Production of monoclonal antibodies against botulinum neurotoxin in Nicotiana benthamiana.

Botulism is a fatal neurologic disease caused by the botulinum toxin (BoNT) produced by Clostridium botulinum. It is a rare but highly toxic disease with symptoms, such as cramps, nausea, vomiting, diarrhea, dysphagia, respiratory failure, muscle weakness, and even death. Currently, two types of antitoxin are used: equine-derived heptavalent antitoxin and human-derived immunoglobulin (BabyBIG®). However, heptavalent treatment may result in hypersensitivity, whereas BabyBIG®, has a low yield. The present study focused on the development of three anti-BoNT monoclonal antibodies (mAbs), 1B18, C25, and M2, in Nicotiana benthamiana. The plant-expressed mAbs were purified and examined for size, purity and integrity by SDS-PAGE, western blotting and size-exclusion chromatography. Analysis showed that plant-produced anti-BoNT mAbs can fully assemble in plants, can be purified in a single purification step, and mostly remain as monomeric proteins. The efficiency of anti-BoNT mAbs binding to BoNT/A and B was then tested. Plant-produced 1B18 retained its ability to recognize both mBoNT/A1 and ciBoNT/B1. At the same time, the binding specificities of two other mAbs were determined: C25 for mBoNT/A1 and M2 for ciBoNT/B1. In conclusion, our results confirm the use of plants as an alternative platform for the production of anti-BoNT mAbs. This plant-based technology will serve as a versatile system for the development botulism immunotherapeutics.

Evaluation of long-term immune response in cattle to botulism using a recombinant E. coli bacterin formulated with Montanide™ ISA 50 and aluminum hydroxide adjuvants.

Botulism is a severe disease caused by potent botulinum neurotoxins (BoNTs) produced by Clostridium botulinum. This disease is associated with high-lethality outbreaks in cattle, which have been linked to the ingestion of preformed BoNT serotypes C and D, emphasizing the need for effective vaccines. The potency of current commercial toxoids (formaldehyde-inactivated BoNTs) is assured through tests in guinea pigs according to government regulatory guidelines, but their short-term immunity raises concerns. Recombinant vaccines containing the receptor-binding domain have demonstrated potential for eliciting robust protective immunity. Previous studies have demonstrated the safety and effectiveness of recombinant E. coli bacterin, eliciting high titers of neutralizing antibodies against C. botulinum and C. perfringens in target animal species. In this study, neutralizing antibody titers in cattle and the long-term immune response against BoNT/C and D were used to assess the efficacy of the oil-based adjuvant compared with that of the aluminum hydroxide adjuvant in cattle. The vaccine formulation containing Montanide™ ISA 50 yielded significantly higher titers of neutralizing antibody against BoNT/C and D (8.64 IU/mL and 9.6 IU/mL, respectively) and induced an immune response that lasted longer than the response induced by aluminum, extending between 30 and 60 days. This approach represents a straightforward, cost-effective strategy for recombinant E. coli bacterin, enhancing both the magnitude and duration of the immune response to botulism.

Botulinum neurotoxin X lacks potency in mice and in human neurons.

Botulinum neurotoxins (BoNTs) are a class of toxins produced by Clostridium botulinum (C. botulinum) and other species of Clostridia. BoNT/X is a putative novel botulinum neurotoxin identified through genome sequencing and capable of SNARE cleavage, but its neurotoxic potential in humans and vertebrates remained unclear. The C. botulinum strain producing BoNT/X, Strain 111, encodes both a plasmid-borne bont/b2 as well as the chromosomal putative bont/x. This study utilized C. botulinum Strain 111 from Japan as well as recombinantly produced full-length BoNT/X to more fully analyze this putative pathogenic toxin. We confirmed production of full-length, catalytically active native BoNT/X by C. botulinum Strain 111, produced as a disulfide-bonded dichain polypeptide similar to other BoNTs. Both the purified native and the recombinant BoNT/X had high enzymatic activity in vitro but displayed very low potency in human-induced pluripotent stem cell-derived neuronal cells and in mice. Intraperitoneal injection of up to 50 µg of native BoNT/X in mice did not result in botulism; however, mild local paralysis was observed after injection of 2 µg into the gastrocnemius muscle. We further demonstrate that the lack of toxicity by BoNT/X is due to inefficient neuronal cell association and entry, which can be rescued by replacing the receptor binding domain of BoNT/X with that of BoNT/A. These data demonstrate that BoNT/X is not a potent vertebrate neurotoxin like the classical seven serotypes of BoNTs. IMPORTANCE: The family of botulinum neurotoxins comprises the most potent toxins known to humankind. New members of this family of protein toxins as well as more distantly related homologs are being identified. The discovery of BoNT/X via bioinformatic screen in 2017 as a putative new BoNT serotype raised concern about its potential as a pathogenic agent with no available countermeasures. This study for the first time assessed both recombinantly produced and native purified BoNT/X for its vertebrate neurotoxicity.

