RESUMEN

The survival and proliferation of pathogenic Leptospira within a host are complex phenomena that require careful consideration. The ErpY-like lipoprotein, found on the outer membrane surface of Leptospira, plays a crucial role in enhancing the bacterium's pathogenicity. The rErpY-like protein, in its recombinant form, contributes significantly to spirochete virulence by interacting with various host factors, including host complement regulators. This interaction facilitates the bacterium's evasion of the host complement system, thereby augmenting its overall pathogenicity. The rErpY-like protein exhibits a robust binding affinity to soluble fibrinogen, a vital component of the host coagulation system. In this study, we demonstrate that the rErpY-like protein intervenes in the clotting process of the platelet-poor citrated plasma of bovines and humans in a concentration-dependent manner. It significantly reduces clot density, alters the viscoelastic properties of the clot, and diminishes the average clotting rate in plasma. Furthermore, the ErpY-like protein inhibits thrombin-catalyzed fibrin formation in a dose-dependent manner and exhibits saturable binding to thrombin, suggesting its significant role in leptospiral infection. These findings provide compelling evidence for the anticoagulant effect of the ErpY-like lipoprotein and its significant role in leptospiral infection.

Asunto(s)

Coagulación Sanguínea , Fibrinógeno , Trombina , Fibrinógeno/metabolismo , Fibrinógeno/química , Humanos , Trombina/metabolismo , Animales , Bovinos , Unión Proteica , Leptospira/metabolismo , Leptospirosis/microbiología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Lipoproteínas/metabolismo , Interacciones Huésped-Patógeno

RESUMEN

BACKGROUND: Leptospiraceae comprise a diverse family of spirochetal bacteria, of which many are involved in infectious diseases of animals and humans. Local leptospiral diversity in domestic animals is often poorly understood. Here we describe the incidental detection of Leptospira (L.) licerasiae in an Austrian pig. CASE PRESENTATION: During an experiment to characterize the pathogenesis of L. interrogans serovar Icterohaemorrhagiae in pigs, cultivation of a urine sample from a non-challenged contact pig resulted in growth of a spirochetal bacterium that tested negative for pathogenic Leptospira (LipL32 gene). PCR, Sanger sequencing and standard serotyping further confirmed that the recovered isolate was clearly different from the challenge strain L. interrogans serovar Icterohaemorrhagiae used in the animal experiment. Whole genome sequencing revealed that the isolate belongs to the species L. licerasiae, a tropical member of the Leptospiraceae, with no prior record of detection in Europe. CONCLUSIONS: This is the first report describing the occurrence of L. licerasiae in Europe. Since L. licerasiae is considered to have intermediate pathogenicity, it will be important to follow the geographical distribution of this species and its pathogenic and zoonotic potential in more detail.

Asunto(s)

Leptospira , Leptospirosis , Enfermedades de los Porcinos , Animales , Porcinos , Leptospirosis/veterinaria , Leptospirosis/microbiología , Leptospira/aislamiento & purificación , Leptospira/genética , Enfermedades de los Porcinos/microbiología , Austria

RESUMEN

Leptospirosis is an anthropozoonosis of economic and public health importance, caused by bacteria of the genus Leptospira. Horses are deemed important in its transmission chain due to their proximity to humans, and because the species is often asymptomatic, making these animals potential silent reservoirs. In this context, the objectives of this study were to determine the prevalence of seropositive horses for Leptospira spp., and to identify the presence of Leptospira spp. serogroups and antibody titers, the occurrence of areas with higher density of infection cases and demographic characteristics associated with seropositivity in the states of Paraíba (PB), Pernambuco (PE), Rio Grande do Norte (RN) and Ceará (CE), in the Northeast region of Brazil, during rainy (May and June) and dry (October and November) seasons from 2017 to 2019. Using the microscopic agglutination test (MAT), 1152 equine serum samples from 225 municipalities were analyzed. Anti-Leptospira antibodies were detected in 23.9 % (95 % CI= 21.4 - 26.3 %) of the samples in the three-year period, with a frequency of 30.4 % (95 % CI= 26.7 - 34.2 %) during the rainy period (with greater emphasis on the Ballum serogroup) and 17.4 % (95 % CI= 14.3 - 20.5 %) in the dry period (with greater emphasis on the Sejroe serogroup). Age of horses ≥ 6 years (6-10 years, 11-15 years and ≥ 16 years), rainy season, and animal belonging to Pernambuco state were factors with higher seropositivities. Regarding spatial distribution, a higher percentage of seropositive animals was observed in Pernambuco (P < 0.05), in interstate border areas, and large urban centers, with a spatial cluster detected in the dry season of 2018 with relative risk of 2.8 (P = 0.049) times higher in municipalities within the cluster. It is suggested that measures for controlling rodents and contact with wild animals in equine farming, both in rainy and dry periods, combined with care regarding the use of pastures shared with cattle and the adoption of immunoprophylaxis are important in preventing and controlling leptospirosis in horses in the Northeast region of Brazil.

