the detection of C. botulinum spores in household dust. We make several recommendations for future work that may help discover a common environmental source of C. botulinum spores that could lead to effective preventative measures for this rare but deadly childhood disease.

Tracing Foodborne Botulism Events Caused by Clostridium botulinum in Xinjiang Province, China, Using a Core Genome Sequence Typing Scheme

Foodborne botulism is a rare but life-threatening illness resulting from the action of a potent toxin mainly produced by Clostridium botulinum. It grows in an oxygen-deficient environment and is extremely viable in meat and soy products, making it one of the most virulent bacteria. How to track foodborne botulism events quickly and accurately has become a key issue. Here, we investigated two foodborne botulism events that occurred in Xinjiang in 2019 based on whole-genome sequencing and also successfully traced the relationship between clinical and food C. botulinum isolates using whole-genome core gene markers. All 59 isolates were classified as group I strains. Of the strains isolated in this study, 44 were found to be botulinum toxin A(B), and 15 isolates contained only the toxin B locus. Both the toxin A and B gene segments were located on the chromosome and organized in an ha cluster. Antibiotic resistance and virulence factors were also investigated. A set of 329 universal core gene markers were established using C. botulinum strains from a public database. These core gene markers were applied to the published C. botulinum genomes, and three outbreaks were identified. This work demonstrates that universal core gene markers can be used to trace foodborne botulism events, and we hope that our work will facilitate this effort in future. IMPORTANCE In this study, we analyzed 59 foodborne botulism (FB)-related strains isolated in Xinjiang Province, China. Our findings not only reveal the group classification, neurotoxin locus organization, antibiotic resistance and virulence factors of these strains but also establish a set of core gene markers for tracing foodborne botulism events, which was verified using published genomes. These findings indicate that these gene markers might be used as a potential tracing tool for FB events caused by C. botulinum group I strains, which have relatively stable genomic components.

Sporulation Strategies and Potential Role of the Exosporium in Survival and Persistence of Clostridium botulinum

Clostridium botulinum produces the botulinum neurotoxin that causes botulism, a rare but potentially lethal paralysis. Endospores play an important role in the survival, transmission, and pathogenesis of C. botulinum. C. botulinum strains are very diverse, both genetically and ecologically. Group I strains are terrestrial, mesophilic, and produce highly heat-resistant spores, while Group II strains can be terrestrial (type B) or aquatic (type E) and are generally psychrotrophic and produce spores of moderate heat resistance. Group III strains are either terrestrial or aquatic, mesophilic or slightly thermophilic, and the heat resistance properties of their spores are poorly characterized. Here, we analyzed the sporulation dynamics in population, spore morphology, and other spore properties of 10 C. botulinum strains belonging to Groups I–III. We propose two distinct sporulation strategies used by C. botulinum Groups I–III strains, report their spore properties, and suggest a putative role for the exosporium in conferring high heat resistance. Strains within each physiological group produced spores with similar characteristics, likely reflecting adaptation to respective environmental habitats. Our work provides new information on the spores and on the population and single-cell level strategies in the sporulation of C. botulinum.

Camelid VHH Antibodies that Neutralize Botulinum Neurotoxin Serotype E Intoxication or Protease Function

Botulinum neurotoxin (BoNT) serotype E is one of three serotypes that cause the preponderance of human botulism cases and is a Tier 1 Select Agent. BoNT/E is unusual among BoNT serotypes for its rapid onset and short duration of intoxication. Here we report two large panels of unique, unrelated camelid single-domain antibodies (VHHs) that were selected for their ability to bind to BoNT/E holotoxin and/or to the BoNT/E light chain protease domain (LC/E). The 19 VHHs which bind to BoNT/E were characterized for their subunit specificity and 8 VHHs displayed the ability to neutralize BoNT/E intoxication of neurons. Heterodimer antitoxins consisting of two BoNT/E-neutralizing VHHs, including one heterodimer designed using structural information for simultaneous binding, were shown to protect mice against co-administered toxin challenges of up to 500 MIPLD₅₀. The 22 unique VHHs which bind to LC/E were characterized for their binding properties and 9 displayed the ability to inhibit LC/E protease activity. Surprisingly, VHHs selected on plastic-coated LC/E were virtually unable to recognize soluble or captured LC/E while VHHs selected on captured LC/E were poorly able to recognize LC/E coated to a plastic surface. This panel of anti-LC/E VHHs offer insight into BoNT/E function, and some may have value as components of therapeutic antidotes that reverse paralysis following BoNT/E exposures.

Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism

Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism.

Pan-Genomic Analysis of Clostridium botulinum Group II (Non-Proteolytic C. botulinum) Associated with Foodborne Botulism and Isolated from the Environment

The neurotoxin formed by Clostridium botulinum Group II is a major cause of foodborne botulism, a deadly intoxication. This study aims to understand the genetic diversity and spread of C. botulinum Group II strains and their neurotoxin genes. A comparative genomic study has been conducted with 208 highly diverse C. botulinum Group II strains (180 newly sequenced strains isolated from 16 countries over 80 years, 28 sequences from Genbank). Strains possessed a single type B, E, or F neurotoxin gene or were closely related strains with no neurotoxin gene. Botulinum neurotoxin subtype variants (including novel variants) with a unique amino acid sequence were identified. Core genome single-nucleotide polymorphism (SNP) analysis identified two major lineages-one with type E strains, and the second dominated by subtype B4 strains with subtype F6 strains. This study revealed novel details of population structure/diversity and established relationships between whole-genome lineage, botulinum neurotoxin subtype variant, association with foodborne botulism, epidemiology, and geographical source. Additionally, the genome sequences represent a valuable resource for the research community (e.g., understanding evolution of C. botulinum and its neurotoxin genes, dissecting key aspects of C. botulinum Group II biology). This may contribute to improved risk assessments and the prevention of foodborne botulism.

Fully Human Monoclonal Antibodies Effectively Neutralizing Botulinum Neurotoxin Serotype B

Botulinum neurotoxin (BoNT) is the most potent natural toxin known. Of the seven BoNT serotypes (A to G), types A, B, E, and F cause human botulism. Treatment of human botulism requires the development of effective toxin-neutralizing antibodies without side effects such as serum sickness and anaphylaxis. In this study, we generated fully human monoclonal antibodies (HuMAbs) against serotype B BoNT (BoNT/B1) using a murine–human chimera fusion partner cell line named SPYMEG. Of these HuMAbs, M2, which specifically binds to the light chain of BoNT/B1, showed neutralization activity in a mouse bioassay (approximately 10 i.p. LD₅₀/100 µg of antibody), and M4, which binds to the C-terminal of heavy chain, showed partial protection. The combination of two HuMAbs, M2 (1.25 µg) and M4 (1.25 µg), was able to completely neutralize BoNT/B1 (80 i.p. LD₅₀) with a potency greater than 80 i.p. LD₅₀/2.5 µg of antibodies, and was effective both prophylactically and therapeutically in the mouse model of botulism. Moreover, this combination showed broad neutralization activity against three type B subtypes, namely BoNT/B1, BoNT/B2, and BoNT/B6. These data demonstrate that the combination of M2 and M4 is promising in terms of a foundation for new human therapeutics for BoNT/B intoxication.

