Botulismo alimentar: relato de caso de uma doença rara, grave e de relevância para a saúde pública / Foodborne botulism: case report of a rare, serious disease of public health relevance

Este resumo apresenta o relato de um caso de Botulismo ocorrido em maio de 2021 no Hospital do Servidor Público Municipal (HSPM) em São Paulo. O objetivo principal é sensibilizar os profissionais de saúde para considerar o Botulismo como uma possível causa de síndrome neuroparalítica aguda, apesar de sua raridade. Destaca-se a importância do diagnóstico precoce e do tratamento com antitoxina, juntamente com cuidados intensivos, para reduzir a mortalidade. O estudo é observacional e descritivo, relatando o caso de uma paciente hospitalizada com Botulismo de origem alimentar entre maio e agosto de 2021. Diante de uma síndrome neuroparalítica aguda, a suspeita de Botulismo e uma revisão da epidemiologia da doença são cruciais. Destaca-se a importância da antitoxina e dos cuidados intensivos no tratamento para reduzir a mortalidade. Complicações pós-infecção, como sequelas motoras, são comuns em pacientes de Botulismo, tornando essencial uma abordagem multidisciplinar de reabilitação física para uma recuperação eficaz. A Vigilância Epidemiológica e Sanitária desempenham um papel vital na prevenção e controle do Botulismo, incluindo a coleta e transporte oportunos de amostras, busca ativa de casos suspeitos e orientação à população sobre medidas preventivas. A qualidade dos dados notificados é fundamental para a eficácia dessas ações. Em vista da alta letalidade do Botulismo, destaca-se a importância de alertar os profissionais de saúde para identificar casos suspeitos, bem como treiná-los na integração com as unidades de Vigilância Sanitária e Epidemiológica. Isso permite uma identificação precoce e tratamento oportuno de casos suspeitos, contribuindo para a saúde pública. Palavras-chave: Botulismo. Neurotoxina botulínica. Intoxicação alimentar.

A Novel Humanized Anti-Abrin A Chain Antibody Inhibits Abrin Toxicity In Vitro and In Vivo.

Abrin, a type-II ribosome inactivating protein from the seed of Abrus precatorius, is classified as a Category B bioterrorism warfare agent. Due to its high toxicity, ingestion by animals or humans will lead to death from multiple organ failure. Currently, no effective agents have been reported to treat abrin poisoning. In this study, a novel anti-abrin neutralizing antibody (S008) was humanized using computer-aided design, which possessed lower immunogenicity. Similar to the parent antibody, a mouse anti-abrin monoclonal antibody, S008 possessed high affinity and showed a protective effect against abrin both in vitro and in vivo, and protected mice that S008 was administered 6 hours after abrin. S008 was found that it did not inhibit entry of abrin into cells, suggesting an intracellular blockade capacity against the toxin. In conclusion, this work demonstrates that S008 is a high affinity anti-abrin antibody with both a neutralizing and protective effect and may be an excellent candidate for clinical treatment of abrin poisoning.

Intravenous rifampicin use in the management of amanita phalloides toxicity.

Context: Amanita phalloides related toxicity from amatoxins can result in acute liver and multi-organ failure and is responsible for 90% of all mushroom poisoning death. However, more evidence is needed in regards to different management strategies.Case details: We present two cases of amanita mushroom ingestion who were treated with intravenous rifampicin.Discussion: Further study is needed to establish the efficacy and role of rifampicin in amatoxin related mushroom poisoning.

The eternal dilemma of antitoxin antibiotics for skin and soft tissue infection.

PURPOSE OF REVIEW: In standard clinical practice, combined antibiotic treatment is used to treat severe skin and soft tissue infections (SSTIs), whereby one of the drugs is usually a protein synthesis inhibitor antibiotic. However, evidence for this practice is only based on data from 'in vitro' studies, animal models and case reports. There are no randomized controlled trials. In the light of several new drugs marketed for the treatment of these infections, there is a need to revise the state of the art. RECENT FINDINGS: New reviews and systematic appraisals of the literature exist on the use of protein synthesis inhibitor antibiotics to treat severe SSTI. Several 'in vitro' studies have assessed the efficacy of some of the new drugs. SUMMARY: Combination therapy, including an adjuvant protein synthesis inhibitor antibiotic for toxin suppression, should be used both in patients with severe SSTI and in those with moderate infection and risk factors for methicillin-resistant positive- or Panton-Valentine leukocidin positive-Staphylococcus aureus infection.

