Feline leptospirosis prevalence worldwide: A systematic review and meta-analysis of diagnostic approaches.

Background and Aim: Leptospirosis in felids (domestic and wild cats) presents an ongoing challenge in our understanding. Numerous studies have reported the detection of Leptospira spp. in these feline populations, highlighting their potential as zoonotic carriers. This systematic review and meta-analysis aimed to provide insight into the global prevalence of leptospirosis in domestic and wild cats. Materials and Methods: We conducted extensive searches across five databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols guidelines. Random-effect meta-analyses were performed using R software version 4.3.0 to estimate pooled prevalence rates. Subgroup meta-analyses were conducted based on continents, diagnostic methods, sample types, and wildcat genera. Results: A total of 71 articles on leptospirosis in domestic cats and 23 articles on leptospirosis in wild cats met the eligibility criteria. Our findings indicated a significantly higher pooled seroprevalence of leptospirosis in domestic cats compared with infection prevalence (9.95% [95% confidence interval (CI), 7.60%-12.54%] vs. 4.62% [95% CI, 2.10%-7.83%], p = 0.01). In contrast, no significant difference was observed in pooled seroprevalence and infection prevalence among wild cats (13.38% [95% CI, 6.25%-21.93%] vs. 2.9% [95% CI, 0.00%-18.91%], p = 0.21). A subgroup meta-analysis of domestic cats revealed significant differences in seroprevalence across continents, sample types, and diagnostic methods. On the contrary, wild cats had no significant differences in any of the subgroups. Conclusion: Leptospira spp. have evidently been exposed to both domestic and wild cats, highlighting their potential roles as reservoir hosts for leptospirosis. These findings highlight the importance of considering felids as a possible public health threat.

Seroprevalence of leptospirosis among stray dogs in Bosnia and Herzegovina.

Leptospirosis is a (re) emerging zoonosis that occurs worldwide. This study aimed to assess seroprevalence of leptospirosis and to identify the most common reactive serovars and risk factors for seropositivity in apparently healthy stray dogs of unknown vaccination status in the Sarajevo region of Bosnia and Herzegovina. Positive microscopic agglutination test titres (≥ 1:25) were detected in 3.87% (156/4028) of samples and most of the sera reacted against one serovar (85.9%). Dogs were most commonly reactive to Canicola (40.4%) and Hardjo (33.3%), followed by Pomona (15.4%) Tarassovi (14.7%), Icterohaemorrhagiae (8.3%), Grippotyphosa (5.8%), Bratislava (1.3%) and Saxkoebing (0.6%). Dogs older than one year had higher odds of seropositivity compared to younger dogs. The seropositivity was higher in spring and autumn than in summer. These results advocate for the need of a control strategy for this zoonosis in the country, which should include sero-surveillance, monitoring, and the inclusion of additional serovars in the testing.

Nucleotide-induced ClpC oligomerization and its non-preferential association with ClpP isoforms of pathogenic Leptospira.

Bacterial caseinolytic protease-chaperone complexes participate in the elimination of misfolded and aggregated protein substrates. The spirochete Leptospira interrogans possess a set of Clp-chaperones (ClpX, ClpA, and ClpC), which may associate functionally with two different isoforms of LinClpP (ClpP1 and ClpP2). The L. interrogans ClpC (LinClpC) belongs to class-I chaperone with two active ATPase domains separated by a middle domain. Using the size exclusion chromatography, ANS dye binding, and dynamic light scattering analysis, the LinClpC is suggested to undergo nucleotide-induced oligomerization. LinClpC associates with either pure LinClpP1 or LinClpP2 isoforms non-preferentially and with equal affinity. Regardless, pure LinClpP isoforms cannot constitute an active protease complex with LinClpC. Interestingly, the heterocomplex LinClpP1P2 in association with LinClpC forms a functional proteolytic machinery and degrade ß-casein or FITC-casein in an energy-independent manner. Adding either ATP or ATPγS further fosters the LinClpCP1P2 complex protease activity by nurturing the functional oligomerization of LinClpC. The antibiotic, acyldepsipeptides (ADEP1) display a higher activatory role on LinClpP1P2 protease activity than LinClpC. Altogether, this work illustrates an in-depth study of hetero-tetradecamer LinClpP1P2 association with its cognate ATPase and unveils a new insight into the structural reorganization of LinClpP1P2 in the presence of chaperone, LinClpC to gain protease activity.

Efficacy and safety of antibiotics for treatment of leptospirosis: a systematic review and network meta-analysis.

