JRF: Acute Toxicity/Pathogenicity for Microbial pesticides

Date:09-26-2022

Author: Vishvesh Dalal, Ph.D. (Assistant Director – Toxicology)

1. Overview

Conversely, with the past, chemical manures and pesticides are being traded by bio-composts and bio-pesticides, separately, because of their solace of purpose, harmless to the ecosystem nature, cost-viability, and nontoxicity.

Bacillus thuringiensis (Bt) is very poisonous to a broad assortment of fundamental farming and wellbeing related bothers alongside different spineless creatures so practically 90% of the microbial bio-pesticides are gotten from this.

The bio-pesticide market is characterized into bio-herbicides, bio-insecticides, and bio-fungicides based on the product type. Concerning fixings, it is again partitioned into:

A. Microbial pesticides

i. Bacteria - e.g., Bacillus sp

ii. Fungi - e.g., Beauveria sp, Metarhizium  sp, Trichoderma sp 

iii. Viruses – e.g., granulosis virus, entomopox virus, cytoplasmic polyhedrosis virus 

iv. Protozoans- e.g., Schizogregrine

v. Algae -e.g., Enteromorpha flexuosa, Sargassum wightii

B. Biochemical pesticides

Plant extracts or sex pheromones

C. Plant-Incorporated-Protectants

Insecticidal transgenic crops

2. Advantages of Bio-pesticide

In the field of agronomy, there are numerous complications of pests like insects, fungi, and weeds from the ancient period resulting in a decrease in yield as well as the efficiency of crops.

1. Bio-pesticides are generally designed to affect target species only and non-hazardous to favourable insects.

2. Bio-pesticides are eco-friendly biodegradable.

3. Bio-pesticides speedily decompose into small remainders and do not show any harmful effect on ground water and surface water.

4. Bio-pesticides are effective in tiny amounts which removes many environment pollutions.

5. Bio-pesticides have high performance, low-residue and a smaller amount of toxic side effects.

6. Difficult to create resistance for insects. 

7. Bio-pesticides are typically a lesser amount of toxic as related to chemical pesticides.

3. Data Requirements for Registration of Bio-Pesticides

For registration of Bio-pesticides, every dominion has requirements for the data package submitted.

3.1 Data requirements for the formulated product:

1.Identity and composition of the formulation

2. Physical and chemical properties

3. Application, labelling, and packaging

4. Supplementary information

5. Analytical methods

6. Efficacy data

7. Toxicology and exposure

8. Residues

9. Fate and behaviour in the environment

10. Effects on non-target organisms

4. Objective of the study

This study was performed to provide initial information on the toxicity, infectivity and pathogenicity of a microbial pest control agents (MPCA), MPCA in rats following a single high dose exposure.

5. Principle of Test Method

The Microbial Pest Control Agent (MPCA) is administered in a single high dose to experimental animals. Subsequent observations of effects and deaths are made and rate of clearance of the MPCA is estimated. Animals those die during the study period will be necropsied, and at the end of the test, the surviving animals will be sacrificed and necropsied. Infectivity of the test item (MPCA) is evaluated periodically during the test, and at the end of the study. 

6. Regulatory Testing for MPCA as per OCSPP guidelines  

6.1 Test System

Rat (Wistar) or Mice (CD1) 

6.2 Method Validation:

Before starting any Study of MPCA, we perform Microbiological Method validation for better clarity of the behaviour of the active ingredient. Method validation part contains,

After Method validation, the Main study is to be initiated.

Acute Oral Toxicity / Pathogenicity (AOP) - EPA 885.3050

Acute Pulmonary Toxicity / Pathogenicity (APP) - EPA 885.3150

Acute Injection Toxicity/ Pathogenicity (AIP) - EPA 885.3200

Test	Necropsy & Interim Sacrifice / Final Sacrifice	Biometrics collection for MPCA clearance & enumeration
Acute Oral Toxicity / Pathogenicity (AOP)	On Day 3,7,14 & 21	Microbiological enumeration of MPCA done from major tissue like Faeces (AOP), Blood (APP), Lung (AIP) & other matrices like brain, liver, kidney, stomach, whole intestine, caecum, mesenteric lymph node, and spleen was also examined.
Acute Pulmonary Toxicity / Pathogenicity (APP)	On Day 0, 3,7,14 & 21
Acute Injection Toxicity/ Pathogenicity (AIP)	On Day 3,7,14 & 21

6.3 Tier Progression:

If MPCA noticed as Pathogenic/ Toxic than higher tier testing may be performed.

7. References

Travis R. Glare and Maria E. Moran-Diez (eds.), Microbial-Based Biopesticides: Methods and Protocols, Methods in Molecular Biology, vol. 1477, DOI 10.1007/978-1-4939-6367-6_1, © Springer Science+Business Media New York 2016

Biopesticides - An Alternative and Eco-Friendly Source For The Control Of Pests In Agricultural Crops, Shashi Prabha et al, Plant Archives Vol. 16 No. 2, 2016 pp. 902-906

Recent Developments in Applied Microbiology and Biochemistr-2019, https://doi.org/10.1016/B978-0-12-816328-3.00015-5

U.S. EPA, 1996: The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines, OCSPP 885.3150, Acute Pulmonary Toxicity/Pathogenicity (EPA 712–C–96–318) February 1996.

U.S. EPA, 1996: The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines, OCSPP 885.3050, Acute Oral Toxicity/Pathogenicity (EPA 712–C–96–315) February 1996.

U.S. EPA, 1996: The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines, OCSPP 885.3200, Acute Injection Toxicity/Pathogenicity (EPA 712–C–96–318) February 1996.

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