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This study investigated infection by Leishmania spp., Leptospira spp., Toxoplasma gondii, and Trypanosoma cruzi in six-banded armadillos (Euphractus sexcinctus) from the semiarid region of northeastern Brazil. Twenty specimens of E. sexcinctus were captured alive by wildlife veterinarians from their natural habitats in different locations. The animals were euthanized following induction of anesthesia, and different biological samples were collected. Infection with four pathogens was subsequently evaluated: Leishmania infection was investigated by spleen and liver Polymerase Chain Reaction (PCR); Leptospira spp. infection was evaluated by kidney PCR and serologically by microscopic agglutination test; T. gondii infection was assessed by PCR of the heart, lung, and spleen; and T. cruzi infection was investigated by heart and whole blood PCR and hemoculture. All tests presented negative results apart from whole blood PCR to detect T. cruzi, which was positive in one of the 20 animals tested and confirmed by genetic sequencing. It is important to highlight that this is the first study comprising a molecular investigation of different zoonotic pathogens in six-banded armadillos, and the findings reported here bring new and important knowledge regarding zoonotic diseases in this species.

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Leptospirosis, a zoonosis with a wide worldwide distribution, causes significant reproductive losses in cattle. The genital presentation of the disease has been reported, and its understanding is crucial for the implementation of adequate sanitary measures. Although Leptospira spp. modulate innate immunity, the response in the genital mucosa of bulls is unknown. The objective of this work was to evaluate the expression of innate immune receptors and cytokines in smegma from bulls with genital infection by Leptospira spp. To do so, routine preputial scraping samples were selected from breeding bulls from four establishments in the Azul District, Buenos Aires, Argentina with no reproductive problems, which were previously evaluated for the presence of Leptospira spp. DNA by qPCR detection of the secY gene. The relative gene expression of TLR2, TLR4, IFN-ß and IFN-λ in the smegma samples of animals infected with Leptospira spp. was determined by RT-qPCR, with subsequent analysis of the results using REST software. The expression of TLR2 was significantly increased in animals infected with Leptospira spp. compared to uninfected control animals (4-fold), while TLR4 did not show differences. Likewise, both IFN-ß and IFN-λ were significantly increased in smegma of infected animals (3.5 and 3.1-fold, respectively). Therefore, this work shows that genital infection of Leptospira spp. in bulls generates and modulates a local innate immune response, with an association between the presence of Leptospira spp. DNA and the expression levels of TLR2, IFN-ß and IFN-λ.

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Leptospirosis is a zoonosis with a worldwide distribution, which is transmitted through direct contact with infected animals or by contact with contaminated water or soil. Objectives was to examine the presence of antibodies against 23 serogroups of Leptospira in Lagostomus maximus and Chaetopractus villosus in La Pampa province, Argentina. Ninety-four serum samples from L. maximus (80) and C. villosus (14) were taken. The samples were analysed by microscopic agglutination test (MAT). Only 5/94 (5.3 %) serum samples presented antibodies against Leptospira sp. Three (21.4 %) serum samples from C. villosus, were reactive to the serogroups, Ballum, Grippotyphosa, Canicola and Celledoni, and two samples (2.5 %) of L. maximus to Pomona, Canicola and Ballum. This constitutes the first record of the presence of antibodies serogroup Celledoni in C. villosus and serogroups Pomona, Canicola and Ballum in L. maximus in Argentina.