Asunto(s)

Enfermedades de los Caballos , Leptospira , Leptospirosis , Estaciones del Año , Animales , Caballos , Leptospirosis/veterinaria , Leptospirosis/epidemiología , Leptospirosis/microbiología , Brasil/epidemiología , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/microbiología , Leptospira/aislamiento & purificación , Leptospira/inmunología , Estudios Seroepidemiológicos , Prevalencia , Masculino , Femenino , Anticuerpos Antibacterianos/sangre , Análisis Espacial , Serogrupo

RESUMEN

Leptospirosis, caused by pathogenic bacteria from the genus Leptospira, is a global zoonosis responsible for more than one million human cases and 60,000 deaths annually. The disease also affects many domestic animal species. Historically, genetic manipulation of Leptospira has been difficult to perform, resulting in limited knowledge on pathogenic mechanisms of disease and the identification of virulence factors. The application of CRISPR/Cas9 and its variations have helped fill these gaps but the generation of knockout mutants remains challenging because double-strand breaks (DSBs) inflicted by Cas9 nuclease are lethal to Leptospira cells. The novel CRISPR prime editing (PE) strategy is the first precise genome-editing technology that allows deletions, insertions, and base substitutions without introducing DSBs. This revolutionary technique utilizes a nickase Cas9 that cleaves a single strand of DNA, coupled with an engineered reverse transcriptase and a modified single-guide RNA (termed prime editing guide RNA) containing an extended 3' end with the desired edits. We demonstrate the application of CRISPR-PE in both saprophytic and pathogenic Leptospira from multiple species and serovars by introducing deletions or insertions into target DNA with a remarkable precision of just one nucleotide. Additionally, we demonstrate the ability to genetically manipulate Leptospira borgpetersenii, a prevalent pathogenic species of humans, domestic cattle, and wildlife animals. Rapid plasmid loss by mutated strains in liquid culture allows for the generation of knockout strains without selective markers, which can be readily used to elucidate virulence factors and develop optimized bacterin and/or live vaccines against leptospirosis.IMPORTANCELeptospirosis is a geographically widespread bacterial zoonosis. Genetic manipulation of pathogenic Leptospira spp. has been laborious and difficult to perform, limiting our ability to understand how leptospires cause disease. The application of the CRISPR/Cas9 system to Leptospira enhanced our ability to generate knockdown and knockout mutants; however, the latter remains challenging. Here, we demonstrate the application of the CRISPR prime editing technique in Leptospira, allowing the generation of knockout mutants in several pathogenic species, with mutations comprising just a single nucleotide resolution. Notably, we generated a mutant in the Leptospira borgpetersenii background, a prevalent pathogenic species of humans and cattle. Our application of this method opens new avenues for studying pathogenic mechanisms of Leptospira and the identification of virulence factors across multiple species. These methods can also be used to facilitate the generation of marker-less knockout strains for updated and improved bacterin and/or live vaccines.

Asunto(s)

Sistemas CRISPR-Cas , Edición Génica , Leptospira , Leptospira/genética , Leptospira/patogenicidad , Edición Génica/métodos , Leptospirosis/microbiología , Animales , Mutación , Humanos

RESUMEN

PURPOSE: The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. METHODS: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). RESULTS: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). CONCLUSION: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.

