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PubMed1990

Evaluation of an enzyme immunoassay for diagnosis of bovine leptospirosis caused by Leptospira interrogans serovar hardjo type hardjo-bovis.

Sensitivity and specificity of 4 different antigen preparations from Leptospira interrogans serovar hardjo were compared in an enzyme immunoassay for detection of antibodies against serovar hardjo type hardjo-bovis in serum. Two antigens prepared using detergents showed serogroup cross-reactivity. A mechanically extracted membrane and a lipopolysaccharide antigen showed a high degree of leptospiral serogroup specificity. The lipopolysaccharide antigen was the most suitable antigen for detection of anti-hardjo antibodies. Enzyme immunoassay was more sensitive than the microscopic agglutination test for detecting antibodies in serum from experimentally and naturally infected cattle. It was not possible to differentiate vaccinated from infected animals or to detect a secondary immune response in vaccinated animals that were subsequently infected.

Agglutination Tests↗
PubMed2004

An indirect enzyme linked immunosorbent assay for the detection of bovine antibodies to multiple Leptospira serovars.

An indirect enzyme linked immunosorbent assay was developed for the detection of bovine antibodies to multiple pathogenic Leptospira serovars, including canicola, copenhageni (represents icterohaemorrhagiae), grippotyphosa, hardjobovis, pomona, and sejroe. The antigen utilized in this assay was a sonicated mixture of equal parts of killed whole cells of each of the 6 serovars named above. A mouse monoclonal antibody against bovine immunoglobulin (Ig)G1 that was conjugated with horseradish peroxidase was used for detection of bound antibodies. This assay was evaluated with sera (n = 3107) that were microscopic agglutination test (MAT)-negative (at a 1:100 dilution) for each of the 6 serovars listed above and sera (n = 601) that were MAT-positive (at a 1:100 dilution) for 1, or any combination of the 6 listed serovars. In addition, sera from serial weekly bleedings of cows, which were individually experimentally infected with serovars hardjobovis, copenhageni, grippotyphosa, or canicola, were also tested in this assay. At an optimal cut-off point determined by receiver operating characteristic (ROC) curve analysis, the relative sensitivity and specificity of the assay were 93.5% (95% confidence interval = 91.2% to 95.3%) and 94.7% (95% confidence interval = 93.9% to 95.5%), respectively. This assay was able to detect antibody in the sera of animals experimentally infected with serovar hardjobovis as early as 1 week postinoculation.

Animals↗
PubMed1979

Isolation of antigenic variants from leptospiras grown in vitro and from heart blood of guinea pigs inoculated with a clonized strain of Leptospira.

A clonized culture of Leptospira interrogans serovar copenhageni strain Shibaura (Cl-Shibaura) was inoculated into guinea pigs. The heart blood of the guinea pigs, obtained at the febrile stage and inoculated onto the solid serum medium containing the homologous immune serum, produced large and small colonies. The serological examinations revealed that the large colonies were found mainly to be the antigenic variants, while the small colonies were mostly the parent. The antigenic variants accounted for 16.4% of all the colonies from the blood of the guinea pigs infected with Cl-Shibaura, and for 1.2% of all the colonies from the blood of the guniea pigs infected with Cl-Shibaura, and for 1.2% of all the ll colonies. The serological examinations revealed that the large colonies were found mainly to be the antigenic variants, while the small colonies were mostly the parent. The antigenic variants accounted for 16.4% of all the colonies from the blood of the guniea pigs infected with Cl-Shibaura, and for 1.2% of all the colonies from the culture of Cl-Shibaura in the normal serum medium. Antigenic variants were also isolated in vitro from the culture of 2 other serovars. The fact that the frequency of the antigenic variants of leptospiras was higher in vivo than in vitro is discussed.

Animals↗
PubMed1999

Incidence of leptospiral abortion in Brazilian dairy cattle.

We examined dams' paired serum samples and foetal kidneys (histopathologically and attempting leptospiral cultures) from 120 Brazilian Holstein abortions from 10 herds near Sao Paulo, Brazil, in 1996. Leptospiras was isolated from 15 foetuses. The Leptospira interrogans serovar hardjo was obtained from four, pomona from three and wolffi from eight foetuses. Ten of these 15 foetuses showed a four-fold rise in titres between the day of abortion and the second samples taken 15 days later. Fifty-seven other foetuses had histologic evidence of leptospires; 27 of their dams (47%) had four-fold rises in titres. In total, 72 of 120 aborted foetuses had evidence of leptospiral infection.

Abortion, Veterinary↗
PubMed2006

Leptospirosis in the tropics and in travelers.

