Phenotypic characterization of the Xenorhabdus bacterial symbiont of a Texas strain of the entomopathogenic nematode Steinernema riobrave, and characterization of the Xenorhabdus bovienii bacterial symbiont of a Newfoundland strain of Steinernema fel

摘要

Two bacterial symbionts of entomopathogenic nematodes, one of which originated from Texas, USA., and the other from Newfoundland, Canada, were characterized phenotypically. These strains belonged to the genus Xenorhabdus. The Newfoundland (NF) strain was shown to be X. bovienii but the Texas (TX) strain was not identified at the species level. Four additional cultures of Xenorhabdus were included in the study. These were a strain of X. bovienii (Umea), which was from a nematode of European origin,and strains of X. nematophilus, X. beddingii, and X. poinarii. The tests used in this study indicated identical properties for the NF (North American) and Umea (European) strains of X. bovienii. These could be differentiated from the other strains studied by their failure to grow at 34deg C and resistance to low concentrations of a mixture of amoxilline and clavulanic acid. The Xenorhabdus TX strain could be differentiated from the other strains studied by its failure to grow at 10deg C. Of the tests done, approximately 30 were useful in distinguishing between the strains and species studied.