Development and characterization of a novel neutralizing scFv vectored immunoprophylaxis against botulinum toxin type A.

Botulinum toxin is a protein toxin secreted by Clostridium botulinum that is strongly neurotoxic. Due to its characteristics of being super toxic, quick acting, and difficult to prevent, the currently reported antiviral studies focusing on monoclonal antibodies have limited effectiveness. Therefore, for the sake of effectively prevention and treatment of botulism and to maintain country biosecurity as well as the health of the population, in this study, we intend to establish a single chain antibody (scFv) targeting the carboxyl terminal binding functional domain of the botulinum neurotoxin heavy chain (BONT/AHc) of botulinum neurotoxin type A, and explore the value of a new passive immune method in antiviral research which based on adeno-associated virus (AAV) mediated vector immunoprophylaxis (VIP) strategy. The scFv small-molecular single-chain antibody sequenced, designed, constructed, expressed and purified by hybridoma has high neutralising activity and affinity level, which can lay a good foundation for the modification and development of antibody engineering drugs. In vivo experiments, AAV-mediated scFv engineering drug has good anti-BONT/A toxin neutralisation ability, has advantages of simple operation, stable expression and good efficacy, and may be one of the effective treatment strategies for long-term prevention and protection of BONT/A botulinum neurotoxin.

Treating rosacea with botulism toxin: Protocol for a systematic review and meta-analysis.

BACKGROUND: Rosacea is a chronic inflammatory disease usually associated with persistent erythema and periodic flushing. This disease is difficult to treat, and the outcomes are often unsatisfactory and prone to recurrence. In recent years, botulinum toxin has been used as a new treatment for rosacea; however, its efficacy and safety remain under discussion. Although a systematic review of the effectiveness and safety of botulinum toxin has been previously conducted by other researchers, our systematic review and meta-analysis evaluate the efficacy of botulinum toxin from a more comprehensive and detailed perspective to provide evidence for clinicians. METHODS: Any study using botulinum toxin for the treatment of rosacea was considered for the analysis. RESULTS: A total of 22 studies were included, 9 of which were randomized controlled trials involving 720 subjects. After treatment, all studies showed varying degrees of improvement in patient signs and symptoms along with reduced Clinician's Erythema Assessment (CEA) scores. The improvement was maintained for several months, and the adverse effects were mild and self-limiting. CONCLUSION: Botulinum toxin may be an effective treatment for patients with rosacea; however, further clinical evidence is needed to confirm its long-term efficacy and side effects. The study was preregistered with Prospero (CRD42022358911).

Electrophysiological evaluation of the neuromuscular junction: a brief review.

The nerve terminal and muscle membrane compose the neuromuscular junction. After opening the voltage-gated calcium channels, action potentials from the motor axons provoke a cascade for the acetylcholine release from synaptic vesicles to the synaptic cleft, where it binds to its receptor at the muscle membrane for depolarization. Low amplitude compound muscle action potential typically presents in presynaptic disorders, increasing by more than 100% after a 10-second effort in the Lambert-Eaton myasthenic syndrome and less in botulism. Needle electromyography may show myopathic motor unit action potentials and morphological instability ("jiggle") due to impulse blocking. Low-frequency repetitive nerve stimulation (RNS) is helpful in postsynaptic disorders, such as myasthenia gravis and most congenital myasthenic syndromes, where the number of functioning acetylcholine receptors is reduced. Low-frequency RNS with a decrement >10% is abnormal when comparing the 4th to the first compound muscle action potential amplitude. High-frequency RNS is helpful in presynaptic disorders like Lambert-Eaton myasthenic syndrome, botulism, and some rare congenital myasthenic syndromes. The high-frequency RNS releases more calcium, increasing the acetylcholine with a compound muscle action potential increment. Concentric needle records apparent single-fiber action potentials (spikes). A voluntary activation measures the jitter between spikes from two endplates. An electrical activation measures the jitter of one spike (one endplate). The jitter is the most sensitive test for detecting a neuromuscular junction dysfunction. Most neuromuscular junction disorders are responsive to treatment.

