Phase variation in Xenorhabdus nematophilus

Antonia Volgyi, A. Fodor, A. Szentirmai, Steven Forst

Research output: Contribution to journalArticle

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Abstract

Xenorhabdus nematophilus is a symbiotic bacterium that inhabits the intestine of entomopathogenic nematodes. The bacterium-nematode symbiotic pair is pathogenic for larval-stage insects. The phase I cell type is the form of the bacterium normally associated with the nematode. A variant cell type, referred to as phase II, can form spontaneously under stationary-phase conditions. Phase II cells do not elaborate products normally associated with the phase I cell type. To better define phase variation in X. nematophilus, several strains (19061, AN6, F1, N2-4) of this bacterium were analyzed for new phenotypic traits. An analysis of pathogenicity in Manduca sexta larvae revealed that the phase II form of AN6 (AN6/II) was significantly less virulent than the phase I form (AN6/I). The variant form of N2-4 was also avirulent. On the other hand, F1/II and 19061/II were as virulent as the respective phase I cells. Strain 19061/II was found to be motile, and AN6/II regained motility when the bacteria were grown in low-osmolarity medium. In contrast, F1/II remained nonmotile. The phase II cells did not produce the outer membrane protein, OpnB, that is normally induced during the stationary phase. Both phase I and phase II cells were able to support nematode growth and development. These findings indicate that while certain phenotypic traits are common to all phase II cells, other characteristics, such as virulence and motility, are variable and can be influenced by environmental conditions.

Original languageEnglish
Pages (from-to)1188-1193
Number of pages6
JournalApplied and Environmental Microbiology
Volume64
Issue number4
Publication statusPublished - 1998

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Xenorhabdus
Xenorhabdus nematophila
nematode
bacterium
motility
Bacteria
cells
bacteria
Nematoda
Virulence
pathogenicity
virulence
growth and development
Manduca
osmolarity
environmental conditions
outer membrane proteins
insect
entomopathogenic nematodes
Manduca sexta

ASJC Scopus subject areas

  • Environmental Science(all)
  • Biotechnology
  • Microbiology

Cite this

Phase variation in Xenorhabdus nematophilus. / Volgyi, Antonia; Fodor, A.; Szentirmai, A.; Forst, Steven.

In: Applied and Environmental Microbiology, Vol. 64, No. 4, 1998, p. 1188-1193.

Research output: Contribution to journalArticle

Volgyi, Antonia ; Fodor, A. ; Szentirmai, A. ; Forst, Steven. / Phase variation in Xenorhabdus nematophilus. In: Applied and Environmental Microbiology. 1998 ; Vol. 64, No. 4. pp. 1188-1193.
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