Microbial biofilm formation creates a persistent and resistant environment in which microorganisms can survive, contributing to antibiotic resistance and chronic inflammatory diseases. Increasingly, biofilms are caused by multi-drug resistant microorganisms, which, coupled with a diminishing supply of effective antibiotics, is driving the search for new antibiotic therapies. In this respect, antimicrobial peptides (AMPs) are short, hydrophobic, and amphipathic peptides that show activity against multidrug-resistant bacteria and biofilm formation. They also possess broad-spectrum activity and diverse mechanisms of action. In this comprehensive review, 150 publications (from January 2020 to September 2023) were collected and categorized using the search terms \'polypeptide antibiotic agent\', \'antimicrobial peptide\', and \'biofilm\'. During this period, a wide range of natural and synthetic AMPs were studied, of which LL-37, polymyxin B, GH12, and Nisin were the most frequently cited. Furthermore, although many microbes were studied, Staphylococcus aureus and Pseudomonas aeruginosa were the most popular. Publications also considered AMP combinations and the potential role of AMP delivery systems in increasing the efficacy of AMPs, including nanoparticle delivery. Relatively few publications focused on AMP resistance. This comprehensive review informs and guides researchers about the latest developments in AMP research, presenting promising evidence of the role of AMPs as effective antimicrobial agents.

Protozoa is a group of microorganisms that cause neglected tropical diseases, such as malaria, Chagas disease, and Leishmaniasis. Due to the growing demand for new therapeutic agents, antimicrobial peptides (AMPs) have gained attention for antiprotozoal action. A systematic literature review described the current scenario of plant and animal AMPs with action antiprotozoal. The terms \"antimicrobial peptides\", \"plant\", and \"animal\" combined with the names of the etiological agents were used in the search. Boolean and Operator were used to connect the terms. The search found 4,825 articles. However, 79 articles were excluded because they were duplicates, and 4,627 were excluded based on title and abstract. Therefore, 119 were evaluated and included here. Of these, the use of antimicrobial peptides of animal origin was predominant. Still, the works with plant peptides focused on the genus Leishmania. Only antimicrobial peptides of animal origin were described for the other genera of protozoa (Toxoplasma spp, Trypanosoma spp, Plasmodium spp). Antimicrobial peptides are an excellent option as a pharmacological tool to fight these infections due to their aggregation and extravasation of cellular content through the formation of pores in the cell membrane of these microorganisms.

Parasitic nematodes infect a variety of organisms including insects and vertebrates. To survive, they evade host immune responses to cause morbidity and mortality. Despite the vast clinical knowledge regarding nematode infections and their biological makeup, molecular understanding of the interactions between host and parasite remains poorly understood. The utilization of model systems has thus been employed to help elucidate the molecular interactions of the host immune response during parasitic nematode infection. Using model systems, it has been well established that parasitic nematodes evade host immunity by releasing excretory/secretory proteins (ESPs), which are involved in immunomodulation. Model systems have enabled researchers to characterize further the underlying mechanisms ESPs use to facilitate evasion and modulation of the host immune response. This review assessed notable ESPs from parasitic nematodes that infect vertebrates or insects and have been studied in mechanistic detail. Being able to characterize how ESPs affect the immune systems of hosts on a molecular level increases our understanding of host-parasite interactions and could lead to the identification of novel therapeutic targets and important molecular pathways.

The emergence of antibiotic-resistant bacteria has become a significant and ever-increasing threat to global public health, increasing both morbidity and mortality rates, and the financial burden on health services. Infection by drug-resistant bacteria is anticipated to contribute to the demise of almost 10 million people by the year 2050 unless a competent and effective response is devised to engage with this issue. The emergence and spread of resistance are commonly caused by the excessive or inappropriate use of antibiotics and substandard pharmaceuticals. It arises when pathogens adapt to different conditions and develop self-defence mechanisms. Currently, novel antimicrobial peptides (AMPs) have been reported to be the sole cure for some clinical cases of infectious diseases such as sepsis and skin infections, although these agents may, on occasion, require administration together with an adjunctive low-dose antibiotic. Although AMPs are a promising alternative form of anti-microbial therapy and easily applied in the medical sector, they still have limitations that should not be taken lightly. Hence, this review explores the characteristics, advantages and disadvantages of AMPs for their potential in treating antibiotic-resistant pathogens.

Antimicrobial peptides (AMPs) are a group of oligopeptides found in most multicellular organisms with a capacity for rapid and nonspecific destruction of pathogens. The action of destroying pathogens is associated with a strong proinflammatory activity, stimulating the secretion of cytokines, chemokines, growth factors but also chemotaxis, the activation of dendritic cells and involving adaptive immunity also. The action of AMPs fits perfectly into the characteristics of innate immunity which makes these peptides candidates to be considered as an important element of this type of immunity. It has been shown that AMPs are involved in a number of cellular processes such as: differentiation, proliferation, maturation, thus widening the degree of involvement of these peptides in the pathogenesis of chronic inflammatory diseases. In psoriasis, AMPs act both as a pro-inflammatory and chemotaxis factor and through the cathelicidin (LL-37)/dc DNA complex as a possible autoantigen for T cells, triggering an autoimmune response, activating the Th17/IL23 axis and maintaining the inflammatory process. Thus, many arguments are accumulated to consider that innate immunity through AMPs is an important link in the pathogenesis of psoriasis. Moreover, the action of antimicrobial peptides in psoriasis is almost entirely characteristic for the general mode of action of innate immunity.