Asunto(s)

Anticuerpos Antibacterianos , Ensayo de Inmunoadsorción Enzimática , Leptospirosis , Sensibilidad y Especificidad , Humanos , Leptospirosis/diagnóstico , Leptospirosis/sangre , Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoensayo/métodos , Inmunoensayo/normas , Leptospira/inmunología , Leptospira/aislamiento & purificación , Inmunoglobulina M/sangre , Masculino , Femenino , Adulto , Persona de Mediana Edad , Método Doble Ciego , Pruebas de Aglutinación/métodos , Adulto Joven

RESUMEN

BACKGROUND: Both dengue and Leptospira infections are endemic to tropical and subtropical regions, with their prevalence increasing in recent decades. Coinfection with these pathogens presents significant diagnostic challenges for clinicians due to overlapping clinical manifestations and laboratory findings. This case report aims to elucidate two clinical scenarios where the coinfection of dengue and leptospirosis complicates the disease course, creating a diagnostic conundrum. CASE PRESENTATION: We present the clinical scenarios of two Bangladeshi males, aged 25 and 35 years, who were admitted to our hospital with acute febrile illness. The first patient exhibited hepatic and renal involvement, while the second presented with symptoms initially suggestive of meningoencephalitis. Both cases were initially managed under the presumption of dengue infection based on positive serology. However, further evaluation revealed coinfection with Leptospira, complicating the disease course. Both patients received appropriate treatment for dengue and antibacterial therapy for leptospirosis, ultimately resulting in their recovery. CONCLUSION: These case scenarios underscore the critical importance for clinicians in regions where dengue and Leptospira are endemic to consider both diseases when evaluating patients presenting with acute febrile illness.

Asunto(s)

Antibacterianos , Coinfección , Dengue , Leptospirosis , Humanos , Dengue/complicaciones , Dengue/diagnóstico , Masculino , Leptospirosis/complicaciones , Leptospirosis/diagnóstico , Leptospirosis/tratamiento farmacológico , Adulto , Antibacterianos/uso terapéutico , Fiebre/etiología , Leptospira/aislamiento & purificación , Resultado del Tratamiento

RESUMEN

Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.

Asunto(s)

Anticuerpos Antibacterianos , Leptospirosis , Sensibilidad y Especificidad , Humanos , Anticuerpos Antibacterianos/sangre , Brasil/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina M/sangre , Leptospira/aislamiento & purificación , Leptospira/inmunología , Leptospirosis/sangre , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Leptospirosis/microbiología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Pruebas Serológicas/métodos

RESUMEN

Leptospirosis is a zoonotic disease whose transmission is linked to multiple factors involving the interface between animals, humans, and the environment. This disease is of great importance for public health, as it profoundly affects the health aspects of the population and animals. Considering the importance of non-human primates in this epidemiological chain, the objective of this research was to conduct a systematic literature review with meta-analysis, providing information on leptospirosis in non-human primates (NHPs) and an update on the infection situation in Brazil and other countries. Thus, a search was performed in five databases, initially finding 3332 studies, of which 32 met the eligibility criteria and were used for the systematic review. According to them, the most prevalent serogroup in non-human primates was Icterohaemorrhagiae, which is adapted to rodents as primary hosts. A wide distribution of the infection was found in the regions of both wild and captive animals. Through meta-analysis, the seroprevalence rate of leptospirosis in non-human primates was 27.21% (CI 17.97-38.95%). Cochran's Q test (p < 0.01) identified heterogeneity between studies, classified as high by the Higgins and Thompson test (I2 = 92.4%). Therefore, seroepidemiological and Leptospira isolation studies in non-human primates are important to investigate and monitor the suspected impact of these species as maintainers or transmitters of the pathogen to humans and other wild and domestic animals, in addition to demonstrating the need for standardization related to control and prevention measures.

Asunto(s)

Leptospirosis , Primates , Animales , Leptospirosis/epidemiología , Leptospirosis/veterinaria , Leptospirosis/microbiología , Estudios Seroepidemiológicos , Primates/microbiología , Leptospira/inmunología , Leptospira/aislamiento & purificación , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/microbiología , Zoonosis/epidemiología , Zoonosis/microbiología

RESUMEN

Leptospirosis is a common but underdiagnosed zoonosis. We conducted a 1-year prospective study in La Guaira State, Venezuela, analyzing 71 hospitalized patients who had possible leptospirosis and sampling local rodents and dairy cows. Leptospira rrs gene PCR test results were positive in blood or urine samples from 37/71 patients. Leptospira spp. were isolated from cultured blood or urine samples of 36/71 patients; 29 had L. interrogans, 3 L. noguchii, and 4 L. venezuelensis. Conjunctival suffusion was the most distinguishing clinical sign, many patients had liver involvement, and 8/30 patients with L. interrogans infections died. The Leptospira spp. found in humans were also isolated from local rodents; L. interrogans and L. venezuelensis were isolated from cows on a nearby, rodent-infested farm. Phylogenetic clustering of L. venezuelensis isolates suggested a recently expanded outbreak strain spread by rodents. Increased awareness of leptospirosis prevalence and rapid diagnostic tests are needed to improve patient outcomes.

