MINIMUM INHIBITORY CONCENTRATION TEST : MIC TEST

MATERIALS AND METHODS

• Microorganisms

• Concentration of BIO-CLEANTM

• Procedure and assay

MICROORGANISMS

• The American Type Culture Collection strain [ATCC]

• Department of Medical Sciences Thailand strain [DMST]

• Escherichia coli ATCC 25922• Salmonella Typhimurium DMST 15674• Salmonella Enteritidis DMST 15676• Enterococcus faecium DMST 17660• Enterococcus faecalis ATCC 29212

MICROORGANISMS (CONT.)

Enterococcus faecalis ATCC 51299 Enterobacter aerogenes DMST 13048 Bacillus cereus ATCC 11778 Pseudomonas aeruginosa ATCC 27853

CONCENTRATION OF BIO-CLEANTM

The following BIO-CLEANTM concentrations were tested : 1,000 ppm 900 ppm 800 ppm 700 ppm 600 ppm 500 ppm 400 ppm 300 ppm 200 ppm 100 ppm

PROCEDURE AND ASSAY

Preparation of microorganisms

Cultivated microorganisms in Tryptic soy broth (TSB) and incubated 37°C at 24 hours.

Microorganisms suspension to McFarland’s pattern of 105 cfu/ml was prepared.

FLOW CHART(PREPARATION OF MICROORGANISM)

Compared with0.5 McFarland= 105 cfu/ml

ten fold dilution with PSS for Mcfarland

Culture in TSB medium

Slant agar

Streak on NA agar and incubated at 37oC; 24 hrs

Picked 3 colonies

10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8

Incubated at 37oC ; 24 hrs

PROCEDURE AND ASSAY (CONT.)

Preparation of Mcfarland 105 cfu/ml To standardized the inoculum density is used

(0.5 McFarland standard)

PREPARATION OF 0.5 MCFARLAND

PREPARATION OF 0.5 MCFARLAND

FLOW CHART(PREPARATION OF 0.5 MCFARLAND)

OD625 = 0.8-0.100.5 McFarland

BaCl2 + H2SO4

(Dilution)

1:1 1:2 1:3 1:4 1:5

PROCEDURE AND ASSAY (CONT.)

Controls Control test tube 1 = 1 ml TSB + 1 ml

microorganism Control test tube 2 = 1 ml TSB + 1 ml BIO-

CLEANTM Control test tube 3 = 2 ml TSB

C1 C2 C3

PROCEDURE AND ASSAY (CONT.)

Sample

1 ml BIO-CLEANTM (start 1,000-100ppm)

1 ml microorganism (105 cfu/ml)

1,000 ppm

--- -+- -++

Report

C1

C2

C3

PROCEDURE AND ASSAY (CONT.)

1,000ppm

900ppm

800ppm

700ppm

600ppm

500ppm

400ppm

300ppm

200ppm

100ppm