Adult Intestinal Toxemia Botulism

Intoxication with botulinum neurotoxin can occur through various routes. Foodborne botulism results after consumption of food in which botulinum neurotoxin-producing clostridia (i.e., Clostridium botulinum or strains of Clostridiumbutyricum type E or Clostridiumbaratii type F) have replicated and produced botulinum neurotoxin. Infection of a wound with C. botulinum and in situ production of botulinum neurotoxin leads to wound botulism. Colonization of the intestine by neurotoxigenic clostridia, with consequent production of botulinum toxin in the intestine, leads to intestinal toxemia botulism. When this occurs in an infant, it is referred to as infant botulism, whereas in adults or children over 1 year of age, it is intestinal colonization botulism. Predisposing factors for intestinal colonization in children or adults include previous bowel or gastric surgery, anatomical bowel abnormalities, Crohn's disease, inflammatory bowel disease, antimicrobial therapy, or foodborne botulism. Intestinal colonization botulism is confirmed by detection of botulinum toxin in serum and/or stool, or isolation of neurotoxigenic clostridia from the stool, without finding a toxic food. Shedding of neurotoxigenic clostridia in the stool may occur for a period of several weeks. Adult intestinal botulism occurs as isolated cases, and may go undiagnosed, contributing to the low reported incidence of this rare disease.

Discrimination of Human Pathogen Clostridium Species Especially of the Heterogeneous C. sporogenes and C. botulinum by MALDI-TOF Mass Spectrometry

Clostridium species cause several local and systemic diseases. Conventional identification of these microorganisms is in part laborious, not always reliable, time consuming or does not always distinguish different species, i.e., C. botulinum and C. sporogenes. All in, there is a high interest to find out a reliable, powerful and rapid method to identify Clostridium spp. not only on genus but also on species level. The aim of the present study was to identify Clostridium spp. strains and also to find differences and metabolic groups of C. botulinum by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). A total of 123 strains of Clostridium spp. (C. botulinum, n = 40, C. difficile, n = 11, C. tetani, n = 11, C. sordellii, n = 20, C. sporogenes, n = 18, C. innocuum, n = 10, C. perfringens, n = 13) were analyzed by MALDI-TOF MS in combination with methods of multivariate statistical analysis. MALDI-TOF MS analysis in combination with methods of multivariate statistical analysis was able to discriminate between the different tested Clostridium spp., even between species which are closely related and difficult to differentiate by traditional methods, i.e., C. sporogenes and C. botulinum. Furthermore, the method was able to separate the different metabolic groups of C. botulinum. Especially, E gene-positive C. botulinum strains are clearly distinguishable from the other species but also from those producing other toxin types. Thus, MALDI-TOF MS represents a reliable and above all quick method for identification of cultivated Clostridium species.

[Herd health problems with a focus on potential involvement of Clostridium botulinum in dairies in Bavaria. - A survey among veterinarians]

OBJECTIVE

To evaluate the perceptions of Bavarian bovine practitioners in regard to ailments that could potentially be associated with chronic Clostridium botulinum infections.

MATERIAL AND METHODS

A questionnaire-based survey consisting of two parts was conducted via telephone. The questionnaire contained five main inclusion criteria and seven further criteria for inclusion in the second, special part of the study. The main focus was on diseases suspected to be associated with chronic Clostridium botulinum infections. For the interview in the special part, for each practice, the farm that fulfilled the most of the main criteria was selected.

RESULTS

In the general section of the questionnaire, 38 (37%) of the 104 participants stated not to have farms with any of the previously indicated disease patterns in their practice. A total of 532 operations (5% of all managed dairies) were classified as a problem facility that had to deal with the aforementioned main inclusion criteria diseases. The most frequently stated on-farm problems were an increased number of recumbent cows (73 %), lameness or cases of ataxia (70 %), udder problems (69 %), metabolic disorders (68 %), high incidence of chronically ill animals (66 %) and high culling rates (66 %). The housing conditions of dairy cows were assessed to be "mediocre" or "poor" in 49 % of dairies. Feeding management was regarded as "moderately good", "good" or "very good" by 91 % of participants. Testing for Clostridium spp. was performed on 11 farms and positive results were found in seven cases.

CONCLUSION

Livestock veterinarians in Bavaria are frequently confronted with an abundance of animal health-related issues on dairy farms. However, even on farms on which there were signs according to the literature of clostridial infection, rather husbandry-related problems were suspec -ted in most cases.

Type C/D botulism in the waterfowl in an urban park in Italy

This report describes an outbreak of botulism occurred among a free-living population of mallards (Anas platyrhynchos) and geese (Anser anser) in an urban park. Mortality rate among investigated population was 86,8% (118 dead out of 136). Twenty-seven carcasses were collected for macroscopic examination and screened for microbiological, virological, toxicological investigations. A sick mallard was captured and neurological symptoms were observed. No causative agent of viral avian diseases was found in the examined animals and screening for environmental neurotoxic substances proved negative as well. In contrast, microbiological cultures from specimens tested positive for botulinum toxin-producing clostridia. Blood serum and fecal extract of the sick mallard proved positive for botulinum neurotoxin in the standard mouse protection test using reference Clostridium botulinum type C antitoxin. Gene content of cultured strains showed a mosaic composition of bont/C and bont/D sequences, defining them as type C/D chimeric organisms.

A Comparison of Human and Animal Botulism: A Review

Botulism can arise from preformed toxin, wound infection or intestinal toxico-infection. All three forms can occur in humans as well as in animals. The examination of botulism in veterinary practice can alert the medical profession to the hazards which can occur with the introduction of dietary alterations and hermetic sealing of foodstuffs. There is also the possibility that the development of pica through lack of essential nutrients could lead to the ingestion of contaminated substances rendering the child (or even adult) susceptible to botulinum intoxication. A positive gain has been that research leading to the elimination of shaker foal disease has provided a comprehensive analysis of factors which may underline the risk of toxico-infection in infants12.

[Infant botulism – why honey should be avoided for children up to one year]

Infant botulism - why honey should be avoided for children up to one year Infant botulism means that Clostridium botulinum colonize and produce toxin in the infant gut, usually during the first year of life. Illness severity varies widely and the incidence may be under-estimated. Infant botulism should be considered in cases of acute muscle weakness or floppiness in infants, especially when accompanied by constipation or feeding difficulties. Respiratory failure and need for mechanical ventilation is common, but full recovery is gradually obtained. Diagnosis is based on stool culture and toxin detection in stool. Botulinum spores are frequently present in honey, which should consequently be avoided for infants.

