A subset of naturally isolated Bacillus strains show extreme virulence to the free-living nematodes Caenorhabditis elegans and Pristionchus pacificus

摘要: The main food source of free-living nematodes in the soil environment is bacteria, which can affect nematode development, fecundity and survival. In order to occupy a reliable bacterial food, some have formed specific relationships with an array invertebrate hosts (where bacteria proliferate once dies), thus forming tritrophic system nematode, insect or other invertebrates. We isolated 768 Bacillus strains from (from Germany UK), horse dung beetles fed them genetically tractable Caenorhabditis elegans Pristionchus pacificus isolate nematocidal strains. While C. bacteriovorous P. omnivorous worm that often found association scarab beetles. 20 (consisting B. cereus, weihenstephanensis, mycoides sp.) were pathogenic causing 70% 100% mortality over 5 days significantly development brood size. most are three cereus-like beetles, exhibit extreme virulence less than 24 h, but remains resistant. Bre mutants also highly susceptible indicating their toxins use different mechanism thuringiensis Cry 5B toxin. Also, mutations daf-2/daf-16 insulin signaling pathway do not rescue profiled toxin genes (bcet, nhe complex, hbl pcpl, sph, cytK, piplc, hly2, hly3, entFM entS) these showed presence absence complex. Taken together, this study shows majority naturally soil, Geotrupes benign both pacificus. Among distinct patterns against two nematodes, we selected investigate resistance susceptibility immune responses nematodes.