O nervo terminal e a membrana muscular compõem a junção neuromuscular. Após a abertura dos canais de cálcio dependentes de voltagem, os potenciais de ação do axônio motor provocam uma cascata de eventos que libera acetilcolina das vesículas para a fenda sináptica, ligando-se ao receptor na membrana muscular para despolarização. O potencial de ação muscular composto de baixa amplitude ocorre nas desordens pré-sinápticas, aumentando em mais de 100% após esforço de 10 segundos na síndrome miastênica de Lambert-Eaton e menos no botulismo. A eletromiografia pode mostrar potenciais de ação da unidade motora miopáticos e instabilidade morfológica ("jiggle") devido ao bloqueio do impulso. Estimulação nervosa repetitiva (ENR) de baixa frequência é útil nos distúrbios pós-sinápticos, como miastenia gravis e a maioria das síndromes miastênicas congênitas, quando há número reduzido de receptores de acetilcolina funcionantes. ENR de baixa frequência com decremento >10% é anormal comparando-se à amplitude do quarto com o primeiro potencial de ação muscular composto. ENR de alta frequência é útil nas doenças pré-sinápticas, como síndrome miastênica de Lambert-Eaton, botulismo e algumas síndromes miastênicas congênitas raras. ENR de alta frequência libera mais cálcio, aumenta acetilcolina, resultando em incremento do potencial de ação muscular composto. O eletrodo de agulha concêntrico registra potenciais de ação aparente de fibra única (PAAFU). Ativação voluntária mede jitter entre dois PAAFUs (duas junções neuromusculares). Ativação elétrica mede jitter de um PAAFU (uma junção neuromuscular). Jitter é o teste mais sensível para detectar disfunção de junção neuromuscular. A maioria dos distúrbios juncionais é responsiva ao tratamento.

Botulismo del lactante: estudio descriptivo en una unidad de cuidados intensivos pediátricos / Infant botulism: a descriptive study in a pediatric intensive care unit

Introducción. El botulismo del lactante (BL) es la forma más frecuente de botulismo humano en Argentina. El objetivo es describir aspectos esenciales del diagnóstico y tratamiento de pacientes con BL internados en el servicio de terapia intensiva pediátrica (STIP). Métodos. Estudio observacional, descriptivo y retrospectivo. Se utilizó la base de datos del STIP con diagnóstico de BL en el período 2005-2020. Se registraron variables demográficas, métodos de diagnóstico, días de asistencia respiratoria mecánica convencional (ARMC), de ventilación no invasiva (VNI), estadía en STIP, mortalidad al alta hospitalaria. Resultados. Se registraron 21 pacientes con BL; 14 pacientes fueron varones, con una mediana de edad de 5 meses (RIC 2-6 m). El diagnóstico se realizó mediante técnica de bioensayo y se detectó la toxina en suero en 12 pacientes. Uno solo no requirió ARMC; 1 paciente fue traqueostomizado; 18 pacientes recibieron antibióticos; 5 recibieron VNI. Ningún paciente recibió antitoxina y no hubo fallecidos. La mediana de estadía hospitalaria fue 66 días (RI: 42-76); de internación en STIP, 48 días (RI: 29-78); y de ARMC, 37 días (RI: 26-64). La demora en la confirmación diagnóstica fue 15,8 ± 4,8 días. Conclusiones. La totalidad de los pacientes fueron diagnosticados con la técnica de bioensayo, que generó un tiempo de demora diagnóstica que excede los lapsos recomendados para la administración del tratamiento específico. Ningún paciente recibió tratamiento específico. El BL presentó baja mortalidad, pero tiempos de ARM e internación prolongados, que se asocian a infecciones sobreagregadas y uso frecuente de antibióticos.

