Evaluation of toxin-antitoxin genes, antibiotic resistance, and virulence genes in Pseudomonas aeruginosa isolates

SUMMARY OBJECTIVE: Toxin-antitoxin genes RelBE and HigBA are known to be involved in the formation of biofilm, which is an important virulence factor for Pseudomonas aeruginosa. The purpose of this study was to determine the presence of toxin-antitoxin genes and exoenzyme S and exotoxin A virulence genes in P. aeruginosa isolates and whether there is a relationship between toxin-antitoxin genes and virulence genes as well as antibiotic resistance. METHODS: Identification of the isolates and antibiotic susceptibilities was determined by a VITEK 2 (bioMérieux, France) automated system. The presence of toxin-antitoxin genes, virulence genes, and transcription levels were detected by real-time polymerase chain reaction. RESULTS: RelBE and HigBA genes were detected in 94.3% (82/87) of P. aeruginosa isolates, and exoenzyme S and exotoxin A genes were detected in all of the isolates (n=87). All of the isolates that harbor the toxin-antitoxin and virulence genes were transcribed. There was a significant increase in the RelBE gene transcription level in imipenem- and meropenem-sensitive isolates and in the HigBA gene transcription level in amikacin-sensitive isolates (p<0.05). There was a significant correlation between RelBE and exoenzyme S (p=0.001). CONCLUSION: The findings suggest that antibiotic resistance may be linked to toxin-antitoxin genes. Furthermore, the relationship between RelBE and exoenzyme S indicates that toxin-antitoxin genes in P. aeruginosa isolates are not only related to antibiotic resistance but also play an influential role in bacterial virulence. Larger collections of comprehensive studies on this subject are required. These studies should contribute significantly to the solution of the antibiotic resistance problem.

Clinical characteristics among 67 cases of botulism in Xinjiang Uygur Autonomous Region, China / 中华神经科杂志

Objective:To investigate epidemiological and clinical characteristics of botulism, and the adverse events among those received botulinum antitoxin treatment.Methods:Patients with discharge diagnosis as botulism in the Second Affiliated Hospital of Xinjiang Medical University were enrolled between 2017 and 2021. The epidemiological and clinical characteristics were evaluated. Infection and mechanical ventilation as in-hospital outcomes according to baseline characteristics were analyzed. Patients with and without the interested outcomes were compared. The adverse outcomes among those received botulinum antitoxin treatment were investigated. Those with and without the adverse outcomes were also compared.Results:Sixty-seven cases of botulism were enrolled, and most cases got sick between January and March (32/67, 47.8%); among them 62 cases were Han ethnicity (92.5%); prevalence was highest in Aksu region (15/67, 22.4%); commonly seen symptoms and signs included fatigue (58/67, 86.6%), dysphagia (48/67, 71.6%), dizziness (42/67, 62.7%), ptosis (42/67, 62.7%), blurred vision (41/67, 61.2%), and limb weakness (35/67, 52.2%). Compared with patients without in-hospital infection ( n=52), patients with in-hospital infection ( n=15) were more likely to have severe botulism (0/52 vs 5/15, χ 2=19.79, P<0.001), diplopia (16/52, 30.8% vs 11/15, χ 2=8.77, P=0.003), dysarthria (17/52, 32.7% vs 11/15, χ 2=7.91, P=0.005), consciousness disorder (1/52, 1.9% vs 4/15, χ 2=10.32, P=0.008). Compared with patients without mechanical ventilation (62/67, 92.5%), patients with mechanical ventilation (5/67, 7.5%) were more likely to have severe botulism (5/5 vs 0/62, χ 2=41.17, P<0.001), and consciousness disorder (4/5 vs 1/62, 1.6%, χ 2=29.58, P<0.001). Among 67 cases of botulism, 19 cases (28.4%) had adverse events after receiving antitoxin treatment, with an average of 6.5 days from the antitoxin treatment beginning to the adverse event onset; among the 19 cases, 18 cases (94.7%) had rash. Age, sex, and severity did not differ between the groups with ( n=19) and without adverse events ( n=48) after receiving antitoxin treatment. Conclusions:Fatigue, dysphagia, dizziness, ptosis were the most frequent symptoms and signs in the botulism in Xinjiang Uygur Autonomous Region, China. Infection was a commonly seen complication of botulism, and proactive prevention and close monitoring were needed. Adverse events after receiving antitoxin were prevalent, and might not be associated with age, sex, and severity of botulism.

