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