Evaluation of colorimetric loop‐mediated isothermal amplification assay for visual detection of Streptococcus agalactiae and Streptococcus iniae in tilapia. (26th June 2013)

• Record Type: Journal Article
• Authors: Suebsing, R.; Kampeera, J.; Tookdee, B.; Withyachumnarnkul, B.; Turner, W.; Kiatpathomchai, W.
• Is Part Of: Letters in applied microbiology. Volume 57:Number 4(2013:Oct.)
• Page Start: 317
• Page End: 324
• Publication Date: 2013-06-26
• Subjects: Microbiology -- Periodicals; 660.62
• DOI: 10.1111/lam.12114
• Languages: English
• ISSNs: 0266-8254

Abstract

<abstract abstract-type="main" id="lam12114-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="lam12114-sec-1001" sec-type="section"> <title>Abstract</title> <p> <italic>Streptococcus agalactiae</italic> and <italic>Strep. iniae</italic> are bacterial pathogens that cause streptococcosis in many fish species. An accelerated colorimetric loop‐mediated isothermal amplification (LAMP) assay with pre‐addition of calcein was established, and the transmission and detection of <italic>Strep. agalactiae</italic> and <italic>Strep. iniae</italic> in tilapia under natural aquatic environment were investigated. A positive reaction was observed by a colour change from orange to green through the naked eyes after completion at 63°C for 30 min with 10 times higher sensitivity than that of nested PCR assays and without cross‐amplification with other fish bacterial pathogens. All sample types of Nile and red tilapia (broodstock, fertilized egg, fry) were <italic>Strep. agalactiae</italic>‐ and <italic>Strep. iniae</italic> positive by this new method, implying that they could be vertically transmitted. With its application for screening broodstock and fry before stocking and for monitoring fish health in grow‐out ponds, the method would become very useful in fish farming industry.</p> </sec> <sec id="lam12114-sec-1002" sec-type="section"> <title>Significance and Impact of the Study</title> <p>The application of colorimetric LAMP with pre‐addition of calcein offers simple, rapid and sensitive technique with applicability for small field laboratories. This technique explored the possible vertical transmission mode of <italic>Strep. agalactiae</italic> and <italic>Strep. iniae</italic> under natural aquatic environment. It could be such preliminary data provided for the screening broodstock before breeding and/or the specific‐pathogen–free production.</p> </sec> </abstract>