On the specific mechanism of the transmission of leptospiral infection.
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Animals↗
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[Two cases of facial diplegia with elevated serum antibodies to Borrelia burgdorferi].
Lyme disease, a tick-borne infection with spirochete named Borrelia burgdorferi, is a complex multi-organ disorder involving neurological complication. Recently, the existence of Lyme disease was also recognized in middle Japan. We described here two cases of facial diplegia with elevated serum antibodies to B. burgdorferi. Case 1 was a 48 year-old man, who developed facial diplegia on April 29, 1987, and referred to our hospital on May 1. Neurological examination showed facial diplegia in addition to right-sided hemiparesis due to head injury of twenty years ago. The cell count of the cerebrospinal fluid was 17/mm3 and the protein was 139.9 mg/dl. The serological examinations for B. burgdorferi were performed by means of immunoperoxidase test. This patient had no serum IgG antibodies to B. burgdorferi on admission. However, twelve weeks later his serum showed significant elevation of IgG antibodies (titer: X400). Tests for syphilis and leptospira were negative. Based on these observation, we considered that facial diplegia of this patient was associated with the infection of B. burgdorferi. His facial diplegia remained unchanged with oral corticosteroid treatment. Case 2 was a 64 year-old man, who developed facial diplegia on May 31, 1987, and referred to our hospital on June 3. Neurological examinations were entirely negative except for facial diplegia. The findings of the cerebrospinal fluid showed the albumin cytologic dissociation with the cell count 2/mm3 and the protein 85.4 mg/dl. Serum IgG antibodies to B. burgdorferi were present (titer: X200) on admission. However, seven weeks later his serum showed a marked elevation of IgG antibodies (titer: X1600). Tests for syphilis were negative.(ABSTRACT TRUNCATED AT 250 WORDS)
Antibodies, Bacterial↗
[Leptospira hardjo on a dairy farm].
The results of a bacteriological and serological study of the presence of L. hardjo on a dairy farm in view of a case of milk fever in a farmer are reviewed. In addition, the epidemiology, prevention and possible treatment of the infection on the dairy farm are discussed.
Adult↗
Nested polymerase chain reaction for detection of pathogenic leptospires.
Leptospirosis is a widespread zoonosis caused by pathogenic members of the genus Leptospira that has a great impact on human and veterinary public health. Early diagnosis of leptospirosis is important because severe lepto spiral infection can have a fulminant course. The available serological techniques for the diagnosis of leptospirosis have low sensitivity during the early stage of the disease. Efforts are being made to develop simpler, effective, efficient, and inexpensive diagnostic methods. In this work, we first evaluate a polymerase chain reaction (PCR) based method for diagnosis of leptospirosis. Primers were designed to amplify a 264 bp region within the lipL32 gene that is conserved among pathogenic Leptospira and absent in nonpathogenic species. The sensitivity and specificity of the assay were evaluated using 7 saprophytic serovars, 37 pathogenic serovars, and 15 other microorganisms. The method was very specific for pathogenic serovars, however, it lacked sensitivity. To enhance the sensitivity, another primer pair was designed to amplify a 183 bp region within the 264 bp region of the lipL32 gene and was used in a nested PCR assay. This approach was much more sensitive than conventional PCR.
Animals↗
Isolation of a spirochete from the soft tick, Ornithodoros coriaceus: a possible agent of epizootic bovine abortion.
A Borrelia-like spirochete was detected in all three parasitic stages of Ornithodoros coriaceus, the soft tick implicated in the epizoology of epizootic bovine abortion. After the spirochete had been isolated, its distinctness from other North American tick-borne borreliae as well as from Spirochaeta aurantia, Treponema pallidum, and Leptospira interrogans serovar pomona was established on the basis of its morphology, protein components, and inability to infect mice. The spirochete is passed trans-stadially and via eggs by ticks, and it is also excreted in coxal fluid after ticks have fed and detached. Circumstantial evidence suggests that the spirochete may be causally related to epizootic bovine abortion.
Abortion, Veterinary↗
[The effect of a vaccine made from 39kd hydrophobic outer membrane protein of Leptospira interrogans on neurohumoral and red cell immunity function of the guinea pigs].