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Leptospirosis is a zoonotic disease caused by Leptospira bacteria, affecting humans and a broad range of wild and domestic animals in diverse epidemiological settings (rural, urban, and wild). The disease's pathogenesis and epidemiology are complex networks not fully elucidated. Epidemiology reflects the One Health integrated approach of environment-animal-human interaction, causing severe illness in humans and animals, with consequent public health burdens. Saprophytic and pathogenic leptospires have been shown to form biofilms in vivo, in vitro, and in environmental samples. Biofilms are characterized by a polymeric matrix that confers protection against hostile environments (both inside and outside of the host), favoring bacterial survival and dissemination. Despite its significance, the role of this bacterial growth mode in leptospiral survival, transmission, and decreased antibiotic susceptibility remains poorly understood and underexplored. Even so, the literature indicates that biofilms might be correlated with lower antimicrobial susceptibility and chronicity in leptospirosis. In this minireview, we discuss the aspects of biofilm formation by Leptospira and their significance for epidemiology and therapeutic management. Understanding the current scenario provides insight into the future prospects for biofilm diagnosis, prevention, and treatment of leptospirosis.

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INTRODUCTION: Acute undifferentiated febrile illnesses are fevers lasting less than fourteen days without an evident focus of infection on the initial physical examination or with inconclusive laboratory tests. OBJECTIVE: Carry out epidemiological surveillance of the etiology of acute undifferentiated febrile syndrome in the Meta department. METHODS: A descriptive, prospective cross-sectional study was carried out between February 2021 and June 2023 in a first-level hospital in the department of Meta, Colombia. All enrolled patients underwent routine hematology and blood biochemistry examinations. RT-qPCR was performed for Dengue and serology for laboratory diagnoses using ELISA and MAT for Hantavirus and Leptospirosis, respectively. A descriptive and bivariate analysis was performed using SPSS vr 23.0. RESULTS: Of the study's total of one hundred patients, 14 % showed antibodies against hantavirus IgG, of which two were seroconverted. In addition, a risk factor OR = 8.3 (CI = 1.8-38.4) for Hantavirus was found in those patients who had contact with farm animals. Regarding leptospirosis, 3 % of the sera agglutinated with titers greater than 1:400, resulting in a primary infection; 11 % of the sera presented agglutination with titers no greater than 1:200 as exposure to leptospirosis. The bivariate analysis showed an OR = 2.4; CI = 0.75-7.4 with water recreational activities in the last 30 days before the onset of symptoms. CONCLUSIONS: Our study demonstrates the importance of Hantavirus, Dengue, and leptospirosis as a cause of acute undifferentiated febrile illnesses. Coinfections are frequent in one of the tropical areas of Colombia, so it is crucial to establish a more precise diagnosis.

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The black rat Rattus rattus is an exotic and synanthropic rodent prominent in Brazil and with high adaptation to urban areas. The species have an omnivorous diet feed on human food resources, potentially becoming infected and spreading infectious agents that cause zoonoses such as leptospirosis, leishmaniosis, Chagas disease, and toxoplasmosis, which are significant public health concerns in the country. We analyzed the epidemiologic profile of R. rattus infected with these agents using molecular diagnostics in the Olivença district, known for its tourism potential, in Ilhéus, Bahia, Brazil. Of 140 animals, the prevalence rates were 30.0% (42) for Leptospira spp., 3.57% (5) for Leishmania spp., and 0.71% (1) for both Trypanosoma cruzi and Toxoplasma gondii. One animal was co-infected with Leptospira interrogans and T. gondii and another with Leptospira spp. and L. (L.) infantum. The high prevalence of Leptospira spp.-infected animals suggests rodents may be a significant infection source for local hosts, as L. interrogans is most common in rodents and humans. Rodents likely become infected through ingestion or contact with contaminated water bodies or food, particularly for Leptospira spp. and T. gondii. It is worth noting that the studied area has beach, high foot traffic, and popular tourist restaurants, which implies the presence of food waste and litter in the environment. This study found synanthropic rodents infected with significant zoonotic agents, indicating their presence in the environment. These agents may not impact the rodent population but can cause serious diseases in humans and other domestic and wild animal species.

