TABLE 1.

Induction of infective endocarditis in rabbits by various bacterial strains

StrainInoculum (CFU/rabbit)VegetationaLog10 bacteria/g of organ (mean ± SD)a,b
Wt (mg) (mean ± SD)Incidence of infection (no. infected/total no. inoculated)VegetationLiverSpleen
Probiotic strains
    L. casei strain Shirota1.3 × 10915 ± 90/5<1.0<1.0<1.0
6.7 × 10711 ± 80/5<1.0<1.0<1.0
    L. rhamnosus ATCC 531031.1 × 10978 ± 305/58.0 ± 0.92.2 ± 0.81.9 ± 0.7
3.4 × 10732 ± 195/59.0 ± 0.74.1 ± 0.64.3 ± 0.5
Endocarditis clinical isolates
    L. casei PHLS A357/844.1 × 10876 ± 375/57.7 ± 1.01.8 ± 0.51.5 ± 0.5
    L. rhamnosus PHLS A103/706.0 × 108126 ± 535/58.6 ± 1.22.1 ± 1.02.1 ± 0.9
    Staphylococcus aureus IE-1c2.0 × 106611/19.16.46.0
    Streptococcus mitis IE-2d3.5 × 105502/29.54.95.3
Type strains
    L. rhamnosus ATCC 7469T3.0 × 109NTe6/68.3 ± 0.5NTNT
6.0 × 107NT4/58.7 ± 1.5NTNT
    L. acidophilus ATCC 4356T1.5 × 1099 ± 70/4<1.0<1.0<1.0
    L. gasseri DSM 20243T2.4 × 10918 ± 130/3<1.0<1.0<1.0
  • a Three to six rabbits per group were injected with the bacterial strains and were killed for bacteriological examination on the 14th day after the injection except for those injected with S. aureus IE-1 and S. mitis IE-2.

  • b Viable counts of the injected bacteria in the organ homogenates were examined by plating appropriate dilutions after incubation on the agar plates.

  • c The rabbit was dissected on the second day after the challenge, because four out of five rabbits died within 2 days after the challenge.

  • d Rabbits were dissected on the seventh day after the challenge, because three out of five rabbits died by day 7 after the challenge.

  • e NT, not tested.