Development and Validation of a New Reliable Method for the Diagnosis of Avian Botulism

Liver is a reliable matrix for laboratory confirmation of avian botulism using real-time PCR. Here, we developed, optimized, and validated the analytical steps preceding PCR to maximize the detection of Clostridium botulinum group III in avian liver. These pre-PCR steps included enrichment incubation of the whole liver (maximum 25 g) at 37°C for at least 24 h in an anaerobic chamber and DNA extraction using an enzymatic digestion step followed by a DNA purification step. Conditions of sample storage before analysis appear to have a strong effect on the detection of group III C. botulinum strains and our results recommend storage at temperatures below -18°C. Short-term storage at 5°C is possible for up to 24 h, but a decrease in sensitivity was observed at 48 h of storage at this temperature. Analysis of whole livers (maximum 25 g) is required and pooling samples before enrichment culturing must be avoided. Pooling is however possible before or after DNA extraction under certain conditions. Whole livers should be 10-fold diluted in enrichment medium and homogenized using a Pulsifier® blender (Microgen, Surrey, UK) instead of a conventional paddle blender. Spiked liver samples showed a limit of detection of 5 spores/g liver for types C and D and 250 spores/g for type E. Using the method developed here, the analysis of 268 samples from 73 suspected outbreaks showed 100% specificity and 95.35% sensitivity compared with other PCR-based methods considered as reference. The mosaic type C/D was the most common neurotoxin type found in examined samples, which included both wild and domestic birds.

Multiple-locus variable number of tandem repeat analysis as a tool for molecular epidemiology of botulism: The Italian experience

Clostridium botulinum is the bacterial agent of botulism, a rare but severe neuro-paralytic disease. Because of its high impact, in Italy botulism is monitored by an ad hoc surveillance system. The National Reference Centre for Botulism, as part of this system, collects and analyzes all demographic, epidemiologic, microbiological, and molecular data recovered during cases and/or outbreaks occurred in Italy. A panel of 312 C. botulinum strains belonging to group I were submitted to MLVA sub-typing. Strains, isolated from clinical specimens, food and environmental samples collected during the surveillance activities, were representative of all forms of botulism from all Italian regions. Through clustering analysis isolates were grouped into 12 main clusters. No regional or temporal clustering was detected, demonstrating the high heterogeneity of strains circulating in Italy. This study confirmed that MLVA is capable of sub-typing C. botulinum strains. Moreover, MLVA is effective at tracing and tracking the source of contamination and is helpful for the surveillance system in terms of planning and upgrading of procedures, activities and data collection forms.

Conformational divergence in the HA-33/HA-17 trimer of serotype C and D botulinum toxin complex

Clostridium botulinum produces a large toxin complex (L-TC) comprising botulinum neurotoxin associated with auxiliary nontoxic proteins. A complex of 33- and 17-kDa hemagglutinins (an HA-33/HA-17 trimer) enhances L-TC transport across the intestinal epithelial cell layer via binding HA-33 to a sugar on the cell surface. At least two subtypes of serotype C/D HA-33 exhibit differing preferences for the sugars sialic acid and galactose. Here, we compared the three-dimensional structures of the galactose-binding HA-33 and HA-33/HA-17 trimers produced by the C-Yoichi strain. Comparisons of serotype C/D HA-33 sequences reveal a variable region with relatively low sequence similarity across the C. botulinum strains; the variability of this region may influence the manner of sugar-recognition by HA-33. Crystal structures of sialic acid- and galactose-binding HA-33 are broadly similar in appearance. However, small-angle X-ray scattering revealed distinct solution structures for HA-33/HA-17 trimers. A structural change in the C-terminal variable region of HA-33 might cause a dramatic shift in the conformation and sugar-recognition mode of HA-33/HA-17 trimer.

Clostridium botulinum type D/C intoxication in a dairy cow stock in Saxony-Anhalt (Germany)--report on an innovative diagnostic approach

Botulism in cattle is a rare but serious disease. In Germany there is no obligation to report botulism in animals and therefore a precise morbidity rate is not available. In this manuscript we describe an outbreak of Clostridium (C.) botulinum neurotoxin (BoNT) intoxication in a Saxony-Anhalt dairy cow stock of 286 Holstein-Friesian cows and offspring in spring/summer 2009 and its diagnostic approach. 122 animals showed clinical signs of BoNT intoxication. 115 of the affected animals (40.2% of the herd) independent of age died or had to be euthanized. Therapeutic attempts failed in almost all diseased cows, only four calves and three heifers recovered. Diagnostic samples of several animals (n = 4) (liver, ruminal and intestinal contents) and feed (n = 6) were tested for BoNT genes by polymerase chain reaction (PCR). BoNT gene type D was found in several (n = 8) organ samples. The PCR results allowed a preselection of samples for BoNT that were then tested by the mouse bioassay. Thus, the number of mice being inoculated in the mouse bioassay could be reduced. The mouse bioassay turned out positive (wasp-waist) in three preselected organ samples and the neutralization test of one sample with type-specific antitoxin confirmed the presence of BoNT type D. We succeeded in isolating a C. botulinum strain from a liver sample which was typed as a D/C mosaic strain by sequence analysis of the toxin gene. However, the source of the BoNT intoxication could not be traced back.

Foodborne botulism in Poland in 2014

OBJECTIVES

The aim of the study is to assess the epidemiology of foodborne botulism in Poland in 2014 compared to previous years.

MATERIALS AND METHODS

We reviewed (1) surveillance data published in the annual bulletin “Infectious diseases and poisonings in Poland in 2014” and in previous publications, and (2) unpublished data retrieved from botulism case reports for 2014 sent to the Department of Epidemiology NIPH-NIH by Sanitary-Epidemiological Stations.

RESULTS

In 2014, a total of 29 foodborne botulism cases (including 17 laboratory confirmed) was reported; the annual incidence rate (0.08 per 100,000 population) increased slightly in comparison to previous year, but was similar to the median incidence for years 2008 to 2012. The highest incidence in the country was reported in Lubelskie province (0.33). Incidence in rural areas (0.09) was only slightly higher than the incidence in urban areas (0.06). Men, had more than 4 times higher incidence than women; the highest incidence rate (0.31) was observed among men in the age group of 20-24 years. Most cases were associated with consumption of different types of commercially canned meat. Home-made vegetable meat preserves were also a common vehicle. All cases were hospitalized. Two deaths related to the disease were reported.

CONCLUSIONS

Since 2008, the epidemiological situation of foodborne botulism in the country remains stable with an average 30 cases per year and corresponding incidence rate of 0.08 per 100,000 population. However, in 2014 draws attention a significant number of cases with undetermined food vehicle and relatively high percentage of cases with no laboratory confirmation. Therefore, it is important to enhance epidemiological investigation as well as laboratory capacity for surveillance.

