The Leptospira interrogans proteome's response to zinc highlights the potential involvement of this metal in translational-machinery and virulence.

Leptospires, as motile Gram-negative bacteria, employ sophisticated strategies for efficient invasion and dissemination within their hosts. In response, hosts counteract pathogens through nutritional immunity, a concept involving the deprivation of essential metals such as zinc. Zinc, pivotal in modulating pathogen-host interactions, influences proteins structural, catalytic, and regulatory functions. A comprehensive understanding of how leptospires regulate intracellular zinc availability is crucial for deciphering their survival mechanisms. This study explores the proteomic profile of Leptospira interrogans sv. Copenhageni str. 10A cultivated in Ellinghausen-McCullough-Johnson-Harris medium supplemented with the zinc chelator TPA or ZnCl2. Among the 2161 proteins identified, 488 were subjected to scrutiny, revealing 102 less abundant and 81 more abundant in response to TPA. Of these 488 proteins, 164 were exclusive to the presence of TPA and 141 were exclusive to the zinc-enriched conditions. Differentially expressed proteins were classified into clusters of orthologous groups (COGs) with a distribution in metabolic functions (37.8%), information storage/processing (21.08%), cellular processes/signaling (28.04%), and poorly characterized proteins (10.65%). Differentially expressed proteins are putatively involved in processes like 1-carbon compound metabolism, folate biosynthesis, and amino acid/nucleotide synthesis. Zinc availability significantly impacted key processes putatively related to leptospires' interactions with their host, such as motility, biofilm formation, and immune escape. Under conditions of higher zinc concentration, ribosomal proteins, chaperones and components of transport systems were observed, highlighting interactions between regulatory networks responsive to zinc and iron in L. interrogans. This study not only revealed hypothetical proteins potentially related to zinc homeostasis, but also identified possible virulence mechanisms and pathogen-host adaptation strategies influenced by the availability of this metal. There is an urgent need, based on these data, for further in-depth studies aimed at detailing the role of zinc in these pathways and mechanisms, which may ultimately determine more effective therapeutic approaches to combat Leptospira infections.

Isolation and molecular characterization of a novel relapsing fever group Borrelia from the white-eared opossum Didelphis albiventris in Brazil.

This study aimed to detect, isolate and to characterize by molecular methods a relapsing fever group (RFG) Borrelia in white-eared opossums (Didelphis albiventris) from Brazil. During 2015-2018, when opossums (Didelphis spp.) were captured in six municipalities of the state of São Paulo, Brazil, molecular analyses revealed the presence of a novel RFG Borrelia sp. in the blood of seven opossums (Didelphis albiventris), out of 142 sampled opossums (4.9% infection rate). All seven infected opossums were from a single location (Ribeirão Preto municipality). In a subsequent field study in Ribeirão Preto during 2021, two new opossums (D. albiventris) were captured, of which one contained borrelial DNA in its blood. Macerated tissues from this infected opossum were inoculated into laboratory animals (rodents and rabbits) and two big-eared opossums (Didelphis aurita), which had blood samples examined daily via dark-field microscopy. No spirochetes were visualized in the blood of the laboratory animals. Contrastingly, spirochetes were visualized in the blood of the two D. aurita opossums between 12 and 25 days after inoculation. Blood samples from these opossums were used for a multi-locus sequencing typing (MLST) based on six borrelial loci. Phylogenies inferred from MLST genes positioned the sequenced Borrelia genotype into the RFG borreliae clade basally to borreliae of the Asian-African group, forming a monophyletic group with another Brazilian isolate, "Candidatus B. caatinga". Based on this concatenated phylogenetic analysis, which supports that the new borrelial isolate corresponds to a putative new species, we propose the name "Candidatus Borrelia mimona".

First molecular detection of Borrelia sp. in tapirs (Tapirus terrestris).

