Deciphering biophysical signatures for microbiological applications

Ranawat, Harsh and Mazumder, Nirmal and Murali, Thokur Sreepathy and Mahato, Krishna Kishore and Satyamoorthy, K (2020) Deciphering biophysical signatures for microbiological applications. Lasers in Medical Science, 35. pp. 1493-1501. ISSN 0268-8921

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Identification and classification of microbes are vital for maintenance of normal and altered state of human health and have applications in pharmaceutical industries, food processing, clinical analysis, and treatment. Development of methods aimed towards achieving these goals must be rapid and reliable. Conventional physiochemical and morphology-based methods of identification are often ambiguous, while newer molecular methods such as flow cytometry and polymerase chain reaction, though reliable, are time and resource intensive. Spectroscopic methods provide advantages over conventional methods as these can be fast, non-destructive, and highly specific. Surface charge of bacteria is an important parameter which can reveal composition of cell wall and is attributed to the presence of carboxyl and phosphoryl groups. Interaction of the cell with the solvent and response to various stresses can hence be measured by the changes in surface charge. In this study, we have obtained autofluorescence spectra (tryptophan) and dynamic light scattering (DLS) measurements from common pathogenic strains of Pseudomonas aeruginosa and Staphylococcus aureus. Fluorescence emission spectra were obtained in the range of 300– 550 nm at excitation wavelength of 280 nm and DLS measurements comprised zeta potential and size parameters. Both types of measurements were performed in physiological and stress-induced conditions such as heat, sonication, and antibiotic treatment with vancomycin and cetylpyridinium chloride. Effects of these antibiotics on membrane integrity and cell viability, as obtained by DLS measurements, were statistically significant and comparable with conventional methods. Multivariate analysis enabled clustering of 83% of the samples at the genera level, based on variances from auto-fluorescence and DLS measurements.

Item Type: Article
Uncontrolled Keywords: Laser induced fluorescence; Dynamic light scattering ;Drug action; Pseudomonas aeruginosa; Staphylococcus aureu.
Subjects: Life Sciences > MLSC Manipal
Depositing User: KMC Library
Date Deposited: 15 Oct 2020 04:03
Last Modified: 15 Oct 2020 04:03

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