Activities of four frog skin-derived antimicrobial peptides (temporin-1DRa, temporin-1Va and the melittin-related peptides AR-23 and RV-23) against anaerobic bacteria
ABSTRACT The activities of two antimicrobial peptides belonging to the temporin family (temporin-1DRa from Rana draytonii and temporin-1Va from Rana virgatipes) and two peptides with structural similarity to the bee venom peptide melittin (AR-23 from Rana tagoi and RV-23 from R. draytonii) were evaluated against a range of reference strains and clinical isolates of anaerobic bacteria. These peptides were selected because they show broad-spectrum growth inhibitory activity against reference strains of several medically important aerobic microorganisms and against clinical isolates of methicillin-resistant Staphylococcus aureus. All peptides showed relatively high potency (minimum inhibitory concentration (MIC) </=25 microM) against the Gram-positive bacilli Propionibacterium acnes and Clostridium tertium and the Gram-positive cocci Peptostreptococcus anaerobius. Activity was lower and more variable against Clostridium septicum, Clostridium perfringens and Peptostreptococcus asaccharolyticus. Growth of the Gram-negative bacilli Bacteroides fragilis and Fusobacterium spp. was poorly inhibited, but all the peptides were active (MIC</=25 microM) against Prevotella melaninogenica. The clinical utility of the melittin-related peptides is limited by their toxicities, but temporin-1DRa and temporin-1Va have relatively low haemolytic activity against human erythrocytes and so represent candidates for drug development, particularly for topical therapy of infected surface lesions.
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- "In vitro growth inhibition assays have been widely used to determine the effectiveness of skin secretions and isolated peptides against a range of different microorganisms (Rollins- Smith et al., 2002a; Urban et al., 2007; Mangoni et al., 2008; Sheafor et al., 2008). The skin secretions of Leiopelmatid species contain a variety of novel peptides and compounds with anti-chytrid properties, which are in the process of being identified (S. "
ABSTRACT: Over the past few decades, amphibian populations have undergone drastic declines on a global scale. Declines in many anuran populations have been linked to the emergent skin-invasive amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Antimicrobial peptides in the skin are thought to act as important components of the innate immune system that may protect some species from infectious diseases. The four archaic species of Leiopelma in New Zealand are of great conservation concern and a severe population crash of Leiopelma archeyi between 1996 and 2001 has been tentatively linked with the outbreak of Bd. Here, we investigated the in vitro activity of skin secretions of six frog species in New Zealand against Bd zoospore growth. The activity of skin secretions produced by frogs in the wild varied significantly between species, with those of Le. archeyi being the most active. The skin secretions of native Leiopelmatid species showed greater Bd zoospore inhibition (31.0–71.9%) than the naturalized Litoria species (17.4–18.2%). Leiopelma archeyi has the most active peptides, even though it is the only native species with known susceptibility to Bd infections.Animal Conservation 11/2010; 13(s1):44 - 52. DOI:10.1111/j.1469-1795.2009.00340.x · 2.52 Impact Factor
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ABSTRACT: AddendumDr Roberto Romero did not participate in the drafting of the text, nor did he review, approve or endorse this manuscript. This article is not approved or endorsed by Perinatology Research Branch, the National Institute of Child Health and Human Development (NICHD), the National Institutes of Health (NIH), or the Department of Health and Human Services of the USA.Ultrasound in Obstetrics and Gynecology 04/2007; 29(4):481-2. DOI:10.1002/uog.4017 · 3.14 Impact Factor
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ABSTRACT: Temporin-SHa and temporin-SHc are 13 residue long antimicrobial peptides from frog skin that have similar sequences but differ markedly in their membrane-damaging properties. Temporin-SHa contains a single basic lysine residue and has a unique antimicrobial spectrum of action among temporins, being very potent against Gram-positive and Gram-negative bacteria, yeasts, fungi, and protozoa. Temporin-SHc, which contains a single basic histidine residue, is inactive against Gram-negative bacteria, has a reduced efficacy against Gram-positive bacteria, but is still active against yeasts and fungi. Temporin-SHb, with no basic residue, has no antimicrobial activity. The three-dimensional structures of the peptides bound to SDS micelles were analyzed by CD and NMR spectroscopy combined with restrained molecular dynamics calculations. The peptides adopt well-defined amphipathic alpha-helical structures extending from residue 3 to residue 12, when bound to SDS micelles. The structures are stabilized by extensive interactions between aliphatic and aromatic side chains on the nonpolar face. Relaxation enhancements caused by paramagnetic probes showed that the peptides adopt nearly parallel orientations to the micelle surface and do not deeply penetrate into the micelle. The interaction of the peptides with model membranes was investigated by differential scanning calorimetry on anionic and zwitterionic multilamellar vesicles and membrane-permeabilization assays on calcein-loaded large unilamellar vesicles. Calorimetric data indicated that both temporin-SHa and -SHc reside at the hydrocarbon core-water interface of the anionic lipid bilayer but interact with anionic bilayers in a very different manner. This suggests that the charge-induced activity of temporins-SH for bacterial cells is due to changes in the membrane-disturbing mechanism of the bound peptides.Biochemistry 10/2008; 47(40):10513-25. DOI:10.1021/bi8006884 · 3.01 Impact Factor