Characterizing the fecal microbiota of infants with botulism

BACKGROUND

Infant botulism is the most prevalent form of botulism in the USA, representing 68.5 % of cases reported from 2001-2012. Infant botulism results when botulinum toxin-producing clostridia (BTPC) colonize the infant gut with concomitant in vivo production of the highly potent botulinum neurotoxin (BoNT). The gut microbiota of infants with botulism is largely uncharacterized; therefore, it remains unclear whether the microbiota profile of these patients are distinct in composition, abundance, or diversity. To address this uncertainty, we employed 16S rRNA gene profiling to characterize the fecal microbiota in 14 stool samples among laboratory-confirmed and non-confirmed infant botulism cases.

RESULTS

Seven bacterial phyla were identified among all 14 infant stool samples examined. Compared to samples from non-confirmed cases, the fecal microbiota of infant botulism patients displayed significantly higher Proteobacteria abundance. Of the 20 bacterial families identified, Enterobacteriaceae was significantly more abundant in samples from infants with botulism. Firmicutes abundance and the abundance ratio of Firmicutes/Proteobacteria was significantly lower in samples from infants with botulism. Lactobacillus spp. abundance was notably reduced in 12 of the 14 samples. Clostridium botulinum and Clostridium baratii were identified in low relative abundances in confirmed and non-confirmed samples based on their 16S rRNA gene profiles, although their toxigenicity remained undetermined. No significant differences were observed in the number of operational taxonomic units (OTUs) observed or in fecal microbiota diversity between laboratory-confirmed and non-confirmed samples. Correlations between individual phylum abundances and infant age were variable, and no significant differences were shown in number of OTUs observed or in fecal microbiota diversity between samples delineated by overall mean age.

CONCLUSIONS

Significant differences in Proteobacteria, Firmicutes, and Enterobacteriaceae abundances were identified in the fecal microbiota of infants with botulism when compared to samples from non-confirmed cases. Fecal microbiota diversity was not significantly altered in infants with botulism, and a limited presence of BTPC was shown. It could not be determined whether the fecal microbiota profiles shown here were comparable prior to patient illness, or whether they were the direct result of infant botulism. The results of this study do, however, provide a detailed and descriptive observation into the infant gut microbiota after intestinal colonization by BTPC.

Evidence for a natural humoral response in dairy cattle affected by persistent botulism sustained by non-chimeric type C strains

Bovine botulism is a sporadic acute disease that usually causes catastrophic losses in the herds. The unusual clinical evolution of a persistent mild outbreak in a dairy herd, prompted us to characterize the neurotoxin gene profile of the strain involved and to evaluate whether seroconversion had occurred. Diagnosis was based on mild classical symptoms and was supported by PCR and bacteriological findings, which revealed the involvement of a non-mosaic type C strain. An in-house ELISA was developed to detect antibodies to botulinum neurotoxin type C and its performance was evaluated in a vaccination study. Fifty days after the index case, fecal and serum samples were collected from the 14 animals of the herd and screened for Clostridium botulinum and anti-botulinum neurotoxin antibodies type C, respectively. The in-house developed ELISA was also used to test 100 sera samples randomly collected from 20 herds. Strong ELISA reactions were observed in 3 convalescent and 5 asymptomatic animals involved in the studied outbreak. The ELISA-positive cows all tested positive for non-mosaic C. botulinum type C in the feces and the same strain was also detected in the alfalfa hay, suspected to be the carrier source. Ten out of the 100 randomly collected sera tested positive for anti-botulinum neurotoxin type C antibodies: 7 had borderline values and 3 from the same herd showed titers three times higher than the cut-off. We concluded that type C botulism in cattle may occur with variable severity and that prolonged exposure to sublethal doses of botulinum neurotoxin C may occur, resulting in detectable antibodies.

Laboratory Investigation of the First Case of Botulism Caused by Clostridium butyricum Type E Toxin in the United States

We report here the laboratory investigation of the first known case of botulism in the United States caused by Clostridium butyricum type E. This investigation demonstrates the importance of extensive microbiological examination of specimens, which resulted in the isolation of this organism.

Heart Rate Variability (HRV) modifications in adult hemiplegic patients after botulinum toxin type A (nt-201) injection

BACKGROUND

The most important adverse effect of BoNT-A is the systemic diffusion of the toxin. There is some evidence that the administration of high doses can increase the risk of systemic diffusion and the development of clinically evident adverse effects, however an international consensus does not exist about its maximum dose.

AIM

The aim of this study was to evaluate changes in autonomic heart drive induced by high doses (higher than 600 units) of incobotulinumtoxinA injection in spastic stroke patients. Moreover, the treatment safety by monitoring adverse events occurrence was assessed.

DESIGN

Case control study.

POPULATION

Eleven stroke survivors with spastic hemiplegia.

METHODS

Patients were treated with intramuscular focal injections of IncobotulinumtoxinA (NT 201; Xeomin®, Merz Pharmaceuticals GmbH, Frankfurt, Germany). Doses were below 12 units/Kg. Each patient underwent an ECG recording before injection and 10 days after treatment. Linear and non-linear Heart Rate variability (HRV) measures were derived from ECGs with a dedicated software.

RESULTS

None of the variable considered showed statistically significant changes after BoNT-A injection.

CONCLUSION

The use of incobotulinumtoxinA in adult patients at doses up to 12 units/kg seems to be safe regarding autonomic heart drive.

CLINICAL REHABILITATION IMPACT

The use of IncobotulinumtoxinA up to 600 units could be a safe therapeutic option in spastic hemiplegic stroke survivors.

Isolation and functional characterization of the novel Clostridium botulinum neurotoxin A8 subtype

Botulism is a severe neurological disease caused by the complex family of botulinum neurotoxins (BoNT). Based on the different serotypes known today, a classification of serotype variants termed subtypes has been proposed according to sequence diversity and immunological properties. However, the relevance of BoNT subtypes is currently not well understood. Here we describe the isolation of a novel Clostridium botulinum strain from a food-borne botulism outbreak near Chemnitz, Germany. Comparison of its botulinum neurotoxin gene sequence with published sequences identified it to be a novel subtype within the BoNT/A serotype designated BoNT/A8. The neurotoxin gene is located within an ha-orfX+ cluster and showed highest homology to BoNT/A1, A2, A5, and A6. Unexpectedly, we found an arginine insertion located in the HC domain of the heavy chain, which is unique compared to all other BoNT/A subtypes known so far. Functional characterization revealed that the binding characteristics to its main neuronal protein receptor SV2C seemed unaffected, whereas binding to membrane-incorporated gangliosides was reduced in comparison to BoNT/A1. Moreover, we found significantly lower enzymatic activity of the natural, full-length neurotoxin and the recombinant light chain of BoNT/A8 compared to BoNT/A1 in different endopeptidase assays. Both reduced ganglioside binding and enzymatic activity may contribute to the considerably lower biological activity of BoNT/A8 as measured in a mouse phrenic nerve hemidiaphragm assay. Despite its reduced activity the novel BoNT/A8 subtype caused severe botulism in a 63-year-old male. To our knowledge, this is the first description and a comprehensive characterization of a novel BoNT/A subtype which combines genetic information on the neurotoxin gene cluster with an in-depth functional analysis using different technical approaches. Our results show that subtyping of BoNT is highly relevant and that understanding of the detailed toxin function might pave the way for the development of novel therapeutics and tailor-made antitoxins.