HipBST Toxin-antitoxin System of Prokaryotes / 中国生物化学与分子生物学报

Toxin-antitoxin system (TA) is a genetic element widely found in chromosomes and plasmids of bacteria, archaea and prophages. TA usually consists a toxin that inhibits the growth of bacteria and an antitoxin that neutralizes its toxicity. Since the discovery of the first CcdB / CcdA TA in the 1980s, TA has been proved to exist in almost all sequenced microorganisms and plays an important role in maintaining plasmid stability, anti-phage and promoting biofilm formation. At present, TA is divided into type I-VIII, among which type IITA is the most widely studied. HipBA is a type II TA. The toxin HipA in Escherichia coli HipBA is a serine / threonine kinase, which inhibits protein translation by phosphorylating bacterial Glutamyl tRNA synthetase (GltX), and its toxicity can be specifically neutralized by HipB. Recently, it has been found that Escherichia coli HipA homologous proteins exist widely in microorganisms, and they form a potential novel TA with genes of the same promoter, in which HipBST has been confirmed by experiments. The toxin HipT and the antitoxin HipS in this TA are similar to the C-terminal and N-terminal of E. coli HipA respectively, and the neutralization mechanism and the substrate of the toxin are different from that of E. coli toxin HipA. This study summarizes the recent discovery of special TA, especially the neutralization mechanism of HipBST which widely exists in prokaryotes.

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.

Tétanos generalizado: Una amenaza persistente, reporte de tres casos y revisión de la literatura / Generalized tetanus: A persistent threat, review of the literature and report of three cases

RESUMEN INTRODUCCIÓN: El tétanos es una enfermedad inmunoprevenible, ocasionada por la bacteria Clostridium tetani, desencadenando una enfermedad caracterizada por espasmos musculares, insuficiencia respiratoria y disautonomías, potencialmente mortal. MATERIALES Y MÉTODOS: Presentamos una serie de tres pacientes que consultaron al servicio de urgencias por presentar trismus, rigidez muscular generalizada y dificultad respiratoria, requiriendo manejo en la unidad de cuidados intensivos, con relajación muscular y administración intramuscular e intratecal de inmunoglobulina antitetánica, con evolución satisfactoria en todos los casos. DISCUSIÓN: Su tratamiento está divido en dos grandes secciones; la primera parte, el control de la infección y eliminación del agente causal, con lavado y desbridamiento de heridas, administración de antibióticos y neutralización de la neurotoxina. La segunda parte del tratamiento está en el soporte vital en la unidad de cuidados intensivos, con la administración de sedación, relajación muscular, control de disautonomías y manejo de complicaciones. CONCLUSIONES: El tétanos a pesar de los avances en vacunación aún es una enfermedad presente, cuyo diagnóstico y tratamiento rápido y adecuado, permite sobrevivir a los pacientes, como en los casos aquí reportados.

ABSTRACT INTRODUCTION: Tetanus is an immuno-preventable disease, produced by the bacterium Clostridium tetani, that causes a disease characterized by muscle spasms, respiratory insufficiency and life-threatening dysautonomia. MATERIALS AND METHODS: We present a series of three patients who consulted for trismus, muscle stiffness and respiratory failure, which required intensive care management, muscle relaxation, intramuscular and intrathecal administration of tetanus immu-noglobulin, with satisfactory outcomes in all the cases. DISCUSSION: Its treatment is divided into two main sections; the first part, the control of infection and elimination of the causative agent, with washing and debridement of wounds, administration of antibiotics and neutralization of the neurotoxin. The second part is life support in the intensive care unit, with the administration of sedation, muscular relaxation and control of dysautonomia and the management of complications. CONCLUSIONS: Despite the advances in vaccination, tetanus is still a present disease, whose diagnosis and rapid and adequate treatment allows patients to survive, as in the cases reported here.

