Serological Analysis by Enzyme-Linked Immunosorbent Assay Using Recombinant Antigen LipL32 for the Diagnosis of Swine Leptospirosis

Abstract

Leptospirosis is an important global zoonotic disease caused by pathogenic Leptospira spp. species. Swine leptospirosis has a major economic impact because pigs are sources of animal protein and by-products. The signs of swine leptospirosis are abortion, stillbirth, birth of weak or ill piglets, appearing 14-60 days after infection. The reference method for diagnosis of leptospirosis is the microscopic agglutination test (MAT), in which serum samples are reacted with live antigen suspensions of leptospiral serovars. However, MAT is laborious and time consuming as a diagnostic procedure when dealing with a large number of samples; therefore, efforts are being made to develop novel, sensitive, and specific diagnostic tests for leptospirosis. In this study, a recombinant LipL32 based on enzyme-linked immunosorbent assay (rLipL32/ELISA) was evaluated as a screening test for the detection of pathogenic leptospiral-specific antibodies. A total of 86 swine serum samples tested by MAT were used to develop rLipL32/ELISA. Compared to positive and negative sera tested by MAT, rLipL32/ELISA showed 100 % sensitivity, 85.1 % specificity, and 91.86 % accuracy. No positive reaction for other bacterial diseases (enzootic pneumonia and brucellosis) was observed. The rLipL32/ELISA reported in this study is a specific, sensitive, and convenient test for the detection of antibodies against swine leptospiral infection and can be used as a rapid screening test in epidemiological surveys.

Development of an Enzyme-Linked Immunosorbent Assay Using a Recombinant LigA Fragment Comprising Repeat Domains 4 to 7.5 as an Antigen for Diagnosis of Equine Leptospirosis

“…Most state animal diagnostic laboratories in the United States use MAT for the serologic diagnosis of animal leptospirosis. Because of the serious drawbacks of the MAT assay, numerous attempts have been made to develop a serodiagnostic ELISA (10)(11)(12)(13)(14)(15)(16)(17)(18) or to develop a dual-path platform (DPP) assay (19). We previously used the LigACon protein for diagnosis of equine and canine leptospirosis (26,27).…”

“…Previously, several research groups have attempted to utilize different recombinant proteins from Leptospira spp. as antigens in an indirect enzyme-linked immunosorbent assay (ELISA) as a serodiagnostic test (10)(11)(12)(13)(14)(15)(16)(17)(18)(19). However, as far as we know, no one has applied them to equine leptospirosis diagnosis.…”

Recombinant LipL32 Protein Developed Using a Synthetic Gene Detects Leptospiraspecific Antibodies in Human Serum Samples

“…This issue needs further confirmation by PCR or testing of serum samples of healthy controls from nonendemic regions. The interpretation of the MAT assay is complicated due to subjectivity and the high degree of cross-reactions occurring among different serogroups, especially in acute-phase samples (28).…”

Serodiagnosis of Equine Leptospirosis by Enzyme-Linked Immunosorbent Assay Using Four Recombinant Protein Markers

“…The diagnosis of leptospirosis by MAT, bacterial culture, PCR, realtime PCR, and/or histopathological examination has been reported previously (21). Because of the serious drawbacks of these assays, numerous attempts have been made to develop an ELISA serodiagnostic test (22)(23)(24)(25)(26)(27)(28)(29)(30) or to develop a dual-path platform (DPP) assay (31). We previously used the rLigA protein for diagnosis of equine and canine leptospirosis (11,32,33).…”