Leptospirosis, a zoonotic disease that is caused by many serovars which are more than 200 in the world, is an emerging worldwide disease. Accurate and rapid diagnostic tests for leptospirosis are a critical step to diagnose the disease. There are some commercial kits available for diagnosis of leptospirosis, but the obscurity of a species- or genus-specific antigen of pathogenic Leptospira interrogans causes the reduced sensitivity and specificity. In this study, the polysaccharide derived from lipopolysaccharide (LPS) of nonpathogenic Leptospira biflexa serovar patoc was prepared, and the antigenicity was confirmed by immunoblot and enzyme linked immunosorbent assay (ELISA). The performance of the rapid diagnostic test (RDT) kit using the polysaccharide as a diagnostic antigen was evaluated in Korea, Bulgaria and Argentina. The sensitivity was 93.9%, 100%, and 81.0% and the specificity was 97.9%, 100%, and 95.4% in Korea (which is a rare region occurring with 2 serovars mostly), Bulgaria (epidemic region with 3 serovars chiefly) and Argentina (endemic region with 19 serovars mainly) respectively. These results indicate that this RDT is applicable for global diagnosis of leptospirosis. This rapid and effective diagnosis will be helpful for diagnosis and manage of leptospirosis to use and the polysaccharide of Leptospira may be called as genus specific antigen for diagnosis.
Antigens, Bacterial/*immunology ; Argentina ; Bulgaria ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Leptospira/isolation & purification/metabolism ; Leptospira interrogans/isolation & purification/metabolism ; Leptospirosis/*diagnosis/microbiology ; Male ; Polysaccharides/*immunology ; Reagent Kits, Diagnostic/*standards ; Republic of Korea ; Sensitivity and Specificity

Leptospirosis, a zoonotic disease that is caused by many serovars which are more than 200 in the world, is an emerging worldwide disease. Accurate and rapid diagnostic tests for leptospirosis are a critical step to diagnose the disease. There are some commercial kits available for diagnosis of leptospirosis, but the obscurity of a species- or genus-specific antigen of pathogenic Leptospira interrogans causes the reduced sensitivity and specificity. In this study, the polysaccharide derived from lipopolysaccharide (LPS) of nonpathogenic Leptospira biflexa serovar patoc was prepared, and the antigenicity was confirmed by immunoblot and enzyme linked immunosorbent assay (ELISA). The performance of the rapid diagnostic test (RDT) kit using the polysaccharide as a diagnostic antigen was evaluated in Korea, Bulgaria and Argentina. The sensitivity was 93.9%, 100%, and 81.0% and the specificity was 97.9%, 100%, and 95.4% in Korea (which is a rare region occurring with 2 serovars mostly), Bulgaria (epidemic region with 3 serovars chiefly) and Argentina (endemic region with 19 serovars mainly) respectively. These results indicate that this RDT is applicable for global diagnosis of leptospirosis. This rapid and effective diagnosis will be helpful for diagnosis and manage of leptospirosis to use and the polysaccharide of Leptospira may be called as genus specific antigen for diagnosis.
Antigens, Bacterial/*immunology ; Argentina ; Bulgaria ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Leptospira/isolation & purification/metabolism ; Leptospira interrogans/isolation & purification/metabolism ; Leptospirosis/*diagnosis/microbiology ; Male ; Polysaccharides/*immunology ; Reagent Kits, Diagnostic/*standards ; Republic of Korea ; Sensitivity and Specificity

Animals ; Female ; Guinea Pigs ; Kidney ; microbiology ; pathology ; Leptospira interrogans ; isolation & purification ; pathogenicity ; Leptospirosis ; microbiology ; pathology ; Liver ; microbiology ; pathology ; Lung ; microbiology ; pathology ; Male ; Time Factors

OBJECTIVETo establish a standardized operation procedure for pulsed-field gel electrophoresis (PFGE) on Leptospira interrogans as well as a figure digital database to develop the Chinese representative reference strains.

METHODSUnder the characteristics of strains and referring to the other SOPs of PFGE on pathogens provided by CDC and PulseNet Asia Pacific, genomic chromosome DNA purification, restriction endonuclease digestion and the parameters for running PFGE were optimized.

RESULTSNot I digestion patterns of leptospiral genome for the Chinese representative strains were established and partial isolates of serogroup icterohaemorrhagiae from the leptospirosis surveillance in Sichuan and Anhui provinces were analyzed by PFGE. Results showed that each of all the 15 Chinese representative strains had a unique pattern. 91.67% (22/24) of the 24 isolates identified as serogroup icterohaemorrhagiae matched to the map of the reference strain 56601 (serogroup icterohaemorrhagiae serovar lai).

CONCLUSIONThe PFGE figures were clear with high resolution and the fragments were equally distributed by this standardized operating procedure so as to reveal the molecular-genetic characteristics of Leptospira interrogans. The patterns had high relativity with the serological identification and seemed to be very important for genetic analysis of strains in studying the outbreak of leptospirosis.

Bacterial Typing Techniques ; methods ; DNA, Bacterial ; analysis ; Databases, Factual ; Electrophoresis, Gel, Pulsed-Field ; methods ; standards ; Genome, Bacterial ; Leptospira interrogans ; classification ; isolation & purification

OBJECTIVE: To investigate the infection of leptospirosa of host animals and the immune level of healthy population in flood areas. METHODS: Korth culture was used to culture leptospira for rodent kidney and oxen urine sample. The serogroups of leptospira and leptospira antibody were tested by microscopic agglutination test (MAT). RESULTS: In flood regions, draw-near-flood region, and new migration region, rodent density was 6.95%, 6.28%, and 8.67%, respectively. The positive rates of rodent with leptospira was 4.63%, 1.35%, and 3.13%, respectively. Leptospira positive rates of oxen urine were 5.88%, 5.98%, and 1.75%, respectively. The main serogroup of leptospira was Icterhamorrhagic and Canicola serogroup. The positive rates of leptospirosa antibody in healthy population was 45.91%, 62.30%, and 58.67%in these 3 regions respectively, which was significantly higher than the average level in China. The dominant serogroups of leptospira in health population were icterhamorrhagic, autumnalis, canicola, pomona and bataviae. The positive rate of antibody had no difference among different age groups. CONCLUSION The main host animals are rodents and oxen infected with leptospira and the positive rate of leptospira antibody is high in healthy population in the study area. The dominant serogroups in host animals are similar to that in healthy population, which is mostly icterhaemorrhagic.
Animals ; Antibodies, Bacterial ; blood ; urine ; Cattle ; China ; epidemiology ; Disasters ; Floods ; Humans ; Leptospira interrogans ; immunology ; isolation & purification ; Leptospirosis ; epidemiology ; Prevalence ; Rats ; Seroepidemiologic Studies

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.
Animals ; Antibodies, Bacterial/blood ; Antigens, Bacterial/biosynthesis/*chemistry/genetics ; Bacterial Outer Membrane Proteins/biosynthesis/*chemistry/genetics ; Cattle ; Cattle Diseases/blood/*microbiology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Leptospira interrogans/*isolation & purification ; Leptospirosis/blood/microbiology/*veterinary ; Lipoproteins/biosynthesis/*chemistry/genetics ; Recombinant Proteins/biosynthesis/chemistry/genetics ; Sensitivity and Specificity