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Leptospirosis is a zoonotic disease that must be studied on the One Health point of view. It is possible that there are particularities in the epidemiology of leptospirosis in Caatinga biome, where the environment is often unfavorable and challenges the adaptability of Leptospira spp. Overall, 100 dogs (47 shelter and 53 stray dogs) selected based on sampling calculation were used to evaluate the Leptospira spp. seroprevalence and associated factors. The microscopic agglutination test (MAT) was applied to detect anti-Leptospira spp. antibodies (cut-off titer 50). Risk factors were identified using the robust Poisson regression analysis. Twenty-four animals (24%; 95% CI = 15.6% - 32.4%) were seroreactive, antibody titers ranged from 50 to 200, and the reacting serogroups were Ballum (17%), Autumnalis (6%) and Djasiman (1%). The factors/categories associated with seropositivity were the environment where the animal stay/soil (prevalence ratio [PR] = 6.03; 95% CI for PR: 1.86 - 7.69; P < 0.001) and access to polluted water/yes (PR = 3.79; 95% CI for PR: 1.85 - 24.22; P = 0.011). The results suggested leptospirosis as a concern in the One Health context in stray and shelter dogs from the Caatinga biome despite the adverse conditions of this biome for the survive of Leptospira spp. on the environment. Moreover, despite being social and government issues, factors such as environment where the animal stay (soil) and access to polluted water must be carefully deemed and corrected to avoid the transmission of leptospires to animals and humans.

A leptospirose é uma doença zoonótica que deve ser estudada sob o ponto de vista da Saúde Única. É possível que existam particularidades na epidemiologia da leptospirose no bioma Caatinga, onde o ambiente é muitas vezes desfavorável e desafia a adaptabilidade de Leptospira spp. No total, 100 cães (47 de abrigos e 53 errantes) selecionados com base em cálculo amostral foram utilizados para avaliar a soroprevalência de Leptospira spp. e os fatores associados. O teste de soroaglutinação microscópica (SAM) foi aplicado para detetar anticorpos anti-Leptospira spp. (título 50 como ponto de corte). Os fatores de risco foram identificados utilizando a análise de regressão de Poisson robusta. Vinte e quatro animais (24%; IC 95% = 15,6% - 32,4%) foram soropositivos, os títulos de anticorpos variaram de 50 a 200, e os serogrupos reagentes foram Ballum (17%), Autumnalis (6%) e Djasiman (1%). Os fatores/categorias associados à seropositividade foram o ambiente onde o animal se encontra/solo (razão de prevalência [RP] = 6,03; IC 95% para RP: 1,86 - 7,69; P < 0,001) e o acesso a água poluída/sim (RP = 3,79; IC 95% para RP: 1,85 - 24,22; P = 0,011). Os resultados sugerem a leptospirose como uma preocupação no contexto da Saúde Única em cães errantes e de abrigos no bioma Caatinga, apesar das condições adversas desse bioma para a sobrevivência de Leptospira spp. no ambiente. Além disso, apesar de serem questões sociais e governamentais, fatores como o ambiente onde o animal fica (solo) e o acesso à água poluída devem ser cuidadosamente analisados e corrigidos para evitar a transmissão de leptospiras para animais e humanos.

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The state of Rio Grande do Sul has a great diversity of reptile species distributed throughout its territory. Due to human actions, such as habitat fragmentation, these animals have been frequently observed in urban and peri-urban environments. This facilitates the spread of pathogens between animals and humans, posing a unique health risk, as many diseases are considered zoonoses. Leptospirosis is among the most common zoonoses in the world and is caused by pathogenic species of bacteria of the genus Leptospira. The role of reptiles in the cycle of this disease is yet unknown. However, serological studies have demonstrated positivity for antibodies against Leptospira spp. in tortoises and snakes, which may indicate that these animals act in maintaining the pathogen in the environment. This observed the presence of anti-Leptospira antibodies in rescued reptiles taken to the Center for Rehabilitation of Wild Fauna and Screening Center for Wild Animals at the Universidade Federal de Pelotas (NURFS-CETAS/UFPEL). Samples were collected from 55 animals (39 Trachemys dorbigni; 3 Philodryas patagoniensis; 3 Caiman latirostris; 3 Salvator merianae; 2 Acanthochelys spixii; 2 Phrynops hilarii; 2 Hydromedusa tectifera; 1 Philodryas aestiva) from August 2022 to December 2023 and tested for 12 reference serovars. Two animals demonstrated positivity, one for the pathogenic serovar Pyrogenes and the other for the pathogenic serovar Canicola. This result reflected the importance of different species besides mammals as potential reservoirs and responsible for maintaining leptospirosis in the environment.