Establishment of a Novel Oral Murine Model of Ricin Intoxication and Efficacy Assessment of Ovine Ricin Antitoxins.

Ricin, produced from the castor beans of Ricinus communis, is a cytotoxin that exerts its action by inactivating ribosomes and causing cell death. Accidental (e.g., ingestion of castor beans) and/or intentional (e.g., suicide) exposure to ricin through the oral route is an area of concern from a public health perspective and no current licensed medical interventions exist to protect from the action of the toxin. Therefore, we examined the oral toxicity of ricin in Balb/C mice and developed a robust food deprivation model of ricin oral intoxication that has enabled the assessment of potential antitoxin treatments. A lethal oral dose was identified and mice were found to succumb to the toxin within 48 h of exposure. We then examined whether a despeciated ovine F(ab')2 antibody fragment, that had previously been demonstrated to protect mice from exposure to aerosolised ricin, could also protect against oral intoxication. Mice were challenged orally with an LD99 of ricin, and 89 and 44% of mice exposed to this otherwise lethal exposure survived after receiving either the parent anti-ricin IgG or F(ab')2, respectively. Combined with our previous work, these results further highlight the benefit of ovine-derived polyclonal antibody antitoxin in providing post-exposure protection against ricin intoxication.

Development of a physiologically-based pharmacokinetic model for ocular disposition of monoclonal antibodies in rabbits.

Development of protein therapeutics for ocular disorders, particularly age-related macular degeneration (AMD), is a highly competitive and expanding therapeutic area. However, the application of a predictive and translatable ocular PK model to better understand ocular disposition of protein therapeutics, such as a physiologically-based pharmacokinetic (PBPK) model, is missing from the literature. Here, we present an expansion of an antibody platform PBPK model towards rabbit and incorporate a novel anatomical and physiologically relevant ocular component. Parameters describing all tissues, flows, and binding events were obtained from existing literature and fixed a priori. First, translation of the platform PBPK model to rabbit was confirmed by evaluating the model's ability to predict plasma PK of a systemically administered exogenous antibody. Then, the PBPK model with the new ocular component was validated by estimation of serum and ocular (i.e. aqueous humor, retina, and vitreous humor) PK of two intravitreally administered monoclonal antibodies. We show that the proposed PBPK model is capable of accurately (i.e. within twofold) predicting ocular exposure of antibody-based drugs. The proposed PBPK model can be used for preclinical-to-clinical translation of antibodies developed for ocular disorders, and assessment of ocular toxicity for systemically administered antibody-based therapeutics.

Efficacy of Mycotoxin Detoxifiers on Health and Growth of Newly-Weaned Pigs under Chronic Dietary Challenge of Deoxynivalenol.

The efficacy of yeast-based mycotoxin detoxifiers on health and growth performance of newly-weaned pigs (27-d-old) fed diets naturally contaminated with deoxynivalenol was investigated. Sixty pigs were individually assigned to five treatments for 34 d: NC (negative control, 1.2 mg/kg of deoxynivalenol); PC (positive control, 3.2 mg/kg of deoxynivalenol); CYC (PC + clay/yeast culture-based product, 0.2%); CYE (PC + clay/yeast cell wall/plant extracts/antioxidants-based product, 0.2%); and CYB (PC + clay/inactivated yeast/botanicals/antioxidants-based product, 0.2%). Blood and jejunal mucosa were sampled, and data were analyzed using Proc Mixed of SAS with pre-planned contrasts. Deoxynivalenol reduced the average daily gain (ADG) in phase 3. Pigs fed CYC had greater overall ADG, average daily feed intake during phase 3, and gain to feed ratio during phase 2 than PC. At d 14, deoxynivalenol reduced blood urea nitrogen/creatinine and tended to reduce blood urea nitrogen. Pigs fed CYB tended to have greater aspartate aminotransferase than PC. At d 34, pigs fed CYC and CYB tended to have lower serum creatine phosphokinase than PC. Pigs fed CYE had lower blood urea nitrogen/creatinine than PC. In jejunal mucosa, deoxynivalenol tended to increase malondialdehydes and decrease glutathione. Pigs fed CYE and CYB had lower malondialdehydes, pigs fed CYB had greater glutathione and tended to have lower immunoglobulin A than PC. Pigs fed CYC and CYE tended to have lower interleukin 8 than PC. In summary, deoxynivalenol challenge (1.2 vs. 3.2 mg/kg) mildly compromised growth performance and increased the oxidative stress of pigs. Mycotoxin detoxifiers could partially overcome deoxynivalenol toxicity enhancing liver health, whereas CYE and CYB reduced oxidative stress, and CYC and CYB reduced immune activation. In conclusion, yeast-based detoxifiers with functional components as clay/inactivated yeast/botanicals/antioxidants had increased detoxifying properties in newly-weaned pigs challenged with deoxynivalenol, potentially by enhancing adsorbability, immune function, gut health, and reducing oxidative stress.

