Sodium salicylate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data from various test chemicals

Justification for type of information:

experimental data from various test chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

WoE report is prepared based on toxicity to microorganisms study namely WoE-2 and WoE-3

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

other: 1. Staphylococcus aureus, 2. activated sludge

Details on inoculum:

1. - Laboratory culture: micro-organisms were collected from the stock of the Department of Pharmaceutical Microbiology,
- Method of cultivation: The test organisms were maintained on nutrient agar slopes and kept in a refrigerator at 4 °C.

Test type:

static

Water media type:

other: 1. Nutrient agar, 2. freshwater

Limit test:

no

Total exposure duration:

24 h

Remarks on exposure duration:

3 hrs exposure was carried out in the 2nd study

Test temperature:

1. 37°C

pH:

2. 7.5

Reference substance (positive control):

yes

Remarks:

1. The positive control for bacteria is gentamicin at the concentration of 5 mg/ml

Key result

Duration:

24 h

Dose descriptor:

other: MIC

Effect conc.:

200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 1st study

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 2nd study

Validity criteria fulfilled:

no

Conclusions:

The toxicity of test chemical to microorganisms determined to be in range of 200 to > 1000 mg/l.

Executive summary:

In different studies, the given test chemical, has been investigated for toxicity to microorganisms to a greater or lesser extent. The studies are summarized as below –

 

In the first key study evaluation of toxicity of test chemical on Staphylococcus aureus toxicity to micro-organisms test was carried for 24 h under static condition.An overnight culture of each organism S. aureus was prepared. The 0.1 ml of organism was taken into 9.9 ml of sterile distilled water (SDW) to give 10 ml of 1:100 (10 ) dilution. The stock was maintained on nutrient agar slant and sub-cultured in nutrient broth for incubation at 37 °C prior to each antimicrobial testing. Inoculation of the test organisms on nutrient agar-prepared plates was achieved by flaming a wire loop on a spirit lamp, cooling the wire loop (air cooling) and fetching the test organisms.The discs were prepared using a Grade No. 1 Whatman filter paper. One hundred discs were obtained by punching and putting in vial bottles and sterilizing in an oven at 150 °C for 15 min. Thereafter the cups (9 mm diameter) were aseptically bored into the solid nutrient agar using a sterile cork-borer. The test solution of Methyl salicylate was introduced .The plates were left at room temperature for 2 h, allowed to diffuse into the medium, turned upside-down and thereafter incubated at 37 °C for 24 h in an incubator. The minimum inhibition concentration (MIC) of test chemical on Staphylococcus aureus was observed to be 200mg/l.

First study was supported by the second study from peer reviewed journal. To evaluate antibacterial activity of  test chemical on Activated sludge toxicity to micro-organisms test was carried out according to the OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test. The test was carried for 3 h under static condition. Test chemicalwas used as a test material to evaluate toxicity to microorganisms as per OECD guideline 209. Activated sludge was used as the test culture at pH 7.5 for 3 h The EC50 value on the basis of respiration inhibition test was observed to be >1000 mg/l.

Thus based on the above effects chemical toxicity value ranges from 200 to > 1000 mg/l.

Description of key information

The toxicity of test chemical to microorganisms determined to be in range of 200 to > 1000 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

200 mg/L

Additional information

In different studies, the given test chemical and structually and functionally similar read across chemicals has been investigated for toxicity to microorganisms to a greater or lesser extent. The studies are summarized as below –

 

In the first key studyevaluation of toxicity of test chemical on Staphylococcus aureus toxicity to micro-organisms test was carried for 24 h under static condition.An overnight culture of each organism S. aureus was prepared. The 0.1 ml of organism was taken into 9.9 ml of sterile distilled water (SDW) to give 10 ml of 1:100 (10 ) dilution. The stock was maintained on nutrient agar slant and sub-cultured in nutrient broth for incubation at 37 °C prior to each antimicrobial testing. Inoculation of the test organisms on nutrient agar-prepared plates was achieved by flaming a wire loop on a spirit lamp, cooling the wire loop (air cooling) and fetching the test organisms.The discs were prepared using a Grade No. 1 Whatman filter paper. One hundred discs were obtained by punching and putting in vial bottles and sterilizing in an oven at 150 °C for 15 min. Thereafter the cups (9 mm diameter) were aseptically bored into the solid nutrient agar using a sterile cork-borer. The test solution of Methyl salicylate was introduced .The plates were left at room temperature for 2 h, allowed to diffuse into the medium, turned upside-down and thereafter incubated at 37 °C for 24 h in an incubator. The minimum inhibition concentration (MIC) of test chemical on Staphylococcus aureus was observed to be 200mg/l.

First study was supported by the second study from peer reviewed journal. To evaluate antibacterial activity of  test chemical on Activated sludge toxicity to micro-organisms test was carried out according to the OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test. The test was carried for 3 h under static condition. Test chemicalwas used as a test material to evaluate toxicity to microorganisms as per OECD guideline 209. Activated sludge was used as the test culture at pH 7.5 for 3 h The EC50 value on the basis of respiration inhibition test was observed to be >1000 mg/l.

Thus based on the above effects chemical toxicity value ranges from 200 to > 1000 mg/l.