A randomized control trial was conducted to determine the immunoprotective efficacy of OmpL39. 36 guinea pigs were divided into OmpL39 group, whole leptospiral cell vaccine (WLCV) group, other proteins of Leptospira group, and negative control group (normal saline, NS). The results showed that all the guinea pigs of infected OmpL39 and WLCV still survived, but all the control guinea pigs died. Immunoprotective efficacy was 100% for OmpL39 and WLCV. OmpL39 levels were similar to WLCV levels and higher than controls (P < 0.05). These suggested that OmpL39 could be used as important immunoprotective antigen to develop the genetic vaccine of the targeting delivery system. Also it was observed that OmpL39 could produce 100% immunoprotective efficacy, have higher MAT level (> 1:3200) and regulate 5-HT, 5-HIAA, DA, NE. The 5-HT, DA, NE concentration was lower and 5-HIAA was higher than that of controls after stimulating the guinea pigs with OmpL39 (P < 0.05). The results suggested that OmpL39 genetic vaccine could produce immunity function and have an active effect on absorbing inflammation and protecting organs and tissues. Besides, the red cell immunity efficacy of the guinea pigs was changed during immunity response and the RBC-C3b RR and the RBC-ICR were increased. The RFER was increased; the RFIR was decreased. RFER/RFIR was remarkably higher than that of control (P < 0.05). These suggested that OmpL39 could increase red cell immunity function.
Animals↗
Magnetic immuno capture PCR assay (MIPA): detection of Leptospira borgpetersenii serovar hardjo.
Magnetic immuno PCR assay (MIPA) was developed for the rapid detection of leptospires excreted in urine samples (n = 59) collected from 35 experimentally infected cattle. The immunomagnetic separation of leptospires from inhibitors in frozen formalin fixed bovine urine prior to PCR detection resulted in a marked improvement on previous detection methods. MIPA is a rapid 5 step protocol requiring 70 mins preparation time prior to amplification, which consistently detects 10(1) organisms. MIPA detected 76% (38/50) of culture positive urines and in addition three urines that were culture negative were shown to be positive by this method of detection. Consequently we conclude that whilst MIPA is an improvement on previously published PCR detection methods, the culture of the organism is still the standard against which other detection methods have to be compared.
Animals↗
The enzyme-linked immunosorbent assay (ELISA) as a serological test for detecting antibodies against Leptospira interrogans serovar hardjo in sheep.
The enzyme-liked immunosorbent assay (ELISA) was compared with the standard microscopic agglutination test (MAT) as a method for detecting antibodies against Leptospira interrogans serovar hardjo in sheep. Peak antibody levels detected by the 2 tests occurred at different times following experimental infection of sheep. In serums from flocks of sheep with naturally acquired infection there was a 95% correlation between MAT and ELISA with respect to the presence or absence of antibody to serovar hardjo, although the levels of correlation of the titres of the 2 tests was low. The 2 tests appeared to measure different antigen-antibody systems. The ELISA would be a useful test for screening large numbers of serums for antibodies to L. interrogans serovar hardjo.
Agglutination Tests↗
Immunity to leptospirosis: bacterins in dogs and hamsters.
Resistance to clinical and renal leptospirosis in dogs vaccinated with a bacterin containing Leptospira interrogans serotype canicola and Leptospira interrogans serotype icterohaemorrhagiae was demonstrated. The relationship between resistance induced in vaccinated dogs and that induced in vaccinated hamsters was also demonstrated, using criteria of leptospiremia, renal infection, leptospiruria, and clinical signs of disease in dogs and death in hamsters.
Animals↗
Association between cessation of leptospiruria in cattle and urinary antibody levels.