BACKGROUND: Leptospirosis, an important zoonotic bacterial disease, commonly affects resource-poor populations and results in significant morbidity and mortality worldwide. The value of antibiotics in leptospirosis remains unclear, as evidenced by the conflicting opinions published. METHODS: We conducted a search in the PubMed, Web of Science, and Cochrane Library databases for studies. These studies included clinical trials and retrospective studies that evaluated the efficacy or safety of antibiotics for leptospirosis treatment. The primary outcomes assessed were defervescence time, mortality rate, and hospital stays. Subgroup analyses were performed based on whether there were cases involving children and whether there were cases of severe jaundice. Safety was defined as the prevalence of adverse events associated with the use of antibiotics. p scores were utilized to rank the efficacy of the antibiotics. RESULTS: There are included 9 randomized controlled trials (RCTs), 1 control trial (CT), and 3 retrospective studies (RS) involving 920 patients and 8 antibiotics. Six antibiotics resulted in significantly shorter defervescence times compared to the control, namely cefotaxime (MD, - 1.88; 95% CI = - 2.60 to - 1.15), azithromycin (MD, - 1.74; 95% CI = - 2.52 to - 0.95), doxycycline (MD, - 1.53; 95% CI = - 2.05 to - 1.00), ceftriaxone (MD, - 1.22; 95% CI = - 1.89 to - 0.55), penicillin (MD, - 1.22; 95% CI = - 1.80 to - 0.64), and penicillin or ampicillin (MD, - 0.08; 95% CI = - 1.01 to - 0.59). The antibiotics were not effective in reducing the mortality and hospital stays. Common adverse reactions to antibiotics included Jarisch-Herxheimer reaction, rash, headache, and digestive reactions (nausea, vomiting, diarrhea, abdominal pain, and others). CONCLUSIONS: Findings recommend that leptospirosis patients be treated with antibiotics, which significantly reduced the leptospirosis defervescence time. Cephalosporins, doxycycline, and penicillin are suggested, and azithromycin may be a suitable alternative for drug-resistant cases. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022354938.

Inter-species Transcriptomic Analysis Reveals a Constitutive Adaptation Against Oxidative Stress for the Highly Virulent Leptospira Species.

Transcriptomic analyses across large scales of evolutionary distance have great potential to shed light on regulatory evolution but are complicated by difficulties in establishing orthology and limited availability of accessible software. We introduce here a method and a graphical user interface wrapper, called Annotator-RNAtor, for performing interspecies transcriptomic analysis and studying intragenus evolution. The pipeline uses third-party software to infer homologous genes in various species and highlight differences in the expression of the core-genes. To illustrate the methodology and demonstrate its usefulness, we focus on the emergence of the highly virulent Leptospira subclade known as P1+, which includes the causative agents of leptospirosis. Here, we expand on the genomic study through the comparison of transcriptomes between species from P1+ and their related P1- counterparts (low-virulent pathogens). In doing so, we shed light on differentially expressed pathways and focused on describing a specific example of adaptation based on a differential expression of PerRA-controlled genes. We showed that P1+ species exhibit higher expression of the katE gene, a well-known virulence determinant in pathogenic Leptospira species correlated with greater tolerance to peroxide. Switching PerRA alleles between P1+ and P1- species demonstrated that the lower repression of katE and greater tolerance to peroxide in P1+ species was solely controlled by PerRA and partly caused by a PerRA amino-acid permutation. Overall, these results demonstrate the strategic fit of the methodology and its ability to decipher adaptive transcriptomic changes, not observable by comparative genome analysis, that may have been implicated in the emergence of these pathogens.

LIC_12757 from the pathogenic spirochaete Leptospira interrogans encodes an autoregulated ECF σE-type factor.

ECF (extracytoplasmic function) σ factors, members of the σ70-family, are the largest class of alternative σ factors which are stimulated in the presence of specific signals and direct RNA polymerase to transcribe a defined subset of genes. Thanks to them, bacterial pathogens can effectively reprogram their gene expression and, consequently, survive in the host and establish infection in a relatively short time. The number of ECF σ factors encoded within bacterial genomes is different depending on a given species and it reflects the likelihood that these bacteria will encounter harsh environmental conditions. The genome of L. interrogans, a zoonotic pathogen responsible for leptospirosis, is predicted to encode 11 ECF σE-type factors, but none of them have been characterized biochemically to date and their functions are still unknown. Here, we focused on one of the leptospiral ECF σ factors, namely LIC_12757, which was previously found to be up-regulated at elevated temperatures and may be related to the expression of clpB encoding an important L. interrogans virulence factor. We report cloning of the coding sequence of the LIC_12757 gene, its expression with the pET system and biochemical characterization of LIC_12757. By performing EMSA and in vitro transcription assays, we provide strong evidence that LIC_12757 indeed functions as a transcriptional factor that enables RNA polymerase to bind to the specific σE-type promoter and to initiate transcription. Interestingly, we demonstrate that LIC_12757 is autoregulated at the transcriptional level. Our study is a first step towards determining key aspects of LIC_12757 function in pathogenic Leptospira.