Leptospirosis, caused by spirochetes of the genus Leptospira, has increasingly been recognized to affect travelers and residents in tropical settings. A zoonotic disease, leptospirosis is transmitted to humans through environmental surface waters contaminated by the urine of chronically infected mammals. Outcome of infection varies, ranging from acute febrile illness (including self-resolving undifferentiated fever) to aseptic meningitis to a fulminant syndrome of jaundice, oliguric renal failure, pulmonary hemorrhage, and refractory shock. Hospitalized cases have mortality rates as high as 25%. A recent clinical trial showed that third-generation cephalosporin is as effective as doxycycline and penicillin in the treatment of acute disease. Doxycycline is effective in preventing leptospirosis in travelers. No protective vaccine is currently available.

Journal Article↗
PubMed1982

Leptospirosis: I. Clinical investigation of the infection in dairy cattle in the Waikato district of New Zealand.

An investigation was made into the prevalence of leptospiral infection in cattle. An area 50 km radius was selected in a region where leptospirosis was reputedly common. Farmers volunteered 250 herds with 39 500 cows for testing and 7 500 animals were selected and sampled. Twenty-nine cows (0.4%) on 14 (5.6%) of the farms had leptospiruria at the first examination. Leptospirae were cultured from the urines of nine of these animals and all were Leptospira interrogans serovar hardjo. Serologically 12.5% of cows had titres of 1:200 or greater to hardjo and 3.5% titres of 1:200 or greater to pomona. In the Spring of 1977, there was evidence of clinical leptospirosis in calves associated with only one of the herds and no clinical leptospirosis in the 250 lactating herds, although leptospiral titres were found in 88% of them. This indicated that clinical disease was much less common than infection. We concluded that leptospirosis was of minor economic importance in dairy cattle, although it could be significant in individual herds, and a health hazard to farm workers.

Journal Article↗
PubMed1976

Immunising potency of Leptospira interrogans serotype canicola after heat inactivation at different temperatures.

The immunogenicity of Leptospira interrogans serotype canicola suspensions inactivated by various degrees of heat exposure was examined in hamsters. No differences between leptospires killed at 50 degrees C and at 98 degrees C were shown. After exposure to 121 degrees C, suspensions retained their ability to protect against lethal infections but lost their ability to prevent leptospiruria. Tests with vaccines inactivated at or below 98 degrees C showed that the doses required for complete protection varied with the interval between vaccination and challenge. Larger doses were required to prevent the development of leptospiruria than to prevent death.

Animals↗
PubMed2005

Human leptospirosis in the Vicenza area (Italy) from 1990 to 2003: an epidemiological and clinical study.

All cases of human leptospirosis observed at the S. Bortolo Hospital, Vicenza, Italy, in the period from September 1990 to December 2003 were retrospectively reviewed. The aim of the study was to define the epidemiological, clinical, diagnostic, and therapeutic aspects of this infection and to compare these with an earlier local study (1979-1990) in order to assess if any changes have occurred over time. The screening test was made using macroscopic agglutination and the diagnosis was definitively confirmed using the microscopic agglutination test (MAT). The etiological serotype was identified in 13 patients (68%) and Leptospira poi was the most frequent serovar. Hepatic and renal involvements were present in a high percentage of patients (71% and 74%, respectively), cardiac involvement in 39%, and hypertriglyceridemia and hepatic steatosis were observed in 68% and 43% of cases, respectively. One patient died because of acute renal and respiratory failure. Intravenous penicillin was the treatment of choice. A consistent reduction in the prevalence was observed during the time period of this study (n = 38) compared with the previous period (n = 86); males were more affected than females in both time periods. In industrialized countries the prevalence of leptospirosis is decreasing; nevertheless, this infection is no longer limited to specific occupational groups and remains a potential fatal disease that should be included in the differential diagnosis of all the patients with unexplained fever.

Adult↗
PubMed1989

Leptospirosis. Do you consider the diagnosis?

Patients with Leptospirosis, usually a water borne zoonotic disease, are likely to present themselves to Royal Naval primary health carers, who deal with a young active population, frequently participating in watersports. Leptospira, which belong to the order Spirochaetaceae, comprise of two distinct species. Within each species there are a number of serologically different serovars (serotypes), arranged in related serogroups. L. interrogans var Icterhaemorrhagiae and L. interrogans var Hebdomadis serovar hardjo are the most commonly reported organisms in Great Britain. Traditionally water and sewage workers have been amongst those most frequently infected, but with improved health care awareness this group has been overtaken by farmworkers, and a growing group of people engaged in aquatic sports. Symptoms of Leptospiral infection vary in severity from a mild flu-like illness to symptoms resulting from severe renal, hepatic or meningeal involvement. Mild symptoms respond to oral penicillin, erythromycin or tetracyclines, whilst more serious illness requires i.v. penicillin and supportive nursing. Spirochaetes can be detected in culture using darkground microscopy, and sero-conversion detected by IgM specific dot ELISA techniques. Suspected sera should be sent to PHLS Leptospira Reference Unit, County Hospital, Hereford. HR1 2ER. (Tel: 0432 277117).