The shedding of Leptospira interrogans serovar hardjo in the urine of cattle and the local and systemic response to these organisms was monitored in experimentally and naturally infected animals. Twenty yearling heifers, 10 infected by the instillation of leptospires into the conjunctival sac (supraconjunctival route) and 10 infected intrauterinely, shed leptospires for up to 60 weeks after infection. Five of 15 naturally infected pregnant heifers with microscopic agglutination test titres > or = 1:300 continued to shed leptospires from 28 to 40 weeks after initial detection. Serovar hardjo was isolated infrequently from the urine of a further five naturally infected animals during the first eight weeks of the study but no leptospires were isolated from the remaining five animals for the duration of the study period (84 weeks). Cessation of leptospiruria in the 20 experimentally infected animals and in the five naturally infected persistent excretors was invariably associated with a sharp increase in urinary anti-leptospiral IgG and IgA antibody levels.
Animals↗
Effect of maternal vaccination on the susceptibility of growing pigs to leptospiral infection.
Serum samples were collected from 30 piglets, derived from 17 litters, whose dams had been vaccinated against leptospirosis. Microscopic agglutination test (MAT) titres against Leptospira interrogans serovar pomona varied greatly from pig to pig; there was less variation among littermates. Titres declined between 4 and 10 weeks of age, with an uncorrected half-life of 15.5 days, consistent with IgG being the main antibody class involved. Twelve pigs, 4 derived from unvaccinated sows and 8 from sows vaccinated against leptospirosis, were challenged intravenously at 8 weeks of age with leptospires of serovar pomona. Colostrum-derived antibody protected 4 out of 8 pigs, and in 1 of the remaining 4 the serological response was reduced. Three of the protected pigs showed reduced serological responses and in the fourth the response was strong, but delayed. All of the pigs derived from unvaccinated sows developed leptospiraemia and leptospiruria and showed strong serological responses. Protection by colostrum-derived antibody bore an inexact relationship to MAT titre, but a titre of 16 appeared to be sufficient for protection.
Agglutination Tests↗
Canine parvovirus infection potentiates canine distemper encephalitis attributable to modified live-virus vaccine.
Twelve gnotobiotic dogs from 2 litters were allotted to 3 groups. Group A dogs received a modified-live polyvalent (canine distemper, adenovirus type 2, and parainfluenza virus and Leptospira -canicola-icterohemorrhagiae bacterin) vaccine 3 days prior to oral inoculation with canine parvovirus (CPV). Group B dogs received CPV alone. Group C dogs received 1 dose of vaccine only. In none of the 9 CPV-inoculated dogs did clinical signs of CPV infection develop, although high serum antibody titers for CPV developed in all of them. However, in 2 of the 5 CPV-inoculated vaccinates, canine distemper virus encephalomyelitis subsequently developed. The results suggested that CPV exerts an immunomodulating effect on canine immune responses and may be responsible for vaccination failures in dogs.
Animals↗
Serodiagnosis of canine leptospirosis by solid-phase enzyme-linked immunosorbent assay.
An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Leptospira interrogans serotype canicola in dogs was developed and evaluated. Comparison of the ELISA with the microscopic agglutination test (MAT) showed that, during the first two weeks after an experimental infection with serotype canicola, the ELISA detected antibody at higher dilutions than the MAT. After the second week post-infection both tests detected antibody at almost equal titres (r = 0.89). The outer envelope (OE) antigen of serotypes icterohaemorrhagiae, copenhageni and canicola was fairly serotype-specific, whereas the pellet (P) antigen showed more cross-reactivity. Both OE and P antigen of Leptospira biflexa strain Patoc I could be used as cross-reacting antigen in the ELISA. Compared to the MAT, the ELISA has some technical advantages. It is suggested that the ELISA would be useful as a screening test.
Agglutination Tests↗
Significance of Neospora caninum in British dairy cattle determined by estimation of seroprevalence in normally calving cattle and aborting cattle.