O Rio Grande do Sul possui uma grande diversidade de espécies de répteis distribuídos por todo o Estado. Devido às ações antrópicas, como a fragmentação de habitats, estes animais vêm sendo observados com frequência no meio urbano e periurbano. Isso facilita a disseminação de patógenos entre animais e seres humanos, sendo um risco a saúde única, visto que muitas doenças são consideradas zoonoses. A leptospirose está entre as zoonoses mais comuns do mundo e é causada pelas espécies patogênicas da bactéria do gênero Leptospira. Ainda não se sabe o papel dos répteis no ciclo da doença, porém, estudos sorológicos demonstraram positividade para anticorpos contra Leptospira spp. em cágados e serpentes, o que pode indicar que estes animais atuam na manutenção do patógeno no ambiente. O objetivo deste estudo foi observar a presença de anticorpos anti-Leptospira em répteis oriundos de resgate e levados ao Núcleo de Reabilitação da Fauna Silvestre e Centro de Triagem de Animais Silvestres da Universidade Federal de Pelotas (NURFS-CETAS/UFPEL). As amostras foram coletadas de 55 animais (39 Trachemys dorbigni; 3 Philodryas patagoniensis; 3 Caiman latirostris; 3 Salvator merianae; 2 Acanthochelys spixii; 2 Phrynops hilarii; 2 Hydromedusa tectifera; 1 Philodryas aestiva), durante o período de agosto de 2022 a dezembro de 2023, e testadas para 12 sorovares de referência. Dois animais demonstraram positividade, um deles para o sorovar patogênico Pyrogenes e outro para o sorovar patogênico Canicola. Este resultado demonstra a importância de outras espécies, além dos mamíferos, como potenciais reservatórios e responsáveis pela manutenção da leptospirose no ambiente.

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Leptospirosis is a spirochetal disease caused by Leptospira spp. bacteria with global distribution affecting multiple mammalian species, including humans. The disease is endemic in many geographic areas and is of particular concern in tropical regions with abundant rainfall, such as the Caribbean. Currently, there are no published reports on Leptospira exposure or infection in Grenadian cat populations, and the role of cats in the epidemiology of the disease is unknown. Our hypothesis is that Grenadian cat population may be a reservoir host for zoonotic Leptospira on the island. During 2019-2021, 160 feral cats were captured from three parishes in Grenada, and their urine and blood were tested for Leptospira. Urine from 4 of 148 (2.7%) cat samples tested PCR-positive for Leptospira. Serum from 6 of 136 (4.4%) cat samples tested PCR-positive for Leptospira. Sequence analysis of the Leptospira rpoB gene showed 86-100% similarity to known or presumed pathogenic Leptospira species. The findings of this study suggest that Grenadian cat populations are infected with and are shedding Leptospira genotypes that are phylogenetically related to known pathogenic Leptospira, including known zoonotic strains. These observations support the hypothesis that Grenadian cat populations may be a reservoir host for zoonotic Leptospira on the Island.

