Serovar Grippotyphosa Research Articles

Prevalence and serovars of leptospira involved in equine abortions in central Kentucky during the 1990 foaling season.

A study to determine the prevalence of leptospira-induced abortions in the central Kentucky equine population during the 1990 foaling season and to determine the leptospira serovars responsible was conducted. From July 1, 1989 through June 30, 1990, 32 (4.4%) of 726 submissions (fetuses, stillborn foals, and/or placentas) were diagnosed as leptospirosis by the fluorescent antibody test and/or microscopic agglutination test. Attempts were made to isolate leptospires from the fetal tissues and/or the dam's urine in 31 of these cases. Leptospira interrogans serovar kennewicki was isolated from 11 (35.5%) and serovar grippotyphosa from 2 (6.5%) of the 31 cases. Of 12 cases that were culture negative with serologically positive fetal fluids, 8 had titers against serovar pomona, 1 against bratislava, 1 against grippotyphosa, 1 against hardjo, and 1 against both bratislava and pomona.

Muskrats as carriers of pathogenic leptospires in The Netherlands.

Leptospires were isolated from 24 of 327 (7%) muskrats (Ondatra zibethicus) caught in The Netherlands. All isolates were identified as Leptospira interrogans. One isolate was typed as serovar copenhageni in the Icterohaemorrhagiae serogroup, one as serovar lora in the Australis serogroup. Twenty-one isolates showed a close relationship with serovars grippotyphosa, valbuzzi, muelleri and ratnapura from the Grippotyphosa serogroup. One isolate was lost. Sera from 196 muskrats were examined by the microscopic agglutination test. Forty-five (23%) sera reacted positively (titers greater than or equal to 1:160), 42 (21%) of these 45 sera to Grippotyphosa and 3 (2%) to Sejroe serogroup antigens. This is the first report of serological and cultural evidence of leptospira infection in muskrats in The Netherlands.

Relationships between prevalence of Leptospira interrogans in cattle, and regional, climatic, and seasonal factors

SUMMARY On the basis of serologic test results and isolation of leptospires from mature cattle, distribution and prevalence of Leptospira interrogans serovars and genotypes were compared by state and region of the United States. Relationships between isolation rate and month of sample collection, mean regional temperature, and mean regional precipitation were examined. Isolation rate and seroprevalence were significantly (P < 0.001) higher for southeastern, south central, and Pacific coastal regions than for other regions of the United States. Isolates of genotypes hardjo-bovis A and kennewicki A and B, and of serovar grippotyphosa appeared to be randomly distributed. Genotype hardjo-bovis B isolates came from a southern area of the country that extends from Georgia to New Mexico. To the authors’ knowledge, this is the first recorded isolation of serovar hardjo from Hawaii. Although significant relationship was not documented between isolation rate and month or season of the year, seroprevalence for summer, fall, and winter was significantly (P < 0.001) higher than that for spring. Regional isolation rate was related more to mean temperature (r = 0.83; P < 0.05) than to mean precipitation amount (r = 0.34; P > 0.50).

Diagnosis and Prevalence of Leptospira Infection in Aborted and Stillborn Horses

A study was conducted to evaluate a recently available fluorescent antibody test (FAT) conjugate for the detection of leptospires in tissues of aborted and stillborn horses, to determine the leptospira antibody titers and compare serologic test results with FAT results, and to determine the prevalence of leptospira-induced abortions and stillbirths in the equine population of central Kentucky. From July 1, 1988 through June 30, 1989, 15 (2.5%) of 594 submissions (fetuses, stillborn foals, and/or placentas) were diagnosed as leptospirosis by the FAT (14 of 15 tested) and/or microscopic agglutination test (12 of 14 tested). Of the 12 serologically positive fetal fluids, 10 had high tigers against Leptospira interrogans serovar pomona and 2 against serovar grippotyphosa.