A case control study was conducted to evaluate the significance of Neospora caninum infections in cattle in England and Wales. The prevalence of N. caninum in normally calving cattle (the control group; n = 418) and aborting cattle (n = 633) was estimated using a commercial antibody-detection ELISA. Prevalence estimates for bovine virus diarrhoea virus, infectious bovine rhinotracheitis virus and Leptospira hardjo were also obtained by serology. The prevalence of N. caninum was significantly higher (P < 0.0001) in the aborting group (18%; 95% confidence interval: 15%, 21%) than in the control group (6%; 95% confidence interval: 4%, 8%); the latter is the first estimate, to date, of the national seroprevalence of N. caninum in dairy cattle in England and Wales. Prevalence estimates for bovine virus diarrhoea virus, infectious bovine rhinotracheitis virus and L. hardjo were not found to be higher in the aborting cattle than in the control group. With N. caninum, a strong association between seropositivity and abortion was found, with seropositive cows being 3.5-times more likely to abort than seronegative cows (odds ratio = 3.49; 95% confidence interval: 2.16, 5.69). Furthermore, 12.5% of abortions in dairy cattle in England and Wales may be attributable to N. caninum, as indicated by estimation of the population aetiological fraction.
Abortion, Veterinary↗
Leptospirosis in poikilothermic vertebrates. A review.
Autochthanous leptospirosis does occur in the poikilothermic vertebrates, as evidenced by positive serological reactions and by the isolation of pathogenic leptospiral serovars. These findings in aquatic members of this group are of special importance in view of the increased worldwide interest in aquaculture farming. Since 1975, 24 of the 101 (23.7%) reported human cases of leptospirosis in Hawaii have been associated with aquaculture industries (taro farms, prawn farms and watercress farms). Antibody synthesis and persistence in these animals is variable, and seems to depend to some extent on environmental temperatures. Some members of the group apparently lack the capacity for immunological memory, experience a considerable delay (lag-phase) in antibody formation, demonstrate the "paradoxical reaction" found in other animals, and can maintain living pathogenic leptospirae in their organs in the absence of detectable antibody utilizing our present serologic methods. For these reasons, serological studies as the sole source of evidence for leptospiral infection cannot be recommended. The immunologic mechanism of lower vertebrates is not known, some studies suggesting that there may be more than one antibody system active in these animals, especially the turtles, and further investigation at the cellular and subcellular levels is indicated. The growth temperatures and nutritional requirements of leptospirae isolated from other than warm-blooded animals is also poorly understood. Some knowledge has been contributed by various investigators in recent years, but much more work needs to be done in studying the nutritional and metabolic requirements of leptospirae isolated from all sources, including the various fauna resident in and around the fresh water streams and ponds.
Amphibians↗
Emergent causes of placentitis and abortion.
The clinical signs, laboratory findings, diagnosis, epidemiology, treatment, and prevention and control of two emerging causes of placentitis and abortion in horses are described in this article. Leptospirosis has been reported as a significant cause of fetal loss in horses in Kentucky, Northern Ireland, and England. Most abortions result from infection by serovars kennewicki or bratislava. Nocardioform placentitis has become the most common cause of placentitis in central Kentucky horses. Nocardioform placentitis is associated with infection by unnamed, gram-positive, filamentous, branching bacteria, and is characterized by distinctive changes in the placental membranes.
Abortion, Veterinary↗
rpoB gene analysis as a novel strategy for identification of spirochetes from the genera Borrelia, Treponema, and Leptospira.
Spirochetes are emerging pathogens for which culture and identification are partly unresolved. In fact, 16S rRNA-based sequencing is by far the most widely used PCR methodology that is able to detect such uncultivable pathogens. However, this assay actually has some limitations linked to potential problems of contamination, which hampers diagnosis. To circumvent this, we have devised a simple PCR strategy involving targeting of the gene encoding the RNA polymerase beta subunit (rpoB), a highly conserved enzyme. The complete sequence of the Leptospira biflexa (serovar patoc) rpoB gene was determined and compared with the published sequences for Borrelia burgdorferi and Treponema pallidum. From the resulting analysis, degenerate nucleotide primers were designed and tested for their ability to amplify a portion of the rpoB gene from various spirochetes. Using two different pairs of these primers, we succeeded in obtaining specific rpoB-amplified fragments for all members of the genera Leptospira, Treponema, and Borrelia tested and no other bacteria. Our findings may have significant implications for the development of a new tool for the identification of spirochetes, especially if clinical samples are contaminated or when the infecting strain is uncultivable.
Borrelia↗
Further bacteriological evaluation of virginiamycin.
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Animals↗