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Experiment ID
242, 243
Pathogen
Legionella pneumophila
Contains Preferred Model
0
Reference
Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection
Host type
mice
# of Doses
9.00
Μodel
exponential
k
4.99E-05
LD50/ID50
1.39E+04
Dose Units
CFU
Response
death
Agent Strain
strain 74/81
Exposure Route
inhalation
Experiment Dataset
Description: 
Dose response data [1][2]
Dose Dead Survived Total
200 0 10 10
4000 1 9 10
1E+04 1 4 5
15000 0 3 3
2E+04 5 2 7
5E+04 12 0 12
5E+04 3 0 3
1E+05 5 0 5
4E+05 16 0 16

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value		 χ20.95,m-k 
p-value
Exponential 8.92 -0.000282 8 3.84 
1		 15.5 
0.349
Beta Poisson 8.92 7 14.1 
0.258
Exponential is preferred to beta-Poisson; cannot reject good fit for exponential.

 

Optimized k parameter for the exponential model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
k 4.99E-05 3.55E-05 3.87E-05 3.95E-05 6.48E-05 6.76E-05 7.46E-05
ID50/LD50/ETC* 1.39E+04 9.29E+03 1.03E+04 1.07E+04 1.75E+04 1.79E+04 1.95E+04
*Not a parameter of the exponential model; however, it facilitates comparison with other models.

 

Parameter histogram for exponential model (uncertainty of the parameter)

Exponential model plot, with confidence bounds around optimized model

References

  1. Fitzgeorge, R. B., Baskerville A., Broster M., Hambleton P., & Dennis P. J. (1983).  Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection. Epidemiology & Infection. 90,
  2. Breiman, R. F., & Horwitz M. A. (1987).  Guinea pigs sublethally infected with aerosolized Legionella pneumophila develop humoral and cell-mediated immune responses and are protected against lethal aerosol challenge. A model for studying host defense against lung infections caused by intracellul. The Journal of Experimental Medicine. 165, 3.