Leptospirosis as a cause of infertility in Uruguayan beef cattle.

Leptospirosis, caused by pathogenic spirochetes of the genus Leptospira spp., is a globally significant zoonotic disease that affects humans and animals. In cattle, leptospirosis is associated not only with overt clinical manifestations but also with reproductive diseases, including infertility. This study assesses the potential correlation between leptospirosis and infertility in Uruguayan beef cattle. A case-control study involved 31 beef herds with no prior history of Leptospira vaccination. In each herd, veterinarians identified 10 non-pregnant (cases) and 25 pregnant cows (controls) using ultrasound, and blood and urine samples were collected from each cow. Serological diagnosis was performed using the Microscopic Agglutination Test (MAT), and quantitative PCR (qPCR) was used to assess Leptospira excretion. Additionally, antibodies against bovine viral diarrhea virus (BVDV) and infectious bovine rhinotracheitis (IBR) were tested. The results demonstrated an association between seropositivity to the Sejroe serogroup (cut-off 1:200) and infertility in cattle (OR=1.31; p-value=0.06). Furthermore, the level of Leptospira excretion (qPCR) in urine was associated with increased infertility risk, with cows excreting over 100 copies per mL of urine having the highest odds of infertility (OR=2.34; p-value<0.01). This study suggests a potential association between leptospirosis and infertility in Uruguayan beef cattle, emphasizing the importance of both serological and molecular diagnostics for assessing reproductive health in cattle herds. Future research should explore the impact of Leptospira serogroups on other reproductive disorders in cattle.

Characterisation of Putative Outer Membrane Proteins from Leptospira borgpetersenii Serovar Hardjo-Bovis Identifies Novel Adhesins and Diversity in Adhesion across Genomospecies Orthologs.

Leptospirosis is a zoonotic bacterial disease affecting mammalian species worldwide. Cattle are a major susceptible host; infection with pathogenic Leptospira spp. represents a public health risk and results in reproductive failure and reduced milk yield, causing economic losses. The characterisation of outer membrane proteins (OMPs) from disease-causing bacteria dissects pathogenesis and underpins vaccine development. As most leptospire pathogenesis research has focused on Leptospira interrogans, this study aimed to characterise novel OMPs from another important genomospecies, Leptospira borgpetersenii, which has global distribution and is relevant to bovine and human diseases. Several putative L. borgpetersenii OMPs were recombinantly expressed, refolded and purified, and evaluated for function and immunogenicity. Two of these unique, putative OMPs (rLBL0972 and rLBL2618) bound to immobilised fibronectin, laminin and fibrinogen, which, together with structural and functional data, supports their classification as leptospiral adhesins. A third putative OMP (rLBL0375), did not exhibit saturable adhesion ability but, together with rLBL0972 and the included control, OmpL1, demonstrated significant cattle milk IgG antibody reactivity from infected cows. To dissect leptospire host-pathogen interactions further, we expressed alleles of OmpL1 and a novel multi-specific adhesin, rLBL2618, from a variety of genomospecies and surveyed their adhesion ability, with both proteins exhibiting divergences in extracellular matrix component binding specificity across synthesised orthologs. We also observed functional redundancy across different L. borgspetersenii OMPs which, together with diversity in function across genomospecies orthologs, delineates multiple levels of plasticity in adhesion that is potentially driven by immune selection and host adaptation. These data identify novel leptospiral proteins which should be further evaluated as vaccine and/or diagnostic candidates. Moreover, functional redundancy across leptospire surface proteins together with identified adhesion divergence across genomospecies further dissect the complex host-pathogen interactions of a genus responsible for substantial global disease burden.

Growth dynamic of Leptospira spp. from Sejroe serogroup in different media formulae.