Análise do sistema toxina-antitoxina HipA/B na indução da persistência bacteriana de cepas de Escherichia coli extraintestinal / The importance of HipA/B Toxin-Antitoxin system in extraintestinal Escherichia Coli persistence

Os sistemas toxina-antitoxinas (TA) compreendem um conjunto de genes que são amplamente difundidos em procariotos. No cromossomo, os sistemas podem estar envolvidos na indução de morte celular em resposta a condições estressantes, indução de persistência, formação de biofilme, colonização de novos nichos, manutenção da mobilidade bacteriana e virulência de bactérias patogênicas. Em E. coli K12, 36 sistemas TA foram descritos, dos quais o do tipo II é o mais abundante e estudado. Dentre as oito toxinas pesquisadas nesse trabalho, o gene da toxina HipA está presente em 76 das 100 cepas de ExPEC estudadas. Apesar da abundância de hipA em ExPEC e em diversos genomas bacterianos, a participação dos sistemas hipA/B na indução da persistência ainda não é clara. Portanto, o sistema hipA/B de duas cepas ExPEC isoladas de infecção sanguínea foi deletado, e estas foram avaliadas quando a indução da persistência bacteriana na presença de antibióticos, formação de biofilme, resistência ao soro e sobrevivência em macrófagos. O sistema TA hipA/B não influenciou no fenótipo de resistência ao soro humano e na sobrevivência intracelular em macrófagos, no entanto, participou da indução da persistência por ciprofloxacino em um isolado (EC182); e da formação de biofilme em superfície de vidro do isolado (EC273)

Toxin-antitoxin (TA) systems comprise a set of genes that are widespread in prokaryotes. On the chromosome, the systems may be involved in the induction of cell death in response to stressful conditions, persistence induction, biofilm formation, colonization of new niches, maintenance of bacterial mobility and virulence. In E. coli K12, 36 TA systems have been described, of which type II is the most abundant. Among the eight toxins searched in this work, hipA is present in 76 bacteria of the 100 ExPEC strains studied. Despite the abundance of hipA in ExPEC and in several bacterial genomes, the participation of hipA/B modules in the persistence is still unclear. Therefore, hipA/B system of two ExPEC strains isolated from blood infection was deleted and consequently evaluated in bacterial persistence induced by antibiotics, serum resistance and macrophage survival. Despite the fact that, the TA hipA/B system did not influence the phenotype of resistance to human serum and intracellular survival in macrophages. Herein, we described that hipA/B was important for persistence induction in one isolate (EC182); and may participate in the biofilm formation on the glass surface in the other studied strain (EC273)

Adult Diphteria: Possible Transmission of Corynebacterium diphtheriae from Unvaccinated Child?

@#A case of a toxigenic strain of Corynebacterium diphtheriae in an immunocompetent adult is presented, with the possibility of the adult acquiring the infection from her unvaccinated child. The abovementioned adult is a 29-year-old housewife who was previously immunised with diphtheria, tetanus, and pertussis (DTaP) vaccination in childhood, who presented fever, cough, sore throat, hoarseness of voice, odynophagia, and bilaterally enlarged tonsils. A throat swab confirmed the presence of toxigenic Corynebacterium diphtheriae. The patient was given 80,000 international units (IU) dose of diphtheria antitoxin (DAT) and treated with 2.4 million units (MU) QID intravenous penicillin and oral erythromycin 800 mg twice daily for two weeks. The patient responded well to the treatment and recovered with no cardiovascular or neurotoxicity.

