Ehrlichia canis DIVA Polypeptides for Infection Detection
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Solution Overview
Problem
Current methods fail to accurately distinguish between animals infected with Ehrlichia canis and those vaccinated against it, as vaccination can produce antibodies that interfere with infection detection, leading to unclear infection status.
Innovation Solution
A method involving purified polypeptides with at least 95% identity to specific sequences (SEQ ID NOs:22-33) that specifically bind to antibodies, allowing differentiation between infected and vaccinated animals by detecting binding to these polypeptides in biological samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional E. canis antigens are used for detection, then vaccination-induced antibodies are detected, but infection status cannot be differentiated from vaccination status
Solution Approach 1:
The invention segments the detection system into two distinct antigen components: a conventional E. canis antigen (present in both vaccine and infection) and a DIVA-specific antigen (present only in infection). This segmentation allows the detection system to distinguish between antibodies from vaccination versus infection by detecting different antigen-antibody interactions separately.
Solution Approach 2:
The DIVA-specific antigen acts as an intermediary marker that mediates the differentiation between infected and vaccinated animals. This intermediate antigen provides a bridge for detecting infection status independently of vaccination status, resolving the information loss caused by conventional antigen detection alone.
2Reliability
If E. canis vaccine is administered, then immunity is provided, but antibody interference prevents accurate infection detection
Solution Approach 1:
The detection method segments the immune response assessment into two parts: detection of antibodies against conventional antigens (indicating both vaccination and potential infection) and detection of antibodies against DIVA-specific antigens (indicating infection only). This segmentation enables reliable infection detection in vaccinated animals by isolating the infection-specific signal.
Solution Approach 2:
The invention converts the harmful effect of vaccination-induced antibodies (which mask infection status) into a beneficial diagnostic tool. By detecting the presence or absence of antibodies against DIVA-specific antigens in addition to conventional antigens, the system uses the vaccinated animal's immune profile as information rather than interference, enabling accurate infection status determination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise determination of infection status by distinguishing between infected and vaccinated animals, facilitating effective treatment and monitoring of Ehrlichia canis infections.
Implementation Method 1
one or more first purified polypeptides that do not specifically bind to antibodies that are a component of the animal's immune response to an E. canis vaccine; wherein the one or more first purified polypeptides have at least 95% identity to SEQ ID NOs:22-33 and wherein the one or more first purified E. canis polypeptides specifically bind an antibody that is specific for E. canis
Data Source
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AI summary
The invention provides Ehrlichia canis antigens that can be used to detect E. canis infected animals regardless of whether the animals have been vaccinated for E. canis. The invention also provides compositions and methods for determining the presence of E. canis antigens and antibodies.