General overview

Entamoeba coliare a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in large intestine of the human. Both cysts and trophozoites of the species are passed in stool and considered diagnostic . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool.  Colonization of the nonpathogenic amebae occurs after ingestion of mature cysts in fecally-contaminated food, water, or fomites .


E. coli is an intestinal protozoa, which belongs to the genus of Entamoeba that cause disease . One of the diseases caused by some species is Amoebiasis, which is defined as infection with the protozoan parasite Entamoeba histolytica.

Summary of Data

Rendtorff, R. C. (1954)  studied the Entamoeba coli exposure to human volunteers with a known numbers of cysts of E. coli were administered orally in capsules to volunteers to determine numbers of parasites necessary to establish the infection.

 

 

ID Exposure Route # of Doses Agent Strain Dose Units Host type Μodel LD50/ID50 Optimized parameters Response type Reference
45 oral 5.00 From an infected human Cysts human beta-Poisson 3.41E+02 a = 1.01E-01 N50 = 3.41E+02 infection
Rendtorff, R. C. (1954). The experimental transmission of human intestinal protozoan parasites. I. Endamoeba coli cysts given in capsules. American Journal of Hygiene, 59, 2. https://doi.org/https://doi.org/10.1093/oxfordjournals.aje.a119633
Highest quality
Exposure Route:
oral
# of Doses:
5.00
Agent Strain:
From an infected human
Dose Units:
Cysts
Host type:
human
Μodel:
beta-Poisson
LD50/ID50:
3.41E+02
Optimized parameters: a = 1.01E-01 N50 = 3.41E+02
Response type:
infection

Humans model data 
Dose Infected Non Infected Total
1 1 7 8
10 3 7 10
100 2 2 4
1000 0 2 2
1E+04 2 0 2

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential 27.8 22.8 4 3.84 
1.81e-06
9.49 
 1.36e-05
Beta Poisson 5.04 3 7.81 
0.169
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 1.01E-01 1.20E-03 2.60E-02 3.61E-02 2.12E-01 2.57E-01 3.08E-01
N50 3.41E+02 5.02E+00 1.73E+01 2.61E+01 1.48E+05 2.08E+06 1.19E+10

 

 

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

  • Prevention, C. for D. C. and. (2022). Parasites - Nonpathogenic (Harmless) Intestinal Protozoa. Retrieved from https://www.cdc.gov/parasites/nonpathprotozoa/
  • Rendtorff, R. C. (1954). The experimental transmission of human intestinal protozoan parasites. I. Endamoeba coli cysts given in capsules. American Journal of Hygiene, 59, 2. https://doi.org/https://doi.org/10.1093/oxfordjournals.aje.a119633