Umbilical Diphtheria: Resurgence of a Forgotten Entity

Diphtheria has had a resurgence in India over the past decade.We present a case of umbilical diphtheria in a neonate, who had agood outcome with administration of anti-toxin and antibiotics.

Persistencia bacteriana: un fenotipo celular de importancia clínica en infecciones crónicas y recurrentes / Bacterial persistence: a cellular phenotype of clinical significance in chronic and recurrent infections

RESUMEN Los persistentes bacterianos son variantes transitorias de una población genéticamente homogénea, generada por exposición al estrés, como el que ocurre durante el tratamiento antibiótico. Es un fenómeno epigenético o un fenotipo no heredado, que puede ser llamado primera línea de defensa antes de que se adquiera la resistencia antimicrobiana. A pesar de su descubrimiento hace más de 70 años, su definición, mecanismos de formación, clasificación y morfologías adoptadas de implicancia clínica son temas de investigación actual. En el presente estudio se describe la relación de persistentes con infecciones crónicas y formación de biopelículas como factores importantes en la recaída, recidivas y mayor virulencia en las infecciones. Así mismo, se hace una revisión breve de los diversos mecanismos implicados en la persistencia bacteriana y su eliminación ineficaz por tolerancia antibiótica para terminar con la presentación de posibles estrategias de tratamiento. En conjunto, se cree que la persistencia impone una carga significativa de atención en salud pública, que se estima, provocará hasta 10 millones de víctimas al año para el 2050. Una mejor comprensión de este fenotipo es fundamental en la lucha contra las bacterias patógenas con la finalidad de obtener una mejor perspectiva en las terapias futuras.

ABSTRACT Persistent bacteria are the transient variants of a genetically homogeneous population generated by exposure to stress as in antibiotic treatment. They are an epigenetic phenomenon or a non-inherited phenotype, which may be considered as the first line of defense before developing antimicrobial resistance. Despite their discovery more than 70 years ago, their definition, mechanisms of formation, classification and morphologies of clinical implication are still current research topics. In the present research, we describe the relationship between chronic persistent infections and the formation of biofilms as important factors in recurrences, relapses and greater virulence in infections. Likewise, a brief review of the various mechanisms involved in bacterial persistence, their ineffective elimination due to antibiotic tolerance and possible treatment strategies is provided. Overall, it is believed that persistence poses a significant burden of public health care. It is estimated that up to 10 million people will be yearly affected by 2050. Thus, a better comprehension of this bacterial phenotype is essential to fight against pathogenic bacteria and improve therapeutic results in the future.

Misdiagnosis of iatrogenic botulinum toxin poisoning:one case report and review of the literature / 中国基层医药

Objective To report 1 case of iatrogenic botulinum poisoning misdiagnosed as myasthenia gravis,to discuss the clinical manifestation,distinguishing feature and prognosis of iatrogenic botulinum poisoning combined with literature.Methods We briefly introduced one patient with botulinum toxin poisoning misdiagnosed as myasthenia gravis.A 26-year old female was admitted in June 2017 in Gaochun People's Hospital of Nanjing,who received two injections of botulinum toxin 500 U for a short period of time due to cosmetic needs,then she suffered from fatigue,chest distress,eyelid ptosis and other symptoms.The patient was once misdiagnosed as myasthenia gravis,but the results of neostigmine test and repeated nerve stimulation examination were negative.After careful examination of the body (mandibular swelling) and repeated medical history requiring,the final diagnosis was clarified.After the treatment such as fluid infusion for 10 days,her discomforts were relieved.The literature was retrieved from "US National Library of Medicine National Institutes of Health (Pubmed) "," China National Knowledge Infrastructure (CNKI)" and "Wanfang Medicine Data China Information",a total of 17 articles were included in the analysis,including 30 effective cases.We analyzed the general characteristics,clinical manifestations and prognosis of botulinum toxin injection.Results Of the 30 cases,28 cases (96.7％) were female,2 cases (3.0％) were male,aged from 3 to 80 years old.Most of them were botulinum toxin type A,except 2 cases unknown.The clinical onset began from the injection day to 3 weeks after injection.The duration of the disease lasted from 10 days to 6 months.Most of the prognosis was good after treatment.Conclusion Careful attention should be paid to the serious reaction of botulinum toxin to ensure safe medication use.