Introduction. Infant botulism (IB) is the most common form of human botulism in Argentina. Our objective was to describe the main aspects of diagnosis and management of patients with IB admitted to the pediatric intensive care unit (PICU). Methods. Observational, descriptive, and retrospective study. The PICU database with IB diagnosis in 2005­2020 period was used. Demographic variables, diagnostic methods, days of conventional mechanical ventilation (CMV), non-invasive ventilation (NIV), length of stay in the PICU and mortality upon hospital discharge were recorded. Results. In total, 21 patients with IB were recorded; 14 were male, their median age was 5 months (IQR: 2­6 m). Diagnosis was made by bioassay, and the toxin was identified in the serum of 12 patients. Only 1 patient did not require CMV; 1 patient had a tracheostomy; 18 patients received antibiotics; 5 received NIV. No patient was administered antitoxin and no patient died. The median length of stay in the hospital was 66 days (IQR: 42­76); in the PICU, 48 days (IQR: 29­78); and the median use of CMV, 37 days (IQR: 26­64). The delay until diagnostic confirmation was 15.8 ± 4.8 days. Conclusions. All patients were diagnosed using the bioassay technique, which resulted in a diagnostic delay that exceeds the recommended period for the administration of a specific treatment. No patient received a specific treatment. IB was related to a low mortality, but also to prolonged use of MV and length of hospital stay, which were associated with cross infections and frequent antibiotic use.

Pathogenicity and virulence of Clostridium botulinum.

Clostridium botulinum, a polyphyletic Gram-positive taxon of bacteria, is classified purely by their ability to produce botulinum neurotoxin (BoNT). BoNT is the primary virulence factor and the causative agent of botulism. A potentially fatal disease, botulism is classically characterized by a symmetrical descending flaccid paralysis, which is left untreated can lead to respiratory failure and death. Botulism cases are classified into three main forms dependent on the nature of intoxication; foodborne, wound and infant. The BoNT, regarded as the most potent biological substance known, is a zinc metalloprotease that specifically cleaves SNARE proteins at neuromuscular junctions, preventing exocytosis of neurotransmitters, leading to muscle paralysis. The BoNT is now used to treat numerous medical conditions caused by overactive or spastic muscles and is extensively used in the cosmetic industry due to its high specificity and the exceedingly small doses needed to exert long-lasting pharmacological effects. Additionally, the ability to form endospores is critical to the pathogenicity of the bacteria. Disease transmission is often facilitated via the metabolically dormant spores that are highly resistant to environment stresses, allowing persistence in the environment in unfavourable conditions. Infant and wound botulism infections are initiated upon germination of the spores into neurotoxin producing vegetative cells, whereas foodborne botulism is attributed to ingestion of preformed BoNT. C. botulinum is a saprophytic bacterium, thought to have evolved its potent neurotoxin to establish a source of nutrients by killing its host.

A novel RRGW derived peptide is a promising inhibitor of BoNT/A.

Clostridium botulinum neurotoxin type A (BoNT/A) is one of the most potent biotoxins ever known. Its entry into neurons could block vesicle exocytosis to abolish the release of neurotransmitters from nerve terminals, thus leading to muscle paralysis. Although there are so many peptides, antibodies and chemical compounds claimed to have anti-toxin activity, no drug is available in the clinical application except equine antitoxin serum. In the present work, a short peptide inhibitor RRGW of BoNT/A was firstly identified by computer-aided ligand-receptor binding simulation, then an RRGW derived peptide was rational designed based on the fragment of SNAP-25 (141-206 aa). Proteolytic assay showed that the anti-toxin activity of the RRGW derived peptide was much higher than that of RRGW. Digit abduction score assay demonstrated that the derived peptide delayed BoNT/A-induced muscle paralysis at a lower concentration by 20-fold than RRGW. The results supported that RRGW derived peptide can be a potential BoNT/A inhibitor candidate for further treating botulism.

Lambert-Eaton Myasthenic Syndrome and Botulism.