Oral immunization of mice with Lactococcus lactis expressing Shiga toxin truncate confers enhanced protection against Shiga toxins of Escherichia coli O157:H7 and Shigella dysenteriae.

Regardless of the communal impact of Shiga toxins, till today neither a specific treatment nor licensed vaccine is available. Lactococcus lactis (L. lactis), generally regarded as safe organism, is well known to provide a valuable approach regarding the oral delivery of vaccines. This study was undertaken to evaluate the protective efficacy of Stx2a1 expressed in nisin-inducible L. lactis, against Shiga toxins (Stx1, Stx2) in mouse model. Oral immunization of BALB/c mice with LL-Stx2a1 elicited significant serum antibody titer with elevated fecal and serum IgA, along with minimized intestinal and kidney damage resulting in survival of immunized animals at 84% and 100% when challenged with 10 × LD50 of Escherichia coli O157 and Shigella dysenteriae toxins, respectively. HeLa cells incubated with immune sera and toxin mixture revealed high neutralizing capacity with 90% cell survivability against both the toxins. Mice immunized passively with both toxins and antibody mixture survived the observation period of 15 days, and the controls administered with sham sera and toxins were succumbed to death within 3 days. Our results revealed protective efficacy and toxin neutralization ability of LL-Stx2a1, proposing it as an oral vaccine candidate against Shiga toxicity mediated by E. coli O157 and S. dysenteriae.

Minerais séricos, características morfométricas ósseas e deposição de minerais ósseos de frangos de corte alimentados com dieta com inclusão de bentonita / Serum minerals, bone morphometric characteristics and deposition of bone minerals from broilers fed diet containing bentonite

O objetivo deste trabalho foi avaliar a concentração sérica de cálcio, cloretos, ferro, fósforo e magnésio, as características morfométricas ósseas e a deposição de cálcio e fósforo nas tíbias de frangos de corte recebendo dieta com zero, 0,25 ou 0,50% de bentonita. Um ensaio foi conduzido com 288 frangos de corte de 14 a 21 dias de idade, submetidos a três dietas experimentais: sem inclusão (0,0); com inclusão de 0,25 e com inclusão de 0,50% do adsorvente bentonita. Não foram observadas diferenças (P>0,05) no desempenho das aves, nos níveis séricos de cálcio, cloretos, ferro e magnésio, no entanto os níveis de fósforo foram reduzidos (P<0,05) nas aves que ingeriram dieta com 0,50% de bentonita. Em relação às tíbias, observou-se redução (P<0,05) na matéria mineral (g e %) e no teor de cálcio com a inclusão de 0,50% de bentonita. Houve redução (P<0,05) nos níveis de fósforo das tíbias com a inclusão de 0,25 e 0,50% de bentonita. Conclui-se que a inclusão de até 0,50% do adsorvente de micotoxinas bentonita na dieta de frangos de corte não altera o desempenho zootécnico das aves. A inclusão de 0,25% de bentonita, na dieta de frangos de corte, não altera a concentração dos minerais séricos e a deposição de minerais nas tíbias, entretanto a inclusão de 0,5% reduz os níveis séricos de fósforo, o teor de matéria mineral e a concentração de cálcio e fósforo ósseos, sem afetar as características morfométricas ósseas.(AU)

The aim of this study was to evaluate performance, serum concentration of calcium, chloride, iron, magnesium, phosphorus, and bone characteristics, ash, calcium, and phosphorus in tibias of broilers receiving diet with zero, 0.25 or 0.50% of bentonite. No differences were found on performance of poultry, on serum mineral calcium, chloride, iron, magnesium, however phosphorus levels of broilers fed on diets containing 0.5% bentonite was reduced. With respect to tibia, reduction was observed on mineral matter (g and %) and calcium levels with inclusion of 0.50% bentonite, and reduction on phosphorus levels with inclusion of 0.25 or 0.50% of bentonite on diet. We conclude that the inclusion of up to 0.50% of mycotoxin adsorbent bentonite in diet of broiler does not change broiler performance. The inclusion of 0.25% of bentonite in diet of broiler does not change serum mineral concentration and mineral deposition; however, the inclusion of 0.5% decrease serum levels of phosphorus, the content of bone mineral matter, with not effects on bone morphometric characteristics.(AU)

Bezlotoxumab.