The mazG gene involvement in the stringent response of Escherichia coli regulated by mazEF / 国际药学研究杂志

Objective: To explore the molecular mechanism of mazG gene involved in regulating mazEF toxin-antitoxin system(TAs)mediated bacterial growth inhibition and programmed death, and to clarify the true physiological function of MazG protein. Methods: The Escherichia coli (E.coli)strain MC4100 was used as a prototype and the relA gene was recovered to obtain the relA wildtype strain MC4200. E. coli mazG, mazEF, mazEFG and other series of gene knockout strains were constructed to test the effects of mazG gene overexpression in different genetic background strains on the survival rate of bacteria. Rifampicin, H2O2 and nalidixic acid and other stress conditions were used to treat the bacteria and study growth curve and survival rate of mazG gene and mazEFG operondeleted strains. The E.coli mazG gene and mutant were cloned into an inducible overexpression to construct pET28a-mazG and pET28amazG E38A. Then the protein was overexpressed in BL21 strain and purified using Ni-NTA resin. The dephosphatase activity of MazG protein was verified by enzyme experiments and the effect of mutant overexpression on bacterial survival was tested. Results: The overexpression of mazG had no significant effect on the growth of E.coli MC4200, but had a significant inhibitory effect on the mazEFG gene knockout strain. The cytotoxicity of MazG depended on its NTP-PPase enzyme activity. The presence of mazEF significantly inhibited the phenotype of mazG;Knockout of the mazEF/mazG/mazEFG genes did not affect the growth curve of E.coli under normal envi- ronment. Under stress conditions, the survival rate of the mazG knockout strain was basically the same as that of the mazEFG knockout strain, which was significantly higher than that of the wild type. Conclusion: The mazG gene is involved in the regulation of bacterial programmed cell death induced by mazEF and has an important role in bacterial growth inhibition. This study provides a new perspective for the study of TAs and further understanding of its role in the regulation of bacterial growth and death.

Vacuna antitetánica adyuvada en alúmina en inmunización simultánea por vías mucosa y parenteral / Alum adjuvant tetanus vaccine in simultaneous immunization by mucosal and parenteral routes

El tétanos es causado por Clostridium tetani, bacteria Gram+ esporulada que produce una potente neurotoxina. Las vacunas parenterales producen IgG antitoxina tetánica (anti TT) protectores en múltiples dosis inductoras y de reactivación; vax-TET® es una vacuna cubana parenteral adsorbida en alúmina. La IgAS (secretora), principal anticuerpo protector mucoso, sólo es inducida por la vía mucosa. La vía oral, la inducción de IgA y su papel protector no han sido exploradas. SinTimVaS se aplica por vía mucosa y parenteral simultánea que induce IgG sistémica similares a la vía parenteral y adiciona de respuesta de IgA mucosa. Evaluamos el efecto de vax-TET® aplicado en SinTimVaS en ratones Balb/c y exploramos la influencia del adyuvante sobre la inducción de IgA anti TT. SinTimVaS indujo similares respuestas de IgG anti TT séricas que dos dosis de vax-TET® intramusculares; pero superiores a una dosis. Tres dosis de vax-TET® orales no indujeron IgG anti TT sérica, mientras que la adyuvación con el adyuvante Finlay Cocleato 1 (AFCo1) sí la indujeron. No se logró determinar la inducción de IgA anti TT mucosa con ninguna de las formulaciones adjuvadas con alúmina; pero si con la formulación AFCo1+TT. Podemos concluir que vax-TET® en SinTimVaS funcionó de forma similar a la inmunización parenteral establecida, por lo que sería posible reducir los esquemas multidosis con formulaciones de adyuvantes más potentes y se confirma que se requieren potentes adyuvantes para inducir IgA mucosa(AU)