Borrelia theileri is a tick-borne spirochete causative agent of fever, apathy and reduced food consumption in cattle. Molecular diagnosis has expanded the understanding of Borrelia theileri with new hosts and geographical locations being described. The present study aimed to describe the first molecular detection of B. theileri in wild tapirs (Tapirus terrestris) from South America. Blood DNA samples obtained from 99 tapirs sampled in Pantanal (n = 61) and Cerrado (n = 38) biomes were screened using a qPCR assay based on the 16 S rRNA gene of Borrelia sp. Positive samples in the qPCR assay were subjected to PCR assays to allow characterization of fragments from 16 S rRNA and flaB genes. Two (2/99; 2.0%) animals from Pantanal biome were positive in the qPCR and one sample presented bands of expected size for the flaB protocol. Amplicons from this sample were successfully cloned and sequenced. In the phylogenetic analysis, Borrelia sp. from T. terrestris grouped together with B. theileri sequences previously detected in Rhipicephalus microplus ticks and cattle from Minas Gerais State in Brazil, Rhipicephalus geigyi from Mali, and R. microplus and Haemaphysalis sulcata from Pakistan. This finding contributes to our knowledge regarding susceptible hosts species for B. theileri. More studies are necessary to understand the potential effects of B. theileri on tapir's health.

The Leptospira interrogans proteome’s response to zinc highlights the potential involvement of this metal in translational-machinery and virulence

Leptospires, as motile Gram-negative bacteria, employ sophisticated strategies for efficient invasion and dissemination within their hosts. In response, hosts counteract pathogens through nutritional immunity, a concept involving the deprivation of essential metals such as zinc. Zinc, pivotal in modulating pathogen-host interactions, influences proteins structural, catalytic, and regulatory functions. A comprehensive understanding of how leptospires regulate intracellular zinc availability is crucial for deciphering their survival mechanisms. This study explores the proteomic profile of Leptospira interrogans sv. Copenhageni str. 10A cultivated in Ellinghausen-McCullough-Johnson-Harris medium supplemented with the zinc chelator TPA or ZnCl2. Among the 2161 proteins identified, 488 were subjected to scrutiny, revealing 102 less abundant and 81 more abundant in response to TPA. Of these 488 proteins, 164 were exclusive to the presence of TPA and 141 were exclusive to the zinc-enriched conditions. Differentially expressed proteins were classified into clusters of orthologous groups (COGs) with a distribution in metabolic functions (37.8%), information storage/processing (21.08%), cellular processes/signaling (28.04%), and poorly characterized proteins (10.65%). Differentially expressed proteins are putatively involved in processes like 1-carbon compound metabolism, folate biosynthesis, and amino acid/nucleotide synthesis. Zinc availability significantly impacted key processes putatively related to leptospires’ interactions with their host, such as motility, biofilm formation, and immune escape. Under conditions of higher zinc concentration, ribosomal proteins, chaperones and components of transport systems were observed, highlighting interactions between regulatory networks responsive to zinc and iron in L. interrogans. This study not only revealed hypothetical proteins potentially related to zinc homeostasis, but also identified possible virulence mechanisms and pathogen-host adaptation strategies influenced by the availability of this metal. There is an urgent need, based on these data, for further in-depth studies aimed at detailing the role of zinc in these pathways and mechanisms, which may ultimately determine more effective therapeutic approaches to combat Leptospira infections.

Borrelia puertoricensis in opossums (Didelphis marsupialis) from Colombia.

BACKGROUND: The genus Borrelia comprises pathogenic species of bacteria that pose a significant risk to public health. Borrelia spp. are emerging or reemerging infectious agents worldwide with complex transmission cycles, and many species use rodents as vertebrate reservoir hosts. Spirochetes morphologically compatible with Borrelia have been recurrently observed in opossums; however, there is currently a lack of genetic evidence confirming infection or supporting that these marsupials are hosts of Borrelia spirochetes. METHODS: During 2017, 53 serum samples of Didelphis marsupialis from the municipality of Colosó (department of Sucre, Colombia) were collected and allocated in a serum bank. DNA extracted from the serum samples was submitted to a Borrelia genus-specific real-time PCR targeting the 16S rRNA gene. Positive samples were subsequently derived from semi-nested PCR protocols to obtain large fragments of the 16S rRNA and flaB genes. Obtained amplicons were subjected to Sanger sequencing. One positive sample was randomly selected for next-generation sequencing (NGS). Obtained reads were mapped to genomes of Borrelia spp. and sequences of two genes used in a multilocus sequence typing scheme retrieved for taxonomic assignment and phylogenetic analyses. RESULTS: Overall, 18.8% (10/53) of the samples were positive by qPCR. Of them, 80% (8/10) and 60% (6/10) were positive for the 16S rRNA and flaB genes after semi-nested PCRs, respectively. Bioinformatic analysis of one sample sequenced with NGS yielded 22 reads of genus Borrelia with different sizes. Two housekeeping genes, rplB and pyrG, were recovered. Nucleotide pairwise comparisons and phylogenetic analyses of 16S rRNA, flaB, rplB and pyrG genes showed that the Borrelia sp. found in opossums from Colosó corresponded to Borrelia puertoricensis. CONCLUSIONS: We describe the first molecular evidence to our knowledge of B. puertoricensis in Colombia, specifically in opossums, and the first detection of this spirochete in a vertebrate host since its isolation from Ornithodoros puertoricensis in Panama. This detection is also relevant because of the epidemiological importance of opossums as reservoirs of zoonotic diseases to humans.

