TABLE 1

Mortality rates among chick embryos inoculated with APEC and NMEC isolates compared using Fisher's exact testd

StrainMortality ratecP value vsa:
DH5αAPEC O2
Uninoculated0/61.000<0.001
PBS3/100.3000.001
E. coli DH5α2/20<0.001
APEC 797/200.127<0.001
APEC 35312/200.0020.064
APEC 35816/20<0.0010.661
APEC 38016/20<0.0010.661
NMEC 1514/20<0.0010.235
NMEC 1811/200.0050.031
NMEC 3819/20<0.0011.000
NMEC 5814/20<0.0010.235
APEC O2b32/40<0.001
  • a P value determined by Fisher's exact test for comparing proportions.

  • b Positive control for the chicken embryo lethality assay.

  • c Data represent the number of embryos that died/total number of embryos tested.

  • d This table is reprinted from reference 6 with permission. APEC, avian-pathogenic E. coli; NMEC, neonatal meningitis E. coli.