A new method for antimicrobial susceptibility testing of in vitro-cultured bacteria by means of resonance light scattering technique.
A new method for antimicrobial susceptibility testing of in vitro-cultured bacteria on an ordinary fluorescence spectrometer was developed. The viable bacteria reduced 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to produce insoluble particles that displayed intense resonance scattering light (RSL). The assay showed a linear relationship between the number of viable bacteria and the intensity of resonance scattering light. Dead bacteria were unable to reduce MTT. Methicillin-resistant Staphylococcus aureus exposed to flavonoids from Marchantia convoluta showed a flavonoids concentration-dependent inhibition of the ability to reduce MTT. In the assay, less than 12 h were required to attain susceptibility results and fewer bacteria were utilized than in traditional methods. The RLS technique could, in combination with the MTT assay, be a rapid and sensitive measuring method to determine the in vitro activity of new antimicrobials.
Shi
Yu Jun
YJ
School of Chemistry and Chemical Engineering, Nantong University, Nantong, Jiangsu 226000, PR China. jnb_xiao@yahoo.com
Chen
Jun
J
Xu
Ming
M
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D004396:Coloring Agents / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008027:Light; D047008:Marchantia / Q000737:chemistry; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence / Q000295:instrumentation; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000378:metabolism; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
D000900:Anti-Bacterial Agents; D004396:Coloring Agents; D005419:Flavonoids; D010936:Plant Extracts; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue