scholarly journals A role for antimicrobial peptides in intestinal microsporidiosis

Parasitology ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 175-181 ◽  
Author(s):  
G. J. LEITCH ◽  
C. CEBALLOS
Keyword(s):  
Antimicrobial Peptides ◽  
Spore Germination ◽  
Parasite Species ◽  
Clinical Isolates ◽  
Cell Infection ◽  
Insect Parasite ◽  
Encephalitozoon Intestinalis ◽  
Microsporidia Species ◽  
Intestinal Microsporidiosis

SUMMARYClinical isolates from 3 microsporidia species,Encephalitozoon intestinalisandEncephalitozoon hellem, and the insect parasiteAnncaliia(Brachiola, Nosema) algerae, were used in spore germination and enterocyte-like (C2Bbe1) cell infection assays to determine the effect of a panel of antimicrobial peptides. Spores were incubated with lactoferrin (Lf), lysozyme (Lz), and human beta defensin 2 (HBD2), human alpha defensin 5 (HD5), and human alpha defensin 1 (HNP1), alone and in combination with Lz, prior to germination. Of theEncephalitozoonspecies onlyE. hellemspore germination was inhibited by HNP1, whileA. algeraespore germination was inhibited by Lf, HBD2, HD5 and HNP1, although HBD2 and HD5 inhibition required the presence of Lz. The effects of HBD2 and HD5 on microsporidia enterocyte infection paralleled their effects on spore germination. Lysozyme alone only inhibited infection withA. algerae, while Lf inhibited infection byE. intestinalisandA. algerae. HNP1 significantly reduced enterocyte infection by all 3 parasite species and a combination of Lf, Lz and HNP1 caused a further reduced infection withA. algerae. These data suggest that intestinal antimicrobial peptides contribute to the defence of the intestine against infection by luminal microsporidia spores and may partially determine which parasite species infects the intestine.

scholarly journals Effects of nifedipine, metronidazole, and nitric oxide donors on spore germination and cell culture infection of the microsporidia Encephalitozoon hellem and Encephalitozoon intestinalis.

1996 ◽  
Vol 40 (1) ◽  
pp. 179-185 ◽  
Author(s):  
Q He ◽  
G J Leitch ◽  
G S Visvesvara ◽  
S Wallace
Keyword(s):  
Nitric Oxide ◽  
Spore Germination ◽  
Cultured Cells ◽  
Inhibitory Effect ◽  
Parasite Development ◽  
Cell Infection ◽  
Combination Drug ◽  
No Donors ◽  
Cultured Cell ◽  
Encephalitozoon Intestinalis

Two species of microsporidia, Encephalitozoon hellem and Encephalitozoon intestinalis, were isolated from AIDS patients and cultured in green monkey kidney cells. A spore germination assay and a cultured-cell infection assay were used to test the efficacy of candidate antiparasitic agents. The calcium channel blocker nifedipine, metronidazole, and two nitric oxide (NO) donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside, were tested in the two assays. Nifedipine (10(-8) M) significantly inhibited E. hellem spore germination in three of four germination media. Metronidazole (10(-5) M) inhibited germination weakly and significantly inhibited E. intestinalis germination in a single germination medium. The inhibitory effect of nifedipine and metronidazole used together was greater than the sum of the effects of the drugs used alone in all E. hellem germination assays. The NO donors also inhibited spore germination. The inhibitory effect of nifedipine and metronidazole could be reversed by washing the spores, while that of the NO donors was not reversible. In early cultured-cell infections, both nifedipine (10(-8) M) and metronidazole (10(-5) M) significantly reduced the number of cells being infected. As the infection spread, these agents were less effective. Some inhibition of the spread of the infection was also demonstrated with the NO donors at a concentration (10(-5) M) not obviously toxic to the cultured cells. These data suggest that combination drug therapy targeting spore germination and intracellular parasite development is promising.

scholarly journals Hevein-Like Antimicrobial Peptides Wamps: Structure–Function Relationship in Antifungal Activity and Sensitization of Plant Pathogenic Fungi to Tebuconazole by WAMP-2-Derived Peptides

2020 ◽  
Vol 21 (21) ◽  
pp. 7912 ◽  
Author(s):  
Tatyana Odintsova ◽  
Larisa Shcherbakova ◽  
Marina Slezina ◽  
Tatyana Pasechnik ◽  
Bakhyt Kartabaeva ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Structure Function ◽  
Spore Germination ◽  
Pathogenic Fungi ◽  
Plant Pathogenic Fungi ◽  
Fungal Cell ◽  
Structure Function Relationship ◽  
Function Relationship