PURPOSE OF REVIEW: This article reviews the pathophysiology, epidemiology, clinical features, diagnosis, and treatment of Lambert-Eaton myasthenic syndrome (LEMS) and botulism, presynaptic disorders of neuromuscular transmission in which rapid diagnosis improves long-term outcomes. RECENT FINDINGS: Therapy for LEMS has seen significant advances in recent years due to the approval of amifampridine-based compounds. LEMS is likely still underdiagnosed, particularly when no underlying malignancy is identified. Clinicians must have a strong suspicion for LEMS in any patient presenting with proximal weakness and autonomic dysfunction. Botulism is another rare disorder of presynaptic neuromuscular transmission that is most commonly associated with improper storage or preservation of food products. Over the past 2 decades, wound botulism has been increasingly reported among users of black tar heroin. A high degree of clinical suspicion and electrodiagnostic studies can be beneficial in distinguishing botulism from other acute neurologic disorders, and early involvement of state and federal health authorities may assist in confirming the diagnosis and obtaining treatment. When botulism is suspected, electrodiagnostic studies can provide clinical evidence of disordered neuromuscular transmission in advance of serologic confirmation, and providers should not wait for confirmation of the diagnosis to initiate treatment. SUMMARY: A targeted clinical history and a thorough neurologic examination with support from serologic and electrodiagnostic studies are key to early diagnosis of LEMS and botulism. Early diagnosis of both conditions creates opportunities for therapy and improves outcomes.

Botulismo del lactante en Argentina. Trabajo multicéntrico / Infant botulism in Argentina. Multicentric work

Resumen El botulismo del lactante (BL), es la forma más frecuente del botulismo humano en la actualidad, es una enfermedad "rara" o "huérfana" ya que afecta a menos del 0,05 % de la población. El objetivo del presente trabajo es determinar la Incidencia del BL en la Argentina, evaluar el diagnóstico y tratamiento realizado, comparar la evolución y las secuelas al alta en pacientes con y sin tratamiento específico y, considerar las características climáticas (precipitaciones y vientos) y los estudios de muestras de suelos de las provincias con mayor cantidad de casos de BL. Presentamos un estudio multicéntrico, de cohorte (longitudinal) observacional, retrospectivo analizando las historias clínicas de los pacientes con BL, que ingresaron a Unidades de Cuidados Intensivos Pediátricos con asistencia respiratoria mecánica, desde el 1 de enero de 2010 hasta 31 de diciembre de 2013. Se consideró: edad, sexo, días previos al ingreso hasta diagnóstico por laboratorio, total internación en Unidades de Cuidados Intensivos Pediátricos con asistencia respiratoria mecánica, alimentación por sonda nasogástrica, tratamiento y secuelas. En Argentina entre 2010 al 2013 se registraron 216 casos de BL. En este trabajo se analizaron 79 pacientes provenientes de 11 provincias, que ingresaron a Unidades de Cuidados Intensivos Pediátricos. La edad promedio de los pacientes ingresados fue de 4 meses, de los cuales 90% recibía alimentación materna. Dieciocho pacientes de seis provincias recibieron antitoxina botulínica equina. El promedio de días de enfermedad previos al ingreso fue de 2 días en los pacientes que recibieron tratamiento con antitoxina botulínica equina y 4 días en los pacientes no tratados. Diagnóstico de laboratorio (Toxina A y Clostridium botulinum) a los 5 días en los tratados con antitoxina botulínica equina, y a los 11,5 en los no tratados. En los pacientes tratados con antitoxina botulínica equina, el promedio de días de internación fue de 30 versus 70 días en los no tratados (p=0,0001). El promedio días en las Unidades de Cuidados Intensivos Pediátricos de los pacientes tratados fue de 20 versus 54 días en los no tratados (p=0,0001). Los días de asistencia respiratoria mecánica en los tratados fue de 16 versus 43 días en los no tratados (p=0,0001) y los tratados requirieron 29 días de alimentación por sonda nasogástrica versus 70 días en los no tratados (p=0,0001). El 40% de los pacientes tratados presentaron neumonía asociada a respirador versus el 56% de los no tratados (p=0,0038), sepsis el 11% versus el 34% (p=0,005) y secuelas al alta 6% versus 64% (p=0,0001), respectivamente. En zonas con mayor número de casos, se observó una alta frecuencia de esporas en los suelos, asociado a clima seco y ventoso. Los resultados sugieren que el tratamiento precoz con antitoxina botulínica equina es una alternativa hasta disponer de inmuno-globulina botulínica humana. Los climas secos y ventosos favorecen la enfermedad.

