Identification of ceftazidime interaction with bacteria in wastewater treatment by Raman spectroscopic mapping

Abstract

Raman spectroscopy yields a fingerprint spectrum and is of great importance in medical and biological sciences as it is non-destructive, non-invasive, and available in the aqueous environment. In this study, Raman spectroscopy and Raman mapping were used to explore the dynamic biochemical processes in screened bacteria under ceftazidime stress. The Raman spectral difference between bacteria with and without antibiotic stress was analyzed by principal component analysis and characteristic peaks were obtained. The results showed that amino acids changed first and lipids were reduced when bacteria were exposed to ceftazidime stress. Furthermore, in Raman mapping, when bacteria were subjected to antibiotic stress, the peak at 1002 cm À1 (phenylalanine) increased, while the peak at 1172 cm À1 (lipids)weakened. This indicates that when bacteria were stimulated by antibiotics, the intracellular lipids decreased and the content of specific amino acids increased. The reduction of intracellular lipids may suggest a change of membrane permeability. The increase of specific amino acids suggests that bacteria resist external stimuli of antibiotics by regulating the activities of related enzymes. This study explored the processes of the action between bacteria and antibiotics by Raman spectroscopy, and provides a foundation for the further study of the dynamics of microbial biochemical processes in the future. Fig. 8 Raman mappings of bacteria in ceftazidime solution with tolerance times of 0 min (a), 30 min (b), 60 min (c), 90 min (d), and 120 min (e).

Phenotypic convergence of bacterial adaption to sub-lethal antibiotic treatment

“…Raman spectroscopy is a powerful approach for comparing the phenotypic difference of bacteria according to the treatment of various antibiotics with high resolution, and comparative research was also conducted at sublethal concentration of antibiotic treatment ( López-Díez et al., 2005 ; Athamneh et al., 2014 ). Since ceftazidime, a cell wall inhibitor, inhibits the expression of acrAB encoding a multi-drug efflux pump, bacteria treated with ceftazidime were found to have decreased Raman peaks related to lipids and proteins ( Athamneh et al., 2014 ; Peng et al., 2019 ). And CIP, a DNA gyrase inhibitor, inhibits the expression of gyrAB encoding DNA gyrase, thereby reducing nucleic acid related peaks in the bacterial SCRS ( Athamneh et al., 2014 ; Germond et al., 2018 ).…”

Classification and Identification of Archaea Using Single-Cell Raman Ejection and Artificial Intelligence: Implications for Investigating Uncultivated Microorganisms

“…Machine learning algorithms such as support vector machines (SVMs) are used to unveil the complex information in a Raman spectrum and identify and classify bacteria in biological investigations. , Due to its generally good performance in Raman-related tasks, easy applicability, and low computational costs, linear SVM algorithm was utilized to train the classification model and distinguish the nine archaeal species based on their SCRS. Cross-validation was used to evaluate the ability of the SVM model.…”

Detection and Tertiary Treatment Technologies of Poly-and Perfluoroalkyl Substances in Wastewater Treatment Plants

“…Spectroscopy has become a tool with enough potential to provide the means for enhanced sensitive detection of plastic microparticles and related environmental contaminants (Chen et al, 2020). This approach also provides the potential of smaller probes, allowing an in-situ, real-time and non-destructive monitoring with positive implications for the decision making at the economical and risk-assessment of operation (Peng et al, 2019). The selection of the appropriate spectrum band for the detection of interest compounds is crucial as molecules may absorb different spectrum bands with varied intensity (Mesquita et al, 2017).…”