Clostridium difficile infection (CDI) is mediated by actions of toxin A and toxin B. Fully human monoclonal antibodies directed against the binding domains of these toxins were developed. Despite preclinical studies suggesting efficacy for the anti-toxin A monoclonal, actoxumab, the anti-toxin B monoclonal, bezlotoxumab, alone was shown to be effective in clinical trials. Intravenous infusion of bezlotoxumab at a 10 mg/kg dosage as adjunctive treatment reduced the risk of recurrent CDI over placebo for adult patients at increased risk for CDI recurrence in 2 large randomized, double-blind trials. Significant benefit was noted for patients with 1 or more of the following predefined risks: age >65 years, history of CDI, immunocompromise, severe CDI. Overall, bezlotoxumab appeared to be safe; however, an unexplained increased risk of heart failure was noted for patients with underlying congestive heart failure. Further refinement of who would benefit most and when best to administer bezlotoxumab is warranted.

Bezlotoxumab use as adjunctive therapy with the third fecal microbiota transplant in refractory recurrent Clostridium difficile colitis; a case report and concise literature review.

Clostridium difficile is the most commonly reported pathogen to cause nosocomial infections in the United States with a high burden affecting morbidity, mortality and healthcare expenditure. The use of Fecal Microbiota Transplantation (FMT) is one of the current standard therapies for recurrent C. difficile infection (CDIr). One emerging promising approach is the use of monoclonal antibodies that bind to and neutralize C. difficile toxins such as Bezlotoxumab. We present the first case report on combining the third FMT with bezlotoxumab after the failure of standard-of-care antibiotics and two trials of FMT alone, with subsequent success in preventing the recurrence of refractory CDI for 12 weeks following treatment. This case highlights the need for further studies and guidelines to recommend the best combination among different treatment options and modalities.

Studying the differential efficacy of postsymptom antitoxin treatment in type A versus type B botulism using a rabbit spirometry model.

Botulinum neurotoxin (BoNT) serotypes A, B and E are responsible for most cases of human botulism. The only approved therapy for botulism is antitoxin treatment administered to patients after symptom onset. However, a recent meta-analysis of antitoxin efficacy in human botulism cases over the past century concluded that a statistically significant reduction in mortality is associated with the use of type E and type A antitoxin, but not with type B antitoxin. Animal models could be highly valuable in studying postsymptom antitoxin efficacy (PSAE). However, the few attempts to evaluate PSAE in animals relied on subjective observations and showed ∼50% protection. Recently, we developed a novel spirometry model for the quantitative evaluation of PSAE in rabbits and used it to demonstrate full protection against BoNT/E. In the current study, a comparative evaluation of PSAE in botulism types A and B was conducted using this quantitative respiratory model. A lethal dose of each toxin induced a comparable course of disease both in terms of time to symptoms (TTS, 41.9±1.3 and 40.6±1.1 h, respectively) and of time to death (TTD, 71.3±3.1 and 66.3±1.7 h, respectively). However, in accordance with the differential serotypic PSAE observed in humans, postsymptom antitoxin treatment was fully effective only in BoNT/A-intoxicated rabbits. This serotypic divergence was reflected by a positive and statistically significant correlation between TTS and TTD in BoNT/A-intoxicated rabbits (r=0.91, P=0.0006), but not in those intoxicated with BoNT/B (r=0.06, P=0.88). The rabbit spirometry system might be useful in the evaluation toolkit of botulism therapeutics, including those under development and intended to act when antitoxin is no longer effective.

Efficacy of bezlotoxumab based on timing of administration relative to start of antibacterial therapy for Clostridium difficile infection.

