Identification and characterization of Photorhabdus temperata mutants altered in hemolysis and virulence.
Photorhabdus temperata is a symbiont of the entomopathogenic nematode Heterorhabditis bacteriophora and an insect pathogen. This bacterium produces a wide variety of virulence factors and hemolytic activity. The goal of this study was to identify hemolysin-defective mutants and test their virulence. A genetic approach was used to identify mutants with altered hemolytic activity by screening a library of 10 000 P. temperata transposon mutants. Three classes of mutants were identified: (i) defective (no hemolytic activity), (ii) delayed (delayed initiation of hemolytic activity), and (iii) early (early initiation of hemolytic activity). The transposon insertion sites for these mutants were identified and used to investigate other physiological properties, including insect pathogenesis and motility. The hemolysin-defective mutants, P10A-C11, P10A-H12, and P79-B5, had inserts in genes involved in RNA turnover (RNase II and 5'-pentaphospho-5'-adenosine pyrophosphohydrolase) and showed reduced virulence and production of extracellular factors. These data support the role of RNA turnover in insect pathogenesis and other physiological functions.
Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824-217, USA.|Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824-217, USA.
Christine
C
Chapman
Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824-217, USA.|Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824-217, USA.
Louis S
LS
Tisa
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D015723:Gene Library; D006460:Hemolysin Proteins / Q000235:genetics*; D006461:Hemolysis; D007313:Insecta / Q000382:microbiology; D016254:Mutagenesis, Insertional; D020637:Photorhabdus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology; D012313:RNA / Q000378:metabolism; D017172:Rhabditoidea / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D037521:Virulence Factors; D012313:RNA
activité hémolytique; agent de lutte biologique; biocontrol agent; hemolytic activity; insect pathogen; interactions microbe–nématode; microbe–nematode interactions; mutant créé par un transposon; pathogène d’insecte; transposon mutant