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General Overview 

Salmonella is a genus of rod-shaped, gram-negative, non-spore forming, predominantly motile enterobacteria . Many species of Salmonella have been isolated from eggs and egg products . Salmonella meleagridis is one of the most common serotype of Salmonella . Twenty human isolates of S. meleagridis had been identified in Canada so far during 1997.

http://www.cdc.gov/salmonella/

Summary Data

McCullough, and Eisele (1951) inoculated human volunteers orally with the S. Meleagridis strain I,II and III.

Recommended Model

Eexperiment number 238 is the recommended one as the strain I was more virulent than strain III.

Exponential and betapoisson model.jpg

ID Exposure Route # of Doses Agent Strain Dose Units Host type Μodel LD50/ID50 Optimized parameters Response type Reference
238 oral (with eggnog) 11.00 strain I CFU human beta-Poisson 1.68E+04 a = 3.89E-01 N50 = 1.68E+04 infection
McCullough, N. ., & Elsele, C. . (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). https://doi.org/https://doi.org/10.1093/infdis/88.3.278
240 oral (with eggnog) 4.00 strain III CFU human beta-Poisson 5.24E+05 a = 8.85E-01 N50 = 5.24E+05 infection
Muller, D. ., Edwards, M. L., & Smith, D. W. (1983). Changes in Iron and Transferrin Levels and Body Temperature in Experimental Airborne Legionellosis. The Journal of Infectious Diseases, 147, 2. https://doi.org/https://doi.org/10.1093/infdis/147.2.302
Highest quality
Exposure Route:
oral (with eggnog)
# of Doses:
11.00
Agent Strain:
strain I
Dose Units:
CFU
Host type:
human
Μodel:
beta-Poisson
LD50/ID50:
1.68E+04
Optimized parameters: a = 3.89E-01 N50 = 1.68E+04
Response type:
infection
Reference:
Experimental Human Salmonellosis: I. Pathogenicity of Strains of Salmonella Meleagridis and Salmonella Anatum Obtained from Spray-Dried Whole Egg
Human / S. meleagridis strain I data
Dose Infected Non-infected Total
12000 3 3 6
24000 4 2 6
52000 3 3 6
96000 3 3 6
155000 5 1 6
3E+05 6 0 6
720000 4 1 5
1150000 6 0 6
5.5E+06 5 1 6
2.4E+07 5 0 5
5E+07 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 71.8 63.8 10 3.84 
1.33e-15 		18.3 
1.98e-11
Beta Poisson 7.99 9 16.9 
0.535
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.

 

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 3.89E-01 1.23E-01 1.74E-01 2.01E-01 1.12E+00 1.91E+00 3.82E+02
N50 1.68E+04 7.98E+01 1.08E+03 2.27E+03 4.78E+04 5.71E+04 7.49E+04

 

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

Exposure Route:
oral (with eggnog)
# of Doses:
4.00
Agent Strain:
strain III
Dose Units:
CFU
Host type:
human
Μodel:
beta-Poisson
LD50/ID50:
5.24E+05
Optimized parameters: a = 8.85E-01 N50 = 5.24E+05
Response type:
infection
Reference:
Changes in Iron and Transferrin Levels and Body Temperature in Experimental Airborne Legionellosis
Human/ S. meleagridis strain III data 
Dose Infected Non-infected Total
158000 1 5 6
1.5E+06 5 1 6
7680000 6 0 6
1E+07 5 1 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 7.81 5.51 3 3.84 
0.019 		7.81 
0.0501
Beta Poisson 2.3 2 5.99 
0.316
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.

 

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 8.85E-01 1.78E-01 2.91E-01 3.68E-01 1.40E+03 1.71E+03 8.24E+03
N50 5.24E+05 4.71E+04 1.20E+05 1.92E+05 1.19E+06 1.39E+06 1.90E+06

 

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

  • Chalker, R. B., & Blaser, M. J. (1988). A review of human salmonellosis: III. Magnitude of Salmonella infection in the United States. Reviews of Infectious Diseases, 10, 111-124.
  • McCullough, N. ., & Elsele, C. . (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). https://doi.org/10.1093/infdis/88.3.278
  • Zaidi, M. B., McDermott, P. F., Fedorka-Cray, P. ., Leon, V. ., Canche, C. ., … Hubert, S. K. (2006). Nontyphoidal Salmonella from human clinical cases, asymptomatic children, and raw retail meats in Yucatan, Mexico. Clinical Infectious Diseases, 42, 21–28.
  • McCullough, N. ., & Elsele, C. . (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). https://doi.org/https://doi.org/10.1093/infdis/88.3.278