Asunto(s)

Brotes de Enfermedades , Leptospira , Leptospirosis , Filogenia , Roedores , Animales , Leptospirosis/epidemiología , Leptospirosis/veterinaria , Leptospirosis/microbiología , Leptospirosis/diagnóstico , Humanos , Venezuela/epidemiología , Bovinos , Leptospira/genética , Leptospira/aislamiento & purificación , Leptospira/clasificación , Femenino , Roedores/microbiología , Adulto , Masculino , Persona de Mediana Edad , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/epidemiología , Adolescente , Leptospira interrogans/genética , Leptospira interrogans/aislamiento & purificación , Leptospira interrogans/clasificación , Adulto Joven , Estudios Prospectivos , Niño , Anciano , Enfermedades Endémicas , Zoonosis/epidemiología , Zoonosis/microbiología , Preescolar

RESUMEN

Leptospirosis is a neglected zoonosis for which investigations assessing host-pathogen interaction are scarce. The aim of this study was to compare the severity and bacterial species involved in human cases of leptospirosis on Reunion and Mayotte islands, territories located in the southwest Indian Ocean that have recorded high human leptospirosis incidence but display fairly distinct epidemiological situations. A retrospective multicentric study including all patients over 18 years of age from Mayotte or Reunion with proven leptospirosis was conducted from January 2018 to April 2020. This study collected demographic, geographical, clinical, and biological data. Overall, 490 patients were included, 222 on Mayotte and 268 on Reunion. More patients were hospitalized on Reunion (n = 215, 80%) compared with Mayotte (n = 102, 46%). Severe disease was more common on Reunion (n = 75, 28%) than on Mayotte (n = 22, 10%). The dominant Leptospira species on Reunion was Leptospira interrogans (79%) followed by Leptospira borgpetersenii (21%), contrasting with the epidemiological situation on Mayotte where L. interrogans was found in only a minority of patients (10%). The high frequency of severe cases on Reunion could be explained not only by higher comorbidities but also by the higher occurrence of L. interrogans infections compared with Mayotte. Finally, the distribution of cases linked to L. borgpetersenii was found almost exclusively on the west coast of Reunion, raising the potential role of a ruminant reservoir.

Asunto(s)

Leptospira , Leptospirosis , Leptospirosis/epidemiología , Leptospirosis/microbiología , Humanos , Reunión/epidemiología , Leptospira/aislamiento & purificación , Femenino , Adulto , Masculino , Estudios Retrospectivos , Persona de Mediana Edad , Comoras/epidemiología , Leptospira interrogans/aislamiento & purificación , Adulto Joven , Adolescente , Anciano , Animales

RESUMEN

Leptospirosis (LTPS) is a bacterial infection that affects humans, often with mild or no symptoms. It is estimated that approximately 10 % of patients with LTPS may experience multi-organ dysfunction, including renal abnormalities. In regions where LTPS is widespread, a considerable number of instances involving acute kidney injury (AKI) and chronic kidney disease (CKD) of unknown etiology (CKDu) have been reported. Additionally, studies have shown a correlation between kidney graft dysfunction in patients with stable kidney transplants after LTPS. These findings indicate that exposure to LTPS may increase the likelihood of kidney transplantation due to the onset of both acute and chronic kidney injuries. Simultaneously, it poses a potential risk to the stability of kidney grafts. Unfortunately, there is limited scientific literature addressing this issue, making it difficult to determine the negative impact that LTPS may have, such as its role as a risk factor for the need of kidney transplantation or as a threat to individuals who have undergone kidney transplants. This study aims to shed light on the immune mechanisms triggered during LTPS infection and their importance in both kidney damage and allograft dysfunction.