The culturing of Leptospira strains from bovine clinical samples is challenging and has resulted in some gaps in securing an epidemiological understanding. Strains related to chronic reproductive leptospirosis in cattle belong to the Sejroe serogroup - not only Hardjoprajitno and Hardjobovis but also Guaricura genotypes. This study analyses the growth of Leptospira strains from serogroup Sejroe in different culture media, with the aim of suggesting better culturing approaches. To meet this objective, two culture media were applied: EMJH and T80/40/LH. In addition, three different cocktails of selective agents were chosen. The combinations of medium and selective additives resulted in 10 different tested formulae. The poor performance of Hardjobovis in EMJH indicated that its growth may represent a possible bias when culturing these strains from bovine samples. The most efficient medium for culturing Hardjobovis was T80/40/LH, while T80/40/LH medium + STAFF combination proved to be the best choice for growth, being recommended for obtaining a higher number of these strains from bovines.

Serological and molecular characterization of Leptospira kirschneri serogroup Grippotyphosa isolated from bovine in Brazil.

Leptospirosis is a zoonotic disease caused by a bacterium of the genus Leptospira that affects domestic animals, including cattle. Despite of this importance in livestock, little is known about the epidemiology of leptospirosis in cattle in Brazil and other tropical countries. In this context, the objective of this study was to perform the culture of urine and kidney (n = 372 animals) of slaughtered bovines of Minas Gerais state (Brazil), in order to obtain pure cultures of Leptospira strains and carry out its characterization by serological (microscopic agglutination test) and molecular techniques (rrs, secY sequencing and variable-number tandem-repeat genotyping). One strain, named UFU 02, was obtained from a male bovine without apparent alterations in ante-mortem examination. The strain was characterized belonging to species Leptospira kirschneri and serogroup Grippotyphosa. The serogroup Grippotyphosa is most often described in wild species, suggesting a link between domestic and wild cycles/environments. Considering the importance of the country in livestock breeding, the knowledge about leptospiral strains could help to control the disease in the herds.

Molecular epidemiology of Leptospira noguchii reveals important insights into a One Health context.

Leptospirosis presents a complex and dynamic epidemiology. Bovine leptospirosis has been described as a major infectious disease impairing reproductive efficiency. Although infections by Leptospira interrogans, L. santarosai and L. borgpetersenii are frequently reported in cattle, the presence of L. noguchii in these animals should not be neglected. In this study, we describe serological (MAT) and molecular characterization (rrs and secY gene sequencing, multilocus sequence typing [MLST] and pulsed-field gel electrophoresis [PFGE]) of eight L. noguchii strains obtained from slaughtered cows. Intraspecific genetic diversity was evaluated, and haplotype networks were constructed based on hosts and geographical localizations. Strains were characterized as belonging to serogroups Australis, Autumnalis and Panama, and molecular characterization showed a high heterogeneity of these strains. Ten different STs were found (including nine new STs and 39 novel alleles) as well as nine different pulsotypes. Two clonal complexes were found. Phylogenetic trees based on secY locus and concatenated MLST loci showed two main clusters, with sequences from the present study included in the first. In general, there was no relationship between the geographical origin and the secY phylogenetic clusters, as well as between secY phylogenetic clusters and serogroups. Molecular diversity indexes confirmed a high variability (H > 0.8). This high intraspecific variation observed may be related to differences in virulence, pathogenicity and antigenicity or even adaptability of the strains. In addition, haplotype networks clearly demonstrated the circulation of genotypes between humans and animals, confirming the zoonotic potential. The present study provides relevant data for the study of leptospirosis in the One Health context, where human, animal and environmental health is closely connected.

Infectivity and virulence of leptospiral strains of serogroup Sejroe other than Hardjo on experimentally infected hamsters.

To assess the virulence of leptospires from the serogroup Sejroe (from ruminants), hamsters were tested against 12 strains. Three Guaricura strains induced severe lethal disease, in contrast to the Hardjo strains. Although with the preliminary outcomes, this finding may be useful for the control of bovine leptospirosis in the Americas, where Guaricura is prevalent.

Circulating Leptospira species identified in cattle of the Brazilian Amazon.

