TABLE 1.
Bacterial strains used in this study and their cytolytic activities
| Taxon | Strain | Source (host nematode or hospital strain) or reference | Sheep blood hemolysisa | Cytolytic activityb of cell supernatants from stationary phase cultures with:
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| SRBC
|
RRBC
|
IHs
|
|||||||
| Earlyc | Lated | Early | Late | Early | Late | ||||
| Xenorhabdus nematophila | F1/1 | Steinernema carpocapsae | T+ | + | − | − | + | + | + |
| F1/2 | 25 | − | − | − | − | − | − | − | |
| ΩIA (F1/1 flhD::Ω) | 25 | AH | − | − | − | + | − | + | |
| Xenorhabdus japonica | JP02 | Steinernema kushidai | T+ | ++ | + | − | + | ++ | ++ |
| Xenorhabdus bovienii | F3 | Steinernema affine | T+W | +W | +W | − | − | ++ | ++ |
| Xenorhabdus poinarii | G6 | Steinernema glaseri | T+W | + | − | ++ | + | − | − |
| Xenorhabdus beddingii | Q58 | Steinernema sp. | T+W | − | − | − | +W | − | + |
| Xenorhabdus sp. | SaV | Steinernema arenarium | T+W | − | +W | +W | +W | − | + |
| Photorhabdus luminescens subsp. luminescens | Hb/1 (ATCC 29999T) | Heterorhabditis bacteriophora group Brecon | P | − | − | +W | − | − | − |
| Hb/2 | Laboratory collection | − | − | − | − | − | − | − | |
| Photorhabdus luminescens subsp. akhurstii | FRG04 (CIP 105564T) | H. indica | V | − | − | − | − | − | − |
| Photorhabdus luminescens subsp. laumondii | TT01 (CIP 105565T) | H. bacteriophora group HP88 | T+W | − | − | +W | − | − | − |
| Photorhabdus temperata | Meg | H. megidis Nearctic group | V | − | − | − | − | − | − |
| Photorhabdus temperata subsp. temperata | XlNach (CIP 105563T) | H. megidis Palaearctic group | P | − | − | − | − | − | − |
| Photorhabdus asymbiotica | 3265–86 (ATCC 43950T) | CDCe Atlanta | AH | − | − | − | − | − | − |
| 1216–79 (ATCC 43948) | CDC Atlanta | AH | − | − | − | − | − | − | |
All blood agar plates were cultured for 2 days at 28°C before assays were interpreted. Interpretations: T, total hemolysis; P, partial hemolysis; AH, annular hemolysis; +, clearing halo up to 5 mm; +W, perceptible halo with size less than 5 mm; −, hemolysis not detected; V, variable (annular hemolysis or total hemolysis, depending on the plates).
Erythrocyte cytolysis and IH cytolysis were expressed as cytolytic units and percent dead hemocytes, respectively (see Materials and Methods for calculation). ++, value up to 0.75; +, value between 0.25 and 0.75; +W, value less than 0.25; −, cytolytic activity not detected.
Supernatants were collected when bacterial cultures reached an OD540 of about 2.5 (20-h-old cultures).
Supernatants were collected when bacterial cultures reached an OD540 up to 4 (48-h-old cultures).
CDC, Centers for Disease Control and Prevention.