Characterization of Resistance Against Live-attenuated Diarrhoeagenic E. Coli
- Conditions
- DiarrheaBacterial InfectionsEscherichia Coli InfectionsGastroenteritis
- Interventions
- Biological: E. coli strain E1392-75-2A
- Registration Number
- NCT02541695
- Lead Sponsor
- NIZO Food Research
- Brief Summary
Although the existing diarrhoeagenic Escherichia coli (E. coli) challenge model is already suitable for dietary interventions in its current form, further characterization of the working-mechanism of the attenuated strain and further optimization of the study design will enable the investigators to better select those ingredients that affect the key pathophysiological processes. The aim of the CORAL study is to further characterize and increase the discriminative power of the diarrhoeagenic E. coli challenge model.
- Detailed Description
Primary Objective:
In the CORAL study the investigators want to determine whether increasing the inoculation dose of diarrhoeagenic Escherichia coli (E. coli) to 5E10 Colony Forming Units (CFU) (at day 14) and addition of a second challenge 1E10 CFU (at day 35) will result in an increased effect-size and duration of measurable outcomes and in an expansion of the relevant clinical and biomarker readouts of the challenge model.
Secondary Objective:
By extensive biomarker and transcriptome analysis of blood and fecal samples, the investigators aim to explore the working mechanism of the non-toxin producing diarrhoeagenic E. coli strain and the kinetics of the host response to this infection. In addition, the investigators want to determine whether adding extended fasting and addition of a standardized evening meal, prior to the inoculation day, will result in a decreased between-subject variation.
Study design:
The CORAL study is a parallel 7-weeks intervention study. Subjects will be randomly assigned to one of two inoculation dosages of a live attenuated diarrhoeagenic E. coli (n=20 per group). Subjects will be instructed to maintain their usual pattern of physical activity and their habitual food intake, but to standardize their dietary calcium intake. After a standardized evening meal and an overnight fast, subjects will be orally infected with a live, but attenuated, diarrhoeagenic E. coli (strain E1392-75-2A; collection NIZO food research; dose will be either 1E10 CFU (n=22) or 5E10 CFU (n=22) at study day 14). At study day 35, after a standardized evening meal and an overnight fast, all subjects will receive a second inoculation of 1E10 CFU of the ETEC vaccine (n=44).
At various time points before and after both diarrhoeagenic E. coli challenges an online diary will be kept to record all food and drinks consumption to assess dietary macronutrient intake. Moreover, subjects will report information on stool consistency, frequency and severity of symptoms. At various time points before and after both diarrhoeagenic E. coli challenges venous blood and (complete) stool samples will be collected. Blood and fecal samples are collected to quantify several infection- and immune system markers.
Study population:
Healthy male subjects, 18-55 years of age who fulfil all of the inclusion criteria and none of the exclusion criteria will participate in the CORAL study.
Intervention:
At study day 14 and 35, after a standardized evening meal and an overnight fast, all subjects will receive an inoculation of the diarrhoeagenic E. coli (1E10 CFU (n=22) or 5E10 CFU (n=22) at study day 14; 1E10 CFU (n=40) at study day 35) Subjects will be instructed to maintain their habitual diet, except for their dairy intake. Dairy has a high calcium content and contributes significantly to total daily calcium intake. These dietary guidelines will limit calcium intake on average to 500 mg/day. From our previous studies, we know that calcium can significantly reduce the gastro-intestinal symptoms induced by the E. coli strain.
Main study parameter:
1. Percentage of faecal dry weight (% determined by freeze-drying)
Secondary study parameters:
1. Total faecal wet weight (faecal weight in g/day)
2. Time to first diarrhoeal stool (reported by the subjects in the online diary)
3. Stool consistency (Bristol Stool Scale reported by the subjects in the online diary
4. Number of stools with Bristol Stool Scale \>4 (Bristol Stool Scale reported by the subjects in the online diary)
5. Stool frequency (Stools per day reported by the subjects in the online diary)
6. Incidence and duration of WHO-defined diarrhoea (Calculated from the Bristol Stool Scale and the Stool frequency reported by the subjects in the online diary)
7. The incidence, duration and severity of Gastro-intestinal symptoms (Gastro-intestinal Symptom Rating Scale reported by the subjects in the online diary).
8. In addition, the study contains an explorative phase consisting of biomarker and transcriptome analysis, in order to further explore and identify the mechanism and kinetics of the host response to the infection.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 44
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description 1E10 CFU Escherichia coli (E. coli) E. coli strain E1392-75-2A 1E10 Colony Forming Units (CFU) Diarrhoeagenic E. coli (strain E1392-75-2A; collection NIZO food research). Diarrhoeagenic E. coli strain E1392/75-2A serotype O6:H16 belongs to Pathogen class 2 . The strain has a deletion of genes encoding the heat-labile (LT) and heat-stable (ST) toxins and can not produce any toxins. However, it continues to express Colonization Factor Antigen II (CFA/II) and provides 75% protection against challenge with an LT, ST, CFA/II strain. At day 14, after a standardized evening meal and overnight fast, subjects receive a single oral dose of 1E10 CFU of the attenuated diarrhoeagenic E. coli strain E1392-75-2A. At day 35, after a standardized evening meal and overnight fast, all subjects receive a second inoculation 1E10 CFU of the diarrhoeagenic E. coli. 5E10 CFU Escherichia coli (E. coli) E. coli strain E1392-75-2A 5E10 Colony Forming Units (CFU) Diarrhoeagenic E. coli (strain E1392-75-2A; collection NIZO food research). Diarrhoeagenic E. coli strain E1392/75-2A serotype O6:H16 belongs to Pathogen class 2 . The strain has a deletion of genes encoding the heat-labile (LT) and heat-stable (ST) toxins and can not produce any toxins. However, it continues to express Colonization Factor Antigen (CFA/II) and provides 75% protection against challenge with an LT, ST, CFA/II strain. At day 14, after a standardized evening meal and overnight fast, subjects receive a single oral dose of 5E10 CFU of the attenuated diarrhoeagenic E. coli strain E1392-75-2A. At day 35, after a standardized evening meal and overnight fast, all subjects receive a second inoculation 1E10 CFU of the diarrhoeagenic E. coli.
- Primary Outcome Measures
Name Time Method Change in percentage of faecal dry weight from baseline Day 14-17 and Day 35-38 % of faecal dry weight determined by freeze-drying
- Secondary Outcome Measures
Name Time Method Change in total faecal wet weight from baseline Day 14-17 and Day 35-38 Total faecal weight in g/day
Time to first diarrhoeal stool Day 14-15 and Day 35-36 Time to first diarrhoeal stool reported by subjects
Change in Stool frequency from baseline Day 14-17 and Day 35-38 Stools per day reported the subjects
Trial Locations
- Locations (2)
Hospital Gelderse Vallei
🇳🇱Ede, Gelderland, Netherlands
NIZO food research
🇳🇱Ede, Gelderland, Netherlands