The present study aimed to detect the most prevalent serogroups and circulating Leptospira species in cows from Brazilian Amazon. Samples of blood serum, urine and kidney of 208 animals were collected at a municipal slaughterhouse in the Baixo Tocantins region of Pará State, Northern Brazil. The tests used were microscopic agglutination test (MAT), bacteriological isolation, polymerase chain reaction (PCR) and DNA sequencing. The frequency of MAT-reactive cows was 46.6% (97/208) with titers ranging from 100 to 3200, being Sejroe serogroup the most prevalent. There was no Leptospira isolation, but the DNA of bacterium was detected in 5.8% (12/208) of the kidney and in 14.9% (31/208) of the urine samples. DNA sequencing was performed directly from PCR products of 30 samples (3 kidneys and 27 urines), with identification of four different species: L. borgpetersenii with 56.7% (17/30), followed by L. kirschneri with 13.3% (4/30), L. interrogans with 6.7% (2/30), L. santarosai with 3.3% (1/30), and 20.0% (6/30) of samples were identified only at the genus level. These results reveal a diversity and peculiarity for bovine leptospirosis in the Amazon region, mainly due to the low frequency of L. santarosai and more surprising, the presence of L. kirschneri, differently of what is observed in other regions of Brazil.

Prevalencia de algunas enfermedades infecciosas en bovinos de resguardos indígenas del cauca, colombia, 2017 / Prevalence of some infectious diseases in cattle of the indigenous resguards in cauca, colombia 2017

RESUMEN La zona del Cauca posee resguardos indígenas que han presentado diferentes problemáticas asociadas a la lucha armada en Colombia, lo que ha limitado que las entidades puedan realizar programas de control de enfermedades bovinas. Por lo anterior, el objetivo de este trabajo fue determinar la prevalencia de algunas enfermedades infecciosas, de carácter reproductivo, en el ganado bovino, de tres resguardos indígenas del Cauca, 2017. Se recolectaron muestras sanguíneas de 30 vacas, para determinar la prevalencia de Neospora caninum, Brucella abortus, diarrea viral bovina (DVB), rinotraqueitis infecciosa bovina (IBR) y Leptospira sp. serovares Hardjo prajitno, bovis y Pomona. Las pruebas, se realizaron por ELISA, rosa de bengala y microaglutinación. Mediante el software R, se efectuó un análisis descriptivo y se determinaron las prevalencias para cada enfermedad, se estimaron las co-infecciones y se realizó un modelo de regresión logística, para determinar el efecto del hato, resguardo, componente racial, grupo etario, número de animales y tamaño del hato, sobre la positividad a las enfermedades. Se encontró una prevalencia del 36%, para N. caninum; 60%, DVB; 30%, IBR; 0%, B. abortus; Leptospira spp. serovares Harjo prajitno, 26%; Hardjo bovis, 12% y Pomona, 10%. De acuerdo con el análisis de riesgo, la seropositividad para DVB e IBR estuvo asociada con el resguardo donde habitaban los animales, en este caso, Tacueyó tuvo más riesgo y estuvo directamente relacionado con el área de los hatos; entre mayor área más animales fueron positivos. En general, se encontró que la situación de la zona es similar a la de otros lugares de Colombia.

ABSTRACT The Cauca region in Colombia has indigenous reservations that have presented different problems associated with the armed conflict, which has limited the entities to carry out bovine disease control programs. Therefore, the aim of this work was to determine the prevalence of some infectious diseases of reproductive traits in cattle of three indigenous resguards in Cauca, 2017. Blood samples of 30 cows were collected to determine the prevalence of Neospora caninum, Brucella abortus, bovine viral diarrhea (BVD), Infectious bovine rhinotracheitis (IBR) and Leptospira sp. serovars Hardjo prajitno, bovis and Pomona. The tests were performed by ELISA, rose bengal and microscopic agglutination. Using R software, a descriptive analysis was carried out and the frequencies for each disease were estimated. In addition, coinfections between diseases were estimated and a logistic regression model was performed to determine the effect of the herd, reservation, racial component, age group, number of animals and size of the farm on the disease positivity. The prevalence was N. caninum 36%, BVD 60%, IBR 30%, B. abortus 0%, Leptospira spp. serovars Hardjo prajitno 26%, Hardjo bovis 12%, y Pomona 10%. According to the risk analysis, the seropositivity for BVD and IBR were associated with the place where the animals lived, in this case Tacueyó, but this was directly related to the size of the herds, since the greater, the area more animals were positive. In general, it was found that the situation in the region is similar to that of other sites in Colombia.