Background: The fully human monoclonal antibody bezlotoxumab binds Clostridioides (Clostridium) difficile toxin B and reduces recurrence rates in patients with C. difficile infection (CDI) receiving antibacterial treatment for a primary or recurrent episode. Objectives: To investigate whether the timing of bezlotoxumab administration relative to the onset of antibacterial treatment affected clinical outcome in the Phase 3 trials MODIFY I (NCT01241552) and MODIFY II (NCT01513239). Methods: Initial clinical cure and CDI recurrence rates of participants who received bezlotoxumab or placebo were summarized by timing of infusion relative to the start of antibacterial drug treatment for CDI: 0-2, 3-4 and ≥5 days after onset. Results: Of 1554 total participants, 649 (41.8%), 469 (30.1%) and 436 (28.1%) received an infusion 0-2, 3-4 and ≥5 days after onset of antibacterial treatment for CDI, respectively. Regardless of timing of administration, there were no differences in initial clinical cure rates between participants receiving bezlotoxumab (range 77.8% to 81.4%) or placebo (77.8% to 81.7%). Bezlotoxumab efficacy was unaffected by timing of administration; rates of CDI recurrence were lower versus placebo in all subgroups (range 19.3% to 22.8% for bezlotoxumab and 31.7% to 35.8% for placebo). Timing of administration also had no effect on time to resolution of diarrhoea, which was achieved by the end of antibacterial treatment in ∼95% of participants in both bezlotoxumab and placebo groups. Conclusions: Bezlotoxumab is effective in preventing CDI recurrence and can be administered at any time before ending antibacterial drug treatment.

Does anthrax antitoxin therapy have a role in the treatment of inhalational anthrax?

PURPOSE OF REVIEW: Inhalational anthrax is a rare disease and Bacillus anthracis is a likely pathogen to be used in a biological attack. The lack of clinical experience with anthrax has led experts to develop treatment guidelines. These guidelines recommend anthrax antitoxin to be used in conjunction with antibiotics for the treatment of patients with systemic anthrax infection, yet there is still a lack of human or animal data to support this recommendation. RECENT FINDINGS: The U.S. Food and Drug Administration-approved anthrax antitoxins in 2012, 2015, and 2016. These products have been stockpiled for use in a public health emergency. Although efficacy is high when given early, their efficacy diminishes quickly when given after the development of bacteremia. Animal studies showing a significant incremental benefit of antitoxin therapy when combined with antibiotic therapy were not required by the U.S. Food and Drug Administration for product approval. SUMMARY: There is no conclusive evidence demonstrating that anthrax antitoxin therapy, when combined with a therapeutic course of antibiotics provides a survival benefit in inhalational anthrax. Additional research is needed in improved anthrax-antitoxin therapies, novel small molecule toxin inhibitors that act intracellularly, and studies of supportive care such as hemodynamic and ventilatory support, to improve the survival for inhalational anthrax patients and help mitigate the threat caused by the misuse of B. anthracis.

Safety, Pharmacokinetics, and Immunogenicity of Obiltoxaximab After Intramuscular Administration to Healthy Humans.

Inhalational anthrax is a highly lethal infection caused by Bacillus anthracis and a serious bioterrorism threat. Protective antigen (PA) is a critical component required for the virulence of Bacillus anthracis. Obiltoxaximab, a high-affinity monoclonal antibody that neutralizes PA, is approved in the United States for intravenous use for the treatment of inhalational anthrax in combination with appropriate antibacterial drugs and for prophylaxis of inhalational anthrax when alternative therapies are not available or appropriate. Here, we explored the safety, pharmacokinetics (PK), and immunogenicity of obiltoxaximab administered by intramuscular injection at doses of 4, 8, 16, 20, and 24 mg/kg in healthy humans. Systemic exposures were approximately dose proportional, maximum serum concentrations were observed after 6-9 days, and terminal half-life ranged from 16 to 23 days. Average absolute intramuscular bioavailability was 64%. Obiltoxaximab was well tolerated, and local tolerability was acceptable up to 24 mg/kg intramuscularly, up to 6 injections per dose, and up to 5 mL per injection. No injection-site abscesses or hypersensitivity reactions occurred; no subjects developed treatment-emergent antitherapeutic antibodies over the study period of 71 days.

[Safety profile of heterologous serum produced by the Butantan Institute, in São Paulo-SP, Brazil, from 2012 to 2015]. / Perfil de segurança dos soros heterólogos produzidos pelo Instituto Butantan, São Paulo-SP, no período de 2012 a 2015.

