Waterborne protozoan pathogens.

Marshall, Marilyn M.; Naumovitz, Donna W.; Ortega, Ynés R.; Sterling, Charles R.

doi:10.1128/cmr.10.1.67-85.1997

Cited by 69 publications

(99 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Acanthamoebae are free-living amoebae, which are ubiquitous and have been isolated from a wide variety of habitats ranging from natural sources like soil, salt water, fresh water and dust, to anthropogenic habitats like tap water, air-conditioning units and sewage systems (Rodriguez-Zaragoza, 1994;Marshall et al, 1997). Acanthamoebae are important predators feeding on various organisms like bacteria and fungi and hence control microbial communities (Rodriguez-Zaragoza, 1994).…”

Section: Introductionmentioning

confidence: 99%

An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts

Heinz

Kolarov

Kästner

et al. 2007

Environmental Microbiology

View full text Add to dashboard Cite

SummaryAcanthamoebae are ubiquitous free-living amoebae and important predators of microbial communities. They frequently contain obligate intracellular bacterial symbionts, which show a worldwide distribution. All Acanthamoeba spp. described so far harboured no or only a single specific endosymbiont phylotype, and in some cases evidence for coevolution between the symbiotic bacteria and the amoeba host has been reported. In this study we have isolated and characterized an Acanthamoeba sp. (strain OEW1) showing a stable symbiotic relationship with two morphologically different endosymbionts. 16S rRNA sequence analysis assigned these symbionts to the candidate genus Procabacter (Betaproteobacteria) and the genus Parachlamydia (Chlamydiae) respectively. Fluorescence in situ hybridization and transmission electron microscopy confirmed the affiliation of the endosymbionts and showed their co-occurrence in the amoeba host cells and their intracellular location within separate compartments enclosed by hostderived membranes. Further analysis of this stable relationship should provide novel insights into the complex interactions of intracellular multiple-partner associations.

show abstract

Section: Introductionmentioning

confidence: 99%

An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts

Heinz

Kolarov

Kästner

et al. 2007

Environmental Microbiology

View full text Add to dashboard Cite

show abstract

“…Entamoeba histolytica is the causative agent of amoebiasis, an infectious disease highly prevalent in developing countries [1]. The protozoan parasite passes through two life stages, the vegetative trophozoite and the infective cyst form [2]. Only the latter is able to survive the harsh conditions of the human stomach.…”

Section: Introductionmentioning

confidence: 99%

Identification of EhICP1, a chagasin‐like cysteine protease inhibitor of Entamoeba histolytica

Riekenberg¹,

Witjes²,

Šarić³

et al. 2005

FEBS Letters

View full text Add to dashboard Cite

Based on the Entamoeba histolytica genome project (www.sanger.ac.uk/Projects/E_histolytica/) we have identified a cysteine protease inhibitor, EhICP1 (amoebiasin 1), with significant homology to chagasin. Recombinant EhICP1 inhibited the protease activity of papain and that of a trophozoite lysate with K i Õs in the picomolar range. By immunocytology, we localized the endogenous $13 kDa EhICP1 in a finely dotted subcellular distribution discrete from the vesicles containing the amoebic cysteine protease, EhCP1 (amoebapain). In an overlay assay, we observed binding of recombinant EhICP1 to EhCP1. As a heptapeptide (GNPTTGF) corresponding to the second conserved chagasin motif inhibited the protease activity of both papain (K i 1.5 lM) and trophozoite extract (K i in sub-mM range), it may be a candidate for the rational development of anti-amoebiasis drugs.

show abstract

“…Giardia lamblia is a major cause of waterborne diarrhoeal disease (Farthing, 1995;Marshall et al, 1997) that contributes greatly to the global burden of malnutrition and malabsorption, leading to childhood mortality. Despite its importance, neither the cellular biology nor the pathophysiology of G. lamblia infection is well understood.…”

Section: Introductionmentioning

confidence: 99%

Reversible interruption of Giardia lamblia cyst wall protein transport in a novel regulated secretory pathway

2001

View full text Add to dashboard Cite

SummaryTo survive in the environment and infect a new host, Giardia lamblia secretes an extracellular cyst wall using a poorly understood pathway. The two cyst wall proteins (CWPs) form disulphide-bonded heterodimers and are exported via novel encystationspecific secretory vesicles (ESVs). Exposure of eukaryotic cells to dithiothreitol (DTT) blocks the formation of disulphide bonds in nascent proteins that accumulate in the endoplasmic reticulum (ER) and induces an unfolded protein response (UPR). Proteins that have exited the ER are not susceptible. Exposure to DTT inhibits ESV formation by . 85%. Addition of DTT to encysting cells causes rapid (t 1/2 , 10 min), reversible disappearance of ESVs, correlated with reduction of CWPs to monomers and reformation of CWP oligomers upon removal of DTT. Neither CWPs nor ESVs are affected by mercaptoethanesulphonic acid, a strong reducing agent that does not penetrate cells. DTT does not inhibit the overall protein secretory pathway, and recovery does not require new protein synthesis. We found evidence of protein disulphide isomerases in the ESV and the surface of encysting cells, in which they may catalyse initial CWP folding and recovery from DTT. This is the first suggestion of non-CWP proteins in ESVs and of enzymes on the giardial surface. DTT treatment did not stimulate a UPR, suggesting that Giardia may have diverged before the advent of this conserved form of ER quality control.

show abstract

Waterborne protozoan pathogens.

Cited by 69 publications

References 53 publications

An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts

An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts

Identification of EhICP1, a chagasin‐like cysteine protease inhibitor of Entamoeba histolytica

Reversible interruption of Giardia lamblia cyst wall protein transport in a novel regulated secretory pathway

Contact Info

Product

Resources

About