Table 1.
Genetic and phenotypic profiles of 50 STEC isolates
| Strain | Phylogroup | stx1 | stx2 | eae | Cytotoxicity ± s.e.m. (CVmean)a,b | ppGpp basal level ± s.e.m. (CVmean)a,c | ppGpp induced level ± s.e.m. (CVmean)a,d |
|---|---|---|---|---|---|---|---|
| AS1 | A | − | + | − | 85 ± 22·5 (26) | 0·22 ± 0·026 (12) | 0·41 ± 0·012 (3) |
| AS2 | A | − | + | − | 96 ± 6·5 (9) | 0·30 ± 0·019 (6) | 0·41 ± 0·008 (2) |
| AS3 | A | − | +(b) | − | 26·7 ± 6·6 (35) | 0·27 ± 0·020 (7) | 0·42 ± 0·002 (1) |
| AS4 | A | − | +(b) | − | 32·3 ± 7·0 (28) | 0·30 ± 0·015 (5) | 0·33 ± 0·003 (1) |
| AS5 | A | − | +(b) | − | 38·8 ± 9·7 (35) | 0·28 ± 0·006 (2) | 0·38 ± 0·007 (2) |
| AS6 | A | − | +(b) | − | 22 ± 6·1 (27) | 0·14 ± 0·003 (2) | 0·30 ± 0·014 (5) |
| AS7 | A | − | +(b) | − | 49·9 ± 10·8 (28) | 0·18 ± 0·007 (4) | 0·31 ± 0·013 (4) |
| AS8 | A | − | +(b) | − | 33·2 ± 7·5 (29) | 0·18 ± 0·029 (17) | 0·30 ± 0·025 (8) |
| AS9 | B1 | + | +(b) | − | 90 ± 14·7 (16) | 0·12 ± 0·001 (1) | 0·29 ± 0·025 (9) |
| AS10 | B1 | + | +(b) | − | 74 ± 17·7 (24) | 0·13 ± 0·005 (4) | 0·31 ± 0·009 (3) |
| AS11 | B1 | + | +(b) | − | 65 ± 26·1 (40) | 0·13 ± 0·007 (6) | 0·32 ± 0·010 (3) |
| AS12 | B1 | + | +(b) | − | 39·9 ± 5·8 (19) | 0·13 ± 0·004 (3) | 0·34 ± 0·005 (2) |
| AS13 | B1 | + | +(b) | − | 72 ± 16·8 (23) | 0·12 ± 0·004 (4) | 0·31 ± 0·019 (6) |
| AS14 | B1 | + | +(b) | − | 96 ± 14·8 (16) | 0·10 ± 0·002 (2) | 0·25 ± 0·020 (8) |
| AS15 | B1 | + | +(b) | − | 79 ± 19·9 (25) | 0·10 ± 0·006 (7) | 0·28 ± 0·016 (6) |
| AS16 | B1 | + | +(b) | − | 84 ± 8·4 (13) | 0·10 ± 0·007 (8) | 0·20 ± 0·029 (15) |
| AS17 | B1 | + | +(b) | − | 62 ± 5·6 (9) | 0·11 ± 0·003 (3) | 0·27 ± 0·012 (5) |
| AS18 | B1 | + | +(b) | − | 69 ± 21·3 (31) | 0·09 ± 0·011 (13) | 0·17 ± 0·016 (10) |
| AS19 | B1 | + | +(b) | − | 65 ± 3·29 (5) | 0·08 ± 0·004 (5) | 0·29 ± 0·004 (1) |
| AS20 | B1 | + | +(b) | − | 71 ± 22·1 (31) | 0·08 ± 0·003 (4) | 0·29 ± 0·006 (2) |
| AS21 | B1 | + | +(b) | − | 88 ± 19·6 (22) | 0·08 ± 0·005 (8) | 0·27 ± 0·006 (2) |
| AS22 | B1 | + | +(b) | − | 63 ± 20·8 (33) | 0·09 ± 0·001 (2) | 0·27 ± 0·003 (1) |
| AS23 | B1 | + | +(b) | − | 91 ± 4·2 (5) | 0·09 ± 0·004 (5) | 0·32 ± 0·006 (2) |
| AS24 | B1 | + | − | − | 77 ± 13·3 (17) | 0·13 ± 0·016 (13) | 0·23 ± 0·014 (6) |
| AS25 | B1 | + | − | − | 91 ± 18·1 (20) | 0·09 ± 0·009 (11) | 0·26 ± 0·006 (3) |
