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General Overview

Salmonella enterica serotype Newport is a gram-negative intracellular bacterium of considerable animal and public health concern. It causes significant clinical disease in livestock, particularly cattle, in humans, and in other animal species. Multiple antimicrobial resistant strains of Salmonella Newport have been recorded in the U.S. and Canada. [1]

http://www.cdc.gov/salmonella/typhiTyphimurium-cantaloupe-08-12/

Summary Data

McCullough and Eisele orally inoculated human volunteers with S. Newport in 1951.[2] 

Recommended Model

Experiment number 235 is the only available model , hence it is the recommended model

Exponential and betapoisson model.jpg

ID # of Doses Agent Strain Dose Units Host type Μodel Optimized parameters Response type Reference
235 3 *Salmonella newport* CFU human exponential
k = 3.97E-06
LD50/ID50 = 1.74E+05

infection McCullough, NB, and CW Elsele. "Experimental Human Salmonellosis: I. Pathogenicity of Strains of Salmonella Meleagridis and Salmonella Anatum Obtained from Spray-Dried Whole Egg." Oxford Journal of Infectious Diseases. 88.3 (1951).
Recommended
Experiment ID:
235
# of Doses:
3
Agent Strain:
*Salmonella newport*
Dose Units:
CFU
Host type:
human
Μodel:
exponential
Optimized parameters:
k = 3.97E-06
LD50/ID50 = 1.74E+05

Reference:
Human/Salmonella newportmodel data [2]]
Dose Infected Non-infected Total
152000 3 3 6
385000 6 2 8
1350000 6 0 6

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom		 χ20.95,1 
p-value		 χ20.95,m-k 
p-value
Exponential 0.16 -3.32e-05 2 3.84 
1		 5.99 
0.923
Beta Poisson 0.16 1 3.84 
0.689
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 3.97E-06 1.75E-06 2.16E-06 2.32E-06 7.36E-06 9.04E-06 1.27E-05
ID50/LD50/ETC* 1.74E+05 5.45E+04 7.67E+04 9.41E+04 2.98E+05 3.20E+05 3.97E+05
*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. McCullough, NB., & Elsele CW. (1951).  Experimental Human Salmonellosis: I. Pathogenicity of Strains of Salmonella Meleagridis and Salmonella Anatum Obtained from Spray-Dried Whole Egg. Oxford Journal of Infectious Diseases. 88(3),