A Novel Relapsing Fever Group Borrelia Isolated from Ornithodoros Ticks of the Brazilian Caatinga.

Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the Brazilian semiarid region, within the Caatinga biome. Collected ticks (Ornithodoros rietcorreai and Ornithodoros cf. tabajara) were allowed to feed under laboratory conditions on guinea pigs, which had blood samples examined daily by dark-field microscopy. No spirochetes were visualized in the blood of any of four O. rietcorreai-infested guinea pigs. Contrastingly, spirochetes were visualized between 9 and 39 days after tick feeding in the blood of three guinea pigs, each infested with O. cf. tabajara ticks from a different locality. Guinea pig infection was confirmed by passages into experimental animals and by generating DNA sequences of Borrelia spp. from the blood of spirochetemic guinea pigs. Three O. cf. tabajara populations were infected by the same borrelial organism, which was characterized as a novel RFG agent (named as 'Candidatus Borrelia caatinga') based on 10 Borrelia loci (rrs, flaB, glpQ, gyrB, clpX, pepX, pyrG, recG, rplB and uvrA). We demonstrated that O. cf. tabajara is a competent vector of the novel Borrelia sp. isolates, although none of the infected rodents developed clinical illness.

Historical overview and update on relapsing fever group Borrelia in Latin America.

Relapsing fever group Borrelia (RFGB) are motile spirochetes transmitted to mammalian or avian hosts through the bite of hematophagous arthropods, such as soft ticks (Argasidae), hard ticks (Ixodidae) and the human clothing lice. RFGB can infect pets such as dogs and cats, as well as birds, cattle and humans. Borrelia recurrentis, B. anserina and B. theileri are considered to have worldwide distribution, affecting humans, domestic birds and ruminants, respectively. Borrelia spp. associated with soft ticks are transmitted mainly by Ornithodoros ticks and thrive in endemic foci in tropical and subtropical latitudes. Nowadays, human cases of soft tick-borne relapsing fever remain neglected diseases in several countries, and the impact these spirochetes have on the health of wild and domestic animals is largely understudied. Human infection with RFGB is difficult to diagnose, given the lack of distinguishing clinical features (undifferentiated febrile illness). Clinically, soft tick or louse-borne relapsing fever is often confused with other etiologies, such as malaria, typhoid or dengue. In Latin America, during the first half of the twentieth century historical documents elaborated by enlightened physicians were seminal, and resulted in the identification of RFGB and their associated vectors in countries such as Mexico, Panama, Colombia, Venezuela, Peru and Argentina. Almost 80 years later, research on relapsing fever spirochetes is emerging once again in Latin America, with molecular characterizations and isolations of novel RFGB members in Panama, Bolivia, Brazil and Chile. In this review we summarize historical aspects of RFGB in Latin America and provide an update on the current scenario regarding these pathogens in the region. To accomplish this, we conducted an exhaustive search of all the published literature for the region, including old medical theses deposited in libraries of medical academies. RFGB were once common pathogens in Latin America, and although unnoticed for many years, they are currently the focus of interest among the scientific community. A One Health perspective should be adopted to tackle the diseases caused by RFGB, since these spirochetes have never disappeared and the maladies they cause may be confused with etiologies with similar symptoms that prevail in the region.

A Novel Genospecies of Borrelia burgdorferi Sensu Lato Associated with Cricetid Rodents in Brazil.

