Antimicrobial Peptides Pom-1 and Pom-2 from Pomacea poeyana Are Active against Candidaauris, C. parapsilosis and C. albicans Biofilms

Abstract

Recently two peptides isolated from the Cuban freshwater snail Pomacea poeyana (Pilsbry, 1927) were described to have antimicrobial activity against bacterial pathogens. Here we show considerable activities of Pom-1 and Pom-2 to reduce the viability of C. albicans, C. parapsilosis and the less common species C. auris measured as the decrease of metabolic activity in the resazurin reduction assay for planktonic cells. Although these activities were low, Pom-1 and Pom-2 turned out to be highly potent inhibitors of biofilm formation for the three Candida species tested. Whereas Pom-1 was slightly more active against C. albicans and C. parapsilosis as representatives of the more common Candida species Pom-2 showed no preference and was fully active also against biofilms of the more uncommon species C. auris. Pom-1 and Pom-2 may represent promising lead structures for the development of a classical peptide optimization strategy with the realistic aim to further increase antibiofilm properties and other pharmacologic parameters and to generate finally the first antifungal drug with a pronounced dedication against Candida biofilms.

Increased Activities against Biofilms of the Pathogenic Yeast Candida albicans of Optimized Pom-1 Derivatives

“…Candida albicans (ATCC 90028) was sourced from the IPK Medical Mycology Laboratory and cultured on Sabouraud dextrose agar (40 g/L glucose, 10 g/L peptone, 20 g/L agar, pH 5.6). For the suspension cultures, 10 mL of RPMI-1640 medium supplemented with L-glutamine (Thermo Fisher Scientific (Waltham, MA, USA)) was inoculated with a single colony in a 100-mL Erlenmayer flask and was grown at 37 °C with orbital shaking at 150 rpm for 16 h [21].…”

“…The Pom-1 wildtype peptide showed a significant activity against C. albicans biofilms [21]. In order to evaluate the potential of the novel Pom-1A-F peptides, the well established crystal violet assay for microbial cultures in microtiter plates was performed to quantify the biomass formed.…”

“…These peptides have been shown to be effective not only against the pathogenic bacteria Pseudomonas aeruginosa, Klipsella pneumonia, and Listeria monocytogenes [20], but also with low activity against planktonic and high activity cells of yeasts of the genus Candida. Pom-1 was used for optimization as it exhibited a higher antimicrobial activity than Pom-2 [21]. This peptide is a 34-amino acid-long fragment of Closticin 574, a bacteriocin with a known antibacterial activity against several Clostridium spp.…”

Combination of Six Individual Derivatives of the Pom-1 Antibiofilm Peptide Doubles Their Efficacy against Invasive and Multi-Resistant Clinical Isolates of the Pathogenic Yeast Candida albicans

“…Therefore, after adhesion of the yeast cells to a surface, proliferation and production of an extracellular matrix occurs, which leads to the formation of microcolonies. Detachment of these biofilm cells results in the formation of new biofilms, thus contributing to the further spread of the infectious disease ( Figure 1 ) [ 23 , 24 ]. The cells acquire a significantly higher resistance to chemical and physical stress and increase the morbidity and mortality of infected patients after the formation of such biofilms and are a major cause of long-term candidemia and chronic infections of several pathogens [ 25 , 26 , 27 ].…”

“…The recently investigated AMPs Pom-1 and Pom-2 originate from this class of organisms and were first isolated from the Cuban freshwater snail Pomacea poeyana and then chemically resynthesized. These peptides showed antimicrobial activity not only against the bacteria Pseudomonas aeruginosa , Klebsiella pneumoniae , and Listeria monocytogenes , but also against planktonic cells and biofilm formation of various Candida species, and in addition, low cytotoxicity against human macrophages was observed [ 24 , 61 ]. Based on their antibiofilm mechanism of action, these and other snail-derived [ 24 , 62 , 63 , 64 ] peptides have been discussed to act not like conventional membrane-active peptides by forming pores, but by binding to the pathogenic membrane and thus preventing cell–cell and/or cell–substrate interactions, resulting in the prevention of biofilms [ 61 ].…”