TABLE 2.
Outer membrane defects of lpp and pal cells
| Strains | OMVa | RNaseb | β-Lacc | SDSd | Vand |
|---|---|---|---|---|---|
| KS272pT7 | 0 | 0 | 9 | >2 | 160 |
| KS303 pT7 | ++ | ++ | 70 | <0.1 | 100 |
| JC8056 pT7 | 0 | 0 | 11 | >2 | 180 |
| JC892pT7 | + | ++ | 71 | <0.1 | 25 |
| KS303pLpp | 0 | 0 | 25 | 1.0 | 170 |
| KS303pPal | 0 | 0 | 17 | >2 | >200 |
| JC892pLpp | + | ++ | 68 | 0.2 | 25 |
| JC892pPal | 0 | 0 | 28 | >2 | 200 |
a
Amounts of outer membrane vesicles observed by electron microscopy after negative staining of cells grown on agar plate. ++, many vesicles on all the cells; +, some vesicles on most cells; 0, no vesicle on most cells.
b
RNase I leakage. The clear zone of RNA hydrolysis was larger (++) or smaller (+) than the size of the colony. 0, no leakage.
c
β-Lactamase activity present in the supernatant indicated in percent of the total activity (average values from duplicate experiments ± 10%).
d
SDS (% [wt/vol]) and vancomycin (μg/ml) values correspond to a 50% decrease of cell turbidity measured after 3 h of culture (average values from triplicate experiments ± 10%).