Foodborne botulism in Poland in 2013

OBJECTIVES

The aim of the study is to assess the epidemiology of foodborne botulism in Poland in 2013.

MATERIALS AND METHODS

We reviewed surveillance data published in the annual bulletin "Infectious diseases and poisonings in Poland in 2013" and in previous publications, and botulism case reports for 2013 sent to the Department of Epidemiology NIPH-NIH by Sanitary-Epidemiological Stations.

RESULTS

In 2013, a total of 24 foodborne botulism cases (including 8 laboratory confirmed cases) was reported, corresponding to the lowest annual incidence rate (0.06 per 100,000 population) since the introduction of botulism as mandatory notifiable disease. The highest incidence in the country was reported in Kujawsko-Pomorskie (0.19). Incidence in rural areas (0.09 per 100,000 population) was more than 2-fold higher than the incidence in urban areas (0.04). Men, had more than 3 times higher incidence than women; the highest incidence rate (0.29 per 100,000 population) was observed among men in the age group of 40-49 years. Most cases were associated with consumption of different types of commercially canned meat. Commercially canned fish was also a common vehicle. All cases were hospitalized. No deaths related to the disease were reported.

CONCLUSIONS

In 2013, in Poland a downward trend in the incidence of foodborne botulism was maintained. Insufficient laboratory capacity remains a major weakness in national surveillance resulting in disproportionate reporting of cases meeting only clinical criteria and an epidemiological link. This situation clearly speaks for the need to improve laboratory capacity for surveillance.

New insight in the epidemiology of avian botulism outbreaks: necrophagous flies as vectors of Clostridium botulinum type C/D

Avian botulism outbreaks spread through the bird carcass-maggot cycle, in which Clostridium botulinum and blowflies interact to ensure their reproduction in a mutualistic relationship where neurotoxin/spore-bearing maggot is one of the keystones. Here we investigated the hypothesis that adult blowflies may also play a significant role in botulism outbreaks by carrying C. botulinum cells between carcasses. We carried out a field experiment placing bird carcasses free of C. botulinum type C/D in containers only accessible to necrophagous flying insects in wetlands where avian botulism outbreaks were occurring and in control sites. Additionally, we performed laboratory trials to evaluate if blowflies may carry C. botulinum type C/D and for how long. Maggots bearing C. botulinum type C/D developed in 27.5% of carcasses placed in wetlands during botulism outbreaks. Calliphoridae flies in laboratory trials were able to transfer C. botulinum between two points and excreted it in their spots for up to 24 h after an infective feeding. Our results confirm that adult necrophagous flies play a role in the spreading of botulism outbreaks, which have implications in the epidemiology of this disease.

Functional dissection of the Clostridium botulinum type B hemagglutinin complex: identification of the carbohydrate and E-cadherin binding sites

Botulinum neurotoxin (BoNT) inhibits neurotransmitter release in motor nerve endings, causing botulism, a condition often resulting from ingestion of the toxin or toxin-producing bacteria. BoNTs are always produced as large protein complexes by associating with a non-toxic protein, non-toxic non-hemagglutinin (NTNH), and some toxin complexes contain another non-toxic protein, hemagglutinin (HA), in addition to NTNH. These accessory proteins are known to increase the oral toxicity of the toxin dramatically. NTNH has a protective role against the harsh conditions in the digestive tract, while HA is considered to facilitate intestinal absorption of the toxin by intestinal binding and disruption of the epithelial barrier. Two specific activities of HA, carbohydrate and E-cadherin binding, appear to be involved in these processes; however, the exact roles of these activities in the pathogenesis of botulism remain unclear. The toxin is conventionally divided into seven serotypes, designated A through G. In this study, we identified the amino acid residues critical for carbohydrate and E-cadherin binding in serotype B HA. We constructed mutants defective in each of these two activities and examined the relationship of these activities using an in vitro intestinal cell culture model. Our results show that the carbohydrate and E-cadherin binding activities are functionally and structurally independent. Carbohydrate binding potentiates the epithelial barrier-disrupting activity by enhancing cell surface binding, while E-cadherin binding is essential for the barrier disruption.

A graphene oxide based fluorescence resonance energy transfer (FRET) biosensor for ultrasensitive detection of botulinum neurotoxin A (BoNT/A) enzymatic activity

Botulinum neurotoxins (BoNTs) are among the most potent toxic bacterial proteins for humans, which make them potential agents for bioterrorism. Therefore, an ultrasensitive detection of BoNTs and their active states is in great need as field-deployable systems for anti-terrorism applications. We report the construction of a novel graphene oxide (GO)-peptide based fluorescence resonance energy transfer (FRET) biosensor for ultrasensitive detection of the BoNT serotype A light chain (BoNT-LcA) protease activity. A green fluorescence protein (GFP) modified SNAP-25 peptide substrate (SNAP-25-GFP) was optimally designed and synthesized with the centralized recognition/cleavage sites. This FRET platform was constructed by covalent immobilization of peptide substrate on GO with BSA passivation which have advantages of low non-specific adsorption and high stability in protein abundant solution. BoNT-LcA can specifically cleave SNAP-25-GFP substrate covalently immobilized on GO to release the fragment with GFP. Based on fluorescence signal recovery measurement, the target BoNT-LcA was detected sensitively and selectively with the linear detection range from 1fg/mL to 1pg/mL. The limit of detection (LOD) for BoNT-LcA is around 1fg/mL.

Complete nucleotide sequence of a plasmid containing the botulinum neurotoxin gene in Clostridium botulinum type B strain 111 isolated from an infant patient in Japan

Botulinum neurotoxins (BoNTs) are highly potent toxins that are produced by Clostridium botulinum. We determined the complete nucleotide sequence of a plasmid containing the botulinum neurotoxin gene in C. botulinum type B strain 111 in order to obtain an insight into the toxigenicity and evolution of the bont gene in C. botulinum. Group I C. botulinum type B strain 111 was isolated from the first case of infant botulism in Japan in 1995. In previous studies, botulinum neurotoxin subtype B2 (BoNT/B2) produced by strain 111 exhibited different antigenic properties from those of authentic BoNT/B1 produced by strain Okra. We have recently shown that the isolates of strain 111 that lost toxigenicity were cured of the plasmid containing the bont/B2 gene. In the present study, the plasmid (named pCB111) was circular 265,575 bp double-stranded DNA and contained 332 predicted open reading frames (ORFs). 85 gene products of these ORFs could be functionally assigned on the basis of sequence homology to known proteins. The bont/B2 complex genes were located on pCB111 and some gene products may be involved in the conjugative plasmid transfer and horizontal transfer of bont genes. pCB111 was similar to previously identified plasmids containing bont/B1, /B5, or/A3 complex genes in other group I C. botulinum strains. It was suggested that these plasmids had been derived from a common ancestor and had played important roles for the bont gene transfer between C. botulinum.