Animals↗
PubMed1986

Comparison of antibodies to Leptospira in white-tailed deer (Odocoileus virginianus) and cattle in Ohio.

A survey was conducted to determine the prevalence of leptospiral antibodies in sera from 248 white-tailed deer (Odocoileus virginianus) in Ohio. The sera were collected at check stations during the hunting season in 1983. The microscopic agglutination microtiter test was used to determine the presence of antibodies to Leptospira interrogans serovars pomona, icterohemorrhagiae, canicola, hardjo, and grippotyphosa. Eighteen of 248 (7.3%) serum samples had antibody titers (greater than or equal to 1:100) to at least one of the five serovars tested, with three of these samples reacting to more than one serovar. Prevalence did not differ significantly between sex or age groups. The serovar antigens reacting most frequently with serum antibodies were grippotyphosa (10 of 22, 45.5%) and pomona (eight of 22, 36.4%). Sera agglutinating with pomona antigen had higher titers (ranging from 1:200 to 1:6,400) than did sera agglutinating with the other serovars. These results were compared to results obtained from cattle tested at the Ohio Department of Agriculture Laboratories during 1983. There was a significant relationship between pomona infections detected in deer and cattle (P less than 0.05), but not with grippotyphosa.

Animals↗
PubMed1979

The occurrence of leptospiral antibodies in rural inhabitants of Argentina.

Sera collected during surveys of presumably healthy rural inhabitants of the Provinces of Corrientes and Neuquén, Argentina, were examined for serological evidence of leptospirosis. Significant antibody levels (1:100 or greater) were found in 8.7 per cent of 1,029 sera from residents of Corrientes Province. The most frequent reactions occurred against the serotypes australis, hebdomadis group, pomona, and icterohaemorrhagiae. The predominance of antibodies to the Australis group in the country is new and suggests the emergence of leptospirosis in an unrecognized animal reservoir host. Out of 706 sera collected from rural school students and sera from 71 adults in the Province of Neuquén, only 4 (0.5%) showed leptospiral agglutinin in the microscopic agglutination test and these were only at a 1:100 serum dilution. The higher percentage of reactors in the Corrientes population appears to reflect a more favorable environment and a greater risk of infection.

Adolescent↗
PubMed1993

Molecular cloning and sequence analysis of the gene encoding OmpL1, a transmembrane outer membrane protein of pathogenic Leptospira spp.

Pathogenic Leptospira spp. are spirochetes that have a low transmembrane outer membrane protein content relative to that of enteric gram-negative bacteria. In a previous study we identified a 31-kDa surface protein that was present in strains of Leptospira alstoni in amounts which correlated with the outer membrane particle density observed by freeze fracture electron microscopy (D. A. Haake, E. M. Walker, D. R. Blanco, C. A. Bolin, J. N. Miller, and M. A. Lovett, Infect. Immun. 59:1131-1140, 1991). The N-terminal amino acid sequence was used to design a pair of oligonucleotides which were utilized to screen a lambda ZAP II library containing EcoRI fragments of L. alstoni DNA. A 2.5-kb DNA fragment which contained the entire structural ompL1 gene was identified. The structural gene deduced from the sequence of this DNA fragment would encode a 320-amino-acid polypeptide with a 24-amino-acid leader peptide and a leader peptidase I cleavage site. Processing of OmpL1 results in a mature protein with a predicted molecular mass of 31,113 Da. Secondary-structure prediction identified repeated stretches of amphipathic beta-sheets typical of outer membrane protein membrane-spanning sequences. A topological model of OmpL1 containing 10 transmembrane segments is suggested. A recombinant OmpL1 fusion protein was expressed in Escherichia coli in order to immunize rabbits with the purified protein. Upon Triton X-114 extraction of L. alstoni and phase separation, anti-OmpL1 antiserum recognized a single band on immunoblots of the hydrophobic detergent fraction which was not present in the hydrophilic aqueous fraction. Immunoelectron microscopy with anti-OmpL1 antiserum demonstrates binding to the surface of intact L. alstoni. DNA hybridization studies indicate that the ompL1 gene is present in a single copy in all pathogenic Leptospira species that have been tested and is absent in nonpathogenic Leptospira species. OmpL1 may be the first spirochetal transmembrane outer membrane protein for which the structural gene has been cloned and sequenced.

