Table 2.
Grading of adhesion and cell-to-cell aggregation propertiesa
| Parameter and medium | Result for: |
||
|---|---|---|---|
| LFI1238 wt | ΔlitR strain | ΔlitRc strain | |
| Adhesion | |||
| LA1 | − | − | − |
| LA3 | − | − | − |
| BA1 | − | + | − |
| BA3 | − | + | − |
| BA1 + BB | − | + | − |
| BA3 + BB | − | + + + | − |
| BA1 + FBS | − | + | − |
| BA3 + FBS | − | + + | − |
| BA1 + ERY | − | + | − |
| BA3 + ERY | − | + + | − |
| BA1 + BSA | − | + | − |
| BA3 + BSA | − | + + | − |
| Cell-to-cell aggregation | |||
| LB1 | (+) | (+) | (+) |
| LB3 | + | + | + |
| BHI-HS | ++ | +++ | ++ |
| L15-FBS | + | ++ | + |
Adhesion of bacterial colonies to different agar media was measured after 7 days of incubation at 4°C on LA1 or LA3, blood agar base with 1% or 3% NaCl without supplements (BA1 or BA3) or with 5% bovine blood (BB), 7% fetal bovine serum (FBS), 5% washed bovine erythrocytes (ERY), or 1% bovine serum albumin (BSA). The adherence was graded as follows: −, none (smooth and creamy colonies); +, weak (more viscous colonies that were slightly adherent in the periphery); ++, moderate (adherent colonies that were partly possible to scrape off); and +++, strong (adherent colonies that were almost impossible to scrape off). Cell-to-cell aggregation properties were measured after 4 days of incubation at 8°C (200 rpm) in LB1 or LB3, brain heart infusion medium with 7% horse serum (BHI-HS), or Leibovitz-15 medium supplemented with 200 mM l-glutamine, 50 mM β-mercaptoethanol, and 10% FBS (L15-FBS). Aggregation was graded as follows: −, none; +, weak; ++, moderate; and +++, strong.