Hevein-like antimicrobial peptides (AMPs) comprise a family of plant AMPs with antifungal activity, which harbor a chitin-binding site involved in interactions with chitin of fungal cell walls. However, the mode of action of hevein-like AMPs remains poorly understood. This work reports the structure–function relationship in WAMPs—hevein-like AMPs found in wheat (Triticum kiharae Dorof. et Migush.) and later in other Poaceae species. The effect of WAMP homologues differing at position 34 and the antifungal activity of peptide fragments derived from the central, N- and C-terminal regions of one of the WAMPs, namely WAMP-2, on spore germination of different plant pathogenic fungi were studied. Additionally, the ability of WAMP-2-derived peptides to potentiate the fungicidal effect of tebuconazole, one of the triazole fungicides, towards five cereal-damaging fungi was explored in vitro by co-application of WAMP-2 fragments with Folicur® EC 250 (25% tebuconazole). The antifungal activity of WAMP homologues and WAMP-2-derived peptides varied depending on the fungus, suggesting multiple modes of action for WAMPs against diverse pathogens. Folicur® combined with the WAMP-2 fragments inhibited the spore germination at a much greater level than the fungicide alone, and the type of interactions was either synergistic or additive, depending on the target fungus and concentration combinations of the compounds. The combinations, which resulted in synergism and drastically enhanced the sensitivity to tebuconazole, were revealed for all five fungi by a checkerboard assay. The ability to synergistically interact with a fungicide and exacerbate the sensitivity of plant pathogenic fungi to a commercial antifungal agent is a novel and previously uninvestigated property of hevein-like AMPs.

scholarly journals Complete Genome Sequences of Two Mutacin-Producing Streptococcus mutans Strains, T8 and UA140

2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Indranil Biswas
Keyword(s):  
Antimicrobial Peptides ◽  
Streptococcus Mutans ◽  
Genome Sequence ◽  
Complete Genome ◽  
Clinical Isolates ◽  
Sequence Information ◽  
Genome Sequences ◽  
Content Type ◽  
Genome Sequence Information

ABSTRACT Streptococcus mutans is known to produce various antimicrobial peptides called mutacins. Two clinical isolates, T8 and UA140, are well characterized regarding their mutacin production, but genome sequence information was previously unavailable. Complete genome sequences of these two mutacin-producing strains are reported here.

scholarly journals Enterovirus Capsid Interactions with Decay-Accelerating Factor Mediate Lytic Cell Infection

2004 ◽  
Vol 78 (3) ◽  
pp. 1431-1439 ◽  
Author(s):  
Nicole G. Newcombe ◽  
E. Susanne Johansson ◽  
Gough Au ◽  
A. Michael Lindberg ◽  
Richard D. Barry ◽  
...  
Keyword(s):  
Clinical Isolates ◽  
Intercellular Adhesion Molecule ◽  
Cross Linking ◽  
Target Cells ◽  
Cellular Receptor ◽  
Intercellular Adhesion Molecule 1 ◽  
Cell Infection ◽  
Decay Accelerating Factor ◽  
Receptor Usage ◽  
Cellular Attachment

ABSTRACT The cellular receptor usage of numerous human enteroviruses can differ significantly between low-cell-culture-passaged clinical isolates and highly laboratory-passaged prototype strains. The prototype strain of coxsackievirus A21 (CVA21) displays a dual-receptor specificity as determined with a receptor complex consisting of decay-accelerating factor (DAF) and intercellular adhesion molecule 1 (ICAM-1). In this study, the cellular receptor interactions of low-cell-passage CVA21 clinical isolates with respect to their interactions with cell surface-expressed DAF and ICAM-1 were compared to those of the CVA21 prototype (Kuykendall) strain. Dual-receptor usage of DAF and ICAM-1 by CVA21 clinical isolates was confirmed by cell transfection and radiolabeled binding assays. The cellular attachment of clinical and prototype CVA21 strains to cells that coexpressed DAF and ICAM-1 was not additive compared to the viral binding to cells expressing one or other receptor. In fact, the binding data suggest there is an inhibition of CVA21 cellular attachment in environments where high-level coexpression of both DAF and ICAM-1 occurs. Antibody cross-linking of DAF rendered cells susceptible to lytic infection by the CVA21 clinical isolates. In a novel finding, three clinical isolates could, to various degrees, infect and lyse DAF-expressing cells in the absence of DAF-antibody cross-linking and ICAM-1 expression. Sequence analysis of the P1 region of clinical and prototype virus genomes identified a number of coding changes that may contribute to the observed enhanced DAF usage phenotype of the clinical CVA21 isolates. None of the amino acid changes was located in the previously postulated ICAM-1 footprint, a receptor-binding environment that was conserved on the capsid surface of all CVA21 clinical isolates. Taken together, the data suggest that community-circulating strains of CVA21 can infect target cells expressing either ICAM-1 or DAF alone and that such interactions extend tissue tropism and impact directly on viral pathogenesis.

