An overview on the molecular diagnosis of animal leptospirosis

• Published in: Letters in applied microbiology Vol. 72; no. 5; pp. 496 - 508
• Main Authors: Di Azevedo, M.I.N., Lilenbaum, W.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.05.2021
• Subjects: animal reproduction; Animals; Animals, Domestic; Bacterial Outer Membrane Proteins - genetics; chronic animal leptospirosis; Chronic infection; Deoxyribonucleic acid; Diagnosis; DNA; DNA sequencing; Domestic animals; Gene sequencing; genes; genetic marker; Genetic markers; Leptospira; Leptospira - genetics; Leptospira sp; Leptospirosis; Leptospirosis - diagnosis; Leptospirosis - veterinary; Lipoproteins - genetics; Markers; microbiology; Molecular Diagnostic Techniques - methods; molecular tools; PCR; Polymerase chain reaction; quantitative polymerase chain reaction; Real-Time Polymerase Chain Reaction - methods; Reproductive disorders; Reproductive system; SEC Translocation Channels - genetics; SecY gene; Sensitivity and Specificity; Sequence Analysis, DNA; Target detection; Urinary tract; chronic animal leptospirosis; Leptospira sp; molecular tools; PCR; genetic marker
• ISSN: 0266-8254; 1472-765X; 1472-765X
• DOI: 10.1111/lam.13442

The most common presentation of animal leptospirosis is the subclinical and silent chronic form, that can lead to important reproductive disorders. The diagnosis of this chronic form remains a challenge. The aim of the present study is to gather and critically analyse the current information about molecular tools applied to animal leptospirosis diagnosis, particularly the silent chronic presentation of the infection. Regarding clinical specimens, samples from urinary tract were the most used (69/102, 67·7%), while few studies (12/102, 11·8%) investigated samples from reproductive tract. Concerning the molecular methods applied, the most used is still the conventional polymerase chain reaction (PCR) (46/102, 45%), followed by real‐time PCR (38/102, 37·2%). The lipL32 gene is currently the most common target used for Leptospira detection, with 48% of studies applying this genetic marker. From all the studies, only few (21/102, 20·5%) performed gene sequencing. According to the majority of authors, current evidence suggests that lipL32‐PCR is useful for an initial screening for Leptospira DNA detection in animal clinical samples. Posteriorly, if DNA sequencing could be performed on positive lipL32‐PCR samples, we encourage the use of secY gene as a genetic marker. The molecular methods appear as the most important tools for the diagnosis of the chronic silent leptospirosis on domestic animals, reinforcing its evident impact not only on animal reproduction but also on a One Health context. Significance and Impact of the Study: The most common presentation of animal leptospirosis is the subclinical and silent chronic form. In this context, much progress has been made in studies with other microorganisms, but in the case of leptospirosis it is still neglected, requiring further studies and standardization. Although the diagnosis of the acute disease is reasonably standardized both for the direct and indirect methods, the diagnosis of the silent chronic form of animal leptospirosis remains a challenge. Since culturing of leptospires is difficult and cannot be performed on large scale, the molecular methods appear as the most important tools for the diagnosis of this silent form on domestic animals, reinforcing its evident impact not only on animal reproduction but also on a One Health context