The activity of diphtheria toxin in catalyzing transfer of the adenosine diphosphate ribose moiety of NAD+ into covalent linkage with the mammalian peptidyl transfer RNA translocation factor, transferase II, is dependent upon exposure of the toxin to thiols. The toxin is almost completely inactive when assayed in the absence of thiols, but may be maximally activated by treatment with 50 mM dith...

Chapter 1: Literature Review I. Allergic Responses II. Animal Allergy Models III. Cholera Toxin and Heat Labile Toxin Chapter 2: Cholera Toxin or Escherichia coli Heat Labile Toxin Subunit B and Mouse Peanut Allergy Model I. Abstract I

Botulinum toxin (BTA) is a bacterial-derived extract that can inhibit muscle contraction, acting directly on the absorption of acetylcholine. Thanks to this property, botulinum has been used in aesthetic and general medicine for several years. Nowadays, use being deepened address problem bruxism. In scoping review, results studies literature last 10 years were analyzed. Indeed, 12 reports (foun...

Staphylococcal alpha-toxin is an important virulence factor for Staphylococcus aureus to cause severe infections. In this study, we explored whether the toxoid of alpha-toxin may be utilized to block the toxicity of wild-type alpha-toxin. We created a series of H35A mutated alpha-toxin expression strains and revealed that the H35A mutation eliminates the activity of alpha-toxin using a human lu...

Objective(s): A newly-introduced protein toxin from a sea anemone, namely fragaceatoxin C is a protein with molecular weight of 20 kDa and pore-forming capability against cell membranes has recently grasped great attentions for its function. In this study, its coding sequence cloned as a fusion protein with His-tag for simple production and rapid purification. Materials and Methods: After PCR a...

Botulism is a serious paralytic disease caused by Clostridium botulinum toxin in foods. There are seven recognized serotypes of botulinum neurotoxins among which the principal prevalent types in humans include A, B and E. Infant botulism results from intestinal colonization and toxin production by C. botulinum spores in babies less than 1 year old. Honey is the most important food discriminated...

Background: The virulence of a pathogenic Vibrio cholerae is dependent on a discrete set of genetic determinants. In this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of V. cholerae. Methods: The antibiotic resistance profiles of the isolates were determined using standard disk diffusion assay. PCR assay was performed to analyze t...

Abstract Clostridioides difficile causes over 200,000 hospitalizations and 13,000 deaths annually in the United States. C. infects large intestine following perturbation of microbiome to cause pathology that ranges severity from diarrhea pseudomembranous colitis. Virulence factors Toxin A B are primarily drivers disease. These toxins damage epithelial barrier leading pathologic inflammation bac...

Bordetella pertussis adenylate cyclase (AC) toxin belongs to the RTX family of toxins but is the only member with a known catalytic domain. The principal pathophysiologic function of AC toxin appears to be rapid production of intracellular cyclic AMP (cAMP) by insertion of its catalytic domain into target cells (referred to as intoxication). Relative to other RTX toxins, AC toxin is weakly hemo...

Botulinum toxin is a highly potent oral and inhalation poison, which means that the toxin must have an efficient mechanism for penetration of epithelial barriers. To date, three models for toxin passage across epithelial barriers have been proposed: (i) the toxin itself undergoes binding and transcytosis; (ii) an auxiliary protein, HA35, transports toxin from the apical to the basal side of epi...