OBJECTIVE: to describe the safety profile of the heterologous serum produced by the Butantan Institute (BI) of São Paulo-SP, Brazil. METHODS: a descriptive study of adverse events (AEs) post-exposure to serum produced by the BI, encoded in the medical terminology of the Medical Dictionary for Regulatory Activities (MedDRA), and spontaneously reported to BI from 2012 to 2015. RESULTS: 52 individuals reported AEs, mainly related to Bothrops antivenom (n=11), diphtheria antitoxin (n=9) and unspecified snakebite serum (n=9); a mean of 3.2 AEs per individual was observed; among the total of 173 AEs, 63.0% were expected considering that they were described in the package insert; most of them were classified as skin and subcutaneous tissue disorders (30.6%); there were six deaths temporally related to the use of serum, but this association was discarded. CONCLUSION: in the studied period, the serum produced by the BI had no changes in their safety profiles, considering that the AEs were expected, according to the information previously described in the package insert.

Perfil de segurança dos soros heterólogos produzidos pelo Instituto Butantan, São Paulo-SP, no período de 2012 a 2015 / Safety profile of heterologous serum produced by the Butantan Institute, in São Paulo-SP, Brazil, from 2012 to 2015 / Perfil de seguridad de los sueros heterólogos producidos por el Instituto Butantan, São Paulo-SP, Brasil, en el período de 2012 al 2015

Resumo OBJETIVO: descrever o perfil de segurança dos soros heterólogos produzidos pelo Instituto Butantan (IB) de São Paulo-SP, Brasil. MÉTODOS: estudo descritivo dos relatos de eventos adversos (EA) pós-exposição aos soros produzidos pelo IB, codificados pela terminologia do Dicionário Médico para Atividades Regulatórias (MedDRA), notificados espontaneamente ao IB entre 2012 e 2015. RESULTADOS: foram notificados 52 usuários com algum evento adverso relacionado, principalmente, aos soros antibotrópico (n=11), antidiftérico (n=9) e antiofídico não especificado (n=9); observaram-se, em média, 3,2 EA por indivíduo; dos 173 EA notificados, 63,0% eram esperados por serem eventos descritos em bula; os EA mais notificados foram categorizados como afecções dos tecidos cutâneos e subcutâneos (30,6%); houve seis óbitos temporalmente relacionados ao uso de soros, porém essa associação foi descartada. CONCLUSÃO: no período estudado, os soros produzidos pelo IB não apresentaram alteração em seu perfil de segurança, já que os EA relatados eram esperados conforme informação descrita em bula.

Abstract OBJECTIVE: to describe the safety profile of the heterologous serum produced by the Butantan Institute (BI) of São Paulo-SP, Brazil. METHODS: a descriptive study of adverse events (AEs) post-exposure to serum produced by the BI, encoded in the medical terminology of the Medical Dictionary for Regulatory Activities (MedDRA), and spontaneously reported to BI from 2012 to 2015. RESULTS: 52 individuals reported AEs, mainly related to Bothrops antivenom (n=11), diphtheria antitoxin (n=9) and unspecified snakebite serum (n=9); a mean of 3.2 AEs per individual was observed; among the total of 173 AEs, 63.0% were expected considering that they were described in the package insert; most of them were classified as skin and subcutaneous tissue disorders (30.6%); there were six deaths temporally related to the use of serum, but this association was discarded. CONCLUSION: in the studied period, the serum produced by the BI had no changes in their safety profiles, considering that the AEs were expected, according to the information previously described in the package insert.

Resumen OBJETIVO: describir el perfil de seguridad de los sueros heterólogos producidos por el Instituto Butantan (IB) de São Paulo-SP, Brasil. MÉTODOS: estudio descriptivo de los informes de eventos adversos (EAs) post-exposición a los sueros del IB y codificados según el Diccionario Médico para Actividades Regulatorias (MedDRA). RESULTADOS: 52 usuarios presentaron EAs relacionados con los sueros antibotrópico (n=11), antidiftérico (n=9) y antiofídico no especificado (n=9); se observó, en los EAs, 3,2 de media por persona; de los 173 EAs reportados, 63,0% fueron "esperados", ya que figuran descritos en la bula farmacológica; los EAs más reportados fueron los trastornos de piel y tejido subcutáneo (30,6%); hubo seis muertes, pero se descartó la asociación con el uso de suero. CONCLUSIÓN: durante el período de estudio, los sueros del IB no mostraron ningún cambio en su perfil de seguridad, ya que los EAs reportados eran esperados conforme información descrita en la bula.

Obiltoxaximab: Adding to the Treatment Arsenal for Bacillus anthracis Infection.