Borrelia burgdorferi sensu lato (Bbsl) spirochetes thrive in sylvatic transmission cycles infecting vertebrates and their ticks. Rodents and ticks of the genus Ixodes are important hosts of these spirochetes globally. Although evidence suggests that Borrelia burgdorferi sensu stricto does not exist in South America, genospecies of the group (Bbsl) can be found in this region but have been poorly characterized from a genetic viewpoint, and data on their ecoepidemiology are still incipient. Aiming to detect the natural foci of Borrelia in Brazil, we targeted small mammals inhabiting seven forests fragments during a period of three years (2015-2018). Organs (lung) from two Oligoryzomys rodents over a total of 382 sampled mammals were positive, and we performed a molecular characterization of 10 borrelial genes to achieve a robust analysis. Phylogenetic trees inferred from 16S rRNA, flaB, ospC, and seven MLST loci (clpA, nifS, pepX, pyrG, recG, rlpB, and uvrA) support the characterization of a novel genospecies of Bbsl that we herein name "Candidatus Borrelia paulista" Rp42. Remarkably, "Ca. B. paulista" is phylogenetically related to Borrelia carolinensis, a genospecies that infects Ixodes ticks and cricetid rodents in North America. A previous study performed in the same area identified Ixodes schulzei feeding on Oligoryzomys rodents. Although this tick species could be considered a probable host for this novel Borrelia sp., further research is needed to confirm this hypothesis.

Identification and distribution of Brachyspira species in feces from finishing pigs in Argentina.

BACKGROUND AND AIM: Brachyspira are Gram-negative, aerotolerant spirochetes that colonize the large intestine of various species of domestic animals and humans. The aim of this study was to determine the presence and distribution of different species of Brachyspira presents in feces from finishing pigs in Argentina. MATERIALS AND METHODS: Fecal samples (n=1550) were collected from finishing pigs in 53 farms of the most important swine production areas of Argentina, and Brachyspiras species were identified by bacteriological and molecular methods. RESULTS: The regional prevalence of Brachyspira spp. was at the level of 75.5% (confidence interval 95%, 62.9-87.9), and it was lower among those farms with >1001 sows. One hundred and twenty-eight isolates of Brachyspira were properly identified and the species found were: Brachyspira hyodysenteriae, Brachyspira pilosicoli, Brachyspira innocens, and Brachyspira murdochii. B. hyodysenteriae and B. pilosicoli had low prevalence (1.9% and 7.5%, respectively), B. innocens was isolated from 34% of the farms and B. murdochii was found in 39.6%. CONCLUSION: The present study provides epidemiological data about herd prevalence of the different Brachyspira species in Argentina, showing that the prevalence figure seems to be higher than that reported in other countries.

Relapsing Fever Group Borreliae in Human-Biting Soft Ticks, Brazil.

We conducted a molecular survey for Borrelia spp. in Ornithodoros ticks previously reported as biting humans. We collected specimens in natural ecosystems and inside human dwellings in 6 states in Brazil. Phylogenetic analyses unveiled the occurrence of 4 putatively new species of relapsing fever group borreliae.

Virulent Leptospira interrogans Induce Cytotoxic Effects in Human Platelets in vitro Through Direct Interactions.

Leptospirosis is a prevalent zoonotic disease, caused by bacteria of the genus Leptospira. Leptospirosis frequently leads to hemostatic disturbances, and the severe cases are marked by hemorrhages and low platelet number in circulation, which is associated with the patients' poor outcomes. Nevertheless, Leptospira-platelet interactions remain poorly explored. In this study, we performed a series of in vitro experiments evaluating whether leptospires induce human platelet aggregation, activation, and morphological changes. Platelets were incubated with virulent L. interrogans and the platelet outcomes were assessed by aggregometry, flow cytometry, and scanning and transmission electron microscopy. Our results show that leptospires alone do not induce platelet aggregation and activation, and induce platelet cytotoxic effects instead, by clearly inducing platelet disruption and detachment. We show for the first time that virulent leptospires do interact directly with platelets, an event that could trigger pathophysiological effects during the infection. This study might serve as a basis for the development of novel treatments for the disease.