Olesicampe monticola (Hedwig) (Hymenoptera: Ichneumonidae) redescribed together with notes on its biology as a parasite of Cephalcia lariciphila (Wachtl) (Hymenoptera: Pamphiliidae)

1985 ◽  
Vol 75 (2) ◽  
pp. 267-274 ◽  
Author(s):  
D. J. Billany ◽  
T. G. Winter ◽  
I. D. Gauld
Keyword(s):  
Parasite Species ◽  
Insect Parasite ◽  
South Wales ◽  
The Status ◽  
Cephalcia Lariciphila

AbstractThe sawfly Cephalcia lariciphila (Wachtl) is a pest of larch (Larix spp.) that has recently become widespread in Britain. Before taking measures to control the sawfly the status of parasites in the infestations was investigated. The only insect parasite species found was the ichneumonid Olesicampe monticola (Hedwig), which is new to Britain. As this insect is taxonomically so poorly known it is redescribed from specimens collected in South Wales. The preliminary biological observations show O. monticola to be well-adapted to its host and that it can significantly reduce an infestation.

scholarly journals Role of Sulfated Glycans in Adherence of the Microsporidian Encephalitozoon intestinalis to Host Cells In Vitro

2005 ◽  
Vol 73 (2) ◽  
pp. 841-848 ◽  
Author(s):  
J. Russell Hayman ◽  
Timothy R. Southern ◽  
Theodore E. Nash
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Mutant Cell ◽  
Host Cells ◽  
Target Cells ◽  
Cell Infection ◽  
Encephalitozoon Intestinalis ◽  
Successful Infection ◽  
Host Cell Surface ◽  
Spore Adherence

ABSTRACT Microsporidia are obligate intracellular opportunistic protists that infect a wide variety of animals, including humans, via environmentally resistant spores. Infection requires that spores be in close proximity to host cells so that the hollow polar tube can pierce the cell membrane and inject the spore contents into the cell cytoplasm. Like other eukaryotic microbes, microsporidia may use specific mechanisms for adherence in order to achieve target cell proximity and increase the likelihood of successful infection. Our data show that Encephalitozoon intestinalis exploits sulfated glycans such as the cell surface glycosaminoglycans (GAGs) in selection of and attachment to host cells. When exogenous sulfated glycans are used as inhibitors in spore adherence assays, E. intestinalis spore adherence is reduced by as much as 88%. However, there is no inhibition when nonsulfated glycans are used, suggesting that E. intestinalis spores utilize sulfated host cell glycans in adherence. These studies were confirmed by exposure of host cells to xylopyranoside, which limits host cell surface GAGs, and sodium chlorate, which decreases surface sulfation. Spore adherence studies with CHO mutant cell lines that are deficient in either surface GAGs or surface heparan sulfate also confirmed the necessity of sulfated glycans. Furthermore, when spore adherence is inhibited, host cell infection is reduced, indicating a direct association between spore adherence and infectivity. These data show that E. intestinalis specifically adheres to target cells by way of sulfated host cell surface GAGs and that this mechanism serves to enhance infectivity.

scholarly journals Engineered Cationic Antimicrobial Peptides To Overcome Multidrug Resistance by ESKAPE Pathogens

2014 ◽  
Vol 59 (2) ◽  
pp. 1329-1333 ◽  
Author(s):  
Berthony Deslouches ◽  
Jonathan D. Steckbeck ◽  
Jodi K. Craigo ◽  
Yohei Doi ◽  
Jane L. Burns ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Peptides ◽  
De Novo ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Resistant Bacteria ◽  
Clinical Settings ◽  
Eskape Pathogens ◽  
Antibiotic Peptides

ABSTRACTMultidrug resistance constitutes a threat to the medical achievements of the last 50 years. In this study, we demonstrated the abilities of twode novoengineered cationic antibiotic peptides (eCAPs), WLBU2 and WR12, to overcome resistance from 142 clinical isolates representing the most common multidrug-resistant (MDR) pathogens and to display a lower propensity to select for resistant bacteriain vitrocompared to that with colistin and LL37. The results warrant an exploration of eCAPs for use in clinical settings.

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