Prospective Serology and Analysis in Diagnosis of Dairy Cow Abortion

A prospective serologic investigation was undertaken on 3 California dairies (herds 1, 3, and 4, as previously designated in a report on abortion surveillance) to determine if fetal loss was associated with infectious disease agents in cows. The diagnostic problem in these herds was typical of many dairies in that abortions were not discovered for several months and aborted fetuses were seldom recovered. Blood from approximately 100 pregnant cows in each herd was sampled at monthly intervals, beginning when the cows were palpated at approximately 40 days gestation. Sera were tested for antibodies to infectious bovine rhinotracheitis virus and bovine viral diarrhea virus (BVDV) and to the Leptospira serovars pomona, hardjo, grippotyphosa, icterohemorrhagiae, canicola, and szwajizak. Logn antibody titers were examined for an association with fetal loss, using multivariate methods of logistic regression and survival analysis. Of the 325 cows followed, 37 aborted, and no fetuses were recovered. Statistical analyses indicated that significant fetal loss was associated with high titers to L. hardjo and with low titers to L. szwajizak (herds 1 and 4) and BVDV (herd 1). Results for herd 3 revealed a connection between abortion and L. icterohemorrhagiae (P = 0.036) and L. canicola (P = 0.050) and possible vaccinal protection against abortion caused by L. grippotyphosa (P = 0.027 and 0.015). For herd 4, there was a marginally significant tendency for the first vaccination of the gestation against leptospirosis to have protected against fetal death (P = 0.077). Advantages of the diagnostic design were that it permitted comparison of titers of aborted cows with those of nonaborted cows and it considered vaccination-induced titers in analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Porcine Leptospirosis in Iowa

The epidemiology of leptospirosis in Iowa swine was examined on the basis of serologic results and herd data from 55 herds in the National Animal Health Monitoring System (NAHMS) program and culture results and histories from 578 cases of reproductive failure submitted to the Iowa Veterinary Diagnostic Laboratory during a 3-year period. Thirty-eight percent of sera from NAHMS herds contained antibodies against 1 or more of 12 leptospira antigens. Leptospires were isolated from 9 (1.6%) of 578 cases of reproductive failure. Seven (78%) of the isolates were identified as Leptospira interrogans serovar kennewicki and 2 (22%) as serovar grippotyphosa. In 7 herds from which leptospires were isolated, attack rates ranged from 1% to 84%. Clinical leptospirosis, characterized by reproductive failure and confirmed by isolation of leptospires, was sporadic. No significant differences in farrowing averages and reproductive problems were observed between vaccinated and nonvaccinated NAHMS herds or between herds with higher (43-63%) or lower (14-40%) percentages of animals that were serologically positive against serovar bratislava.

Use of saprophytic Leptospira strains in the serodiagnosis of experimental leptospirosis in guinea-pigs (Cavia sp).

The efficiency of four Leptospira biflexa strains (Buenos Aires, Patoc 1, Rufino and São Paulo) as single antigen in the serodiagnosis in guinea-pigs experimentally infected with seven Leptospira interrogans serovars (canicola, grippotyphosa, hardjo, icterohaemorrhagiae, pomona, tarassovi and wolffi) was evaluated by the microscopic agglutination test. The four saprophytic strains were not able to reveal antibody titres in sera of guinea-pigs experimentally infected with Leptospira interrogans. Serological cross-reactions were observed between strains Patoc 1 and São Paulo and between serovars wolffi and hardjo.

Incidence of abortions caused by leptospirosis in sheep and goats in Spain

From 1970 to 1985, 973 outbreaks of abortion in sheep and 262 outbreaks of abortion in goats from southern Spain were studied. Of these, 1.7 and 2.6% respectively were caused by leptospiras, chiefly by the serovar pomona (11 flocks of sheep, 64.7%, and six herds of goats, 75.0%) and in a lower proportion the serovars sejroe (three flocks of sheep 17.6%, and one herd of goats, 12.5%), icterohaemorrhagiae (two and one outbreaks respectively) and grippotyphosa in one ovine flock (5.8%). The mean rates of attach (X + SD) of abortions by leptospirosis have been estimated as 16.9 + 6.5% in ovine outbreaks and 20.7 + 8.3% among goats.

ELISA for the detection of specific IgM and IgG in human leptospirosis.

ELISA was used to detect specific IgM and IgG in sera from humans with current or past leptospirosis. A serological pattern of a high IgM titre (greater than or equal to 1280), or moderately increased IgM (160-640) in conjunction with a low IgG titre (less than or equal to 20), with serovar copenhageni antigen was characteristic for approximately two-thirds of the sera from serovar icterohaemorrhagiae patients obtained in the first two months of the disease. The antigen was the supernatant of a heated and centrifuged culture of leptospires. Antigens were prepared from serovars copenhageni, grippotyphosa, hardjo and patoc. Sera from patients with icterohaemorrhagiae, grippotyphosa and hardjo infections showed cross-reactivity when different antigens were used. In past infections the IgG titres were clearly higher with the homologous antigen. ELISA for IgM and IgG allows the rapid diagnosis of acute leptospirosis.

