Effect of copper, herbicides, and a mixed effluent on chemoattraction of <i>tetrahymena pyriformis</i>

Roberts, Robert O.; Berk, Sharon G.

doi:10.1002/tox.2530080108

Cited by 8 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The inhibitory effect of 2,4-D on chemoattraction had previously been described in Tetrahymena Ž . pyriformis Roberts and Berk, 1993 . Although motility organelles are different in T. pyriformis and E. coli, it is interesting to note that the diminution in motility Ž .…”

Section: Discussionmentioning

confidence: 99%

Effect of 2,4-dichlorophenoxyacetic acid herbicide onEscherichia coli growth, chemical composition, and cellular envelope

et al. 2001

View full text Add to dashboard Cite

2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide widely used in the world and mainly excreted by the renal route in exposed humans and animals. Herbicides can affect other nontarget organisms, such as Escherichia coli. We observed that a single exposure to 1 mM 2,4-D diminished growth and total protein content in all E. coli strains tested in vitro. In addition, successive exposures to 0.01 mM 2,4-D had a toxic effect decreasing growth up to early stationary phase. Uropathogenic E. coli adhere to epithelial cells mediated by fimbriae, adhesins, and hydrophobic properties. 2,4-D exposure of uropathogenic E. coli demonstrated altered hydrophobicity and fimbriation. Hydrophobicity index values obtained by partition in p-xylene/water were 300-420% higher in exposed cells than in control ones. Furthermore, values of hemagglutination titer, protein contents in fimbrial crude extract, and electron microscopy demonstrated a significant diminution of fimbriation in treated cells. Other envelope alterations could be detected, such as lipoperoxidation, evidenced by decreased polyunsaturated fatty acids and increased lipid degradation products (malonaldehyde), and motility diminution. These alterations decreased cell adherence to erythrocytes, indicating a diminished pathogenic capacity of the 2,4-D-exposed E. coli.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of 2,4-dichlorophenoxyacetic acid herbicide onEscherichia coli growth, chemical composition, and cellular envelope

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Several test methods for xenobiotic toxicity using the ciliate Tetrahymena have been proposed [10][11][12][13]. The biology and general responses of this protozoan are well understood [14].…”

Section: Introductionmentioning

confidence: 99%

Bioassay Technique Using Nonspecific Esterase Activities of Tetrahymena Pyriformis for Screening and Assessing Cytotoxicity of Xenobiotics

Bogaerts¹,

Sénaud²,

Bohatier³

1998

Environ Toxicol Chem

View full text Add to dashboard Cite

Abstract-A simple and rapid test for screening and assessing the cytotoxicity of xenobiotics was developed with Tetrahymena pyriformis. The method estimates the activities of nonspecific esterases of a cell by concentrating within it a specific amount of fluorescence associated with fluorescein dye. The 1-h median effective concentration (EC50) values of 10 inorganic and eight organic substances are presented and compared to those of three other bioassays: the conventional T. pyriformis proliferation rate 9-h median inhibitory concentrations, the Microtox 30-min EC50s, and the Daphnia magna 4-methylumbelliferyl ␤-D galactoside 1-h EC50s. A highly significant correlation was found between the results obtained with the fluorescein diacetate test and those obtained with the growth inhibition and Microtox tests. This in vivo enzymatic test showed high sensitivity to all compounds tested except Cr 6ϩ and sodium dodecyl sulfate.

show abstract

“…Several test methods for xenobiotic toxicity using the ciliate Tetrahymena have been proposed [10–13]. The biology and general responses of this protozoan are well understood [14].…”

Section: Introductionmentioning

confidence: 99%

Bioassay technique using nonspecific esterase activities of tetrahymena pyriformis for screening and assessing cytotoxicity of xenobiotics

Bogaerts

Sénaud

Bohatier

1998

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

A simple and rapid test for screening and assessing the cytotoxicity of xenobiotics was developed with Tetrahymena pyriformis. The method estimates the activities of nonspecific esterases of a cell by concentrating within it a specific amount of fluorescence associated with fluorescein dye. The 1‐h median effective concentration (EC50) values of 10 inorganic and eight organic substances are presented and compared to those of three other bioassays: the conventional T. pyriformis proliferation rate 9‐h median inhibitory concentrations, the Microtox® 30‐min EC50s, and the Daphnia magna 4‐methylumbelliferyl β‐D galactoside 1‐h EC50s. A highly significant correlation was found between the results obtained with the fluorescein diacetate test and those obtained with the growth inhibition and Microtox tests. This in vivo enzymatic test showed high sensitivity to all compounds tested except Cr6+ and sodium dodecyl sulfate.

show abstract

Effect of copper, herbicides, and a mixed effluent on chemoattraction of tetrahymena pyriformis

Cited by 8 publications

References 20 publications

Effect of 2,4-dichlorophenoxyacetic acid herbicide onEscherichia coli growth, chemical composition, and cellular envelope

Effect of 2,4-dichlorophenoxyacetic acid herbicide onEscherichia coli growth, chemical composition, and cellular envelope

Bioassay Technique Using Nonspecific Esterase Activities of Tetrahymena Pyriformis for Screening and Assessing Cytotoxicity of Xenobiotics

Bioassay technique using nonspecific esterase activities of tetrahymena pyriformis for screening and assessing cytotoxicity of xenobiotics

Contact Info

Product

Resources

About