Asunto(s)

Trasplante de Riñón , Leptospirosis , Humanos , Trasplante de Riñón/efectos adversos , Leptospirosis/inmunología , Factores de Riesgo , Lesión Renal Aguda/etiología , Leptospira/inmunología , Rechazo de Injerto/etiología , Rechazo de Injerto/inmunología , Insuficiencia Renal Crónica/etiología , Insuficiencia Renal Crónica/inmunología , Susceptibilidad a Enfermedades , Riñón

RESUMEN

AIMS: Currently, immunoinformatic approaches have shown promise in rapidly and cost-effectively identifying new antigens from the Leptospira proteome. Chimeric multiepitope proteins offer a strategy with significant potential for implementation in diagnosis and vaccines development. METHODS AND RESULTS: In this study, we detail the immunoinformatic analyses and design of a new recombinant chimeric protein constructed with epitopes identified from the sequences of ErpY-like and LemA proteins, previously identified as potential antigens for controlling leptospirosis. We expressed the chimeric protein using Escherichia coli heterologous systems, evaluated its antigenicity using serum from naturally infected patients, and its immunogenicity in mice as an animal model, with Freund as an adjuvant. The resulting recombinant chimeric protein, named rErpY-LemA, was successfully expressed and purified using a prokaryotic system, with an expected mass of 35 kDa. Serologic assays using serum samples from naturally infected patients demonstrated recognition of the chimera protein by antibodies present in sera. Animals immunized with the chimera exhibited a significant IgG antibody response from the 7th day (P < 0.001), persisting until day 49 of experimentation, with a titer of 1:12,800 (P < 0.05). Notably, significant production of IgA, IgM, and IgG subclasses was observed in animals immunized with the chimera. CONCLUSIONS: These results highlight the promising role of immunoinformatics in rapidly identifying antigens and the potential of chimeric multiepitope proteins in developing effective strategies for leptospirosis control.

Asunto(s)

Antígenos Bacterianos , Leptospirosis , Proteínas Recombinantes de Fusión , Leptospirosis/inmunología , Leptospirosis/prevención & control , Animales , Ratones , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/genética , Humanos , Anticuerpos Antibacterianos/sangre , Leptospira/inmunología , Leptospira/genética , Biología Computacional , Epítopos/inmunología , Epítopos/genética , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/genética , Escherichia coli/genética , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética

RESUMEN

The dot-blot is a simple, fast, sensitive, and versatile technique that enables the identification of minimal quantities of DNA specifically targeted by probe hybridization in the presence of carrier DNA. It is based on the transfer of a known amount of DNA onto an inert solid support, such as a nylon membrane, utilizing the dot-blot apparatus and without electrophoretic separation. Nylon membranes have the advantage of high nucleic acid binding capacity (400 µg/cm2), high strength, and are positively or neutrally charged. The probe used is a highly specific ssDNA fragment of 18 to 20 bases long labeled with digoxigenin (DIG). The probe will conjugate with the Leptospira DNA. Once the probe has hybridized with the target DNA, it is detected by an anti-digoxigenin antibody, allowing its easy detection through its emissions revealed in an X-ray film. The dots with an emission will correspond to the DNA fragments of interest. This method employs the non-isotopic labeling of the probe, which may have a very long half-life. The drawback of this standard immuno-label is a lower sensitivity than isotopic probes. Nevertheless, it is mitigated by coupling polymerase chain reaction (PCR) and dot-blot assays. This approach enables the enrichment of the target sequence and its detection. Additionally, it may be used as a quantitative application when compared against a serial dilution of a well-known standard. A dot-blot application to detect Leptospira from the three main clades in water samples is presented here. This methodology can be applied to large amounts of water once they have been concentrated by centrifugation to provide evidence of the presence of Leptospiral DNA. This is a valuable and satisfactory tool for general screening purposes, and may be used for other non-culturable bacteria that may be present in water, enhancing the comprehension of the ecosystem.

Asunto(s)

Leptospira , Reacción en Cadena de la Polimerasa , Leptospira/genética , Leptospira/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , ADN Bacteriano/genética , ADN Bacteriano/análisis , Hibridación de Ácido Nucleico/métodos , Microbiología del Agua