Amino Acid Sequence↗
PubMed1976

Primary isolation of Mycobacterium avium complex-serotype 6 on blood agar.

Mycobacterium avium complex-serotype 6 was isolated in pure culture on blood agar plates from inocula taken from the heart blood, lungs, liver, kidneys, and spleen of a naturally infected captive female opossum (Didelphis marsupialis virginiana). Repeat cultures from stored tissues and transfer of colonies from original blood agar plates revealed that the mycobacterium grew on tryptose, brilliant green, eosin-methylene blue. Sabouraud glucose, and mycobiotic agar plates and in Fletcher leptospira medium. The cultural, biochemical, and serological characteristics of the test isolate were compared with other mycobacteria. This is the first report to describe the primary isolation of a serotype from the M. avium complex from an animal species on blood agar or in Fletcher broth. In addition, this is the second documented report describing the isolation and identification of a mycobacterial species from the American opossum.

Agar↗
PubMed1992

Antibodies in dogs against Leptospira interrogans serovars copenhageni, ballum and canicola.

In a nationwide survey carried out during 1990-91 of more than 5800 dogs to detect antibodies against Leptospira interrogans serovars copenhageni, ballum and canicola, only one weak reactor against serovar canicola was found. Reactors of varying titre were found against serovar ballum in 0.7% of dogs tested, indicating sporadic infection with this serovar. Reactors (0.9%) to serovar copenhageni came mainly from the Waikato, Northland and the Auckland region. This was in agreement with the reported occurrence of the clinical syndrome and with the results of a smaller survey in urban Auckland, in which more than 5% of dogs tested were seropositive to serovar copenhageni.

Journal Article↗
PubMed1998

Observations of leptospirosis in farmed deer.

AIMS: Slaughterhouse and on-farm surveys were undertaken to investigate some aspects of leptospirosis (Leptospira interrogans) in farmed deer in the lower North Island of New Zealand. METHODS: Blood samples and kidneys were collected at slaughter from 601 l-year and older red and red X Wapiti stags and 21 adult hinds from 53 farms (10 or 12 deer per farm). Serum samples were analysed for up to seven Leptospiral serovars. Gross and histological examinations of kidneys were undertaken. Kidneys from 202 deer were cultured for leptospires. A follow-up postal questionnaire (68% response) indicated one herd had been vaccinated prior to the survey. Serological analyses were also carried out on serum bank samples from a previous on-farm survey involving male and female weaner, yearling and adult red deer from 16 commercial deer farms in March and November. RESULTS: Serological reactions at titres > or = 96 to serovar hardjo were present in 73.6%, pomona in 41.5%, copenhageni in 11.3% and tarassovi in 15.1% of farms from the slaughterhouse survey. Antibodies to serovars australis, ballam and balanica were present in three, one and four of six herds studied, respectively. Titre prevalence to hardjo was higher than that of pomona and other serovars within farms. Cultures for Leptospira were positive in 10 stags from six lines with similar prevalence across age groups. Histological examination showed many gross lesions were associated with mild interstitial cellular infiltration characteristic of subclinical Leptospiral infections. Some sections from culture-positive kidneys contained spirochetes in renal tubules. The on-farm survey showed a 10-30% within-herd prevalence of pomona and hardjo titres in 56% of 3-month-old deer herds, but by 11 months of age, 100% of herds were titre-positive with high prevalences to one or both serovars. Concurrently, herds of 1-year-old and adult deer on the same farms were all seropositive. CONCLUSION: This study has shown that Leptospiral infections are common in farmed deer in the survey area.

Journal Article↗
PubMed1992

Identification of the tick-borne relapsing fever spirochete Borrelia hermsii by using a species-specific monoclonal antibody.

Borrelia hermsii causes a relapsing fever in humans and is one of several species of tick-borne spirochetes known to occur in the western United States. Spirochetes observed in the peripheral blood of patients acutely ill have been presumptively identified in the past by the geographic location of exposure and the probable species of tick vector. We describe a monoclonal antibody (H9826) that bound to the flagellar protein of B. hermsii but not to those of any of the other species tested, which included B. parkeri, B. turicatae, B. coriaceae, B. anserina, B. burgdorferi, and Leptospira interrogans serovar ballum. This antibody bound efficiently to B. hermsii in an indirect immunofluorescence assay and was used to rapidly detect and identify this spirochete in the peripheral blood of experimentally infected mice and in the central ganglia of Ornithodoros hermsi ticks. H9826 can rapidly confirm the identification of B. hermsii to increase our understanding concerning the geographic distribution, vector specificity, and epidemiological significance of this zoonotic human pathogen.

Antibodies, Bacterial↗