Levels of some reproductive diseases in the dairy cattle of Colombia

Of 4,144 serum samples collected from cows on 113 farms from eight areas of Colombia 3.3% had positive and 8.8% inconclusive titres to Brucella abortus, 21.7, 6.3, 1.6, 0.6 and 0.7% of cows had positive titres to Leptospira serovars hardjo, pomona, canicola, icterohaemorrhagiae and grippotyphosa respectively. Questionnaires completed on 110 farms revealed that 6, 2.5 and 4.6% of cows had had metritis, aborted or retained their placentas respectively in the previous 12 months. Trichomonas foetus and Campylobacter fetus were isolated from 13.7% and 15% of the bulls sampled on 103 farms. Six and two bulls had inconclusive and positive titres to Brucella abortus. Eight and 23 bulls had positive titres to pomona and hardjo. The results were discussed and remedies for control suggested.

Serologic studies on brucellosis, leptospirosis and tularemia in moose (Alces alces) in Quebec.

Blood samples were obtained from 208 moose in La Vérendrye and Matane Reserves and in Laurentides Park, Quebec, Canada. Sera were tested for antibodies to Brucella abortus, Leptospira interrogans serovar ballum, canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona, and Francisella tularensis. Fifteen sera contained evidence of prior exposure to F. tularensis. Only one animal was a seroreactor to L. interrogans serovar grippotyphosa and none of them had antibodies to B. abortus.

Characterization of monoclonal antibodies against Leptospira causing Weil's disease

Monoclonal antibodies against causal organisms of Weil's disease were produced by the somatic cell hybridization technique. Leptospira interrogans serovar copenhageni Shiromizu and M 20 strains and serovar icteroharmorrhagiae RGA strain were used as immunogens. Twenty monoclonal antibodies were established; 10 anti-Shiromizu monoclonal antibodies, 5 and-M 20 monoclonal antibodies and 5 anti-RGA monoclonal antibodies. In oder to clarify the immunological characteristics of these antibodies, microagglutination titers of these 20 monoclonal antibodies against the following 12 strains were estimated; serovar copenhageni Shiromizu and M 20, serovar icterohaemorrhagiae RAG and Ictero 1, serovar javanica Verdrat Batavia 46, serovar canicola Hond Utrecht IV, serovar pyrogenes Salinem, serovar autumnalis Akiyami A, serovar Pomona Pomona, serovar australis Ballico, serovar grippotyphosa Moskva V and serovar hebdomadis Ballico, serover grippotyphosa Moskva V and serovar hebdomadis hebdomadis.According to the patterns of the microagglutination titers, 20 monoclonal antibodies were diviede into following types.1. Anti-Shiromizu monoclonal antibodies.1) One monoclonal antibody reacted only to serovar copenhageni.2) Two monoclonal antibodies reacted to serovar copenhageni in a high titer and serovar icteroharmorohagiae in a low titer.3) Seven monoclonal antibodies reacted to both serovars in almost the same titer.2. Anti-M 20 monoclonal antibodies.1) Three monoclonal antibodies were reactive to serovar copenhageni and serovar icterohaemorrhagiae in almost the same titer. 2) One monoclonal antibody was reactive to serovar copenhageni in a low titer and serovar icterohaemorrhagiae in a high titer.3) One monoclonal antibody was reactive not only to serogroup Icterohaemorrhagiae but also serovar pyrogenes.3. Anti-RGA monoclonal antibodies.1) Two monoclonal antibodies reacted only to serovar icterohaemorrhagiae.2) Two monoclonal antibodies reacted to serovar icterohaemorrhagiae in a high titer and serovar copenhageni in a low titer.3) One monoclonal antibody reacted not only to serogroup Icterohaemorrhagiae but also to serovar pyrogenes and serovar canicola.It is suggested that serovar copenhageni and serovar icterohaemorrhagiae are closely related to serovar pyrogenes and serovar canicola. Serologically, serovar copenhageni has been classified as a complete type and serovar icterohaemorrhagiae has been classified as a incomplete type, but it is indicated that each serovar has it's own antigen (s) and the common antigens.As for the findings of agglutination, some of these 20 monoclonal antibodies exhibited unique agglutination patterns in which leptospira agglutinated like a long piece of string. Some of these monoclonal antibodies which had a narrow reactive range showed the remarkable prozone phenomenon.Monoclonal antibodies which react to only serovar copenhageni or serovar icterohaemorrhagiae and monoclonal antibodies which react to these two serovars may be useful for identification of causal organisms of Weil's disease.