Tetanus is caused by Clostridium tetani, a sporulated Gram+ bacterium that produces a potent neurotoxin. Parenteral vaccines produce protective tetanus antitoxin (anti TT) IgG in multiple induction and reactivation doses; vax-TET® is a Cuban parenteral vaccine adsorbed onto alumina. IgAS (secretory), the main mucosal protective antibody, is only induced by the mucous membrane. The oral route, the induction of IgA and its protective role have not been explored. SinTimVaS is applied by simultaneous mucosal and parenteral route that induces systemic IgG similar to the parenteral route and adds an IgA mucosal response. We evaluated the effect of vax-TET® applied in SinTimVaS in Balb/c mice and we explored the influence of adjuvant on the induction of anti-TT IgA. SinTimVaS induced similar serum anti TT IgG responses to two intramuscular doses of vax-TET®; but higher than one dose. Three doses of oral vax-TET® did not induce serum anti-TT IgG, whereas adjuvanted with adjuvant Finlay Cocleate 1 (AFCo1) did induce it. It was not possible to determine the IgA anti-TT mucous induction with any of the formulations adjuvanted with alumina; but with the formulation AFCo1 + TT it was induced. We can conclude that vax-TET® in SinTimVaS worked in a similar way to the established parenteral immunization, so it would be possible to reduce the multi-dose vaccination schemes with more potent adjuvant formulations and it is confirmed that powerful adjuvants are required to induce mucosal IgA(AU)

Botulinum toxin A poisoning by local aesthetic injection: clinical and electrophysiological analyses of 20 cases / 中华医学美学美容杂志

Objective@#To observe the clinical and electrophysiological characteristics of botulinum toxin A poisoning induced by local cosmetic injection, and to explore the possible pathogenesis.@*Methods@#Clinical data of 20 patients with botulinum toxin type A local cosmetic injection poisoning admitted to our hospital from January 2016 to December 2018 were collected and electrophysiological tests were carried out.@*Results@#The clinical manifestations of 20 patients were mainly 15/20 (75.0%) with limb weakness, and the proximal end was heavier than the distal 20/20 (100%), and the upper limb was heavier than the lower limb 26/20 (80%), followed by dysphagia 12/20 (60%), dysarthria 5/20 (25%), cervical muscle weakness 5/20 (25%), extraocular muscle paralysis 4/20 (20%), masseter muscle weakness 3/20 (15%) and respiratory muscle weakness 2/20 (5.0%) with respiratory failure 1/20 (5.0%). The results of neurophysiological examination showed the highest rate of SFEMG (90.0%), followed by RNS (80.0%), EMG (65.0%) and NCV (40.0%), suggesting that neuromuscular junction dysfunction was the main presentation. Patients who actively gave botulinum antitoxin injection therapy and symptomatic support treatment had good prognosis.@*Conclusions@#Local cosmetic injection of botulinum toxin type A may lead to poisoning. The symptoms of poisoning are mainly caused by limb weakness. Neuroelectrophysiological examination can assist in the diagnosis of botulinum toxin poisoning.

Therapeutic effect of antitoxin on botulism type A: a preliminary observation of 8 cases / 中华整形外科杂志

Objective@#The study aimed to explore the recommended treatment for toxicosis of botulism toxin type A.@*Methods@#From January 2016 to August 2017, 8 patients with toxicosis of botulism toxin type A were hospitalized in Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine. All patients were female, 21-33 years of age, with an average age of 26.4 years. All patients showed progressive myasthenia and abnormal electromyography. The clinical manifestations and treatment outcomes of 8 patients in antitoxin group or non-antitoxin group were retrospectively analyzed. Five patients treated in plastic and reconstructive surgery department were included in the antitoxin group. They received skin test before injection, followed by intramuscular injection of 10 000-20 000 U antitoxins once a day for 2-3 days. Three patients treated in neurology department were included in the non-antitoxin group. They received only intravenous drip of neurotrophic drugs. After treatment, the improvement of clinical symptoms such as myasthenia and blepharoptosis was observed, and the electromyogram was followed up.@*Results@#The symptoms of myasthenia of the 5 patients in antitoxin treatment group were significantly improved, and the electromyogram signal returned to normal. However, for the 3 patients in non-antitoxin group, the symptoms of myasthenia did not significantly improve, and their electromyogram signal did not return to normal, even after 5 days′continuous treatment.@*Conclusions@#To regulate the cosmetic medical market is the key to prevent the accident of toxicosis of botulism toxin type A. It is necessary to make a definite diagnosis and medical intervene in time for the toxicosis. Antitoxin has a better curative effect, but further research is needed, to verify its safety and effectiveness.

