Table 1.
Strain behaviour according to tested phenotypes. Supernatant C clear, T turbid; G1 corresponding to long chains with large tangles, G2 medium chains with small tangles. Maximum growth is compared to wildtype strains * as a percent. Biofilm formation index results are expressed compared to wildtype strains* as a percent. * 12/111 for plasmid-free strains and 12/111 pTCV-PTet n°1 for strains carrying plasmid; SEM analysis: R = Regular and tight spherical structures, I = Irregular and distended structure. R = Homogeneous and regular ovoid cells, I = Irregular, deformed cocci. TEM analysis: SD = standard deviation.
| Strains | Culture Aspect | Gram Stanning | Maximal Growth | Biofilm Formation Index | SEM | TEM | ||
|---|---|---|---|---|---|---|---|---|
| Cluster Appearance | Cocci Morphology | Wall Thickness (in nm) |
Glycocalyx Frequency | |||||
| 12/111 | C | G1 | 100 | 100 | R | R | 14.0 (SD = 4.41) | 23% |
| 12/111∆phiA | T | G2 | 73.8 (p < 0.0001) | 39.8 (p < 0.0001) | I | R | 14.3 (SD = 1.88) | 5% |
| Deleted mutants | ||||||||
| 12/111∆relB-metK n°1 | T | G2 | 73.9 (p < 0.0001) | 47.2 (p < 0.0001) | - | - | - | - |
| 12/111∆relB-metK n°2 | T | G2 | 77.7 (p < 0.0001) | 50.1 (p < 0.0001) | R/I | R | 13.4 (SD = 1.84) | 3.5% |
| 12/111∆relB-yafQ | T | G2 | 74.8 (p < 0.0001) | 49.0 (p < 0.0001) | - | - | - | - |
| 12/111∆metK | T | G2 | 78.4 (p < 0.0001) | 57.9 (p < 0.001) | - | - | - | - |
| 12/111∆endonuclease | T | G2 | 76.1 (p < 0.0001) | 46.6 (p < 0.0001) | - | - | - | - |
| 12/111∆endonuclease-metK | T | G2 | 79.2 (p < 0.0001) | 47.6 (p < 0.0001) | - | - | - | - |
| in situ complemented mutants | ||||||||
| 12/111ΔrelB-metK::relB-metK n°1 | T | G2 | 74.9 (p < 0.0001) | 47.6 (p < 0.0001) | - | - | - | - |
| 12/111ΔrelB-metK::relB-metK n°2 | C | G1 | 95.5 (ns) | 93.0 (ns) | R/I | R | 13.5 (SD = 1.20) | 21.5% |
| 12/111∆relB-yafQ::relB-yafQ | T | G2 | 76.2 (p < 0.0001) | 64.1 (p < 0.05) | - | - | - | - |
| 12/111∆metK::metK | T | G2 | 79.8 (p < 0.0001) | 45.3 (p < 0.0001) | - | - | - | - |
| 12/111∆endonuclease::endonuclease | T | G2 | 73.0 (p < 0.0001) | 46.2 (p < 0.0001) | - | - | - | - |
| 12/111∆endonuclease-metK::endonuclease-metK | T | G2 | 76.2 (p < 0.0001) | 37.2 (p < 0.0001) | - | - | - | - |
| 12/111 pTCV-PTet n°1 | T | G2 | 100 | 100 | - | - | - | - |
| 12/111 pTCV-PTet n°2 | T | G2 | 100.2 (ns) | 87.1 (ns) | - | - | - | - |
| 12/111∆phiA pTCV-PTet | T | G2 | 99.4 (ns) | 61.5 (p < 0.01) | R/I | R | 13.4 (SD = 4.06) | 2% |
| 12/111∆phiA plasmidic complemented mutants | ||||||||
| 12/111∆phiA pTCV-PTet::relB-yafQ | T | G2 | 96.5 (ns) | 65.8 (p < 0.05) | - | - | - | - |
| 12/111∆phiA pTCV-PTet::metK | C | G1 | 97.9 (ns) | 66.0 (p < 0.05) | R/I | I | 12.3 (SD = 3.07) | 6% |
| 12/111∆phiA pTCV-PTet::endonuclease | T | G2 | 93.3 (ns) | 58.3 (p < 0.001) | - | - | - | - |
| 12/111∆phiA pTCV-PTet::endonuclease-metK | C | G1 | 91.1 (ns) | 54.0 (p < 0.0001) | R/I | I | 11.5 (SD = 1.53) | 3% |
| 12/111ΔrelB-metK pTCV-PTet | T | G2 | 95.6 (ns) | 79.5 (ns) | R/I | R | 13.5(SD = 3.86) | 4% |
| 12/111∆relB-metK plasmidic complemented mutants | ||||||||
| 12/111∆relB-metK pTCV-PTet::relB-yafQ | T | G2 | 100.0 (ns) | 62.8 (p < 0.01) | - | - | - | - |
| 12/111∆relB-metK pTCV-PTet::metK | C | G1 | 91.2 (ns) | 51.3 (p < 0.0001) | R/I | I | 10.9 (SD = 0.93) | 12.5% |
| 12/111∆relB-metK pTCV-PTet::endonuclease | T | G2 | 99.2 (ns) | 61.3 (p < 0.01) | - | - | - | - |
| 12/111∆relB-metK pTCV-PTet::endonuclease-metK | C | G1 | 102.1(ns) | 71.4 (ns) | R/I | I | 11.3 (SD = 1.93) | 4% |