RESUMEN

This study evaluated the level of risk practices and awareness of leptospirosis among residents of Zaria, Nigeria. A pre-tested questionnaires were administered via face-to-face interview to 100 residents. The data was analyzed using chi-square and multivariate analysis to identify risk factors for leptospirosis. The demography showed that the majority of the respondents were male, aged 21-40 years, and majorly crop farmers. The risk factors identified showed that males were 4.14 times more likely to be affected by leptospirosis (OR 4.14, 95% CI [1.93-5.37], p = 0.02) and the source of animal's water was 5.56 times more likely to be contaminated by Leptospira spp. (OR 4.14, 95% CI [2.88-8.03], p = 0.01) and these relationships were significant. The majority of respondents were not aware of the disease (OR 1.87, 95% CI [1.22-4.57], p = 0.01) with 78% of the respondents not sure of which of the animal species leptospirosis affected (OR 1.67, 95% CI [1.07-2.62], p = 0.02). This study has demonstrated the existence of risk behaviors, and paucity of knowledge about leptospirosis in the study area. It is therefore recommended to organize an enlightenment program and the need for protective clothing for individuals occupationally at risk of infection by Leptospira spp.

Asunto(s)

Conocimientos, Actitudes y Práctica en Salud , Leptospirosis , Humanos , Leptospirosis/epidemiología , Masculino , Nigeria/epidemiología , Adulto , Femenino , Adulto Joven , Factores de Riesgo , Encuestas y Cuestionarios , Persona de Mediana Edad , Leptospira/aislamiento & purificación , Animales , Adolescente

RESUMEN

Pathogenic Leptospira are spirochete bacteria which cause leptospirosis, a re-emerging zoonotic disease of global importance. Here, we use a recently described lineage of environmental-adapted leptospires, which are evolutionarily the closest relatives of the highly virulent Leptospira species, to explore the key phenotypic traits and genetic determinants of Leptospira virulence. Through a comprehensive approach integrating phylogenomic comparisons with in vitro and in vivo phenotyping studies, we show that the evolution towards pathogenicity is associated with both a decrease of the ability to survive in the environment and the acquisition of strategies that enable successful host colonization. This includes the evasion of the mammalian complement system and the adaptations to avoid activation of the innate immune cells by the highly-virulent Leptospira species (also called P1+ species), unlike other species belonging to the phylogenetically related P1- and P2 groups, as well as saprophytes. Moreover, our analysis reveals specific genetic determinants that have undergone positive selection during the course of evolution in Leptospira, contributing directly to virulence and host adaptation as demonstrated by gain-of-function and knock-down studies. Taken together, our findings define a new vision on Leptospira pathogenicity, identifying virulence attributes associated with clinically relevant species, and provide insights into the evolution and emergence of these life-threatening pathogens.

Asunto(s)

Leptospira , Leptospirosis , Filogenia , Leptospira/patogenicidad , Leptospira/genética , Virulencia , Leptospirosis/microbiología , Animales , Humanos , Ratones , Evolución Biológica , Evolución Molecular

RESUMEN

BACKGROUND: Habitat modification and land use changes impact ecological interactions and alter the relationships between humans and nature. Mexico has experienced significant landscape modifications at the local and regional scales, with negative effects on forest cover and biological biodiversity, especially in the Yucatan peninsula in southeastern Mexico. Given the close relationship between landscape modification and the transmission of zoonotic and vector-borne diseases, it is essential to develop criteria for identifying priority zoonoses in the south of the country. METHODOLOGY/PRINCIPAL FINDINGS: We reviewed 165 published studies on zoonotic and vector-borne diseases in the region (2015-2024). We identified the most frequent vectors, reservoirs, and hosts, the most prevalent infections, and the factors associated with transmission risk and the anthropogenic landscape modification in urban, rural, ecotone, and sylvatic habitats. The most relevant pathogens of zoonotic risk included Trypanosoma cruzi, arboviruses, Leishmania, Rickettsia, Leptospira, and Toxoplasma gondii. Trypanosoma cruzi was the vector-borne agent with the largest number of infected vertebrate species across habitats, while Leishmania and arboviruses were the ones that affected the greatest number of people. Dogs, cats, backyard animals, and their hematophagous ectoparasites are the most likely species maintaining the transmission cycles in human settlements, while rodents, opossums, bats, and other synanthropic animals facilitate connection and transmission cycles between forested habitats with human-modified landscapes. Pathogens displayed different prevalences between the landscapes, T. cruzi, arbovirus, and Leptospira infections were the most prevalent in urban and rural settlements, whereas Leishmania and Rickettsia had similar prevalence across habitats, likely due to the diversity and abundance of the infected vectors involved. The prevalence of T. gondii and Leptospira spp. may reflect poor hygiene conditions. Additionally, results suggest that prevalence of zoonotic and vector-borne diseases is higher in deforested areas and agricultural aggregates, and in sites with precarious health and infrastructure services. CONCLUSIONS: Some hosts, vectors, and transmission trends of zoonotic and vector-borne diseases in the YP are well known but others remain poorly recognized. It is imperative to reinforce practices aimed at increasing the knowledge, monitoring, prevention, and control of these diseases at the regional level. We also emphasize the need to perform studies on a larger spatio-temporal scale under the socio-ecosystem perspective, to better elucidate the interactions between pathogens, hosts, vectors, environment, and sociocultural and economic aspects in this and many other tropical regions.

