TABLE 1.
Quorum-sensing components and quorum-regulated phenotypes in various V. cholerae strains
| Strain (reference) | Place and yr of isolation | Biotype and serogroup | Quorum-sensing component
|
Quorum-sensing regulation
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| hapR sequence | HapR productiona | lux expressionb | Mean CT production (μg/ml/OD600) (SD)c | Biofilm formation in LB/SW (OD570)d | Mean HA/protease production (azocasein units) (SD)e | Mean protease recovery (azocasein units) (SD)f | |||
| N16961 (4) | Bangladesh, 1971 | El Tor, O1 | Frameshift | − | − | 0.86 (0.07) | 0.38/0.54 | 3.3 (1.6) | 30.1 (1.7) |
| C6706 (4) | Peru, 1991 | El Tor, O1 | +g | + | + | 2.97 (0.03) | 1.03/0.59 | 22.9 (4.3) | NA |
| HK1 (4) | Hong Kong, 1961 | El Tor, O1 | + | − | − | 2.86 (0.92) | 2.45/1.16 | 2.9 (0.3) | 27.1 (0.5) |
| NCTC8457 (4) | Saudi Arabia, 1910 | El Tor, O1 | + | + | + | 0.08 (0.08) | 1.79/0.84 | 27.6 (7.3) | NA |
| MAK757 (4) | Celebes Islands, 1937 | El Tor, O1 | + | + | − | 0.31 (0.18) | 0.20/0.18 | 1.3 (1.2) | 12.1 (0.8) |
| 857h | Bangladesh, 1996 | El Tor, O1, environmental | + | + | − | NA | 0.20/0.79 | 5.5 (3.5) | 45.1 (0.1) |
| 2740-80 (4) | Gulf Coast, 1980 | El Tor, O1, environmental | + | + | + | NA | 1.25/0.76 | 58.1 (1.9) | NA |
| O395 (4) | India, 1965 | Classical, O1 | Frameshift | − | − | 8.87 (0.97) | 0.15/0.29 | 3.0 (0.1) | 23.6 (1.3) |
| CA401 (12, 16) | India, 1953 | Classical, O1 | + | + | Constitutive | 4.46 (1.40) | 0.15/0.29 | 51.5 (4.7) | NA |
| MO10 (4) | India, 1992 | El Tor, O139 | + | + | − | 0.69 (0.26) | 0.69/0.97 | 0.7 (0.0) | 26.4 (0.3) |
| MDO14 (6, 17, 27) | India, 1992 | El Tor, O139 | + | + | + | 1.42 (0.36) | 0.16/0.58 | 48.7 (2.6) | NA |
| MDO14-T (6, 17, 27) | India, 1992 | El Tor, O139 | No hapR | − | − | 0.69 (0.26) | 0.70/1.04 | 3.8 (0.1) | 38.6 (1.9) |
| SG21 (14) | India, 1992 | El Tor, O139 | C-terminal deletion | Short | Low | 0.70 (0.11) | 0.85/0.74 | 3.3 (0.8) | 24.5 (1.2) |
| SG38-2 (14) | India, 1992 | El Tor, O139 | + | + | Constitutive | 0.06 (0.05) | 1.07/1.50 | 56.2 (0.2) | NA |
| MZO-2 (5) | Bangladesh, 2001 | Non-O1/non-O139 | + | + | + | NA | 0.94/0.83 | 24.4 (4.2) | NA |
| AM15622 (5) | Bangladesh, 2001 | Non-O1/non-O139 | + | + | + | NA | 0.27/0.52 | 52.2 (0.6) | NA |
Results summarized from the Western blot analysis of HapR protein (Fig. 2). −, not produced; +, produced.
Results summarized from strains carrying pBB1 plasmid (Fig. 1). −, not expressed; +, expressed.
Classical strains were grown in LB (pH 6.5) at 30°C. Others were grown under AKI conditions. NA (not applicable) refers to CTX− strains.
Strains were grown in LB or sea water (SW) on a glass surface, and biofilm mass was quantified using dimethyl sulfoxide. The standard deviations were ≤10%.
Cell-free supernatants from cultures grown at 37°C for 7 h were collected and measured for protease activity as described previously.
A plasmid carrying Ptac-hapR was introduced into these strains, and protease activities were then measured. NA, not applicable.
+ the hapR sequence encodes intact HapR protein.
From the strain collection of John Mekalanos.