Maltose Induced Expression of Cecropin AD by SUMO Technology in Bacillus subtilis WB800N

Construction and bacteriostatic effect analyses of a recombinant thermostable Newcastle disease virus expressing cecropin AD

Cecropin AD (CAD), a hybrid antimicrobial peptide composed of the first 11 residues of cecropin A and last 26 residues of cecropin D, is a promising antibiotic candidate. Therefore, an efficient and convenient method for producing CAD is necessary for commercial applications. The Newcastle disease virus (NDV) has been widely used as a platform for gene delivery and exogenous protein expression. In this study, we constructed a recombinant NDV that expresses CAD. To obtain high expression of the CAD peptide, tandem repeats of the cad gene were inserted into the genomes of the thermostable NDV strain TS09-C using reverse genetic technology. The thermostable recombinant NDV, namely rTS-CAD3, showed thermostability and growth kinetics similar to those of their parental strain. A bacteriostatic test showed that rTS-CAD3 inhibited Staphylococcus aureus (gram-positive bacteria) and Escherichia coli (gram-negative bacteria) in vitro. We further determined the bacteriostatic effects of rTS-CAD3 expressed CAD against S. aureus in skin wound infections. The results showed that rTS-CAD3 subcutaneously injection improved wound healing and reduced S. aureus decolonization. In summary, our results indicate that the rTS-CAD3 expressing CAD peptide is a potent antimicrobial agent against S. aureus and E. coli and may be applied to accelerate wound healing in farm animals.

Advances in Artificially Designed Antibacterial Active Antimicrobial Peptides

Antibacterial resistance has emerged as a significant global concern, necessitating the urgent development of new antibacterial drugs. Antimicrobial peptides (AMPs) are naturally occurring peptides found in various organisms. Coupled with a wide range of antibacterial activity, AMPs are less likely to develop drug resistance and can act as potential agents for treating bacterial infections. However, their characteristics, such as low activity, instability, and toxicity, hinder their clinical application. Consequently, researchers are inclined towards artificial design and optimization based on natural AMPs. This review discusses the research advancements in the field of artificial designing and optimization of various AMPs. Moreover, it highlights various strategies for designing such peptides, aiming to provide valuable insights for developing novel AMPs.

The Efficacy of Cecropin Against Multidrug-Resistant Bacteria Is Linked to the Destabilization of Outer Membrane Structure LPS of Gram-Negative Bacteria

The escalating prevalence of antibiotic-resistant bacteria has emerged as a formidable threat to global health, and the quest for alternative antimicrobial agents is imperative. Cecropins, a class of antimicrobial peptides (AMPs), have garnered attention due to their potent bactericidal properties. This investigation delves into the antibacterial prowess of Cecropin A (CA) and Cecropin AD (CAD), showcasing their robust activity against Gram-negative bacteria, inclusive of multidrug-resistant bacteria. The bactericidal efficacy of CA and CAD is characterized by a dose-responsive paradigm, affirming their potential as therapeutic agents. These peptides exhibit minimal cytotoxicity and hemolytic effects, underscoring their safety profile. Advanced experimentation has elucidated that cecropins could disrupt the outer bacterial membrane, targeting lipid A, a pivotal constituent of the lipopolysaccharides (LPS) in the outer membrane as their antimicrobial bullseye. The affinity of cecropins for LPS and their antimicrobial action underscore the therapeutic potential of these peptides in targeting Gram-negative bacterial infections. These insights accentuate the promise of cecropins as viable "antibiotic substitutes," paving the path for their expanded application in combating antibiotic resistance.

Strategies for improving antimicrobial peptide production

Antimicrobial peptides (AMPs) found in a wide range of animal, insect, and plant species are host defense peptides forming an integral part of their innate immunity. Although the exact mode of action of some AMPs is yet to be deciphered, many exhibit membrane lytic activity or interact with intracellular targets. The ever-growing threat of antibiotic resistance has brought attention to research on AMPs to enhance their clinical use as a therapeutic alternative. AMPs have several advantages over antibiotics such as broad range of antimicrobial activities including anti-fungal, anti-viral and anti-bacterial, and have not reported to contribute to resistance development. Despite the numerous studies to develop efficient production methods for AMPs, limitations including low yield, degradation, and loss of activity persists in many recombinant approaches. In this review, we outline available approaches for AMP production and various expression systems used to achieve higher yield and quality. In addition, recent advances in recombinant strategies, suitable fusion protein partners, and other molecular engineering strategies for improved AMP production are surveyed.

The multifunctionality of expression systems in Bacillus subtilis: Emerging devices for the production of recombinant proteins

Bacillus subtilis is a successful host for producing recombinant proteins. Its GRAS (generally recognized as safe) status and its remarkable innate ability to absorb and incorporate exogenous DNA into its genome make this organism an ideal platform for the heterologous expression of bioactive substances. The factors that corroborate its value can be attributed to the scientific knowledge obtained from decades of study regarding its biology that has fostered the development of several genetic engineering strategies, such as the use of different plasmids, engineering of constitutive or double promoters, chemical inducers, systems of self-inducing expression with or without a secretion system that uses a signal peptide, and so on. Tools that enrich the technological arsenal of this expression platform improve the efficiency and reduce the costs of production of proteins of biotechnological importance. Therefore, this review aims to highlight the major advances involving recombinant expression systems developed in B. subtilis, thus sustaining the generation of knowledge and its application in future research. It was verified that this bacterium is a model in constant demand and studies of the expression of recombinant proteins on a large scale are increasing in number. As such, it represents a powerful bacterial host for academic research and industrial purposes.