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Leptospirosis is caused by pathogenic leptospires, posing a significant public health problem. Host susceptibility to Leptospira infection is a multifactorial trait, and the host's genetic background can influence both the establishment of infection and the severity of the disease. Complement Factor H (FH) plays a crucial role in the interaction between pathogenic bacteria and the host. Genetic variants in the FH gene CFH have previously been associated with non-infectious diseases. Here, we aimed to analyze the effect of CFH variants on individual susceptibility to leptospirosis and disease severity. To accomplish this, we sequenced CFH exons 7, 9, 21, 22, and 23 in a case/control cohort (184/162) from two endemic leptospirosis areas in Brazil and Argentina. We identified twenty-one single nucleotide variants (SNVs). In the Brazilian cohort, the intronic variant rs34815383 exhibited a higher frequency in patients than in controls, resulting in a significant association with leptospirosis (p = 0.032; OR: 0.32; 95% CI 0.1-1) and also renal disorder (p = 0.001; OR: 5.3; 95%CI 1.8-15.57). This SNV is reported to be a splicing variant, negatively impacting CFH expression, and has previously been associated with Complement-driven renal disease. A second synonymous variant, rs61822181, was significantly less frequent in patients than in controls (p = 0.002; OR: 7.33; 95% CI 1.59-33.7), representing a protective factor against the development of leptospirosis. Our study represents the first documentation of the frequency of CFH SNVs in South America and identifies the variant rs34815383 T > C as a risk factor for leptospirosis and leptospirosis-related renal complications.

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BACKGROUND: Leptospirosis poses a diagnostic challenge owing to its wide array of symptoms, ranging from asymptomatic cases and febrile syndromes to severe disease with a high mortality rate. Risk factors are associated with exposure and the immune response, particularly in immunosuppressed patients. CASE PRESENTATION: A clinical case involving a 49-year-old patient with a history of splenectomy and no immunization schedule. The patient presented to the emergency room with non-specific symptoms, primarily myalgias, arthralgias, and emesis, initially suggestive of a viral infection. However, there was a rapid progression to hypoxemic respiratory failure, requiring invasive ventilatory support. Given the immune status due to spleen absence, antibiotic treatment with meropenem and linezolid was promptly initiated, to mitigate the risk of post-splenectomy sepsis. During antibiotic administration, the patient experienced febrile episodes, accompanied by chills, myalgias, and emesis, which gradually decreased in both duration and intensity. Ultimately, the patient exhibited satisfactory progress, successfully underwent extubation, and completed a 7-day antibiotic course. Final reports confirmed positive IgM for Leptospira. CONCLUSION: Leptospirosis is a global zoonotic disease, displaying a diverse array of manifestations; recognized as a potential cause of undifferentiated fever, often confused with other prevalent tropical infections. The imperative to consider this diagnosis extends beyond the general population to encompass individuals in states of altered immunity. Recognizing and addressing leptospirosis in at-risk populations is crucial, as it can significantly impact the prompt initiation of treatment and, consequently, influence associated mortality rates.

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Introduction: Leptospirosis is a global zoonosis that affects more than one million people per year, with a lethality rate of approximately 15%. Chemokines are crucial in the immune response against Leptospira, recruiting leukocytes to the site of infection and regulating immune activity. In previous studies, we have shown that CCL2, CXCL5, and CCL8 are involved in the leptospirosis process, although the mechanisms are not understood. Methods: In this study, we present the frequency of Leptospira serovars in human samples. We then evaluated the profile of various chemokines in sera from patients diagnosed with leptospirosis, assessing the possible correlation between them. Moreover, we evaluated the changes in the chemokine profile on different days after the first symptoms. The frequency of the Leptospira serovars in human samples is presented. Results and discussion: The main findings were that CCL5, CXCL5, and CXCL9 are highly expressed during leptospirosis, indicating a special role of these molecules in the immunity and pathogenesis of the disease. The correlation analysis of detected chemokines CXCL11, CXCL9, CCL3, and CCL2 helps to clarify the role of each cytokine in leptospirosis. The possible use of CCL5 as a biomarker for complementary diagnosis of the disease is suggested.