OBJECTIVE: To review the safety and efficacy of obiltoxaximab, a monoclonal antibody indicated for the treatment of Bacillus anthracis inhalational anthrax in adult and pediatric patients. DATA SOURCES: A MEDLINE (1946 to May, week 1, 2017) and EMBASE (1980 to 2017, week 19) search was performed using the search terms obiltoxaximab OR ETI-204 OR Anthim AND anthrax. STUDY SELECTION AND DATA EXTRACTION: All English-language clinical studies in both animal and human models assessing the safety and efficacy of obiltoxaximab were included. DATA SYNTHESIS: A total of 5 articles have been published on clinical studies examining safety and efficacy of obiltoxaximab. Efficacy studies in 2 animal models, New Zealand White rabbits and cynomolgus macaques, showed higher rates of survival post-anthrax exposure when obiltoxaximab was administered. Safety studies in healthy human volunteers showed that it was tolerated, with a relatively low incidence of adverse events. CONCLUSION: Based on these clinical studies and the implausibility of conducting a trial in infected individuals, obiltoxaximab is a safe and efficacious addition to the anthrax antitoxin armamentarium to protect against and treat inhalational anthrax.

Animal-to-Human Dose Translation of Obiltoxaximab for Treatment of Inhalational Anthrax Under the US FDA Animal Rule.

Obiltoxaximab, a monoclonal antibody against protective antigen (PA), is approved for treatment of inhalational anthrax under the US Food and Drug Administration's (FDA) Animal Rule. The human dose was selected and justified by comparing observed obiltoxaximab exposures in healthy and infected New Zealand White rabbits and cynomolgus macaques to observed exposures in healthy humans, to simulated exposures in healthy and infected humans, and to serum PA levels in infected animals. In humans, at 16 mg/kg intravenous, obiltoxaximab AUC was >2 times that in animals, while maximum serum concentrations were comparable to those in animals and were maintained in excess of the concentration required for PA neutralization in infected animals for 2-3 weeks. Obiltoxaximab 16 mg/kg in humans provided exposure beyond that of 16 mg/kg in animals, ensuring a sufficient duration of PA neutralization to allow for adaptive immunity development. Our approach to dose translation may be applicable to other agents being developed under the Animal Rule.

The Monoclonal Antitoxin Antibodies (Actoxumab-Bezlotoxumab) Treatment Facilitates Normalization of the Gut Microbiota of Mice with Clostridium difficile Infection.

Antibiotics have significant and long-lasting impacts on the intestinal microbiota and consequently reduce colonization resistance against Clostridium difficile infection (CDI). Standard therapy using antibiotics is associated with a high rate of disease recurrence, highlighting the need for novel treatment strategies that target toxins, the major virulence factors, rather than the organism itself. Human monoclonal antibodies MK-3415A (actoxumab-bezlotoxumab) to C. difficile toxin A and toxin B, as an emerging non-antibiotic approach, significantly reduced the recurrence of CDI in animal models and human clinical trials. Although the main mechanism of protection is through direct neutralization of the toxins, the impact of MK-3415A on gut microbiota and its restoration has not been examined. Using a CDI murine model, we compared the bacterial diversity of the gut microbiome of mice under different treatments including MK-3415A, vancomycin, or vancomycin combined with MK-3415A, sampled longitudinally. Here, we showed that C. difficile infection resulted in the prevalence of Enterobacter species. Sixty percent of mice in the vehicle group died after 2 days and their microbiome was almost exclusively formed by Enterobacter. MK-3415A treatment resulted in lower Enterobacter levels and restoration of Blautia, Akkermansia, and Lactobacillus which were the core components of the original microbiota. Vancomycin treatment led to significantly lower survival rate than the combo treatment of MK-3415A and vancomycin. Vancomycin treatment decreased bacterial diversity with predominant Enterobacter and Akkermansia, while Staphylococcus expanded after vancomycin treatment was terminated. In contrast, mice treated by vancomycin combined with MK-3415A also experienced decreased bacterial diversity during vancomycin treatment. However, these animals were able to recover their initial Blautia and Lactobacillus proportions, even though episodes of Staphylococcus overgrowth were detected by the end of the experiments. In conclusion, MK-3415A (actoxumab-bezlotoxumab) treatment facilitates normalization of the gut microbiota in CDI mice. It remains to be examined whether or not the prevention of recurrent CDI by the antitoxin antibodies observed in clinical trials occurs through modulation of microbiota.