Antimicrobial susceptibility testing for Gram positive cocci towards vancomycin using scanning electron microscopy

Antimicrobial Susceptibility Testing for Colistin: Extended Application of Novel Quantitative and Morphologic Assay Using Scanning Electron Microscopy

“…Tis distinction of diferences in bacterial cell contrast, coupled with a description of morphological changes, allows direct quantifcation of live and dead bacteria on the obtained micrographs, providing clear evidence of the efect of Colistin on the viability of the organisms, thus determining the susceptibility profle to Colistin. Tis work is the fourth application [10][11][12]17] of our SEM-AST assay, confrming the promising results this assay provides compared to traditional AST assays. Future applications of this assay will include other antibiotics and continue to answer the simple question of whether a bacterial isolate is sensitive or resistant to a particular antibiotic.…”

“…Our current work has enabled us to perform Colistin antimicrobial susceptibility testing on fve clinically signifcant species by applying a novel rapid SEM-AST assay [10][11][12]. Using our novel assay, we were able to quantitatively determine the efect of exposing bacteria to the antibiotic Colistin, providing a simplifed approach to determining bacterial susceptibility to this molecule limited to the description of whether an isolate is sensitive or resistant to Colistin.…”

“…We have recently reinstated the use of scanning electron microscopy (SEM) in microbiological diagnostic applications and recently described the success of using SEM in AST applications for imipenem [10,11], vancomycin [12], and Colistin [11], demonstrating the feasibility of performing AST through morphological analysis. We have also demonstrated the utility of Phosphotungstic Acid (PTA) staining using SEM for quantitative analysis of the bacterial viability status after imipenem and Colistin treatments [11].…”