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Dispersal patterns of zoonotic pathogens can be strongly influenced by mobility and contact among hosts. Toxoplasma gondii infection has been documented in many avian species, however, there is little information regarding free-living seabird populations. Leptospira can infect domestic and wild animals, with birds being potential carriers of the bacteria. The continental shelf of the southwestern Atlantic Ocean is a foraging area for seabirds that breed locally, as well as migratory seabirds wintering in the area, which may come into contact with each other in prey aggregation areas and contribute to T. gondii and Leptospira spread. Therefore, this study aimed to investigate the prevalence of two important zoonotic pathogens in free-living seabirds. Blood samples were collected from 322 birds of three local breeders (Phaethon aethereus, Sula leucogaster and S. dactylatra) in the eastern coast of Brazil (Abrolhos Archipelago), and two migratory species using the area during the pre-laying (Pterodroma arminjoniana) and the non-breeding periods (Thalassarche chlororhynchos). Serological agglutination tests for detection of anti-Toxoplasma gondii and anti-Leptospira spp. antibodies were performed. None of the seabirds in this study was seroreactive to Leptospira spp., whereas 34.5% (n = 111) of the animals presented antibodies anti-T. gondii. Antibody titers in seropositive birds ranged from 10 to 640. There were seropositive birds in all sampled localities. This study provides the first records for P. arminjoniana and T. chlororhynchos as seropositive to T. gondii, suggesting their potential role as sentinels for the environmental contamination by T. gondii and also T. gondii infection. These findings indicate the circulation of the parasite in the Brazilian coastal and oceanic regions, probably due to the ingestion of T. gondii oocysts by birds, the epidemiological involvement of migratory birds as hosts of pathogens, as well as the role of the historical introduction of invasive vertebrates on Brazilian islands. Therefore, due to the serological evidence of infection, the dynamics of toxoplasmosis in seabirds, regarding their susceptibility towards the disease and the possible anthropogenic influence need to be better understood for the colonies to be included in the wildlife cycle of T. gondii.

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Rats are major reservoirs for pathogenic Leptospira, the bacteria causing leptospirosis, particularly in urban informal settlements. However, the impact of variation in rat abundance and pathogen shedding rates on spillover transmission to humans remains unclear. This study aimed to investigate how spatial variation in reservoir abundance and pathogen pressure affect Leptospira spillover transmission to humans in a Brazilian urban informal settlement. A longitudinal eco-epidemiological study was conducted from 2013 to 2014 to characterize the spatial distribution of rat abundance and Leptospira shedding rates in rats and determine the association with human infection risk in a cohort of 2,206 community residents. Tracking plates and live-trapping were used to measure rat abundance and quantify rat shedding status and load. In parallel, four sequential biannual serosurveys were used to identify human Leptospira infections. To evaluate the role of shedding on human risk, we built three statistical models for: (1) the relative abundance of rats, (2) the shedding rate by individual rats, and (3) human Leptospira infection, in which "total shedding", obtained by multiplying the predictions from those two models, was used as a risk factor. We found that Leptospira shedding was associated with older and sexually mature rats and varied spatially and temporally-higher at valley bottoms and with seasonal rainfall (December to March). The point estimate for "total shedding" by rat populations was positive, i.e., Leptospira infection risk increased with total shedding, but the association was not significant [odds ratio (OR) = 1.1; 95% confidence interval (CI): 0.9, 1.4]. This positive trend was mainly driven by rat abundance, rather than individual rat shedding (OR = 1.8; 95% CI: 0.6, 5.4 vs. OR = 1.0; 95% CI: 0.7, 1.4]. Infection risk was higher in areas with more vegetative land cover (OR = 2.4; 95% CI: 1.2, 4.8), and when floodwater entered the house (OR = 2.4; 95% CI: 1.6, 3.4). Our findings indicate that environmental and hydrological factors play a more significant role in Leptospira spillover than rat associated factors. Furthermore, we developed a novel approach combining several models to elucidate complex links between animal reservoir abundance, pathogen shedding and environmental factors on zoonotic spillover in humans that can be extended to other environmentally transmitted diseases.