| AS26 | B1 | + | − | − | 65 ± 17·1 (26) | 0·10 ± 0·002 (3) | 0·30 ± 0·011 (4) |
| AS27 | B1 | + | − | − | 72 ± 19·5 (27) | 0·11 ± 0·005 (5) | 0·29 ± 0·000 (0·1) |
| AS28 | B1 | + | − | − | 66 ± 25·2 (38) | 0·08 ± 0·008 (10) | 0·31 ± 0·016 (5) |
| AS29 | B1 | + | − | − | 88 ± 14·4 (16) | 0·11 ± 0·003 (3) | 0·21 ± 0·032 (15) |
| AS30 | B1 | + | − | − | 113 ± 14·4 (13) | 0·11 ± 0·007 (7) | 0·18 ± 0·002 (1) |
| AS31 | B1 | + | − | − | 95 ± 28·2 (30) | 0·10 ± 0·006 (6) | 0·22 ± 0·015 (7) |
| AS32 | B1 | + | − | − | 100 ± 13·9 (14) | 0·11 ± 0·001 (1) | 0·22 ± 0·011 (5) |
| AS33 | B1 | + | − | − | 83 ± 25·4 (31) | 0·12 ± 0·005 (4) | 0·28 ± 0·024 (9) |
| AS34 | B1 | + | − | − | 87 ± 18·0 (21) | 0·13 ± 0·021 (16) | 0·23 ± 0·013 (6) |
| AS35 | B1 | + | − | − | 79 ± 23·8 (30) | 0·18 ± 0·008 (5) | 0·28 ± 0·014 (5) |
| AS36 | B1 | + | − | − | 83 ± 19·0 (23) | 0·19 ± 0·009 (5) | 0·28 ± 0·009 (3) |
| AS37 | B1 | + | − | − | 86 ± 30·0 (35) | 0·15 ± 0·011 (7) | 0·27 ± 0·007 (3) |
| AS38 | B1 | + | − | − | 96 ± 8·5 (9) | 0·08 ± 0·008 (10) | 0·26 ± 0·007 (3) |
| AS39 | B1 | + | − | − | 90 ± 11·3 (13) | 0·11 ± 0·014 (14) | 0·28 ± 0·009 (3) |
| AS40 | B1 | + | − | − | 91 ± 22·8 (25) | 0·10 ± 0·012 (12) | 0·28 ± 0·014 (5) |
| AS41 | B1 | + | − | − | 59 ± 22·0 (37) | 0·12 ± 0·005 (5) | 0·31 ± 0·011 (4) |
| AS42 | B1 | + | − | − | 79 ± 13·4 (17) | 0·11 ± 0·003 (3) | 0·32 ± 0·014 (4) |
| AS43 | B1 | + | − | − | 50 ± 19·7 (40) | 0·11 ± 0·004 (4) | 0·22 ± 0·026 (12) |
| AS44 | B1 | + | − | − | 115 ± 7·8 (7) | 0·12 ± 0·008 (7) | 0·22 ± 0·011 (5) |
| AS45 | B1 | + | − | − | 74 ± 8·7 (12) | 0·17 ± 0·009 (5) | 0·29 ± 0·007 (2) |
| AS46 | B1 | + | − | − | 116 ± 12·2 (11) | 0·14 ± 0·004 (3) | 0·27 ± 0·008 (3) |
| AS47 | B1 | + | − | − | 93 ± 21·7 (23) | 0·15 ± 0·000 (0·3) | 0·28 ± 0·016 (4) |
| AS48 | B1 | + | − | − | 110 ± 14·2 (13) | 0·16 ± 0·002 (2) | 0·27 ± 0·022 (8) |
| AS49 | Unknown | + | − | − | 89 ± 30·3 (34) | 0·17 ± 0·004 (3) | 0·25 ± 0·010 (4) |
| AS50 | B1 | + | − | − | 77 ± 16·8 (22) | 0·20 ± 0·009 (5) | 0·36 ± 0·022 (6) |
a
Each values represents the mean ± s.e.m. (standard error of the mean) of three independent experiments.
b
Cytotoxicity against Vero cells relative to the cytotoxicity displayed by strain EDL933.
c
ppGpp level of exponentially growing cells.
d
ppGpp level of phosphate-starved cells.