TABLE 1.
L. monocytogenes strains used and their characteristic morphological and physiological properties identified in this study
| Strain | Serotype | Reference strain no. | Origin | Cell morphology
|
Colony area (μm2)a
|
Titer by ELISA (A492) with anti-p60 MAbb | |||
|---|---|---|---|---|---|---|---|---|---|
| Form | Designation | Length (μm)c | TSYEA | LSA | |||||
| S1 | 4b | NCTC 11994 | Adult meningitis | Single, paired cells | Wild-type smooth | 3.0 ± 1.0 A | (6.1 ± 0.6) × 105 A | (9.4 ± 0.6) × 104 A | 0.63 ± 0.06 B |
| S2 | 4b | NCTC 9863 | Infantile meningitis | Single, paired cells | Wild-type smooth | 3.7 ± 1.2 A | (6.4 ± 0.4) × 105 A | (2.1 ± 1.1) × 105 B | 0.53 ± 0.09 B |
| S3 | 1/2a | NCTC 10357 | Type strain (rabbit) | Single, paired cells | Wild-type smooth | 3.3 ± 0.9 A | (5.9 ± 0.3) × 105 A | (1.7 ± 0.7) × 105 B | 0.55 ± 0.04 B |
| RId | 1/2a | SLCC 5764 | Kathariou et al. (13) | Long cell chains | MCR variant | 71 ± 18.9 B | (1.1 ± 0.8) × 106 B | (1.2 ± 0.7) × 106 C | 0.26 ± 0.08 D |
| RIIe | 1/2a | Kathariou et al. (13) | Long cell chains | MCR variant | 80 ± 28.1 B | (1.6 ± 1.3) × 106 B | (1.8 ± 0.8) × 106 C | 0.28 ± 0.02 D | |
| RIII | 1/2a | SLCC 5779 | J. Potel (see text) | Long cell chains | MCR variant | 81.5 ± 19.1 B | (1.8 ± 0.9) × 106 B | (2.1 ± 0.8) × 106 C | 0.23 ± 0.03 D |
| PHLRII | L7071 | Dried custard powder | Long cell chains | MCR variant | 68.8 ± 22.4 B | (9.1 ± 1.1) × 105 B | (9.4 ± 0.7) × 105 C | 0.31 ± 0.05 D | |
| SURIf | 4b | Rowan and Anderson (23) | Long filaments | FR variant | 56.1 ± 31 B | (9.5 ± 0.5) × 105 B | (9.8 ± 1.3) × 105 C | 0.60 ± 0.06 B | |
| SURIIg | 4b | Rowan and Anderson (23) | Long filaments | FR variant | 59.2 ± 37.9 B | (9.7 ± 1.1) × 105 B | (1.0 ± 0.8) × 106 C | 0.49 ± 0.08 C | |
| SURIIIh | 1/2a | This study | Long filaments | FR variant | 61.7 ± 42.1 B | (9.5 ± 0.5) × 105 B | (9.7 ± 0.6) × 105 C | 0.58 ± 0.05 B | |
| PHLRI | L6705 | Dried custard powder | Long filaments | FR variant | 49.9 ± 34.1 B | (9.2 ± 0.6) × 105 B | (9.3 ± 0.6) × 106 C | 0.75 ± 0.04 A | |
| PHLRIII | L7346 | Blood culture | Long filaments | FR variant | 58.2 ± 25.3 B | (8.9 ± 0.7) × 105 B | (9.1 ± 1.0) × 105 C | 0.71 ± 0.06 B | |
| PHLRIV | L1342 | Blood culture | Long filaments | FR variant | 73.5 ± 18.3 B | (9.9 ± 0.5) × 105 B | (1.4 ± 1.1) × 106 C | 0.65 ± 0.04 B | |
| RIVd | 1/2a | Kathariou et al. (13) | Cells and long filaments | IR variant | 62 ± 28.3 B | (9.6 ± 1.0) × 105 B | (8.5 ± 1.6) × 105 C | 0.72 ± 0.06 A | |
Mean of area measurements for 20 colonies.
ODs at 492 nm of greater than 0.1 were considered a positive result. BHI broth controls gave a value of 0.03 ± 0.01.
Average length from 20 measurements. Single and paired cells were measured and averaged for the smooth-cell forms. Values in the same column followed by the same letter did not differ at the level of P < 0.05, while values with different letters differed at the level of P < 0.05.
Derived from L. monocytogenes Mackaness (SLCC 5764).
Derived from L. monocytogenes EGD.
Derived from L. monocytogenes NCTC 11994.
Derived from L. monocytogenes NCTC 9863.
Derived from L. monocytogenes NCTC 10357.