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BACKGROUND: Leptospirosis is one of the most common zoonoses in the world which is associated with a severe febrile disease in humans causing a variety of syndromes including meningitis, interstitial nephritis, hepatitis, and sometimes death. Leptospirosis is caused by different pathogenic Leptospira species divided into almost 30 serogroups and more than 300 serovars which are carried by some animal asymptomatic chronic infections. Humans can become infected through direct contact with animal urine or indirectly by coming into contact with fresh water or mud contaminated with urine. METHODOLOGY/PRINCIPAL FINDINGS: In this research, we looked for leptospiral DNA in urine samples from dogs living in a rural, low-income and highly endemic community in the coast of Ecuador. We used molecular biology and next-generation sequencing for the detection. Our results showed evidence of two Leptospira species, L interrogans and L. santarosai, genomes in three dogs. CONCLUSIONS/SIGNIFICANCE: It has been widely known that animal carriers are typically infected with a single leptospiral strain. However, recent reports, including the present one, indicate that carrier animals may be coinfected with two or more leptospiral species.

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Leptospira spp. infection is a worldwide zoonosis that causes economic losses to goat rearing, mainly due to reproductive disorders. Hence, the objective of this research was to determine the seroprevalence and associated risk factors of leptospirosis in a goat milk-producing region in the states of Paraiba and Pernambuco, Northeast Brazil. The microscopic agglutination test was used as serological method and risk factor analysis was carried out using univariable and multivariable analyses. Out of the 937 animals sampled, 102 (10.9 %; 95 % CI = 8.9-12.9 %) were seropositive for Leptospira spp. and the most frequent serogroups were Ballum (41.2 %; 95 % CI = 31.6-50.7 %), Icterohaemorrhagiae (25.5 %, 95 % CI = 17-33.9 %) and Semaranga (23.5 %, 95 % CI = 15.3-31.8 %), with antibody titres ranging from 1:50 to 1:200. Thirty-four of 51 herds (66.7 %; 95 % CI = 53.7-79.6 %) had at least one seropositive animal. The risk factor identified in the multivariable two-level random effect binary logistic regression was the animal being an adult (odds ratio = 4.2; 95 % CI = 1.93-9.13; P < 0.001). Our results provide important information on the epidemiology and risk factors associated with goat leptospirosis seroprevalence in one of the main Brazilian goat milk-producing regions. Furthermore, the need for adopting sanitary control measures, especially those involving sanitary management practices, is highlighted.

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Leptospirosis and toxoplasmosis are re-emerging zoonosis caused by infection with pathogenic spirochaetes of Leptospira and the protozoa Toxoplasma gondii, respectively. Wild boars (Sus scrofa), an exotic invasive species in Brazil, could play a role in the diseases' epidemiological cycles, but this issue is still unexplored. This study aimed to evaluate the Leptospira spp. and T. gondii seropositivity in wild boars in Rio Grande do Sul state, south Brazil. Of evaluated animals, 16% (13/80) and 85% (52/61) had antibodies to T. gondii and Leptospira spp., respectively. Sex, weight, age, hunt location and season of hunt were evaluated by their association with seropositivity for both pathogens, but none of them had statistical significance. This study revealed that wild boars should be considered as a potential source of Leptospira spp. and T. gondii dissemination for humans and animal species in shared environments in Rio Grande do Sul state.

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Heme and iron metabolic pathways are highly intertwined, both compounds being essential for key biological processes, yet becoming toxic if overabundant. Their concentrations are exquisitely regulated, including via dedicated two-component systems (TCSs) that sense signals and regulate adaptive responses. HemKR is a TCS present in both saprophytic and pathogenic Leptospira species, involved in the control of heme metabolism. However, the molecular means by which HemKR is switched on/off in a signal-dependent way, are still unknown. Moreover, a comprehensive list of HemKR-regulated genes, potentially overlapped with iron-responsive targets, is also missing. Using the saprophytic species Leptospira biflexa as a model, we now show that 5-aminolevulinic acid (ALA) triggers the shutdown of the HemKR pathway in live cells, and does so by stimulating the phosphatase activity of HemK towards phosphorylated HemR. Phospho~HemR dephosphorylation leads to differential expression of multiple genes, including of heme metabolism and transport systems. Besides the heme-biosynthetic genes hemA and the catabolic hmuO, which we had previously reported as phospho~HemR targets, we now extend the regulon identifying additional genes. Finally, we discover that HemR inactivation brings about an iron-deficit tolerant phenotype, synergistically with iron-responsive signaling systems. Future studies with pathogenic Leptospira will be able to confirm whether such tolerance to iron deprivation is conserved among Leptospira spp., in which case HemKR could play a vital role during infection where available iron is scarce. In sum, HemKR responds to abundance of porphyrin metabolites by shutting down and controlling heme homeostasis, while also contributing to integrate the regulation of heme and iron metabolism in the L. biflexa spirochete model.

