Enhanced expression of recombinant beta toxin of Clostridium perfringens type B using a commercially available Escherichia coli strain

Immobilization of Clostridium perfringens type D in calcium alginate beads: toxin production mimics free cell culture

Background and Objectives

Cell-immobilization is used to maintain microbial culture to produce metabolites in repeated-batch or continuous fermentations, thereby reducing the time and resources spent on delivering mass production of microbe. The technique also enables shortening of the detoxification phase and the amount of formaldehyde required due to low incidence of viable bacteria in the extract.

Materials and Methods

A solution of sodium alginate containing Clostridium perfringens cells was dropped into stirring CaCl solution via a sterile syringe needle. Optimizations resulted in reasonably uniform beads containing C. perfringens. Beads were externally stabilized by poly L-lysine, followed by immersion in a solution of Na-alginate to coat them with a new layer of alginate forming an alginate-PLL-alginate cortex.

Results

This study proved successful in immobilizing C. perfringens cells inside uniform alginate microspheres. Cell loading and cell propagation inside the beads were measured. The cell loaded beads were cultivable in liquid media producing 550 minimum lethal doses per milliliter (MLD/ml) in a 72 h.

Conclusion

The research paved the way for further investigations to optimize and establish an efficient bacterial encapsulation method. Thus, it seems possible to produce toxins from beads engulfing C. perfringens on larger scales via repeated-batch or continuous fermentation processes.

Vaccination against pathogenic clostridia in animals: a review

Clostridium is a Gram-positive, rod-shaped, anaerobic, and spore-forming bacterium, which is found in the surrounding environments throughout the world. Clostridium species cause botulism, tetanus, enterotoxaemia, gas gangrene, necrotic enteritis, pseudomembranous colitis, blackleg, and black disease. Clostridium infection causes severe economic losses in livestock and poultry industries. Vaccination seems to be an effective way to control Clostridial diseases. This review discusses the toxins and vaccine development of the most common pathogenic Clostridium species in animals, including Clostridium perfringens, Clostridium novyi, Clostridium chauvoei, and Clostridium septicum. In this comprehensive study, we will review different kinds of clostridial toxins and the vaccines that are experimentally or practically available and will give a short description on each vaccine focusing on its applications, advantages, and disadvantages.

Molecular Cloning of a New Bi-Functional Fusion Protein of Clostridium perfringens Type A Alpha and Clostridium septicum Alpha Toxin Genes in E. coli

Background: A synthetic construct bi-functional protein fusion includes two protein domains, or proteins bind by a fragment. The synthetic construct is designed to achieve better characterize and new functionality. Therefore, having proper cells is essential for cloning fusion genes. Clostridium perfringens type A produces the alpha-toxin and can cause gas gangrene and gastrointestinal diseases. C. septicum produces the alpha-toxin and can cause non-traumatic and traumatic gas gangrene. Objectives: The current study aimed to investigate molecular cloning of a new bi-functional fusion protein of C. perfringens alpha (cpa) and C. septicum alpha (csa) toxin genes in E. coli TOP10. In silico analysis was used for the chimeric fusion protein structural prediction. Methods: To produce chimeric fusion protein, the alpha-alpha (α-α) fusion gene was designed according to nucleotide sequences of cpa (KY584046.1) and csa (JN793989.2) genes. Tertiary structural prediction and validation of the fusion protein were determined by online software. In the new synthetic construction, α-α fusion protein genes are bind via the linker AEAAAKEAAAKA. The linker was introduced between the two domains by fusion PCR. The synthetic fusion gene was cloned into the pUC57cloning vector and then transferred into the host cell. Results: Analysis of the chimeric protein fusion is showed using the I-TASSER server as C-score equal to -2.68 as well as Rampage software in order to confirm the geometrical model as a natural like protein. Also, 1.0% agarose gel electrophoresis of fusion PCR product and sequencing analysis revealed a DNA fragment length of 2346 bp. Screening gel electrophoresis showed 996 bp length, which the designed linker was contained in it. Gel electrophoresis of extracted and purified recombinant plasmid (pUC57/αα) showed that a pUC57/αα of 5056 bp. The digested recombinant pUC57/αα showed one 2.3 kb (our fusion gene) band and one 2.7 kb (pUC57) band. Conclusions: This study presented a new approach for the fusion of cpa and csa genes based on the fusion PCR strategy. According to the latest information, this is the first time that α-α fusion gene is designed and cloned into a suitable cloning vector.

Recombinant Alpha, Beta, and Epsilon Toxins of Clostridium perfringens: Production Strategies and Applications as Veterinary Vaccines

Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A-E) according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans. Alpha, beta, and epsilon toxins are the main causes of disease. Vaccinations that generate neutralizing antibodies are the most common prophylactic measures that are currently in use. These vaccines consist of toxoids that are obtained from C. perfringens cultures. Recombinant vaccines offer several advantages over conventional toxoids, especially in terms of the production process. As such, they are steadily gaining ground as a promising vaccination solution. This review discusses the main strategies that are currently used to produce recombinant vaccines containing alpha, beta, and epsilon toxins of C. perfringens, as well as the potential application of these molecules as vaccines for mammalian livestock animals.