Molecular identification of Leptospira interrogans in naturally infected cows from a rural property in the border region: case report / Identificação molecular de Leptospira interrogans em vacas naturalmente infectadas de uma propriedade rural em região fronteiriça: relato de caso

The aim of this study was to investigate the antibodies and DNA of Leptospira spp. isolated from infected cattle in a small rural dairy farm in a border region between Brazil and Paraguay. Blood and urine samples were collected from 50 Holstein cows aged between 1 and 15 years. The diagnostic tests performed were microscopic serum agglutination for antibody detection and polymerase chain reaction for Leptospira spp. detection. Out of the samples analyzed, 48% were MAT positive with titers ranging from 100 to 400, and the most prevalent antibody was to the serovar Hardjo. One serum sample was amplified to 549 bp for the sec y gene, and sequencing identified it as L. interrogans. This is the first report from northwestern Paraná (PR) State of L. interrogans identification in naturally infected milk cattle. Thus, based on these results, to enhance production efficiency, new serological and molecular studies on dairy cattle from border regions are required to characterize the epidemiology of possible genotypes and their consequences in affected herds.(AU)

O objetivo deste trabalho foi pesquisar anticorpos e DNA de Leptospira spp. em uma propriedade rural leiteira de uma região fronteiriça entre Brasil e Paraguai. Foram coletadas amostras de sangue e urina de 50 animais da raça Holandesa com idade variando de um a quinze anos, de uma pequena propriedade rural de exploração leiteira em uma região de fronteira entre Brasil e Paraguai. Quanto aos diferentes diagnósticos foi utilizado a soroaglutinação microscópica para a detecção de anticorpos e também foi realizada a reação em cadeia pela polimerase para a detecção de DNA de Leptospira spp. Das amostras analisadas, 48,00% foram soro reagentes na SAM com títulos variando de 100 a 400 e o anticorpo contra o sorovar mais prevalente foi o Hardjo. Uma amostra de soro amplificou 549pb para o gene sec y, e no sequenciamento foi identificada como Leptospira interrogans. Este é o primeiro relato da região noroeste do estado do Paraná (PR) relacionado à identificação de L. interrogans de bovinos de leite naturalmente infectados e em virtude dos resultados deste trabalho são necessários novos estudos sorológicos e moleculares em criações de gado de leite de regiões fronteiriças para se caracterizar a epidemiologia dos possíveis genótipos e suas possíveis consequências nos rebanhos afetados visando sempre à eficiência da produção.(AU)

Leptospira patógena en murciélagos de Campeche y Yucatán, México / Pathogenic Leptospira in bats from Campeche and Yucatán, Mexico

RESUMEN Objetivo. Reportar la infección con Leptospira en ríñones de murciélagos de Campeche y Yucatán, México, a través de la amplificación por PCR de dos fragmentos distintos del gen 16S RNA ribosomal. Materiales y métodos. Se realizaron capturas en un sitio de Campeche y dos de Yucatán. A los murciélagos capturados se les aplicó la eutanasia y se les realizó una necropsia para recolectar tejido renal que se usó en la extracción de ADN total. Se realizaron dos PCR convencionales para la amplificación de los fragmentos de 16S RNA ribosomal. Se obtuvieron las secuencias de algunos productos positivos y se analizaron con herramientas bioinformáticas para identificar la especie infectante de Leptospira. Resultados. Se capturaron 69 murciélagos pertenecientes a cuatro familias y a ocho especies distintas. La familia con mayor diversidad fue Phyllostomidae con cinco especies. La especie con mayor frecuencia de captura fue Artibeusjamaicensis (41, 59.4%). Las PCR arrojaron una frecuencia global de infección de 21.7%. Las especies infectadas fueron A. jamaicensis, Pteronotus parnellii y Chiroderma villosum. El análisis bioinformático arrojó un 99.0% de identidad para Leptospira noguchii, Leptospira borgpetersenii y Leptospira santarosai. Conclusiones. Algunas especies de murciélagos de Yucatán y Campeche son portadores renales de leptospiras patógenas, por lo que podrían participar en el ciclo silvestre de transmisión en la región. La frecuencia de infección encontrada en los riñones de los murciélagos utilizados es mayor en comparación con aquellas obtenidas en otros reservorios de Yucatán y Campeche. Nuevas especies de murciélagos son reportadas como portadores de Leptospira para México.

