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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
genetic toxicity in vitro
Remarks:
Type of genotoxicity: genome mutation
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Not reported
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1984

Materials and methods

Principles of method if other than guideline:
The test material was studied to determine the ability to cause DNA damage and thereby induce a pleiotropic response in the E. coli strain. The pleiotopic response was determined by checking for the induction of λ prophage.
GLP compliance:
not specified
Type of assay:
other: Induction of λ prophage in E. coli WP2s (λ)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Zinc chloride

Method

Target gene:
Not reported
Species / strain
Species / strain / cell type:
E. coli WP2
Details on mammalian cell type (if applicable):
- Type and identity of media: Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)
Additional strain / cell type characteristics:
not specified
Metabolic activation:
not specified
Metabolic activation system:
Not reported
Test concentrations with justification for top dose:
3.2 mM
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
Streptomycin
Negative solvent / vehicle controls:
yes
Remarks:
Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-Methyl-N'-nitro-N-nitrosoguanidine
Untreated negative controls:
yes
Remarks:
Streptomycin
Negative solvent / vehicle controls:
yes
Remarks:
Minimal Broth Davis (Difco) containing 0.2 % glucose and 20 µg/mL tryptophan (MST)
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 20 h


NUMBER OF REPLICATIONS: Duplicate


Evaluation criteria:
Clear (non-turbid) wells can occur because of toxicity of the test agent, inhibition of growth, or induction of λ prophage and cell lysis. Thus clear wells indicate toxicity and growth inhibition.
Statistics:
Not reported

Results and discussion

Test results
Species / strain:
E. coli WP2
Metabolic activation:
without
Genotoxicity:
ambiguous
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Not reported

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
Under the test conditions, 3.2 mM of the test material caused two-fold increase in induction of λ prophage over control (reported as +/-).
Executive summary:

A study was conducted to determine the potential of the test material for induction of λ prophage in E coli WP2 (λ).

 

The test material in MST was inoculated with 75 µL of a mid-exponential culture of WPs(λ) diluted so that each well receives approximately 2 x 107bacteria. The test plate was incubated at 37 °C and scored after 20 h for turbidity. MNNG and 4NQO served as positive controls and streptomycin as negative control.

 

Under the test conditions, 3.2 mM of the test material caused a two-fold increase in induction of λ prophage over control (reported as +/-).