Table 4.
Frequencies and assignments of absorbance peaks in FT–IR spectra of wild-type (WT), ciprofloxacin-induced (CIP), oxacillin-induced (OIAR), and clinical acquired (CAAR) Staphylococcus aureus, Salmonella Typhimurium, and Klebsiella pneumonia a
| Wave no. | S. aureus | S. Typhimurium | K. pneumonia | Band assignment | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| (cm−1) | WT-SA | OI-SA | CA-SA | WT-ST | CI-ST | CA-ST | WT-KP | CI-KP | CA-KP | |
| 720 | 0.32 | 0.30 | 0.30 | 0.26 | 0.28 | 0.29 | 0.26 | 0.27 | 0.25 | C–H rocking of CH2 |
| 960 | 0.17 | 0.18 | 0.18 | 0.16 | 0.17 | 0.18 | 0.15 | 0.13 | 0.15 | C–H rocking of CH2 and CH3 |
| 1036 | 0.40 | 0.40 | 0.47 | 0.34 | 0.53 | 0.49 | 0.31 | 0.56 | 0.32 | Carbohydrate C–O stretching mode |
| 1080 | 0.26 | 0.27 | 0.26 | 0.25 | 0.25 | 0.26 | 0.25 | 0.19 | 0.24 | Phosphodiester groups of DNA and RNA |
| 1154 | 0.13 | 0.13 | 0.12 | 0.14 | 0.13 | 0.14 | 0.12 | 0.10 | 0.13 | Carbohydrate C–O stretching mode |
| 1211 | 0.16 | 0.16 | 0.13 | 0.14 | 0.12 | 0.13 | 0.14 | 0.10 | 0.13 | Stretching of PO bond in phosphate |
| 1222 | 0.17 | 0.17 | 0.14 | 0.15 | 0.13 | 0.14 | 0.16 | 0.11 | 0.14 | PO bond in phosphate |
| 1303 | 0.16 | 0.16 | 0.16 | 0.15 | 0.17 | 0.16 | 0.13 | 0.16 | 0.13 | Vibration C–N of amides II |
| 1370 | 0.19 | 0.19 | 0.21 | 0.17 | 0.19 | 0.19 | 0.16 | 0.14 | 0.15 | Bending of C–H |
| 1384 | 0.22 | 0.22 | 0.23 | 0.20 | 0.23 | 0.23 | 0.18 | 0.17 | 0.18 | Symmetric stretching of COO– and CH2/CH3 |
| 1420 | 0.24 | 0.23 | 0.26 | 0.20 | 0.25 | 0.25 | 0.19 | 0.20 | 0.19 | Symmetric stretching of COO– |
| 1450 | 0.22 | 0.22 | 0.24 | 0.20 | 0.24 | 0.24 | 0.19 | 0.20 | 0.19 | C-H bending of CH2; CH2 scissoring |
| 1455 | 0.22 | 0.22 | 0.24 | 0.20 | 0.24 | 0.24 | 0.19 | 0.20 | 0.19 | Asymmetric bending of CH3/CH2 of proteins |
| 1600 | 0.24 | 0.24 | 0.23 | 0.21 | 0.20 | 0.20 | 0.21 | 0.18 | 0.20 | Asymmetric COO– stretches |
| 1654 | 0.28 | 0.30 | 0.25 | 0.30 | 0.25 | 0.26 | 0.27 | 0.22 | 0.27 | Amide I of α-helical structure of proteins |
| 2850 | 0.12 | 0.12 | 0.13 | 0.11 | 0.14 | 0.13 | 0.10 | 0.12 | 0.10 | Symmetric stretching of C–H in fatty acids |
| 2855 | 0.13 | 0.12 | 0.13 | 0.11 | 0.14 | 0.13 | 0.10 | 0.12 | 0.10 | C–H of CH2 in fatty acid chains |
| 2870 | 0.13 | 0.13 | 0.14 | 0.12 | 0.15 | 0.15 | 0.11 | 0.14 | 0.11 | Symmetric stretching of CH3 of methyl |
| 2918 | 0.16 | 0.15 | 0.16 | 0.14 | 0.20 | 0.19 | 0.13 | 0.20 | 0.13 | CH2 stretching of methylene in fatty acids |
| 2929 | 0.16 | 0.15 | 0.17 | 0.15 | 0.21 | 0.19 | 0.14 | 0.21 | 0.14 | Asymmetric stretching of C–H and CH2 |
| 2960 | 0.16 | 0.15 | 0.17 | 0.14 | 0.22 | 0.20 | 0.14 | 0.24 | 0.14 | C–H of –CH3 in fatty acids |
aWT-SA, WT-ST, WT-KP, OI-SA, CI-ST, CI-KP, CA-SA, CA-ST, and CA-KP denote wild-type S. aureus, S. Typhimurium, K. pneumoniae, oxacillin-induced S. aureus, ciprofloxacin-induced S. Typhimurium, K. pneumoniae, clinically-acquired antibiotic-resistant S. aureus, S. Typhimurium, and K. pneumoniae, respectively