ABSTRACT Objective. To report the infection with Leptospira in the kidneys of bats from Campeche and Yucatán, Mexico, through the amplification by PCR of two different 16S RNA ribosomal gene fragments. Materials and methods. Bat captures were carried out at one site in Campeche and two sites in Yucatán. Euthanasia was applied to the captured bats and a necropsy was performed to collect a renal tissue sample that was used in the total DNA extraction. Two different conventional PCR were performed for the amplification of the 16S RNA ribosomal gene fragments. Some sequences from positive products were obtained and analyzed with bioinformatics tools to identify the infectious species of Leptospira. Results. Sixty-nine bats belonging to four families and eight different species were captured. The family with the greatest diversity was Phyllostomidae with five species. The most captured species was Artibeus jamaicensis (41, 59.4%). Both PCR showed a global infection frequency of 21.7%. The infected species were A. jamaicensis, Pteronotus parnellii, and Chiroderma villosum. The bioinformatic analysis of the positive products yielded a 99.0% identity for Leptospira noguchii, Leptospira borgpetersenii, and Leptospira santarosai. Conclusions. Some bat species of Yucatán and Campeche, Mexico, are renal carriers of pathogenic Leptospira, therefore participating in the transmission cycle in the region. The frequency of infection found in the renal tissue of the captured bats is higher than the one obtained from other reservoirs captured in Yucatán and Campeche. New species of bats are reported as renal Leptospira carriers in Mexico.

Molecular detection of reptile-associated Borrelia in Boa constrictor (Squamata: Boidae) from Veracruz, Mexico.

The reptile-associated Borrelia represent a monophyletic group of bacteria transmitted by several species of hard ticks, which has been reported to only infect amphibians and reptiles in Eurasia and Middle East, however, this bacterial group has not been studied in North America. The aim of this study was to assess the presence of Borrelia spirochetes in blood samples of native reptiles of Mexico. Blood samples were directly obtained from individuals, DNA extractions were performed using Chelex-100. The Borrelia detection was performed by conventional PCR. From 102 reptiles tested, only five individuals of Boa constrictor were positive for the presence of DNA of the reptile-associated Borrelia group. Supported by phylogenetic analysis, this study presents the first record of these spirochetes group in Mexico, and initial evidence of B. constrictor as a host of this group.

Virulent leptospira interrogans induce cytotoxic effects in human platelets in vitro through direct interactions

Leptospirosis is a prevalent zoonotic disease, caused by bacteria of the genus Leptospira. Leptospirosis frequently leads to hemostatic disturbances, and the severe cases are marked by hemorrhages and low platelet number in circulation, which is associated with the patients’ poor outcomes. Nevertheless, Leptospira-platelet interactions remain poorly explored. In this study, we performed a series of in vitro experiments evaluating whether leptospires induce human platelet aggregation, activation, and morphological changes. Platelets were incubated with virulent L. interrogans and the platelet outcomes were assessed by aggregometry, flow cytometry, and scanning and transmission electron microscopy. Our results show that leptospires alone do not induce platelet aggregation and activation, and induce platelet cytotoxic effects instead, by clearly inducing platelet disruption and detachment. We show for the first time that virulent leptospires do interact directly with platelets, an event that could trigger pathophysiological effects during the infection. This study might serve as a basis for the development of novel treatments for the disease.

Molecular Identification of Leptospira interrogans in Naturally Infected Cows from a Rural Property in the Border Region - Case Report / Identificação molecular de Leptospira interrogans em Vacas naturalmente infectadas de uma propriedade rural em Região Fronteiriça - Relato de caso

The aim of this study was to investigate the antibodies and DNA of Leptospira spp. isolated from infected cattle in a small rural dairy farm in a border region between Brazil and Paraguay. Blood and urine samples were collected from 50 Holstein cows aged between 1 and 15 years. The diagnostic tests performed were microscopic serum agglutination for antibody detection and polymerase chain reaction for Leptospira spp. detection. Out of the samples analyzed, 48% were MAT positive with titers ranging from 100 to 400, and the most prevalent antibody was to the serovar Hardjo. One serum sample was amplified to 549 bp for the sec y gene, and sequencing identified it as L. interrogans. This is the first report from northwestern Paraná (PR) State of L. interrogans identification in naturally infected milk cattle. Thus, based on these results, to enhance production efficiency, new serological and molecular studies on dairy cattle from border regions are required to characterize the epidemiology of possible genotypes and their consequences in affected herds.