Abstract Infant botulism (BL), the most common form of human botulism today, is a "rare" or "orphan" disease as it affects less than 0.05% of the population. The objective of this work is to determine the incidence of BL in Argentina. Evaluate the diagnosis and treatment performed. To compare evolution and sequelae at discharge in patients with and without specific treatment. Consider the climatic characteristics (precipitations and winds) and the studies of soil samples from the provinces with the highest number of BL cases. We present a retrospective, observational, multicenter, cohort (longitudinal) study analyzing the medical records of patients with BL, who were admitted to Pediatric Intensive Care Units with mechanical ventilation, from January 1,2010 to December 31,2013. The following were considered: age, sex, days prior to admission, until laboratory diagnosis, Pediatric Intensive Care Units, me-chanical respiratory assistance, average hospital days, nasogastric tube feeding, treatment and sequelae. In the country, 216 cases of BL were registered between 2010 and 2013. We analyzed 79 who were admitted to Pediatric Intensive Care Units from 11 provinces. Average age 4 months. Maternal nutrition 90%. Eighteen patients (6 provinces) received equine botulinum antitoxin .Mean days of illness prior to admission: 2 in those treated with equine botulinum antitoxin and 4 in those not treated. Laboratory diagnosis (Toxin A and Clostridium botulinum) at 5 days in treated with equine botulinum antitoxin, at 11.5 in untreated. Patients with equine botulinum antitoxin average hospital days 30 vs 70 in untreated patients (p=0.0001). Mean Pediatric Intensive Care Unit days 20 vs 54 (p=0.0001) of mechanical respiratory assistance 16 vs 43 (p=0.0001) and nasogastric tube feeding 29 vs 70 (p=0.0001). Those treated presented ventilator-associated pneumonia 40% vs 56% (p=0.0038) and sepsis 11% vs 34% (p=0.005). Sequelae at discharge 6% vs 64% (p=0.0001) in those not treated. In areas with a higher number of cases, high frequency of spores in soils, dry and windy weather. The results suggest that early treatment with equine botulinum antitoxin is an alternative until human botulinum immunoglobulin is available. The dry and windy climates favor the disease.

Botulismo del lactante grave por toxina tipo A y uso de antitoxina equina AB luego de 5 días de evolución, reporte de caso y revisión bibliográfica / Severe infant botulism due to type A toxin and use of equine AB antitoxin AB after 5 days of evolution, a case report and literature review

Resumen El botulismo del lactante (BL) es una enfermedad neuroparalítica potencialmente grave que afecta a niños menores de un año, ocasio nada por la ingesta y germinación de esporas de la bacteria del género Clostridium en tubo digestivo y la producción in situ de toxina botulínica (TB). Ésta se absorbe de manera intermitente y puede ser sostenida en el tiempo, condicionando una mayor exposición a la TB respecto a otras formas de botulismo. La TB representa el agente más letal conocido para el ser humano, con capacidad de producir parálisis flácida descendente, insuficiencia respiratoria y la muerte. Los lactantes representan la población más susceptible a esta toxiinfección. El eje central del manejo del BL radica en el diagnóstico precoz y tratamiento de sostén adecuado y oportuno. Si bien en la bibliografía consultada se describe que el tratamiento específico con antitoxina botulínica humana (BabyBIG® reduce el tiempo de hospitalización y estadía en Unidad de Cuidados Intensivos, la misma no se encuentra disponible en muchos países, incluida la Argentina. En nuestro país se encuentra disponible la antitoxina botulínica de origen equino (AtBE) bivalente A-B. La misma no posee indicación formal para el tratamiento del BL por la escasa experiencia en esta población, su corta vida media y los efectos adversos descritos, como son la sensibilización a antígenos equinos de por vida y posibles reacciones anafilácticas más graves en lactantes, basados en trabajos de la década de 1980 y opiniones de expertos. Se presenta el caso de una paciente de 5 meses asistida en el Hos pital de Niños "Superiora Sor María Ludovica" con BL severo, con requerimientos de asistencia ventilatoria mecánica y deterioro clínico durante la internación. Recibió AtBE a los 48 días de enfermedad, con respuesta favorable, a partir de una búsqueda bibliográfica sobre la eficacia y el perfil de seguridad de la AtBE en BL grave y la eficacia de su administración luego de 5 días de inicio del cuadro. A pesar de no haberse hallado bibliografía que avale la eficacia de la AtBE pasados 5 días de evolución, se plantea su uso en pacientes con BL grave e indicadores compatibles con presencia de TB en circulación, como la intensificación de la hipotonía muscular o la identificación de TB en materia fecal o suero. La búsqueda realizada arrojó datos sobre posibles beneficios de su uso, tanto antes como después de los 5 días de evolución del cuadro, y la ausencia de reportes de reacciones adversas severas en lactantes. Se concluye que el uso de la AtBE podría ser una opción terapéutica frente a la ausencia de BabyBIG® en pacientes con BL grave confirmado que requieran cuidados intensivos con soporte ventilatorio mecánico, frente a indicadores compatibles con TB circulante, independientemente del tiempo de evolución.