Distinguishing highly-related outbreak-associated Clostridium botulinum type A(B) strains

BACKGROUND

In the United States, most Clostridium botulinum type A strains isolated during laboratory investigations of human botulism demonstrate the presence of an expressed type A botulinum neurotoxin (BoNT/A) gene and an unexpressed BoNT/B gene. These strains are designated type A(B). The most common pulsed-field gel electrophoresis (PFGE) pattern in the C. botulinum PulseNet database is composed of A(B) strains. The purpose of this study was to evaluate the ability of genome sequencing and multi-loci variable number of tandem repeat analysis (MLVA) to differentiate such strains.

RESULTS

The genome sequences of type A(B) strains evaluated in this study are closely related and cluster together compared to other available C. botulinum Group I genomes. In silico multilocus sequence typing (MLST) analysis (7-loci) was unable to differentiate any of the type A(B) strains isolated from seven different outbreak investigations evaluated in this study. A 15-locus MLVA scheme demonstrated an improved ability to differentiate these strains, however, repeat unit variation among the strains was restricted to only two loci. Reference-free single nucleotide polymorphism (SNP) analysis demonstrated the ability to differentiate strains from all of the outbreaks examined and a non-outbreak associated strain.

CONCLUSIONS

This study confirms that type A(B) strains that share the same PFGE pattern also share closely-related genome sequences. The lack of a complete type A(B) strain representative genome sequence hinders the ability to assemble genomes by reference mapping and analysis of SNPs at pre-identified sites. However, compared to other methods evaluated in this study, a reference-free SNP analysis demonstrated optimal subtyping utility for type A(B) strains using de novo assembled genome sequences.

Animal botulism outcomes in the AniBioThreat project

Botulism disease in both humans and animals is a worldwide concern. Botulinum neurotoxins produced by Clostridium botulinum and other Clostridium species are the most potent biological substances known and are responsible for flaccid paralysis leading to a high mortality rate. Clostridium botulinum and botulinum neurotoxins are considered potential weapons for bioterrorism and have been included in the Australia Group List of Biological Agents. In 2010 the European Commission (DG Justice, Freedom and Security) funded a 3-year project named AniBioThreat to improve the EU's capacity to counter animal bioterrorism threats. A detection portfolio with screening methods for botulism agents and incidents was needed to improve tracking and tracing of accidental and deliberate contamination of the feed and food chain with botulinum neurotoxins and other Clostridia. The complexity of this threat required acquiring new genetic information to better understand the diversity of these Clostridia and develop detection methods targeting both highly specific genetic markers of these Clostridia and the neurotoxins they are able to produce. Several European institutes participating in the AniBioThreat project collaborated on this program to achieve these objectives. Their scientific developments are discussed here.

The workshop on animal botulism in Europe

A workshop on animal botulism was held in Uppsala, Sweden, in June 2012. Its purpose was to explore the current status of the disease in Europe by gathering the European experts in animal botulism and to raise awareness of the disease among veterinarians and others involved in biopreparedness. Animal botulism is underreported and underdiagnosed, but an increasing number of reports, as well as the information gathered from this workshop, show that it is an emerging problem in Europe. The workshop was divided into 4 sessions: animal botulism in Europe, the bacteria behind the disease, detection and diagnostics, and European collaboration and surveillance. An electronic survey was conducted before the workshop to identify the 3 most needed discussion points, which were: prevention, preparedness and outbreak response; detection and diagnostics; and European collaboration and surveillance. The main conclusions drawn from these discussions were that there is an urgent need to replace the mouse bioassay for botulinum toxin detection with an in vitro test and that there is a need for a European network to function as a reference laboratory, which could also organize a European supply of botulinum antitoxin and vaccines. The foundation of such a network was discussed, and the proposals are presented here along with the outcome of discussions and a summary of the workshop itself.

An electrochemiluminescence assay for the detection of bio threat agents in selected food matrices and in the screening of Clostridium botulinum outbreak strains associated with type A botulism

BACKGROUND

Specific screening methods for complex food matrices are needed that enable unambiguous and sensitive detection of bio threat agents (BTAs) such as Bacillus anthracis spores and microbial toxins (e.g. staphylococcal enterotoxin B (SEB) and clostridial botulinum neurotoxins (BoNTs)). The present study describes an image-based 96-well Meso Scale Discovery (MSD) electrochemiluminescence (ECL) assay for simultaneous detection of BTAs in dairy milk products.

RESULTS

The limit of detection of this ECL assay is 40 pg mL⁻¹ for BoNT/A complex, 10 pg mL⁻¹ for SEB and 40000 CFU mL⁻¹ for Bacillus anthracis spores in dairy milk products. The ECL assay was successfully applied to screen type A Clostridium botulinum outbreak strains.

CONCLUSION

The results of the study indicate that this ECL assay is very sensitive, rapid (<6 h) and multiplex in nature. The ECL assay has potential for use as an in vitro screening method for BTAs over other comparable immunoassays.

[Infant botulism]

Infant botulism is a paralytic syndrome which manifests as a result of ingesting spores of the toxin secreting bacterium Clostridium botulinum by infants. As opposed to botulism in adults, treating infant botulism with horse antiserum was not approved due to several safety issues. This restriction has led to the development of Human Botulism Immune Globulin Intravenous (BIG-IV; sells under BabyBIG). In this article we review infant botulism and the advantages of treating it with BIG-IV.

Infant botulism with prolonged faecal excretion of botulinum neurotoxin and Clostridium botulinum for 7 months

In Finland in April 2010, a 3-month old baby was diagnosed with type A infant botulism. He excreted botulinum neurotoxin and/or Clostridium botulinum in his faeces until November 2010. Five months of excretion was after clinical recovery and discharge from hospital. C. botulinum isolates recovered from the household dust in the patient's home were genetically identical to those found in the infant's stool samples. Long-term faecal excretion of C. botulinum may pose a possible health risk for the parents and others in close contact with the infant.

Molecular characterization of Clostridium botulinum isolates from foodborne outbreaks in Thailand, 2010

Background

Thailand has had several foodborne outbreaks of botulism, one of the biggest being in 2006 when laboratory investigations identified the etiologic agent as Clostridium botulinum type A. Identification of the etiologic agent from outbreak samples is laborious using conventional microbiological methods and the neurotoxin mouse bioassay. Advances in molecular techniques have added enormous information regarding the etiology of outbreaks and characterization of isolates. We applied these methods in three outbreaks of botulism in Thailand in 2010.

