Plain English Summary
Background and study aims
Healthy human skin and mucosa is colonized by a variety of protective bacteria and microorganisms. A common component of this skin flora is the bacterium Staphylococcus aureus (S. aureus). Dialysis patients are chronically exposed to S. aureus, due to their frequent stays in dialysis centers, hospitals or rest homes, where this bacterium is common. In dialysis patients, the access point for the dialysis is a potential entry site for S. aureus, in particular when using a central venous catheter instead of an arteriovenous fistula. It has been shown that S. aureus carriers have a lower risk of sepsis in case of an endogenous infection (i.e. by their “own” S. aureus strain).
So far, it has not been possible to develop a vaccine that protects against an infection with S. aureus. The aim of this study is to collect information on the functionality of the immune system in dialysis patients, and a long-term reduction of serious clinical complications due to S. aureus infections.
Who can participate?
Hemodialysis patients in the KfH e.V. outpatient dialysis center in Greifswald, and 20 healthy control patients
What does the study involve?
We will follow a group of 86 hemodialysis patients from an outpatient dialysis center over a 30 month period. We will collect their demographic data and medical history, along with taking blood samples, nasal swabs and swabs from the hemodialysis access site every 6 months. These samples and swabs will be tested for S. aureus. We will then compare this to the results from healthy controls to reveal differences resulting from dialysis. We will also look at connections between demographic data and medical history and S. aureus infection.
What are the possible benefits and risks of participating?
The benefit of participating is that we will identify potential risk factors that make the occurrence of a bacterial infection more likely, especially in dialysis patients. We want to get an overview of the types of bacteria that are involved in infections, and we are also interested in the proportion of resistant S. aureus strains. With this knowledge, we aim to minimize the risk of infection for our patients. There are no known risks of participating in this study.
Where is the study run from?
1. University Medicine Greifswald (Germany)
2. Kuratorium für Dialyse und Nierentransplantation e.V., KfH-Nierenzentrum Greifswald (Germany)
When is the study starting and how long is it expected to run for?
January 2015 to December 2018
Who is funding the study?
1. DAMP Foundation (Germany)
2. University Medicine Greifswald (Germany)
Who is the main contact?
Prof. Dr. med. Sylvia Stracke
Mortality and bloodstream infections in hemodialysis patients from an outpatient dialysis center (KfH e.V.) in Greifswald with respect to S. aureus carrier status, colonization density, S. aureus genotyping and host immune response (SaDial-study) compared to the general population of the same geographical region (SHIP-TREND-0)
1. The S. aureus genotypes in hemodialysis patients differ from the general population due to frequent contact with medical environment
2. Nasal S. aureus colonisation protects hemodialysis patients from fatal outcome in case of bloodstream infection by S. aureus
3. The host immune response against S. aureus in hemodialysis patients predicts the course and the outcome of S. aureus sepsis
University Medicine Greifswald, 17/03/2015, internal registration number: BB O29/15
Observational prospective cohort study
Primary study design
Secondary study design
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Staphylococcus aureus bloodstream infection and S. aureus carrier status in hemodialysis patients
A cohort of 86 hemodialysis patients are followed over a 30 month period. Patient demographic data and medical history are collected, followed and statistically evaluated. Blood samples, nasal swabs and swabs from the hemodialysis access site are taken every 6 months for a period of 30 months and are tested for Staphylococcus aureus. The pathogens are cultured and further characterised by spa-PCR and DNA microarrays. Patient samples are analysed for S. aureus-specific antibodies using Luminex, and T-cell responses are analysed using Fluorospot.
20 healthy control patients will receive the same treatment as the cohort of hemodialysis patients; however, swabs and blood and serum samples are only take once in 2015 for this group.
There is no follow-up period.
Primary outcome measure
1. Overall mortality rates, assessed using Kaplan-Meier analysis after the final sampling
2. Course and severity of bloodstream infection, determined by assessing for symptoms such as leukocytosis, fever and systemic inflammatory response syndrome, and a positive test for S. aureus in blood culture. This was assessed at the time of infection, and 7 and 14 days after
Secondary outcome measures
1. S. aureus genotype profiles over time, assessed after each 6 month sampling:
1.1. S. aureus spa-types determined by spa-PCR and out coming sequences classified by Ridom software
1.2. Clonal complexes (CC types) of S. aureus determined using S. aureus Genotyping Kit 2.0 from Alere Technologies (now Abbott)
2. S. aureus specific antibody response over time assessed using a multiplex assay and ELISA, with antibodies isolated every 6 months and stored and overall measurement taken once all samples are collected
3. T-cell response over time, assessed by a Fluorospot assay, with T-cells isolated every 6 months and stored and overall measurement taken once all samples are collected
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Hemodialysis patients of an outpatient dialysis centre (KfH e.V.) in Greifswald
2. Voluntary participation
1. Voluntary participation
2. Aged 50-70
3. Renally healthy
4. In hospital for at least 1 week
Target number of participants
86 hemodialysis patients, 20 renal healthy control patients
Total final enrolment
Participant exclusion criteria
1. Refusal to participate
2. Moving to another town that is not Greifswald
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
(0431) 220 39 60 - 00
University Medicine Greifswald
Körperschaft des öffentlichen Rechts
Funding Body Type
Funding Body Subtype
University Medicine Greifswald
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
S. aureus carrier rates, genetic studies on S. aureus strains and comparison with the general population are currently being published in a peer-reviewed nephrological journal.
Immunological work is planned to be published in the end of 2019 in a high-impact peer-reviewed journal.
IPD sharing statement:
The data could be made available on request after publication.
Intention to publish date
Participant level data
To be made available at a later date
Basic results (scientific)
2019 results in: https://www.ncbi.nlm.nih.gov/pubmed/31060511 (added 08/05/2019)