LABÉO Frank Duncombe, Caen, France.
Université de Bretagne Occidentale, Brest, France.
J Fish Dis. 2021 Aug;44(8):1169-1177. doi: 10.1111/jfd.13377. Epub 2021 Apr 15.
The current study describes the development and application of a TaqMan real-time PCR assay for the detection of the bacterium Francisella halioticida. Previously, detection of F. halioticida is relied on bacterial culture and conventional PCR; however, the real-time PCR provides many advantages because it is faster, less labour-intensive and reduces the risk of cross-contamination. DNA samples from mussels collected in April 2020 from seven sites in northern Brittany (France) were tested using the newly developed real-time PCR assay. The objective was to screen for the presence of F. halioticida during spring mortality events. The bacterium was detected in 71.4% of the samples tested and was present at all sites except for Saint-Brieuc and Mont-Saint-Michel, two sites which were not concerned by mortality at the time of sampling. Less than a month later, Saint-Brieuc was affected by unusual mortalities and F. halioticida was detected in almost all mussels (81.25%). The findings from this study provide further evidence indicating that F. halioticida may be contributing to mussel mortalities; however, a direct causal relationship has not yet been established. The real-time PCR assay developed in this study allows for rapid, specific and sensitive detection of F. halioticida which should prove useful for future studies concerning the involvement of this bacterium with shellfish mortalities.
本研究描述了一种 TaqMan 实时 PCR 检测方法的开发和应用，用于检测鱼类弗朗西斯氏菌（Francisella halioticida）。之前，鱼类弗朗西斯氏菌的检测依赖于细菌培养和常规 PCR；然而，实时 PCR 具有许多优势，因为它更快、劳动强度更低，并且减少了交叉污染的风险。使用新开发的实时 PCR 检测方法，对 2020 年 4 月从法国布列塔尼北部七个地点采集的贻贝的 DNA 样本进行了测试。目的是在春季死亡事件中筛查鱼类弗朗西斯氏菌的存在。在测试的 71.4%的样本中检测到了该细菌，除了圣布里厄和圣米歇尔山两个当时未发生死亡事件的地点外，所有地点均有该细菌存在。不到一个月后，圣布里厄受到了异常死亡事件的影响，几乎所有贻贝（81.25%）中都检测到了鱼类弗朗西斯氏菌。本研究的结果进一步表明，鱼类弗朗西斯氏菌可能是贻贝死亡的原因之一；然而，尚未建立直接的因果关系。本研究中开发的实时 PCR 检测方法可快速、特异性和敏感地检测鱼类弗朗西斯氏菌，这对于未来涉及这种细菌与贝类死亡的研究应该是有用的。
