Serological diagnosis of Leptospirosis in bovine serum samples using a microsphere immunoassay

Abstract

Leptospirosis causes significant economic loss within the cattle industry worldwide. Current diagnostic methods are generally inadequate for dealing with large numbers of samples, are outdated, and provide little useful diagnostic and epidemiological information. This aim of this study was to apply a microsphere immunoassay (MIA), utilising Luminex xMap technology, to 200 bovine serum samples to determine this method's usefulness in leptospirosis diagnosis in comparison with the current gold standard, the microscopic agglutination test (MAT). Although MAT is the most widely used laboratory test for the diagnosis of leptospirosis, its reliance on live cultures, subjective interpretation of results and an inability to differentiate between antibody classes, suggest MAT is no longer the best method for the diagnosis of leptospirosis. The results presented in this paper show that MIA was able to determine reactive from non-reactive samples when compared with MAT, and was able to differentiate IgG and IgM classes of antibody. The results suggest increased sensitivity in MIA and the ability to multiplex up to 500 antigens at one time allows for significant improvements in cost-effectiveness as well as a reduced dependency on live cultures. The relatively low cost, high throughput platform and differentiation of antibody class, as shown in previous research, make this assay worthy of consideration for the diagnosis of leptospirosis in small-scale or large-scale bovine populations.

Leptospira interrogans Serovar Hardjo Seroprevalence and Farming Practices on Small-Scale Dairy Farms in North Eastern India; Insights Gained from a Cross-Sectional Study

“…The use of the Leptospira serovar Hardjo indirect ELISA kit in this study avoided additional expense and time in comparison to the MAT method [35], acting as a quick and inexpensive screening tool [7,16], thereby providing an insight into how larger-scale, future herd screening programmes could be achieved. The interpretation of a single indirect ELISA result, as done in this study, must be done with caution; low antibody titres do not exclude a diagnosis of leptospirosis, as titres are often low in acute disease and maintenance hosts [36], and the test is focused of only one of many serovars. A second round of sampling should be incorporated into future study designs to offset this diagnostic limitation.…”

Epidemiology of leptospirosis in Tanzania: A review of the current status, serogroup diversity and reservoirs

“…MAT is a widely used diagnostic reference method for many studies, though not accessible in many laboratories due to its cost. MAT testing has many limitations: high levels of PLOS NEGLECTED TROPICAL DISEASES detectable antibodies are needed for a positive result and usually do not occur before the fourth week after disease onset [50](50) and it is time consuming and labour intensive [51,52]. Despite these drawbacks, the MAT test remains the only gold standard serological test and is considered a reference diagnostic test for leptospirosis in many settings [6,53].…”

“…In most studies conducted in Tanzania, the MAT is the only diagnostic test used widely for leptospirosis detection however MAT may be impractical in many clinical laboratories due to the cost and complexity [ 52 ]. An alternative tool, such as rapid diagnostic tests (RDTs), was proposed by a recent policy brief and may be appropriate in a clinical setting for routine screening of patients with non-malaria fever [ 58 ].…”

Molecular and serological diagnostic of leptospirosis: a review (2014–2020)

“…The IgG isotype antibodies appear approximately 10 to 14 days, as they are more specific (Lessa-Aquino et al, 2017). Some serological diagnostic tests aim at an early result with the of IgM in the acute phase of the disease (Alizadeh et al, 2014;Courdurie et al, 2017;Kitashoji et al, 2015;Wynwood et al, 2016). Nonetheless, other tests aim for a more specific response, with the detection of IgG in the convalescent phase (Alizadeh et al, 2014;Anita et al, 2016;Brownlow et al, 2014;Nagalingam et al, 2015;Padilha et al, 2019;Shiokawa et al, 2016;Wynwood et al, 2016;Ye et al, 2014).…”