Control of bovine leptospirosis: Aspects for consideration in a tropical environment.

Due to the complex and dynamic epidemiology of leptospirosis on livestock, control is still controversial and frustrating. In this context, this paper discusses the main challenges and perspectives for the control of bovine leptospirosis, particularly under tropical conditions. In order to reduce the effects of the disease in cattle, it has been proposed that the control should integrate the trinomial antibiotic therapy (mainly streptomycin); vaccination (whole-cell bacterins); and environmental management. This last element should be carefully considered in tropics. Despite the enormous economic impact of the disease, mainly on its chronic and silent reproductive presentation, research on control programs is not proportional. Conversely, the number of studies regarding the new vaccine strategies, such as recombinant antigens has been increasing and should be encouraged.

Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran.

OBJECTIVE: To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. METHODS: One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. RESULTS: Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. CONCLUSION: This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.

Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

Objective: To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. Methods: One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. Results: Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. Conclusion: This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.

Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

Objective:To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. Methods: One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. Results:Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. Conclusion:This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.

Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

<p><b>OBJECTIVE</b>To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans.</p><p><b>METHODS</b>One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran.</p><p><b>RESULTS</b>Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples.</p><p><b>CONCLUSION</b>This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.</p>

Análisis retrospectivo de las pruebas diagnósticas de leptospirosis bovina procesadas en la unidad de investigación y diagnóstico de leptospirosis de la Universidad del Zulia 1998-2001 / Retrospective analysis of bovine leptospirosis diagnostic tests performered at the research and diagnosis unit of leptospirosis of Zulia University 1998-2001

En el presente estudio se analizaron los resultados de sueros de bovinos procesados en la Unidad de Investigación y Diagnóstico de Leptospirosis de la Universidad del Zulia durante el período 1998-2001. De un total de 819 muestras provenientes de la región occidental de Venezuela, procesadas mediante la Técnica de Microaglutinación (MAT), se observó que 38 por ciento animales fueron seropositivos a uno o más serovares. Los serovares icterohaemorrhagiae (49 por ciento), hardjo (45 por ciento) y hebdomadis (44 por ciento) fueron los más frecuentes, sin evidenciar diferencias estadísticamente significativas entre si. En cuanto a la vacunación, se observó un 56 por ciento de seropositividad en animales no vacunados y 26 por ciento en animales vacunados. En relación a la edad, se obtuvo un 46 por ciento de seropositividad en animales mayores de 48 meses de edad, 35 por ciento en animales entre 12 y 48 meses de edad y 100 por ciento en bovinos menores de 12 meses de edad. De 270 animales con registros clínicos completos, 99 por ciento reportaron abortos como signo clínico más relevante, de los cuales el 49 por ciento fueron realmente positivos a leptospirosis. Se concluye que L. icterohaemorrhagiae y L. hardjo, fueron los serovares que circularon mayormente en el ganado bovino en la región occidental de Venezuela desde 1998 hasta 2001, siendo asociados en varias oportunidades a problemas abortivos. También se observó que los animales no vacunados presentaron una mayor seropositividad que los vacunados. Este estudio permitirá establecer una línea base para comparar las seroprevalencias actuales y futuras de la leptospirosis bovina en esta región, aportando información epidemiológica importante que permita el mejoramiento de medidas de prevención y control en contra de esta enfermedad.