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BACKGROUND: Leptospirosis is responsible for various clinical syndromes, classically linked with fever and acute kidney injury. METHODOLOGY/PRINCIPAL FINDINGS: A prospective multicenter observational study was conducted in six health institutions in the region of Urabá, Colombia. Enrollment was based on leptospirosis-compatible clinical syndrome and a positive preliminary serological test, with PCR used to confirm the disease. Clinical data were collected using a standard questionnaire at enrollment, complemented with a review of clinical records. A total of 100 patients were enrolled, 37% (95% CI 27.0-46.9%) had a positive PCR result confirming acute leptospirosis. The most frequent symptoms in patients with a positive PCR test were headache (91.9%; 34/37), chills and sweating (80.6%; 29/37), nausea (75%; 27/37), dizziness (74.3%; 26/37), vomiting (61.1%; 22/37), congestion (56.8%; 21/37), and conjunctival suffusion (51.4%; 19/37). The frequency of clinical signs classically described in leptospirosis was low: jaundice (8.3%; 3/36) and anuria/oliguria (21.6%; 8/37). An increased neutrophile percentage was reported in 60.6% (20/33) of patients. The presence of complications was 21.6% (8/37), with pulmonary complications being the most frequent (75.0% 6/8). One confirmed case died resulting in a fatality of 2.7% (95% CI 0.5-13.8). CONCLUSIONS/SIGNIFICANCE: Leptospirosis should be considered within the differential diagnoses of an undifferentiated acute febrile syndrome. Leptospirosis presents diagnostic challenges due to limitations in both clinical and laboratory diagnosis thus it is important to improve understanding of disease presentation and identify signs and symptoms that might help differentiate it from other causes of febrile illness.

RESUMO

Bovine Genital Leptospirosis (BGL) is a chronic reproductive syndrome characterized by genital infection by Leptospira spp. An accurate diagnosis of BGL is crucial to implementing proper control measures in field conditions. This study aimed to evaluate the reliability of serology by Microscopic Agglutination Test (MAT) for diagnosing leptospirosis in subfertile cows with genital infection. Of three herds, 93 non-pregnant cows with reproductive failures were submitted to the blood sampling (serology by MAT) and genital samples (lipL32-PCR). A total of 62/93 (66.6%) cows presented seroreactive to cutoff 100, while 45/93 (48.4%) cows were positive to cutoff 200, mainly against the Sejroe serogroup. In PCR analysis, 55/93 (59.1%) were positive. MAT results were compared with PCR (considered the standard), and test parameters and Cohen's kappa (ƙ) were calculated for the cut-offs 100 and 200. A ROC curve was performed for each cut-off of titers 100 to 1,600. The sensitivity and specificity of MAT100 were calculated at 66.6% and 33.3%, while for MAT200 the sensitivity was estimated as 35% and specificity as 54.5%. The accuracy of MAT was poor, being 54.8% in MAT100 and 42% in MAT200. Furthermore, the area under the curve of ROC analysis was low for all titers, and the correlation was poor for MAT100 and MAT200 (ƙ < 0). The results demonstrated that MAT is a limited technique to diagnose bovine genital carriers individually, and if only MAT is applied, genital carriers may pass undetected, impairing the control programs.