METHODOLOGY/PRINCIPAL FINDINGS: Two ORFeome phage display libraries of the entire Leptospira spp. genomes from five local strains isolated in Malaysia and seven WHO reference strains were constructed. Subsequently, 18 unique Leptospira peptides were identified in a screen using a pool of sera from patients with acute leptospirosis. Five of these were validated by titration ELISA using different pools of patient or control sera. The diagnostic performance of these five peptides was then assessed against 16 individual sera from patients with acute leptospirosis and 16 healthy donors and was compared to that of two recombinant reference proteins from L. interrogans. This analysis revealed two peptides (SIR16-D1 and SIR16-H1) from the local isolates with good accuracy for the detection of acute leptospirosis (area under the ROC curve: 0.86 and 0.78, respectively; sensitivity: 0.88 and 0.94; specificity: 0.81 and 0.69), which was close to that of the reference proteins LipL32 and Loa22 (area under the ROC curve: 0.91 and 0.80; sensitivity: 0.94 and 0.81; specificity: 0.75 and 0.75).
CONCLUSIONS/SIGNIFICANCE: This analysis lends further support for using ORFeome phage display to identify pathogen-associated immunogenic peptides, and it suggests that this technique holds promise for the development of peptide-based diagnostics for leptospirosis and, possibly, of vaccines against this pathogen.
Aim: The objectives of this study were to determine the leptospirosis seroprevalence and to identify the predominant infecting serovars among cattle.
Materials and Methods: A cross-sectional study involving 420 cattle from six randomly selected districts in Kelantan was conducted. A serological test using the microscopic agglutination test was conducted in the Institute of Medical Research with a cutoff titer for seropositivity of ≥1:100.
Results: The overall prevalence of leptospirosis seropositivity among cattle in this study was 81.7% (95% confidence interval: 63.5, 80.1). The most common reaction obtained with the sera tested was from the serovar Sarawak with 78.8%.
Conclusion: A high seroprevalence of leptospiral antibodies was found among cattle in Northeastern Malaysia. These findings urge that more studies are required to determine the reasons for the high seroprevalence among the cattle along with its transmission and pathogenicity of the local serovar Sarawak.
Methods: A prospective cohort study involving different populations within the Vidarbha regions of Maharashtra, India was conducted through camps organised from May 2009 to October 2015. A total of 568 serum samples were collected from high-risk people recruited as study cohorts based on inclusion criteria, additional risk factors and clinical symptoms. Samples were evaluated by indirect ELISA using the whole-cell antigens of B. abortus. The results were compared with the commercially available IgG detection ELISA kit to ascertain the specificity and sensitivity of the developed test.
Results: Fever, body ache, joint pain, lower back pain, loss of appetite and weight loss were major symptoms associated with the disease. With the cut-off of > 0.8, the positivity of brucellosis infection was at 12.32% (70/568) compared to 9.33% (53/568) as detected by the commercial kit. The in-house developed ELISA method yielded a sensitivity of 87.5% and specificity of 99.18% as compared to the commercial kits (sensitivity -80.30% and specificity -99.6%).
Discussion: The B. abortus S19-derived whole-cell protein-based ELISA is rapid and cost-effective and can be used for screening brucellosis infection in lieu of the commercially available ELISA kits.