TABLE 2.
HPLC analysis of muropeptides prepared from the peptidoglycans of the cystic fibrosis strains studied in this work.
| Strain | Relative abundance (mol%) of muropeptidea | Cross-linkb (%) | Peptidoglycan lengthc | ||||||
| Mono | Di | Tri | D-D | Lpp | Anh | Penta | |||
| PAO1 | 65.46 | 32.51 | 2.04 | 1.55 | 4.86 | 4.25 | 2.83 | 36.58 | 23.54 |
| PA14 | 66.08 | 32.37 | 1.56 | 1.73 | 3.75 | 4.25 | 1.50 | 35.48 | 24.11 |
| PAOΔdacB ΔdacCΔpbpG | 55.40 | 39.71 | 4.89 | 0.17 | 0.34 | 5.59 | 79.83 | 49.49 | 17.90 |
| PAFQ05-03 | 59.45 | 37.11 | 3.44 | 0.49 | 4.98 | 6.99 | 1.00 | 43.99 | 14.40 |
| PAFQ05-11 | 67.56 | 29.43 | 3.02 | 0.41 | 3.72 | 5.47 | 0.50∗ | 35.46 | 18.39 |
| PAFQ06-03 | 66.79 | 30.96 | 2.25 | 0.22∗ | 8.20∗ | 5.12 | 3.47 | 35.46 | 19.64 |
| PAFQ06-10 | 66.49 | 31.45 | 2.06 | 0.81 | 7.56 | 3.79 | 2.02 | 35.57 | 26.58 |
| PAFQ10-03 | 66.52 | 31.80 | 1.68 | 0.10∗ | 3.81 | 2.99 | 0.57 | 35.16 | 33.52 |
| PAFQ10-11 | 67.37 | 31.39 | 1.24 | 0.63 | 5.81 | 4.02 | 3.58 | 33.88 | 28.05 |
| PAFQ11-03 | 61.94 | 34.95 | 3.12 | 1.47 | 3.62 | 7.45∗ | 1.49 | 41.18 | 13.82∗ |
| PAFQ11-10 | 69.22 | 29.36 | 1.41 | 1.26 | 4.42 | 3.52 | 6.28∗ | 32.19 | 28.72 |
| PAFQ12-146-07 | 63.24 | 34.77 | 1.99 | 1.39 | 4.67 | 3.35 | 0.69 | 38.75 | 30.54 |
| PAFQ12-146-10 | 64.04 | 34.94 | 1.02 | 1.31 | 7.29 | 4.68 | 2.16 | 36.98 | 23.47 |
| PAFQ12-299-03 | 59.05 | 37.73 | 3.22 | 0.54 | 5.97 | 6.42 | 2.98 | 44.17 | 15.60 |
| PAFQ12-299-06 | 57.72 | 38.58 | 3.70 | 1.21 | 4.05 | 6.36 | 2.93 | 45.99 | 15.77 |
| PAFQ15-03 | 66.25 | 31.65 | 2.10 | 0.46 | 3.27 | 7.05 | 2.78 | 35.84 | 14.57 |
| PAFQ15-10 | 62.16 | 35.66 | 2.18 | 3.18 | 3.82 | 5.61 | 2.36 | 40.02 | 18.19 |
| PAFQ16-03 | 62.78 | 34.66 | 2.55 | 0.20∗ | 6.71 | 6.28 | 1.53 | 39.77 | 16.86 |
| PAFQ16-10 | 60.11 | 36.74 | 3.15 | 0.10∗ | 4.36 | 5.98 | 1.79 | 43.04 | 16.85 |
| PAFQ21-1088-03 | 55.72∗ | 38.02 | 6.26∗ | 4.89∗ | 5.16 | 7.58 | 7.10∗ | 50.54∗ | 17.97 |
| PAFQ21-1088-10 | 64.95 | 32.26 | 2.79 | 0.21∗ | 3.61 | 7.31 | 1.92 | 37.84 | 14.06 |
| PAFQ21-1109-05 | 65.22 | 32.31 | 2.47 | 0.70 | 4.57 | 5.91 | 1.76 | 37.25 | 17.06 |
| PAFQ21-1109-10 | 65.14 | 32.89 | 1.98 | 0.43 | 5.67 | 6.13 | 4.87 | 36.84 | 16.37 |
| PAFQ24-04 | 69.66 | 29.04 | 1.30 | 0.10∗ | 4.95 | 5.05 | 2.02 | 31.65 | 25.40 |
| PAFQ24-10 | 68.37 | 29.76 | 1.87 | 1.63 | 5.19 | 9.41∗ | 5.28 | 33.50 | 11.75∗ |
| PAFQ28-06 | 67.63 | 30.59 | 1.79 | 0.76 | 3.97 | 6.23 | 2.77 | 34.16 | 16.71 |
| PAFQ28-10 | 66.59 | 31.57 | 1.84 | 0.77 | 4.41 | 5.45 | 2.37 | 35.25 | 19.79 |
aMol%, molar fraction; Mono, monomers; Di, dimers; Tri, trimers; D-D, muropeptides having mDAP–mDAP crosslinking; Lpp, muropeptides bound to C-terminal Arg-Lys dipeptide of OprI lipoprotein; Anh, muropeptides having anhydro-1,6-anhydromuramic acid; Penta, muropeptides having a pentapeptide stem (all these pentapeptides were shown to possess glycine instead of D-alanine in terminal position). bCross-link, degree of peptidoglycan cross-linking (percentage). cAverage number of disaccharide (N-acetylglucosamine and N-acetylmuramic acid) units in the sacculus sugar chains of each strain. The displayed value of each parameter and strain is the mean obtained from two independent replicates of peptidoglycan extraction and HPLC analysis. In all the cases, the SD was below 20% of each value (data not shown). ∗Statistically significant (One way ANOVA with Tukey’s post Hoc test, P-value < 0.05), compared to PAO1. The previously described mutant of P. aeruginosa PAOΔdacBΔdacCΔpbpG (Ropy et al., 2015) was used for comparative purposes and as a control for our procedures’ capacity to detect differences in the muropeptides composition.