Biocide Efficacy Testing Or Antimicrobial Susceptibility Test (AST)

Welcome to Microbiology Testing Services of Shubhda Research Institute –Simulation Studies information page.

The information and outline given below is only for presenting the gist of the method to sponsors intending to test their product and is purely for educational purpose.

Antibiotic sensitivity is the susceptibility of micro organisms to antibiotics. Antibiotic susceptibility testing (AST) is usually carried out to determine which antibiotic will be most successful in treating a bacterial and fungal infection in vitro.

Samples such as antimicrobial compounds or clinical isolates, antibiotic isolate, raw product, intermediate or finished product, nosocomial product, and cultural antagonism can be tested.

Methods used for AST:

1. Agar Diffusion Method- Qualitative method

2. Agar Dilution Method - Quantitative method

1. Agar Diffusion method:

A) Disc diffusion method:

Kirby-Bauer Antimicrobial Susceptibility Test method is recommended by the NCCLS simple and reliable test in routine clinical bacteriology in order to find out the effect of particular antibiotic or chemical compound on specific bacteria. Substance is impregnated in small disc of specific concentration and placed on the solid agar surface spread with organism..Results are presented by inhibition in the contact area and zone of inhibition around the test article in millimeters.

B) Agar well diffusion method:

It is also known as cup or plate hole/ well diffusion method to study the inhibitory effect of various antimicrobial compound on bacterial, fungal and anaerobic cultures. Sensitivity is determined by zone of inhibition.

Antimicrobial is tested against following organisms:

Bacterial: E. coli, P .mirabilis, C. diphtheria, P vulgaris, P aeruginosa, S. aureus, S faecalis, E. aerogenes

Fungal: C albicans, A. niger, A. fumigates, T. verrucosum, T. rubrum.

Anaerobic cultures: C. diphtheria, C. sporogenes, Propionibacterium acnes.

Total turn over time: 7 days. .

2. Agar Dilution Method :

Useful to determine the Minimum Inhibitory Concentration (MIC) of the antimicrobial in order to kill the micro organism.

  1. Broth dilution method:

Test is performed by adding different concentrations of the antimicrobial to the tubes containing broth and observing for the turbidity indicating growth. The lowest concentration showing no turbidity is reported as the minimum inhibitory concentration. Small number of isolates or even single isolate can be tested.

  1. Agar dilution method:

The test involves incorporation of varying concentrations of Antimicrobial in agar medium. Then addition of test several organisms on each plate of different concentration.

Bacterial: P. aeruginosa, E.coli, S. aureus, S. typhi, MRS. aureus, P. acnes, S.pyogenes.

Fungal: A. niger, C.albicans.

Antibacterial Susceptibility Testing of anaerobic bacteria:

Popularly known as Wadsworth method is performed by SRI as per NCCLS method to determine the antibacterial susceptibility of fastidious,anaerobic bacteria

Anaerobic cultures: Fusobacterium nucleatum, Bacteroides vulgatus and others.

Turn over time: 2 to 3 weeks

If your firm wants to perform the “Simulation Study” simply Contact our Lab today
Probiotic Formulations Bioassay
  • Bioassays
  • pH Simulation studies
read more..
Microbiology Training
Shubhda Research Institute offers hands-on practical training programs at different levels addressing specific industries so as to hone your skills and techniques.
read more..
Ready-To-Use Media Plates
Rapid testing and quick reliable results are of utmost importance today. To serve this purpose, Shubhda Research Institute offers “Ready-To-Use” pre-poured petri plates.
read more..
Sample Based Tests
Antimicrobial Hard Surfaces For Bacteria
Antimicrobial Hard Surfaces For Fungi
Antimicrobial Textiles For Bacteria
Antimicrobial Textiles For Fungi
Disinfectants And Sanitizers Testing
Paint Films Testing
Probiotic Formulations Bioassay
Food, Water & Dairy Product Testing
Industries that we serve
Plastic and Glass
Textiles, Mattresses & Carpets
Pharmaceutical & Biotechnology 
Medical Devices and Surgical
Probiotic and Prebiotics
Water and Beverages
Food and Nutraceuticals
Dairy and Milk Products
Cosmetics and Personal Care
Paper and Paint
Contact Us
Shubhda Research Institute

Unit No. 104, Building No. 14, HDIL Industrial Park, Chandansar, Off Western Express Highway, VIRAR (East), District: Thane, Maharashtra, INDIA 401305.

Tel : +91-8087737733 / +91-250-3298345
Mobile : +91-8007237812 / +91-9326841474
Email : info@sribioservices.com /

Copyright © 2011-12  Shubhda Research Institute  All Rights Reserved. Website Designed & Promoted By B2B RESPONSE MEDIA