title: Characterization of Lactococcus lactis response to ampicillin and ciprofloxacin using surface-enhanced Raman spectroscopy.
abstract: Decades of antibiotic use or misuse has resulted in antibiotic resistance in lactic acid bacteria, a group of common culture starters and probiotic microorganisms. This has urged researchers to study how lactic acid bacteria respond to antibiotics, so as to have a better strategy to identify and predict the antibiotic-resistant bacteria. This study aimed to characterize the biochemical profiles of Lactococcus lactis responding to antibiotics using surface-enhanced Raman spectroscopy (SERS). Lactococcus lactis exposed to antibiotics was mixed with 50-nm gold nanoparticles for subsequent SERS measurements. The SERS spectra analyzed by principal component analysis showed no significant change after 30 min of antibiotic treatment, whereas distinct changes were clearly observed after 60 and 90 min of antibiotic treatment. Different antibiotics induced different spectral changes, and these changes revealed the detailed biochemical information of cellular responses. This study demonstrates that the SERS method developed not only senses the changes in the bacterial cell wall, but also reveals details of the biochemical profiles, which help us to understand how lactic acid bacteria respond to antibiotics, as well as to set a base for the detection of antibiotic susceptibility of bacteria by SERS.
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA, 01003, USA.|College of Food Science and Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Panxue
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA, 01003, USA.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Pang
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA, 01003, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China.
authors.forename: Mingtao
authors.initials: M
authors.lastname: Fan
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, MA, 01003, USA. lilihe@foodsci.umass.edu.
authors.forename: Lili
authors.initials: L
authors.lastname: He
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects; D002939:Ciprofloxacin / Q000494:pharmacology*; D013294:Lactococcus lactis / Q000737:chemistry / Q000187:drug effects*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin; D000667:Ampicillin
keywords: Ampicillin; Ciprofloxacin; Gold nanoparticles; Lactococcus lactis; Surface-enhanced Raman spectroscopy