Results from bovine serum samples processed at the Unit of Investigation and Diagnose of Leptospirosis of Zulia University, during the period 1998-2001 were analyzed in the present study. From a total of 819 samples submitted across the Western region in Venezuela, 38 percent were positive to one or more serovars by the Microagglutination Test (MAT). The most frequent serovars observed were icterohaemorrhagiae (49 percent), hardjo (45 percent) and hebdomadis (44 percent), however, no statistical significant differences were found between them. In regards to vaccination, 56 percent of the non-vaccinated animals and 26 percent of the vaccinated were seropositive. The age distribution showed that 46 percent of the animals older than 48 months, 35 percent of the animals between 12 and 48 months-old, and 100 percent of the animals younger than 12 months-old were positive to leptospira. From 270 animals with complete clinical records, 99 percent reported abortion as the main clinical sign, and 49 percent of them were indeed positives to leptospirosis. In conclusion, L. icterohaemorrhagiae and L. hardjo were the most common serovars circulating in the cattle population in the Western region in Venezuela between 1998 and 2001, in which several cases were associated with reproductive problems. It was also observed that non-vaccinated animals presented a higher seropositivity than animals that were vaccinated. This study will allow the establishment of a baseline to compare present and future studies on Bovine Leptospirosis in this region, providing important epidemiological information to be used in improving preventive and control measures against this disease.

Leptospirosis serosurvey in bovines from Brazilian Pantanal using IGG ELISA with recombinant protein LipL32 and microscopic agglutination test

This investigation was carried out in Brazilian Pantanal: region with important biodiversity. This region's climatic conditions, hydrology and geomorphology as well as the existence of great variety of wild species favor the maintenance of the Leptospira in the environment. The aim of this study was to evaluate IgG ELISA with recombinant protein LipL32 in comparison with microscopic agglutination test (MAT) and additionally contribute to the knowledge of the distribution of the one of most important worldwide zoonotic infection, assessing the seropositivity of bovine leptospirosis in beef cattle herds of Brazilian Pantanal, an important ecological preserved area, where cattle constitute not only the most important economic resource but also the major activity compatible of the conservation of natural resource of the region. Out of 282 samples of cattle serum analyzed, 143 (50.71 percent) were positive in MAT. The serovar Hardjo (genotypic Hardjoprajitno and Hardjobovis), Wolffi and Ballum showed the largest frequency of reactive samples. In the IgG ELISA rLipL32, 161 samples (57.09 percent) were positive. This result was higher than obtained by MAT (p<0.001). The sensitivity of the ELISA test was 99.30 percent and the specificity was 86.33 percent, based on the MAT. This test was shown to be a more sensitive, specific and accurate test for the diagnosis of bovine leptospirosis compared to the MAT.

Este estudo foi realizado no Pantanal brasileiro: região que apresenta importante biodiversidade. As condições de clima, hidrologia e geomorfologia dessa região, bem como a existência de grande variedade de espécies animais silvestres, favorecem a manutenção da Leptospira no meio ambiente. O objetivo desse estudo foi avaliar o ELISA IgG com proteína recombinante LipL32 em comparação com a soroaglutinação microscópica (SAM) para o diagnóstico sorológico de Leptospira. Adicionalmente, contribuir para o conhecimento da distribuição da leptospirose bovina, uma das mais importantes zoonoses mundialmente distribuída. Foi avaliada a soropositividade para essa bactéria em rebanhos bovinos de corte da região do Pantanal, uma área onde o bovino constitui não apenas o recurso econômico mais importante, como também a principal atividade econômica compatível com a conservação dos recursos naturais da região. Das 282 amostras de soro bovino analisadas, 143 (50,71 por cento) foram positivas na SAM. O sorovar Hardjo (genótipos Hardjoprajitno e Hardjobovis), Wolffi e Ballum apresentaram freqüências altas de amostras reativas. No IgG ELISA rLipL32, 161 amostras (57,09 por cento) foram positivas, apresentando esse teste uma maior soropositividade em relação à SAM (p<0,001). A Sensibilidade do ELISA em comparação com a SAM foi de 99,30 por cento e a especificidade de 86,33 por cento. O IgG ELISA rLipL32 mostrou ser um teste sensível, específico e de alta acurácia para o diagnóstico de leptospirose bovina.