TABLE 4.

S. carpocapsae nematode colonization by Xenorhabdus species

SpeciesPresence of nil locusMean CFU/nematodeaProportion of nematodes colonizedbMean CFU/nematodecMean CFU/colonized nematoded
X. nematophila<0.005<0.001<0.005
X. nematophila+65.5 ± 9.70.9737.7 ± 4.438.8
X. bovienii<0.005<0.001<0.005
X. bovienii+0.89 ± 0.20.0260.6 ± 0.224.0
X. poinarii<0.005<0.001<0.005
X. poinarii+1.2 ± 0.30.1211.1 ± 0.39.1
  • a Mean CFU/nematode for strains lacking the nil locus (X. nematophila Tn7-nil deletion strain HGB777 or X. bovienii or X. poinarii strains with a chromosomal control vector) or carrying the nil locus (wild-type X. nematophila, X. bovienii Tn7-nil, or X. poinarii Tn7-nil). The data represent the means and standard deviations of five replicates.

  • b Colonization frequency was determined by epifluorescence microscopic examination of 1,000 nematodes from duplicate populations reared in cocultures with the indicated species carrying the nil locus and expressing GFP.

  • c Mean CFU/nematode of the indicated species carrying the nil locus and expressing GFP. The data represent the means and standard deviations of five replicates.

  • d Calculated by dividing the mean CFU/nematode in column 4 by the proportion of nematodes colonized in column 3.