Enhanced detection of Taylorella equigenitalis by qPCR using ‘Dry’ swabs.
Abstract: Detection of Taylorella equigenitalis (CEMO) in the horse uses genital swabs. These swabs traditionally have been put in Amies charcoal transport medium for detection by culture but are also used for PCR. We determined the suitability of swabs without transport medium (Dry swabs) for CEMO PCR compared to swabs in Amies charcoal transport medium. The experiment was a factorial design using swab type and dilution of organism in culture suspensions, done in two parts. Simulated genital swabs were prepared in the laboratory by dipping in pairs into culture suspensions containing T. equigenitalis with or without other organisms, and then inserting them into a sleeve either with or without transport medium. In study 1, the difference in Ct value for the two swab types was compared. In study 2 genital swab material was then also added to culture suspensions and the swab types again compared. The swabs were tested by a validated quantitative PCR method. The Ct value of the PCR test was used as the measure for comparison, and the effect of variables assessed with linear regression. There was an 7.7% (6.5-8.9) higher mean Ct value of TM versus Dry swabs (P<0.001) overall. The Ct difference was more marked at higher dilutions. Addition of genital swab material had no effect on the Ct value. Dry swabs perform at least as well for PCR as swabs in Amies charcoal transport medium, especially when relatively low numbers of organism are present, and are advantageous for routine sampling when culture is not being used.
©2023 The Japanese Society of Equine Science.
Publication Date: 2023-03-24 PubMed ID: 37155493PubMed Central: PMC10122987DOI: 10.1294/jes.34.7Google Scholar: Lookup
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- Journal Article
- Clinical Study
- Contagious Equine Metritis
- Diagnosis
- Diagnostic Technique
- Disease
- Disease Diagnosis
- Disease Management
- Epidemiology
- Equine Diseases
- Equine Health
- Horses
- In Vitro Research
- Infection
- Infectious Disease
- Laboratory Methods
- Pathogens
- Polymerase Chain Reaction
- Taylorella equigenitalis
- Veterinary Medicine
- Veterinary Research
Summary
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This study assesses the suitability of using ‘Dry’ swabs, swabs without transport medium, to detect the bacterium Taylorella equigenitalis in horses via PCR testing, in comparison to traditional swabs that use Amies charcoal transport medium. The findings conclude that ‘Dry’ swabs perform at least equivalently in this application, and may even be advantageous for routine sampling when culture is not being used.
Study Aim and Design
- The aim of this study was to determine if dry swabs, ones that are not placed in a transport medium after collection, can be as effective as Amies Charcoal transport medium based swabs for detecting Taylorella equigenitalis via PCR testing.
- The design of the experiment involved a factorial structure using both the type of swab and the dilution of organism in culture suspensions.
- Simulated genital swabs were prepared for the research by dipping them into a culture suspension containing T. equigenitalis along with other organisms, and then placed them inside a protective sleeve, either with or without transport medium. This was conducted in two stages.
Research Procedure and Techniques
- In the first part of the experiment, the researchers compared ‘cycle threshold’ (Ct value) differences between the two swab types.
- In the second part, they introduced genital swab material into the cultural suspensions and recompared the swab types.
- The researchers then tested the swabs using a validated quantitative PCR method. This method amplifies and quantifies DNA, thereby providing a measure of the presence and amount of T. equigenitalis in the sample.
- The Ct values of the PCR tests were used as the comparative measure. Effects of variables were assessed through linear regression.
Outcomes and Conclusion
- The study found that dry swabs had a 7.7% higher mean Ct value compared to the swabs in a transport medium. The difference was particularly evident at higher dilutions.
- The inclusion of genital swab material did not affect the Ct value.
- In conclusion, dry swabs are at least as effective for PCR detection of T. equigenitalis as transport medium-based swabs, especially with a relatively low number of organisms are present, hence advantageous for routine sampling when culture is not being used.
Cite This Article
APA
Mawhinney I, Bollard A.
(2023).
Enhanced detection of Taylorella equigenitalis by qPCR using ‘Dry’ swabs.
J Equine Sci, 34(1), 7-12.
https://doi.org/10.1294/jes.34.7 Publication
Researcher Affiliations
- APHA Bury St Edmunds, Rougham Hill, Bury St Edmunds, IP33 2RX, UK.
- ETQAS Quality Assurance Unit, APHA Sutton Bonington, Loughborough, LE12 5RB, UK.
References
This article includes 12 references
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