Abstract Infant botulism (BL) is a potentially serious neuroparalytic disease that affects children under one year old, caused by the ingestion and germination of spores of the Clostridium genus bacterium in the digestive tract and the in situ production of botulinum toxin (TB), which is absorbed intermittently and can be sustained over time, with longer exposure time to TB than other botulism forms. The TB represents the most lethal toxin known to humans and can cause descending flaccid paralysis, respiratory failure and death. Infants represent an especially susceptible population. Early diagnosis and supportive care are the cornerstone of BL management. Although specific treatment with human botulinum antitoxin (BabyBIG® has shown to reduce the hospitalization time and Intensive Care Unit stay in the consulted bibliography, it is not currently available in many countries, including Argentina. Botulinum antitoxin of equine origin (AtBE) bivalent A-B is available in our country. This antitoxin has not a formal indication in BL due to the limited experience of its use in this population, its short half-life and the adverse effects described, such as lifelong sensitization to equine antigens and possible more severe anaphylactic reactions in infants, based on studies from the 1980s and expert opinions. We present the case of a 5 month old patient assisted at the Children's Hospital "Superiora Sor María Ludovica" with severe BL, in need of mechanical ventilatory assistance and worsening of her clinical state during hospitalization, who received ATBE at 48 days of illness with a favorable response. A bibliographic search was carried out on the efficacy and safety profile of AtBE in severe BL and the efficacy of its administration after 5 days of illness onset. Even though bibliography on efficacy of ATBE after 5 days of evolution was not found, its use is proposed in patients with compatible indicators of circulating TB, such as worsening of muscular hypotonia or TB presence in feces or serum in severe ill patients. The carried out search has shown data of the possible benefits of its use, both before and after 5 days of disease onset, and the absence of severe adeverse reaction reports in infants. We concluded that the use of AtBE could be a therapeutic option in absence of BabyBIG® in patients with confirmed severe BL who require intensive care with mechanical ventilatory support and compatible indicators with circulating TB, regardless of the evolution time.

Vigilancia de botulismo / Botulism surveillance

El botulismo se presenta como una enfermedad de distribución mundial, rara pero potencialmente mortal, de rápida evolución. Es una emergencia médica y epidemiológica y a los fines de la vigilancia, requiere notificación individual e inmediata. En el presente informe se describen medidas de prevención y control, y medidas de educación y prevención.

Type C botulism in dogs from rural properties located in Goiânia, Brazil

Botulism is a disease usually fatal, caused by the ingestion of neurotoxins produced by Clostridium botulinum. In dogs, intoxication is caused by the ingestion of botulinum toxin type C, and animals often recover spontaneously. The present study describes the occurrence of type C botulism in two dogs domiciled on neighboring rural properties in the municipality of Goiânia, state of Goiás, Brazil, probably associated with ingestion of decomposing bovine carcass. Upon clinical evaluation, the dogs were alert in the lateral decubitus position with ascending flaccid paralysis, absence of eyelid reflexes, and reduced muscle tone. Due to their worsening clinical symptoms, the animals died within 12 h and 3 days after supportive treatment. Botulinum toxin type C was identified, in the serum and feces of both dogs, by seroneutralization in mice with homologous monovalent antitoxin. The results of the high-throughput gene sequencing showed that the abundance of C. botulinum in the fecal microbiota of one of the affected dogs was low (0.53%). In this way, the present study highlights the need of sanitary practices related to the appropriate collection and disposal of bovine carcasses in rural areas since they represent a risk factor for the occurrence of botulism in dogs domiciled on rural properties.

Open Tibial Fracture Complicated by Wound Botulism: A Case Study.

Botulism is a neuroparalytic disease most commonly caused by foodborne ingestion of neurotoxin types A, B, and E, and is often fatal if untreated. Clinicians should be able to recognize the classic symptoms of botulinum intoxication (12). Owing to its rarity, there are a limited number of studies evaluating the clinical care of patients with wound botulism (10). We present an infected tibial non-union with botulism who underwent a successful radical excision and bone transport. The patient tolerated the procedure well.