Gentilini Fabio, Zanoni Renato Giulio, Zambon Elisa, Turba Maria Elena
Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, Ozzano dell'Emilia, Bologna, Italy (Gentilini, Zanoni, Zambon).
Genefast srl, Valsamoggia, Bologna, Italy (Turba).
J Vet Diagn Invest. 2017 Jan;29(1):100-104. doi: 10.1177/1040638716672503. Epub 2016 Dec 20.
We compared 2 novel loop-mediated isothermal amplification (LAMP) assays that target either the 16S ribosomal RNA ( rrs) gene or the gene encoding a 32-kDa leptospiral lipoprotein ( lipL32) in order to assess the effect of the target on the accuracy of the LAMP assays. The most sensitive assay was the rrs assay with a limit of detection (LOD) of 1.2 × 10 genome equivalents per reaction. The novel lipL32 assay showed an LOD of 1.2 × 10 genome equivalents per reaction. Both assays showed adequate specificity when tested against a collection of bacteria commonly found in voided canine urine. However, when field samples were assayed, the rrs assays gave many false-positive results and a poor positive predictive value of 8.33%. In conclusion, even if the LAMP assay is used in low prevalence areas, the lipL32 assay would be preferable. Conversely, the higher analytical sensitivity of the rrs assay could be effectively used as a screening test in endemic areas with high disease prevalence, followed by confirmation of the positive results using the lipL32 assay.
我们比较了两种新型环介导等温扩增（LAMP）检测方法，一种靶向16S核糖体RNA（rrs）基因，另一种靶向编码32 kDa钩端螺旋体脂蛋白（lipL32）的基因，以评估靶标对LAMP检测准确性的影响。最灵敏的检测方法是rrs检测，每个反应的检测限（LOD）为1.2×10个基因组当量。新型lipL32检测显示每个反应的LOD为1.2×10个基因组当量。当针对犬类尿液中常见的一系列细菌进行测试时，两种检测方法均显示出足够的特异性。然而，在对现场样本进行检测时，rrs检测产生了许多假阳性结果，阳性预测值较低，为8.33%。总之，即使在疾病低流行地区使用LAMP检测，lipL32检测也更可取。相反，rrs检测较高的分析灵敏度可有效地用作疾病高流行的流行地区的筛查试验，随后使用lipL32检测对阳性结果进行确认。
