Fig 1.
Schematics of the experimental design.
Fig 2.
Representative culture plates of MRSA.
(A) Control I. (B) Control II. (C) Triclocarban-treated sample. (D) Representative plate showing no bacterial growth from samples treated with either Ethanol, Isopropanol, Sodium hypochlorite or Triclosan.
Fig 3.
PCA-LDA scores and loadings plot from comparison of the ethanol-treated, isopropanol-treated, sodium-hypochlorite-treated, triclosan-treated and triclocarban-treated spectra.
A) Three-dimensional scores plot of IR spectra from all treated-MRSA groups, which clearly show the separation of spectra. Each point in the scatter plot represents a pixel IR spectrum (an area of 1.1×1.1μm2). B) Corresponding cluster vector plot for each treatment showing the discriminatory features in the spectral region between 1800 and 900 cm-1, responsible for the separation of spectra; i.e. triclocarban-treated (yellow); triclosan-treated (black); sodium hypochlorite-treated (red); isopropanol-treated (blue) and ethanol-treated (green), respectively. Nearly 10,000 IR spectra were derived from each group for the comparison.
Table 1.
Discriminatory frequencies (cm-1) of the ethanol-treated, isopropanol-treated, sodium hypochlorite-treated, triclosan-treated and triclocarban-treated MRSA derived from PCA-LDA.
Fig 4.
Comparison of the ethanol-treated and isopropanol-treated MRSA vs. control groups.
A,B) Average IR spectra from control I (purple), control II (pink), ethanol-treated (green) and isopropanol-treated (blue) MRSA. The spectra were averaged over nearly 40,000 individual IR spectra (64×64 pixels; 4096 spectra per measurement, 10 measurement per sample). C,D) Two-dimensional scores plot from PCA-LDA analysis (LD-2 vs. LD-1) derived from the comparison between control I, control II and ethanol-treated spectra (C) and between the controls and isopropanol-treated spectra (D). E,F) Corresponding cluster vector plot for the comparison made in C,D and the vector plot per cluster showing the significant discriminatory features, is shown.
Table 2.
Discriminatory frequencies (cm-1) of the comparison between ethanol-treated and isopropanol-treated, with control groups of MRSA derived from PCA-LDA.
Fig 5.
Comparison of the sodium hypochlorite-treated, triclosan-treated and triclocarban-treated spectra vs. control I and control II groups.
A,B,C) Average IR spectra from control I (purple), control II (pink), sodium hypochlorite-treated (red), triclosan-treated (black) and triclocarban-treated (yellow) MRSA. The spectra were averaged over nearly 40,000 individual IR spectra in each case. D,E,F) Two-dimensional scores plot from PCA-LDA analysis (LD-2 vs. LD-1) derived from the comparison of control I, control II and sodium hypochlorite-treated (D), triclosan-treated (E) and triclocarban-treated (F). G,H,I) Corresponding cluster vector plot for the comparison made in D, E and F and the vector plot per cluster highlighting the significant discriminatory features, is demonstrated.
Table 3.
Discriminatory frequencies (cm-1) of the comparison between sodium hypochlorite-treated, triclosan-treated and triclocarban-treated, and control groups of MRSA derived from PCA-LDA.