Methodology/Principal Findings

A total of 19 cases were involved (seven each in Lampang and Saraburi and five in Maehongson provinces). The first outbreak in Lampang province in April 2010 was associated with C. botulinum type F, which was detected by conventional methods. Outbreaks in Saraburi and Maehongson provinces occurred in May and December were due to C. botulinum type A1(B) and B that were identified by conventional methods and molecular techniques, respectively. The result of phylogenetic sequence analysis showed that C. botulinum type A1(B) strain Saraburi 2010 was close to strain Iwate 2007. Molecular analysis of the third outbreak in Maehongson province showed C. botulinum type B8, which was different from B1–B7 subtype. The nontoxic component genes of strain Maehongson 2010 revealed that ha33, ha17 and botR genes were close to strain Okra (B1) while ha70 and ntnh genes were close to strain 111 (B2).

Conclusion/Significance

This study demonstrates the utility of molecular genotyping of C. botulinum and how it contributes to our understanding the epidemiology and variation of boNT gene. Thus, the recent botulism outbreaks in Thailand were induced by various C. botulinum types.

[Bacterial infections, what we can learn from each outbreak]

Studies on outbreaks or incidences of infectious diseases and food poisonings are the starting points in research. Analyses of the outbreaks will provide the mechanism by which the illnesses occur and the establishment of countermeasure. We report here some sensational outbreaks which recently occurred in Japan: 1) enterohemorrhagic Escherichia coli (EHEC) O157 outbreaks by pickled Chinese cabbage in Hokkaido, 2) EHEC O157/O111 outbreaks by raw beef in Toyama Prefecture, 3) parasitic food poisoning due to raw olive flounder consumption in the western Japan, and 4) botulism due to the consumption of vacuum packed food in Tottori Prefecture.

Application of high-density DNA resequencing microarray for detection and characterization of botulinum neurotoxin-producing clostridia

BACKGROUND

Clostridium botulinum and related clostridia express extremely potent toxins known as botulinum neurotoxins (BoNTs) that cause severe, potentially lethal intoxications in humans. These BoNT-producing bacteria are categorized in seven major toxinotypes (A through G) and several subtypes. The high diversity in nucleotide sequence and genetic organization of the gene cluster encoding the BoNT components poses a great challenge for the screening and characterization of BoNT-producing strains.

METHODOLOGY/PRINCIPAL FINDINGS

In the present study, we designed and evaluated the performances of a resequencing microarray (RMA), the PathogenId v2.0, combined with an automated data approach for the simultaneous detection and characterization of BoNT-producing clostridia. The unique design of the PathogenID v2.0 array allows the simultaneous detection and characterization of 48 sequences targeting the BoNT gene cluster components. This approach allowed successful identification and typing of representative strains of the different toxinotypes and subtypes, as well as the neurotoxin-producing C. botulinum strain in a naturally contaminated food sample. Moreover, the method allowed fine characterization of the different neurotoxin gene cluster components of all studied strains, including genomic regions exhibiting up to 24.65% divergence with the sequences tiled on the arrays.

CONCLUSIONS/SIGNIFICANCE

The severity of the disease demands rapid and accurate means for performing risk assessments of BoNT-producing clostridia and for tracing potentials sources of contamination in outbreak situations. The RMA approach constitutes an essential higher echelon component in a diagnostics and surveillance pipeline. In addition, it is an important asset to characterise potential outbreak related strains, but also environment isolates, in order to obtain a better picture of the molecular epidemiology of BoNT-producing clostridia.

Persistence of Botulinum neurotoxin inactivation of nerve function

The extraordinary persistence of intoxication occurring after exposure to some Botulinum neurotoxin (BoNT) serotypes is both a therapeutic marvel and a biodefense nightmare. Understanding the mechanisms underlying BoNT persistence will offer new strategies for improving the efficacy and extending the applications of BoNT therapeutic agents as well as for treating the symptoms of botulism. Research indicates that the persistence of BoNT intoxication can be influenced both by the ability of the toxin protease or its cleaved soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein substrate to resist turnover. Protease turnover seems to be mediated in part by the ubiquitin-proteasome system (UPS) and efforts to manipulate the UPS may prove to be an effective strategy for improving therapeutic utility of BoNT products and in the development of botulism antidotes.

Transforming the domain structure of botulinum neurotoxins into novel therapeutics

Botulinum neurotoxins are comprised of multiple identifiable protein domains. Recent advances in understanding the relationships between domain structure and neurotoxin function have provided a number of opportunities to engineer innovative therapeutic proteins that utilise the neurotoxins and neurotoxin domains. For example, recent insights into the properties of the catalytic, translocation and binding domains open up opportunities to develop botulinum neurotoxins with enhanced properties of selectivity, potency and duration of action. In parallel, the broad scope for utilisation of the individual domains is becoming clearer as significant advancements are made to exploit the unique biology of the catalytic and translocation domains. These opportunities and the status of their development will be reviewed in this chapter.

Glyphosate suppresses the antagonistic effect of Enterococcus spp. on Clostridium botulinum

During the last 10-15 years, an increase of Clostridium botulinum associated diseases in cattle has been observed in Germany. The reason for this development is currently unknown. The normal intestinal microflora is a critical factor in preventing intestinal colonisation by C. botulinum as shown in the mouse model of infant botulism. Numerous bacteria in the gastro-intestinal tract (GIT) produce bacteriocines directed against C. botulinum and other pathogens: Lactic acid producing bacteria (LAB) such as lactobacilli, lactococci and enterococci, generate bacteriocines that are effective against Clostridium spp. A reduction of LAB in the GIT microbiota by ingestion of strong biocides like glyphosate could be an explanation for the observed increase in levels of C. botulinum associated diseases. In the present paper, we report on the toxicity of glyphosate to the most prevalent Enterococcus spp. in the GIT. Ingestion of this herbicide could be a significant predisposing factor that is associated with the increase in C. botulinum mediated diseases in cattle.

Association of toxin-producing Clostridium botulinum with the macroalga Cladophora in the Great Lakes

Avian botulism, a paralytic disease of birds, often occurs on a yearly cycle and is increasingly becoming more common in the Great Lakes. Outbreaks are caused by bird ingestion of neurotoxins produced by Clostridium botulinum, a spore-forming, gram-positive, anaerobe. The nuisance, macrophytic, green alga Cladophora (Chlorophyta; mostly Cladophora glomerata L.) is a potential habitat for the growth of C. botulinum. A high incidence of botulism in shoreline birds at Sleeping Bear Dunes National Lakeshore (SLBE) in Lake Michigan coincides with increasingly massive accumulations of Cladophora in nearshore waters. In this study, free-floating algal mats were collected from SLBE and other shorelines of the Great Lakes between June and October 2011. The abundance of C. botulinum in algal mats was quantified and the type of botulism neurotoxin (bont) genes associated with this organism were determined by using most-probable-number PCR (MPN-PCR) and five distinct bont gene-specific primers (A, B, C, E, and F). The MPN-PCR results showed that 16 of 22 (73%) algal mats from the SLBE and 23 of 31(74%) algal mats from other shorelines of the Great Lakes contained the bont type E (bont/E) gene. C. botulinum was present up to 15000 MPN per gram dried algae based on gene copies of bont/E. In addition, genes for bont/A and bont/B, which are commonly associated with human diseases, were detected in a few algal samples. Moreover, C. botulinum was present as vegetative cells rather than as dormant spores in Cladophora mats. Mouse toxin assays done using supernatants from enrichment of Cladophora containing high densities of C. botulinum (>1000 MPN/g dried algae) showed that Cladophora-borne C. botulinum were toxin-producing species (BoNT/E). Our results indicate that Cladophora provides a habitat for C. botulinum, warranting additional studies to better understand the relationship between this bacterium and the alga, and how this interaction potentially contributes to botulism outbreaks in birds.

