Universidade Federal Fluminense, Departamento de Biologia Celular e Molecular, Niterói, RJ, Brasil.
Universidade Federal Fluminense, Programa de Pós-Graduação em Biotecnologia, Niterói, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2023 May 12;118:e220265. doi: 10.1590/0074-02760220265. eCollection 2023.
Leptospirosis is an emerging zoonosis that affects humans and animals. Immunochromatography rapid test is widely used for early diagnosis of leptospirosis, but with low sensitivity and specificity.
To evaluate Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography.
Insoluble fraction derived from the crude bacterial extract was obtained by serial centrifugation. The polypeptide profile was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immune reactivity of this fraction was assessed by Western Blotting and lateral flow immunochromatography (LFI). It was tested 160 microagglutination test (MAT)-positive sera from patients in the acute phase, 100 MAT-negative sera from patients with acute febrile illness, and 45 patients with other infectious diseases.
There was a predominance of low molecular mass-polypeptide bands, ranging from 2 to 37 kDa. The antibody reactivity of theses polypeptides was found to range from 13-50%, especially between 10 and 38 kDa. Among MAT-positive sera of patients with leptospirosis in the acute phase, 97% were also positive in LFI, indicating high sensitivity. Among MAT-negative sera, all were negative in LFI, indicating high specificity. Only 2% of cross-reactivity was detected.
The insoluble fraction can be a valuable antigen source for development of point-of-care diagnosis test for leptospirosis.
钩端螺旋体病是一种新兴的人畜共患传染病。免疫层析快速检测法广泛用于钩端螺旋体病的早期诊断，但敏感性和特异性均较低。
评估问号钩端螺旋体不可溶性部分作为侧向流动免疫层析法的潜在抗原来源。
通过连续离心从粗菌提取物中获得不可溶部分。使用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）确定多肽图谱。通过 Western Blotting 和侧向流动免疫层析法（LFI）评估该部分的免疫反应性。检测了 160 份来自急性期患者的微凝集试验（MAT）阳性血清、100 份来自急性发热疾病患者的 MAT 阴性血清和 45 份来自其他传染病患者的血清。
存在大量低分子量多肽带，分子量范围为 2 至 37 kDa。发现这些多肽的抗体反应性在 13-50%之间，尤其是在 10 至 38 kDa 之间。在钩端螺旋体病急性期的 MAT 阳性患者血清中，97%也在 LFI 中呈阳性，表明敏感性高。在 MAT 阴性血清中，LFI 均为阴性，表明特异性高。仅检测到 2%的交叉反应性。
不可溶部分可以作为开发即时检测钩端螺旋体病的有价值的抗原来源。