O objetivo deste trabalho foi pesquisar anticorpos e DNA de Leptospira spp. em uma propriedade rural leiteira de uma região fronteiriça entre Brasil e Paraguai. Foram coletadas amostras de sangue e urina de 50 animais da raça Holandesa com idade variando de um a quinze anos, de uma pequena propriedade rural de exploração leiteira em uma região de fronteira entre Brasil e Paraguai. Quanto aos diferentes diagnósticos foi utilizado a soroaglutinação microscópica para a detecção de anticorpos e também foi realizada a reação em cadeia pela polimerase para a detecção de DNA de Leptospira spp. Das amostras analisadas, 48,00% foram soro reagentes na SAM com títulos variando de 100 a 400 e o anticorpo contra o sorovar mais prevalente foi o Hardjo. Uma amostra de soro amplificou 549pb para o gene sec y, e no sequenciamento foi identificada como Leptospira interrogans. Este é o primeiro relato da região noroeste do estado do Paraná (PR) relacionado à identificação de L. interrogans de bovinos de leite naturalmente infectados e em virtude dos resultados deste trabalho são necessários novos estudos sorológicos e moleculares em criações de gado de leite de regiões fronteiriças para se caracterizar a epidemiologia dos possíveis genótipos e suas possíveis consequências nos rebanhos afetados visando sempre à eficiência da produção.

Molecular Identification of Leptospira interrogans in Naturally Infected Cows from a Rural Property in the Border Region - Case Report / Identificação molecular de Leptospira interrogans em Vacas naturalmente infectadas de uma propriedade rural em Região Fronteiriça - Relato de caso

The aim of this study was to investigate the antibodies and DNA of Leptospira spp. isolated from infected cattle in a small rural dairy farm in a border region between Brazil and Paraguay. Blood and urine samples were collected from 50 Holstein cows aged between 1 and 15 years. The diagnostic tests performed were microscopic serum agglutination for antibody detection and polymerase chain reaction for Leptospira spp. detection. Out of the samples analyzed, 48% were MAT positive with titers ranging from 100 to 400, and the most prevalent antibody was to the serovar Hardjo. One serum sample was amplified to 549 bp for the sec y gene, and sequencing identified it as L. interrogans. This is the first report from northwestern Paraná (PR) State of L. interrogans identification in naturally infected milk cattle. Thus, based on these results, to enhance production efficiency, new serological and molecular studies on dairy cattle from border regions are required to characterize the epidemiology of possible genotypes and their consequences in affected herds.

O objetivo deste trabalho foi pesquisar anticorpos e DNA de Leptospira spp. em uma propriedade rural leiteira de uma região fronteiriça entre Brasil e Paraguai. Foram coletadas amostras de sangue e urina de 50 animais da raça Holandesa com idade variando de um a quinze anos, de uma pequena propriedade rural de exploração leiteira em uma região de fronteira entre Brasil e Paraguai. Quanto aos diferentes diagnósticos foi utilizado a soroaglutinação microscópica para a detecção de anticorpos e também foi realizada a reação em cadeia pela polimerase para a detecção de DNA de Leptospira spp. Das amostras analisadas, 48,00% foram soro reagentes na SAM com títulos variando de 100 a 400 e o anticorpo contra o sorovar mais prevalente foi o Hardjo. Uma amostra de soro amplificou 549pb para o gene sec y, e no sequenciamento foi identificada como Leptospira interrogans. Este é o primeiro relato da região noroeste do estado do Paraná (PR) relacionado à identificação de L. interrogans de bovinos de leite naturalmente infectados e em virtude dos resultados deste trabalho são necessários novos estudos sorológicos e moleculares em criações de gado de leite de regiões fronteiriças para se caracterizar a epidemiologia dos possíveis genótipos e suas possíveis consequências nos rebanhos afetados visando sempre à eficiência da produção.

