Identification, Typing, and Insecticidal Activity of Xenorhabdus Isolates from Entomopathogenic Nematodes in United Kingdom Soil and Characterization of the xpt Toxin Loci
- 1 September 2006
- journal article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 72 (9), 5895-5907
- https://doi.org/10.1128/aem.00217-06
Abstract
Xenorhabdus strains from entomopathogenic nematodes isolated from United Kingdom soils by using the insect bait entrapment method were characterized by partial sequencing of the 16S rRNA gene, four housekeeping genes ( asd , ompR , recA , and serC ) and the flagellin gene ( fliC ). Most strains (191/197) were found to have genes with greatest similarity to those of Xenorhabdus bovienii , and the remaining six strains had genes most similar to those of Xenorhabdus nematophila . Generally, 16S rRNA sequences and the sequence types based on housekeeping genes were in agreement, with a few notable exceptions. Statistical analysis implied that recombination had occurred at the serC locus and that moderate amounts of interallele recombination had also taken place. Surprisingly, the fliC locus contained a highly variable central region, even though insects lack an adaptive immune response, which is thought to drive flagellar variation in pathogens of higher organisms. All the X. nematophila strains exhibited a consistent pattern of insecticidal activity, and all contained the insecticidal toxin genes xptA1A2B1C1 , which were present on a pathogenicity island (PAI). The PAIs were similar among the X. nematophila strains, except for partial deletions of a peptide synthetase gene and the presence of insertion sequences. Comparison of the PAI locus with that of X. bovienii suggested that the PAI integrated into the genome first and then acquired the xpt genes. The independent mobility of xpt genes was further supported by the presence of xpt genes in X. bovienii strain I73 on a type 2 transposon structure and by the variable patterns of insecticidal activity in X. bovienii isolates, even among closely related strains.Keywords
This publication has 30 references indexed in Scilit:
- When mutualists are pathogens: an experimental study of the symbioses between Steinernema (entomopathogenic nematodes) and Xenorhabdus (bacteria)Journal of Evolutionary Biology, 2004
- Toll-like receptor 5 recognizes a conserved site on flagellin required for protofilament formation and bacterial motilityNature Immunology, 2003
- Interactions of Insecticidal Toxin Gene Products from Xenorhabdus nematophilus PMFI296Applied and Environmental Microbiology, 2003
- A Bacitracin-Resistant Bacillus subtilis Gene Encodes a Homologue of the Membrane-Spanning Subunit of the Bacillus licheniformis ABC TransporterJournal of Bacteriology, 2003
- The lumicins: novel bacteriocins fromPhotorhabdus luminescenswith similarity to the uropathogenic-specific protein (USP) from uropathogenicEscherichia coliFEMS Microbiology Letters, 2002
- Oral Toxicity of Photorhabdus luminescens W14 Toxin Complexes in Escherichia coliApplied and Environmental Microbiology, 2001
- Genome sequence of Yersinia pestis, the causative agent of plagueNature, 2001
- Sequence Analysis of Insecticidal Genes from Xenorhabdus nematophilus PMFI296Applied and Environmental Microbiology, 2001
- Pathogenicity Islands and the Evolution of MicrobesAnnual Review of Microbiology, 2000
- IS1327,a New Insertion-Like Element in the Pathogenicity-Associated Plasmid ofErwinia herbicolapv.gypsophilaeMolecular Plant-Microbe Interactions®, 1996