Asunto(s)

Enfermedades Transmitidas por Vectores , Zoonosis , Animales , Humanos , Zoonosis/transmisión , Zoonosis/epidemiología , Enfermedades Transmitidas por Vectores/transmisión , Enfermedades Transmitidas por Vectores/epidemiología , Prevalencia , México/epidemiología , Ecosistema , Trypanosoma cruzi/aislamiento & purificación , Vectores de Enfermedades , Reservorios de Enfermedades/microbiología , Leptospira/aislamiento & purificación , Leptospira/genética , Leptospira/clasificación , Enfermedad de Chagas/transmisión , Enfermedad de Chagas/epidemiología , Toxoplasma , Arbovirus/fisiología , Leishmania/aislamiento & purificación , Leishmaniasis/transmisión , Leishmaniasis/epidemiología

RESUMEN

Leptospirosis is a global public health problem caused by Gram-negative pathogenic bacteria belonging to the genus Leptospira. The disease is transmitted through the urine of infected animals, which contaminates water and soil, leading to the infection of other animals and humans. Currently, several approaches exist to detect these bacteria; however, a new sensitive method for the live-cell imaging of Leptospira is required. In this study, we report the green synthesis of cadmium telluride quantum dots (CdTe QDs) which are unique fluorescent nanocrystals with a high fluorescence quantum yield capable of modifying cell surfaces and are biocompatible with cells. The fabrication of QDs with concanavalin A (ConA), a carbohydrate-binding lectin and known biological probe for Gram-negative bacteria, produced ConA-QDs which can effectively bind on Leptospira and exhibit strong fluorescence under simple fluorescence microscopy, allowing the live-cell imaging of the bacteria. Overall, we performed the simple synthesis of ConA-QDs and demonstrated their potential use as versatile fluorescent probes for the live-cell imaging of Leptospira. This technique could be further applied to track leptospiral cells and study the infection mechanism, contributing to a more thorough understanding of leptospirosis and how to control it in the future.

Asunto(s)

Leptospira , Puntos Cuánticos , Puntos Cuánticos/química , Colorantes Fluorescentes/química , Compuestos de Cadmio/química , Telurio/química , Concanavalina A/química , Canavalia/química , Materiales Biocompatibles/química , Microscopía Fluorescente

RESUMEN

Leptospirosis is a zoonotic disease of global significance, contributing to morbidity and mortality worldwide. It is endemic to tropical regions, with outbreaks during monsoons. The disease manifestations are similar to that of other febrile illness such as dengue, malaria hence often misdiagnosed and underreported. The zoonoses if undetected, progresses to cause severe life-threatening complications also known as Weil's disease. Routine diagnostic tests are based on the detection of antibodies in patient serum and are not accurate during the initial phase of the infection. Therefore, it is necessary to detect novel biomarkers that can be used in early detection of leptospirosis. Circulating miRNAs are known to be promising biomarkers for various diseases including cancer, tuberculosis, influenza; hence in this study the potential of miRNAs as biomarkers for leptospirosis was evaluated. A total of 30 leptospirosis cases were screened for the differential expression of 10 miRNA by RT-qPCR assay. The differential expression was calculated by relative quantification using healthy individuals as controls. Among the 10 miRNA,3 miRNA, miR-28-5p, miR-302c-3p and miR-302a-3p were reported to exhibit a significant trend of upregulation. Further their role in immune pathways and biological processes was investigated by KEGG analysis and Gene Ontology. The 3 miRNAs were observed to target various immune response pathways, thus confirming their role in host immune response. Based on the results obtained in this study, miR-28-5p, miR-302c-3p and miR-302a-3p can be considered as potential biomarkers for the detection of leptospirosis.

