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Experiment ID
246
Pathogen
Salmonella nontyphoid
Agent Strain
strain 216 and 219
Contains Preferred Model
Yes
Reference
Meynell, G. G., & Meynell, E. W. (1958). The growth of micro-organisms in vivo with particular reference to the relation between dose and latent period. The Journal of Hygiene, 56(3). https://doi.org/10.1017/s0022172400037827
Exposure Route
intraperitoneal
Response
death
Host type
mice
# of Doses
10.00
Dose Units
CFU
Μodel
beta-Poisson
a
2.1E-01
N50
4.98E+01
LD50/ID50
4.98E+01
Description
Mice/Salmonella strain 216 and 219 data 
Dose Dead Survived Total
5 7 8 15
25 4 11 15
125 7 8 15
630 9 6 15
3160 8 7 15
16000 13 2 15
8E+04 15 0 15
4E+05 15 0 15
2E+06 15 0 15
1E+07 15 0 15

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value 		χ20.95,m-k 
p-value
Exponential 133 113 9 3.84 
0 		16.9 
0
Beta Poisson 20.5 8 15.5 
0.00846
Neither the exponential nor beta-Poisson fits well; beta-Poisson is less bad.

 

Optimized parameters for the beta-Poisson model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
α 2.1E-01 1.45E-01 1.58E-01 1.65E-01 2.92E-01 3.14E-01 3.63E-01
N50 4.98E+01 8.10E+00 1.40E+01 1.72E+01 1.31E+02 1.62E+02 2.34E+02

 

Parameter scatter plot for beta Poisson model ellipses signify the 0.9, 0.95 and 0.99 confidence of the parameters.

beta Poisson model plot, with confidence bounds around optimized model

References

  • Meynell, G. G., & Meynell, E. W. (1958). The growth of micro-organisms in vivo with particular reference to the relation between dose and latent period. The Journal of Hygiene, 56(3). https://doi.org/10.1017/s0022172400037827