Application of lysis system in bacterial vector vaccines / 生物工程学报

Recombinant bacterial vector vaccines have been widely used as carriers for the delivery of protective antigens and nucleic acid vaccines to prevent certain infectious diseases because of their ability to induce mucosal immunity, humoral immunity and cellular immunity. However, protective antigens and nucleic acids recombined into bacterial vector vaccines are difficult to be released into host cells because of the presence of bacterial cell wall. Vaccine strains that are residual in animals or livestock products may also cause environmental contamination and spread of the vaccine strains. The effective solution for these problems is to construct an auto-lysis system that can regulate the vaccine strains to grow normally in vitro while lysis in vivo. The lysis systems that have been applied in germs mainly include: the lysis system based on regulated delayed peptidoglycan synthesis, the lysis system based on the regulation of bacteriophage lysis protein and the lysis system based on the toxin-antitoxin system. In addition, a potential lysis system based on bacterial Type Ⅵ Secretion System (T6SS) is also expected to be a new method for the construction of auto-lysis strains. This review will focus on the regulatory mechanisms of these bacterial lysis systems.

Association Between Toxin-antitoxin Systems on Plasmids and Persister Formation in CTX-15-producing Klebsiella pneumoniae ST11 Isolates

We investigated the effect of toxin-antitoxin (TA) systems in bla(CTX-M-15)-bearing plasmids of Klebsiella pneumoniae on persister formation. The persister formation rate was notably high in transconjugants in plasmids bearing TA system than the transconjugants in plasmids bearing no TA systems. Activation of relA and spoT expression was higher in transconjugants with plasmids bearing TA systems. Thus, TA systems in plasmids may contribute to the maintenance of bla(CTX-M-15)-bearing plasmids and host survival via persister formation.

Validación de un ensayo inmunoenzimático tipo ELISA para cuantificar niveles de antitoxina diftérica en suero humano / Validation of an ELISA-type immune-enzymatic test to quantify levels of diphtheria antitoxin in human serum

Introducción: La difteria aún persiste en numerosos países. En Cuba, estudios realizados en diferentes grupos etarios han demostrado que existen niveles no protectores de antitoxina diftérica en la población, por lo que es necesario contar con métodos que permitan la estimación serológica de la inmunidad poblacional. La cuantificación de anticuerpos contra antígenos vacunales como la toxina diftérica es además un método útil, rápido y económico para evaluar la respuesta inmune. Objetivo: Validar un ensayo inmunoenzimático tipo ELISA para cuantificar los niveles de antitoxina diftérica en suero humano. Material y Método: Se realizó un estudio experimental de desarrollo tecnológico, en el cual se determinaron los valores óptimos de las variables que influyen en el resultado de un ensayo inmunoenzimático heterogéneo indirecto para la cuantificación de antitoxina diftérica, desarrollado en el laboratorio de Inmunología del Centro Nacional de Genética Médica de Cuba. La curva de calibración se evaluó contra el estándar de la OMS (Diphtheria Antitoxin Human Serum 00/496). Se realizó la validación analítica del método estandarizado. Resultados: Los coeficientes de variación intraensayo e interensayo fueron inferiores a 10 por ciento y 20 por ciento, respectivamente. En la exactitud y selectividad se encontraron valores de recobrado entre 90 y 110 por ciento. El paralelismo entre la curva estándar y las muestras estudiadas presentó un coeficiente de variación menor o igual a 10 por ciento. El límite de cuantificación fue 0,015 UI/mL y el de detección 0,0039 UI/mL. Conclusiones: El resultado obtenido en la precisión, exactitud y selectividad del ensayo inmunoenzimático tipo ELISA desarrollado demostró que puede ser utilizado en la práctica clínica para cuantificar los valores de antitoxina diftérica en suero humano(AU)