Molecular identification of Leptospira interrogans in naturally infected cows from a rural property in the border region: case report / Identificação molecular de Leptospira interrogans em vacas naturalmente infectadas de uma propriedade rural em região fronteiriça: relato de caso

The aim of this study was to investigate the antibodies and DNA of Leptospira spp. isolated from infected cattle in a small rural dairy farm in a border region between Brazil and Paraguay. Blood and urine samples were collected from 50 Holstein cows aged between 1 and 15 years. The diagnostic tests performed were microscopic serum agglutination for antibody detection and polymerase chain reaction for Leptospira spp. detection. Out of the samples analyzed, 48% were MAT positive with titers ranging from 100 to 400, and the most prevalent antibody was to the serovar Hardjo. One serum sample was amplified to 549 bp for the sec y gene, and sequencing identified it as L. interrogans. This is the first report from northwestern Paraná (PR) State of L. interrogans identification in naturally infected milk cattle. Thus, based on these results, to enhance production efficiency, new serological and molecular studies on dairy cattle from border regions are required to characterize the epidemiology of possible genotypes and their consequences in affected herds.

O objetivo deste trabalho foi pesquisar anticorpos e DNA de Leptospira spp. em uma propriedade rural leiteira de uma região fronteiriça entre Brasil e Paraguai. Foram coletadas amostras de sangue e urina de 50 animais da raça Holandesa com idade variando de um a quinze anos, de uma pequena propriedade rural de exploração leiteira em uma região de fronteira entre Brasil e Paraguai. Quanto aos diferentes diagnósticos foi utilizado a soroaglutinação microscópica para a detecção de anticorpos e também foi realizada a reação em cadeia pela polimerase para a detecção de DNA de Leptospira spp. Das amostras analisadas, 48,00% foram soro reagentes na SAM com títulos variando de 100 a 400 e o anticorpo contra o sorovar mais prevalente foi o Hardjo. Uma amostra de soro amplificou 549pb para o gene sec y, e no sequenciamento foi identificada como Leptospira interrogans. Este é o primeiro relato da região noroeste do estado do Paraná (PR) relacionado à identificação de L. interrogans de bovinos de leite naturalmente infectados e em virtude dos resultados deste trabalho são necessários novos estudos sorológicos e moleculares em criações de gado de leite de regiões fronteiriças para se caracterizar a epidemiologia dos possíveis genótipos e suas possíveis consequências nos rebanhos afetados visando sempre à eficiência da produção.

Carriage of pathogenic Leptospira in carnivores at the wild/domestic interface.

The carriage of pathogenic Leptospira was investigated by PCR in 51 wild carnivores, 20 domestic dogs with outdoor access, and 27 free-roaming domestic cats sampled in periurban Barcelona (NE Spain). Overall prevalence was 7.7%, with DNA confirmed in 3/30 common genets (Genetta genetta) (serovars Icterohaemorraghiae and Sejröe), 1/9 red foxes (Vulpes vulpes) (Canicola) and 2/27 cats (Icterohaemorraghiae). Though most of the dogs were vaccinated against Leptospira, DNA of the serovar Canicola was detected in the urine of 25% of the vaccinated animals, and the serovar Icterohaemorraghiae in one non-vaccinated dog.

Crystallization of FcpA from Leptospira, a novel flagellar protein that is essential for pathogenesis.

The protein FcpA is a unique component of the flagellar filament of spirochete bacteria belonging to the genus Leptospira. Although it plays an essential role in translational motility and pathogenicity, no structures of FcpA homologues are currently available in the PDB. Its three-dimensional structure will unveil the novel motility mechanisms that render pathogenic Leptospira particularly efficient at invading and disseminating within their hosts, causing leptospirosis in humans and animals. FcpA from L. interrogans was purified and crystallized, but despite laborious attempts no useful X ray diffraction data could be obtained. This challenge was solved by expressing a close orthologue from the related saprophytic species L. biflexa. Three different crystal forms were obtained: a primitive and a centred monoclinic form, as well as a hexagonal variant. All forms diffracted X-rays to suitable resolutions for crystallographic analyses, with the hexagonal type typically reaching the highest limits of 2.0 Šand better. A variation of the quick-soaking procedure resulted in an iodide derivative that was instrumental for single-wavelength anomalous diffraction methods.