Foodborne botulism in Poland in 2111

OBJECTIVES

The main objective of this article is to assess the epidemiology of foodborne botulism in Poland in 2011, using national surveillance data.

MATERIALS AND METHODS

We reviewed surveillance data published in the annual bulletin "Infectious diseases and poisonings in Poland" from 2005 to 2011, and botulism case reports from 2011 sent to the Department of Epidemiology NIPH-NIH by Sanitary-Epidemiological Stations.

RESULTS

In 2011, a total of 35 foodborne botulism cases (including 21 laboratory confirmed cases) was reported, corresponding to the one of the lowest annual incidence rate (0.09 per 100,000 population) since the introduction of botulism as mandatory notifiable disease. The higher incidence rates compared to the previous year were in the Warmińsko-Mazurskie, Kujawsko-Pomorskie, Lubelskie, Podkarpackie, Mazowieckie and Dolnoślaskie. Incidence in rural areas (0.13 per 100,000 population) was higher than the incidence in urban areas (0.07). Men, had more than 3,5 times higher incidence than women; the highest incidence rate (0.23 per 100,000 population) was observed among men in the age group of 60 + years. Most cases were associated with consumption of commercially canned meat (including pork and other types of meat). Home canned foods containing meats or vegetables and meats were also a common vehicle. Almost all cases were hospitalized (33 cases). One death related to the disease was reported.

CONCLUSIONS

In 2011, in Poland epidemiology of the foodborne botulism remains stable. From the point of view of national surveillance, it is necessary to increase the percentage of cases investigated with laboratory tests.

National outbreak of type a foodborne botulism associated with a widely distributed commercially canned hot dog chili sauce

BACKGROUND

On 7 and 11 July 2007, health officials in Texas and Indiana, respectively, reported 4 possible cases of type A foodborne botulism to the US Centers for Disease Control and Prevention. Foodborne botulism is a rare and sometimes fatal illness caused by consuming foods containing botulinum neurotoxin.

METHODS

Investigators reviewed patients' medical charts and food histories. Clinical specimens and food samples were tested for botulinum toxin and neurotoxin-producing Clostridium species. Investigators conducted inspections of the cannery that produced the implicated product.

RESULTS

Eight confirmed outbreak associated cases were identified from Indiana (n = 2), Texas (n = 3), and Ohio (n = 3). Botulinum toxin type A was identified in leftover chili sauce consumed by the Indiana patients and 1 of the Ohio patients. Cannery inspectors found violations of federal canned-food regulations that could have led to survival of Clostridium botulinum spores during sterilization. The company recalled 39 million cans of chili. Following the outbreak, the US Food and Drug Administration inspected other canneries with similar canning systems and issued warnings to the industry about the danger of C. botulinum and the importance of compliance with canned food manufacturing regulations.

CONCLUSIONS

Commercially produced hot dog chili sauce caused these cases of type A botulism. This is the first US foodborne botulism outbreak involving a commercial cannery in >30 years. Sharing of epidemiologic and laboratory findings allowed for the rapid identification of implicated food items and swift removal of potentially deadly products from the market by US food regulatory authorities.

[Food-borne botulism]

Botulism is a neuroparalytic disease caused by neurotoxins produced by Clostridium botulinum, and classically presents as palsies of cranial nerves and acute descending flaccid paralysis. Food-borne botulism is the most common form of botulism, and caused by preformed neurotoxins produced by Clostridium botulinum. Electrophysiological studies play an important role in the early diagnosis. Confirmation of the diagnosis is based on the detection of botulinum toxins in the patient's serum or stool. In Japan, decades ago, botulism type E occurred, though only sporadically, almost every year, but in recent years, has dramatically decreased in frequency. Botulism is a curable disease when treated early and adequately. Differential diagnosis of cranial nerves and limb muscle palsies with rapid exacerbation should include food-borne botulism.

[Botulism: structure and function of botulinum toxin and its clinical application]

Clostridium botulinum produces seven immunological distinct poisonous neurotoxins, A to G, with molecular masses of approximately 150kDa. In acidic foods and culture fluid, the neurotoxins associate with non-toxic components, and form large complexes designated progenitor toxins. The progenitor toxins are found in three forms named LL, L, and M. These neurotoxins and progenitor toxins were purified, and whole nucleotide sequences of their structure genes were determined. In this manuscript, the structure and function of these toxins, and the application of these toxins to clinical usage have been described.

[Botulism in Poland in 2010]

OBJECTIVE

The main objective of this article is to assess the epidemiology of foodborne botulism in Poland in 2010, using national surveillance data. In Poland, botulism is a mandatory notifiable disease based on the European Union case definition (probable or confirmed), however given limited laboratory capacity, in national surveillance we also use "possible" case definition for cases reported by physicians based on clinical symptoms (with no laboratory confirmation).

RESULTS

The number of botulism cases reported has decreased over the past years. Between 2004-2008 the median annual number of cases in years 2004-2008 was 49, whereas in 2009 alone, was only 31 cases. In 2010 a total 32 botulism cases (0.08 per 100,000 inhabitants)--including 22 confirmed cases (in 20 cases--toxin type B, and in 2 -toxin type B / E was found) were reported. There was only one--'probable case'--reported on the basis of clinical symptoms and the presence of an 'epidemiological link' (exposure from the same source). Other cases (9 patients) were reported, on the basis of clinical diagnosis without laboratory confirmation and registered as 'possible cases'. Incidence in rural areas (0.18) was 9-fold higher than the incidence in urban areas. Men had higher (0.12) incidence than women (0.05); the highest incidence (0.17) was observed among people aged 50-59 years. All cases were people aged over 25 years of age. In 28% of all cases--homemade canned pork was implicated. Canned fish were also a common vehicle. All patients were hospitalized--for between 5 and 35 days (median 11 days). No deaths related to the disease were reported.

CONCLUSIONS

Botulism in Poland is still an important epidemiological problem. A large number of poisonings is primarily due to consumption of homemade canned foods.