Asunto(s)

Biomarcadores , MicroARN Circulante , Diagnóstico Precoz , Leptospirosis , Leptospirosis/diagnóstico , Leptospirosis/sangre , Humanos , Biomarcadores/sangre , MicroARN Circulante/sangre , MicroARN Circulante/genética , MicroARNs/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto , Masculino , Perfilación de la Expresión Génica , Leptospira/genética , Leptospira/aislamiento & purificación , Leptospira/inmunología , Femenino

RESUMEN

Leptospirosis, a neglected zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira and has one of the highest morbidity and mortality rates worldwide. Vaccination stands out as one of the most effective preventive measures for susceptible populations. Within the outer membrane of Leptospira spp., we find the LIC12287, LIC11711, and LIC13259 lipoproteins. These are of interest due to their surface location and potential immunogenicity. Thorough examination revealed the conservation of these proteins among pathogenic Leptospira spp.; we mapped the distribution of T- and B-cell epitopes along their sequences and assessed the 3D structures of each protein. This information aided in selecting immunodominant regions for the development of a chimeric protein. Through gene synthesis, we successfully constructed a chimeric protein, which was subsequently expressed, purified, and characterized. Hamsters were immunized with the chimeric lipoprotein, formulated with adjuvants aluminum hydroxide, EMULSIGEN®-D, Sigma Adjuvant System®, and Montanide™ ISA206VG. Another group was vaccinated with an inactivated Escherichia coli bacterin expressing the chimeric protein. Following vaccination, hamsters were challenged with a virulent L. interrogans strain. Our evaluation of the humoral immune response revealed the production of IgG antibodies, detectable 28 days after the second dose, in contrast to pre-immune samples and control groups. This demonstrates the potential of the chimeric protein to elicit a robust humoral immune response; however, no protection against challenge was achieved. While this study provides valuable insights into the subject, further research is warranted to identify protective antigens that could be utilized in the development of a leptospirosis vaccine. KEY POINTS: • Several T- and B-cell epitopes were identified in all the three proteins. • Four different adjuvants were used in vaccine formulations. • Immunization stimulated significant levels of IgG2/3 in vaccinated animals.

Asunto(s)

Anticuerpos Antibacterianos , Vacunas Bacterianas , Leptospirosis , Lipoproteínas , Animales , Leptospirosis/prevención & control , Leptospirosis/inmunología , Lipoproteínas/inmunología , Lipoproteínas/genética , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/genética , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Cricetinae , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito B/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/genética , Adyuvantes Inmunológicos/administración & dosificación , Inmunoglobulina G/sangre , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/genética , Leptospira interrogans/inmunología , Leptospira interrogans/genética , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas de la Membrana Bacteriana Externa/genética , Vacunación , Inmunidad Humoral , Leptospira/inmunología , Leptospira/genética , Inmunogenicidad Vacunal

RESUMEN

A simple IgG-specific ELISA for Leptospira spp. was compared with the microscopic agglutination test (MAT) to detect IgG antibody responses to a commercial vaccine in cattle. We used an enzyme-linked immunosorbent assay (ELISA) with sonicated Leptospira interrogans serovar copenhageni M 20. After initial vaccination, specific antibodies against Leptospira spp. were detected in 90 % of the animals by IgG-ELISA and 60 % by MAT, while after booster, antibodies were detected in 100 % and 80 % of the animals by IgG-ELISA and MAT, respectively. Both serological MAT and ELISA tests revealed interferences of vaccine antibodies. Disease diagnosis with ELISA and MAT methods should be made two and a half months and four months, respectively, after vaccination to avoid interference of vaccine antibodies. On the other hand, our results suggest that IgG-ELISA may be a useful method to assess the development of IgG antibodies induced by Leptospira vaccine.

Asunto(s)

Pruebas de Aglutinación , Anticuerpos Antibacterianos , Vacunas Bacterianas , Enfermedades de los Bovinos , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G , Leptospirosis , Animales , Leptospirosis/veterinaria , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Bovinos , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/sangre , Ensayo de Inmunoadsorción Enzimática/veterinaria , Anticuerpos Antibacterianos/sangre , Vacunas Bacterianas/inmunología , Inmunoglobulina G/sangre , Pruebas de Aglutinación/veterinaria , Leptospira interrogans/inmunología , Leptospira/inmunología , Vacunación/veterinaria , Pruebas Serológicas/veterinaria