Introduction: Diphtheria still persists in many countries. In Cuba, studies conducted in different age groups have demonstrated that there are non-protective levels of diphtheria antitoxin in the population, so it is necessary to have methods that allow the serologic survey of population immunity. The quantification of antibodies against vaccine antigens such as diphtheria toxin is also a useful, rapid and economic method to evaluate the immune response. Objective: To validate an ELISA-type immune-enzymatic test to quantify the levels of diphtheria antitoxin in human serum. Material and Method: An experimental study of technological development was carried out in the Immunology Laboratory of the National Medical Genetics Center, Havana, Cuba. The optimal values ​​of the variables that influence on the result of the indirect heterogeneous immune-enzymatic test for the quantification of diphtheria antitoxin were determined. The calibration curve obtained was evaluated against the WHO standard (Diphtheria Antitoxin Human Serum 00/496). The analytical validation of the standardized method was performed. Results: The intra-assay and inter-assay coefficients of variation were less than 10 percent and 20 percent, respectively. Recovery values ​​between 90 and 110% were found in accuracy and selectivity. The parallelism between the standard curve and the samples studied showed a coefficient of variation lower or equal to 10 percent. The limit of quantification was 0,015 IU/mL and the one of detection was 0,0039 IU/mL. Conclusions: The result obtained in the precision, accuracy and selectivity of the ELISA-type immune-enzymatic test developed and validated in the National Medical Genetics Center demonstrated that it can be used in the clinical practice to quantify the values ​​of diphtheria antitoxin in human serum(AU)

Chinese expert consensus on tetanus immunization / 中华外科杂志

Tetanus is an acute specific infection caused by obligate anaerobes, which is still a serious public health problem. Tetanus bacterium is an obligate anaerobic bacterium, widely distributed in nature, which can exist in dust, soil, human or animal excrement. The bacteria invade the body primarily through the skin or mucosal wounds, and most commonly in trauma and burn patients, unclean newborns, and unsafe surgical instruments. Exotoxin produced by tetanus bacteria can cause temporary changes in the central nervous system, manifested as systemic skeletal muscle persistence and paroxysmal spasm, severe cases of laryngospasm, asphyxia, lung infections and organ failure, which is a very serious and potentially fatal disease. This article is an expert consensus on the tetanus immunologic defense, aiming to aid the clinical decision making after open injury. According to epidemiological investigation of tetanus, types of injured population, wound exposure and misunderstandings of immunologic defense, the key measures to prevent tetanus are good wound management and immunization. This statement describes a preventive framework of tetanus immunization, including the tetanus immunization programs of infants, pregnant women, potentially high-risk population, immunodeficiency patients and children born to HIV-infected mothers. This consensus only provides academic guidance, the treatment of the patient must be based on the prevailing medical conditions.

Functions of bacterial Toxin-Antitoxin systems / 生物工程学报

TA (Toxin-Antitoxin) systems are widely spread in chromosomes and plasmids of bacteria and archaea. These systems consist of two co-expression genes, encoding stable toxin and sensitive antitoxin, respectively. The toxicity of toxins usually inhibits bacterial growth and antitoxins can neutralize the toxins. Interaction between them would regulate the growth state of bacteria precisely. According to the composition of TA and nature of antitoxin, six types of TA have been found. The role of these TA systems in bacteria has been a hot research topic in recent years. Now, the research status on functions of bacterial TA is reviewed.