TABLE 4.
Membrane integrity of macrophages and HEp-2 epithelial cells incubated with strains of Y. enterocolitica
| Strain | LDH retention (%) bya:
|
Trypan blue exclusion (%) fromb:
|
||
|---|---|---|---|---|
| Macrophages | HEp-2 cells | Macrophages | HEp-2 cells | |
| W22703 (pYV+, biotype 2) | 84.6 ± 4.5 | 72.1 ± 4.4 | 78.7 ± 3.3 | 76.2 ± 4.8 |
| W22703c (pYV−, biotype 2) | 98.5 ± 0.9 | 97.8 ± 1.4 | 98.7 ± 1.3 | 99.1 ± 0.6 |
| 937 (clinical, biotype 1A) | 99.9 ± 0.1 | 99.9 ± 0.1 | 99.9 ± 0.1 | 99.9 ± 0.1 |
| AM5 (nonclinical, biotype 1A) | 99.9 ± 0.1 | 99.9 ± 0.1 | 99.9 ± 0.1 | 99.9 ± 0.1 |
a
The percentage of LDH retention by cells incubated with bacteria is expressed as the percentage of LDH retained by uninfected control cells. Results are expressed as mean ± standard deviation of at least three independent determinations. The assay and the equation for calculating the amount of LDH released are provided in Materials and Methods.
b
Data are the percentage of macrophages and HEp-2 cells incubated with bacteria that excluded trypan blue and are the mean ± standard deviation of at least three independent determinations.