OBJECTIVETo study the infection status of Leptospira in rodents on Heixiazi island Heilongjiang province in 2011.

METHODSA total of 356 rodents were captured by night trap on the Heixiazi island from April to October 2011. The kidney tissue samples were collected by asepsis operation and the genomic DNA were extracted from them. Leptospira strains were confirmed by polymerase chain reaction(PCR) amplification of the 482 bp 23 S rDNA gene. Fifteen PCR products selected by the month were purified and sequenced by the methods of Sanger dideoxy, the sequences then compared with other Leptospira strains in Genebank, and phylogenetic analyses were drafted by software Mega 4.0.

RESULTSAmong 356 rodents, the dominant species were Clethrionomys rutilus (39.3%, 140/356) and Apodemus agrarius (36.0%, 128/356). The infection rate of Leptospira was 11.0%, with 39 rodent samples detected positive. All the rodent species were infected except for Rattus norvegicus. The infection rate was 9.4% (12/128) in Apodemus agrarius, 12.9%(18/140) in Clethrionomys rutilus, 10.8%(7/65) in Microtus fortis Buchner. No significant difference was found between the infection rate and the species of rodents by chi square test(χ(2) = 1.92, P > 0.05). Among months, the infection rate was 5.6% (4/72) in May, 8.8% (5/57) in June, 12.8% (5/39) in July, 9.8% (5/51) in August, 33.3% (11/33) in September, 22.5% (9/40) in October,but no infection in April. There was significant difference in infection in different months (χ(2) = 32.92, P < 0.05). All the Leptospira in rodents on the Heixiazi island were in the same phylogenetic branch with a high similarity of 97.1%-99.6%, close with the Australia strain U90865 by the similarity above 96.3%.

CONCLUSIONLeptospira is probably prevalent in rodents on the Heixiazi island, and the phylogene of the strains were similar. The infection rate in rodents was significantly different in months but not in hosts.

Animals ; China ; Leptospira ; isolation & purification ; Leptospirosis ; prevention & control ; Murinae ; microbiology ; Phylogeny ; Rats

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

OBJECTIVETo analyze the changes of leptospirosis epidemic characteristics before and after the Phase 2 'reservoir store water project' in Chongqing section of the Three Gorges dam area and to provide prevention, control and intervention measures to prevent the spread of leptospirosis from infectious focus to the Three Gorges dam area and downstream region of Changjiang River.

METHODSChangshou district and Fengdu county were selected as surveillance sites. We monitored the source of infection through examining the serum antibody of patients, healthy groups together with farm cattle measured by micro agglutination test (MAT).

RESULTSporadic cases were reported before and after the storage of water in the reservoir. There was no significant difference found between mouse density before and after the Phase 2 reservoir project (chi2 = 1.00, P > 0.05). The main species of rat were Sewer rat before and Insectivorea after the storage of water. The germ-carrying rate of rats was 1.72% (10/583) and positive carrying rate of rats was 16.51% (18/109) when using PCR. Results showed a significant difference when comparing it to culture method (chi2 = 51.80, P < 0.01). Positive rate of leoptopirosis appeared in the serum of patients was 73.33% (33/45) with the major serum group as the Australia group. The rate of infection among the healthy group was 26.84% (233/868). There was significant difference seen between the serum antibody positive rate of epidemic prophase (23.85%) and epidemic anaphase (29.86%) of the healthy group (chi2 = 3.99, P < 0.05). The GMRT of ox serum antibody of leoptopirosis was 29.97 with Bailen group as the predominant microbial population.

CONCLUSIONThere was no epidemics of leptopirosis occurred in the Three Gorges dam area. There was no significant difference between mouse density before and after the storage of water in the reservoir. However, the major species of rats had a change. The natural infection level of people living in the dam area was low, but there existed potential of leoptopirosis outbreak.

Animals ; China ; Humans ; Leptospira ; genetics ; isolation & purification ; Leptospirosis ; epidemiology ; Polymerase Chain Reaction ; Population Surveillance ; Rats ; microbiology ; Rivers ; Water Supply

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

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

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

Antimicrobial susceptibility testing was conducted with 6 different spirochetal strains (4 strains of Leptospira spp. and 2 strains of Borrelia burgdorferi) against 3 antimicrobial agents, commonly used in equine and bovine practice. The ranges of MIC and MBC of amoxicillin against Leptospira spp. were 0.05 - 6.25 microgram/ml and 6.25 - 25.0 microgram/ml, respectively. And the ranges of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of amoxicillin against B. burgdorferi were 0.05 - 0.39 microgram/ml and 0.20 - 0.78 microgram/ml, respectively. The ranges of MIC and MBC of enrofloxacin against Leptospira spp. were 0.05 - 0.39 microgram/ml and 0.05 - 0.39 microgram/ml, respectively. Two strains of B. burgdorferi were resistant to enrofloxacin at the highest concentration tested for MBC (> or = 100 microgram/ml). Therefore, the potential role of tilmicosin in the treatment of leptospirosis and borreliosis should be further evaluated in animal models to understand whether the in vivo studies will confirm in vitro results. All spirochetal isolates were inhibited (MIC) and were killed (MBC) by tilmicosin at concentrations below the limit of testing (< or = 0.01 microgram/ml).
Amoxicillin/pharmacology ; Anti-Bacterial Agents/*pharmacology ; Borrelia burgdorferi/*drug effects/growth & development/isolation & purification ; Fluoroquinolones/pharmacology ; Leptospira/*drug effects/growth & development/isolation & purification ; Leptospirosis/*microbiology ; Lyme Disease/*microbiology ; Macrolides/pharmacology ; Microbial Sensitivity Tests ; Reproducibility of Results ; Tylosin/analogs & derivatives/pharmacology

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