Leptospirosis: predictores de mala evolución clínica en pacientes hospitalizados, 25 años de experiencia / Leptospirosis: predictors of poor outcomes in hospitalized patients, 25 years of experience

Introducción: La leptospirosis es una zoonosis que cons-tituye un problema emergente de salud pública. La insufi-ciencia renal, plaquetopenia y compromiso respiratorio se describen como predictores de mortalidad.Objetivos: Describir características clínicas, radiológicas y de laboratorio de individuos hospitalizados por leptos-pirosis y evaluar los predictores de mala evolución clínica (MEC).Materiales y métodos: Estudio de cohorte de inclusión ambispectiva de pacientes con leptospirosis internados en un hospital de la ciudad de Santa Fe entre 1997 y 2022. Se definió MEC como la admisión a Unidad de Cuidados Intensivos (UCI), requerimiento de asistencia respiratoria mecánica (ARM) y/o muerte. Se utilizaron las pruebas de Chi2, test T de Student o la U de Mann-Whitney, según co-rrespondiera. Se construyó una regresión logística binaria con las variables con p<0,05.Resultados: 101 pacientes, 87,1% (n=88) hombres, media-na de edad de 29 (RIC 20-44) años. La fiebre fue el síntoma más frecuente [83,2% (n=84)], seguido del compromiso di-gestivo [62,4% (n=63)]. Las alteraciones de laboratorio más frecuentes fueron: eritrosedimentación elevada [91,9% (n=79)] y leucocitosis [61% (n=61)]. Se observó MEC en el 25,7% (n=26). El 25,7% (n=26) fue admitido en UCI, el 13,9% (n=14) requirió ARM y el 5% (n=5) falleció. La presencia de plaquetopenia (OR=13,3, IC95% 2-80), las alteraciones en la radiografía de tórax (OR=33,5, IC95% 5-225) y la ausencia de cefalea (OR=6,8, IC95% 1-32) fueron predictores inde-pendientes de MEC.Conclusiones: En concordancia con la bibliografía, la afec-tación pulmonar y plaquetopenia son factores de riesgo para la mala evolución clínica. En nuestra serie, la cefalea constituyó un síntoma protector

Introduction: Leptospirosis is an emerging zoonotic di-sease that poses a public health problem. Renal failu-re, thrombocytopenia, and respiratory involvement have been described as predictors of mortality.Objectives: To describe the clinical, radiological, and la-boratory characteristics of hospitalized individuals with leptospirosis and evaluate predictors of poor clinical outcomes (PCO).Materials and methods: A prospective cohort study was conducted including patients with leptospirosis admit-ted to a hospital in the city of Santa Fe between 1997 and 2022. PCO was defined as admission to the Intensive Care Unit (ICU), requirement for mechanical respiratory assistance (MRA), and/or death. The chi-square test, Student>s t-test, or Mann-Whitney U test were used as appropriate. A binary logistic regression was performed with variables having p<0.05.Results: Out of the 101 patients included, 87.1% (n=88) were male, with a median age of 29 (IQR 20-44) years. Fever was the most common symptom [83.2% (n=84)], followed by digestive involvement [62.4% (n=63)]. The most frequent laboratory abnormalities were elevated erythrocyte sedimentation rate [91.9% (n=79)] and leuko-cytosis [61% (n=61)]. PCO was observed in 25.7% (n=26) of patients, with 25.7% (n=26) admitted to the ICU, 13.9% (n=14) requiring MRA, and 5% (n=5) resulting in death. The presence of thrombocytopenia (OR=13.3, 95% CI 2-80), abnormalities in chest X-rays (OR=33.5, 95% CI 5-225), and absence of headache (OR=6.8, 95% CI 1-32) were predictors of PCO. Conclusions: Consistent with the literature, pulmonary involvement and thrombocytopenia are independent risk factors for poor clinical outcomes. In our series, the pre-sence of headache was a protective symptom

Concomitant Salmonella and Leptospira Meningitis: A Rare Case Report.

This study presents a unique case of concurrent salmonella and Leptospira meningitis in a 20-year-old woman with no prior medical history. Coinfection with endemic pathogens is plausible, especially in regions like Pakistan. While Salmonella meningitis is uncommon, it presents a significant medical emergency, particularly in immunocompromised adults. Neuroleptospirosis, though rare, can manifest in certain cases. The patient displayed persistent high fever, confusion, irritability, and a single seizure episode. Initial tests, including blood and cerebrospinal fluid (CSF) cultures and serological examinations, detected Salmonella typhi and positive leptospiral antibodies, respectively. Leptomeningeal enhancement was confirmed by an MRI. Treatment with azithromycin, meropenem, and ceftriaxone led to improvement after seven days. She was advised to complete a 28-day course for Salmonella meningitis. This case emphasizes the importance of considering multiple infectious causes, especially in endemic regions. Timely and thorough diagnostic evaluation, followed by appropriate antimicrobial therapy, is essential for effective management. Further research is warranted to enhance understanding of the epidemiology, clinical features, and optimal treatment strategies for such dual infections.

Outer membrane vesicles as nanovaccine candidates against pathogenic Leptospira in experimental Guinea pig model.

Leptospira interrogans serovar Hardjo is a long slender bacterium of size 0.1-0.3 µm × 5-50 µm. It is one of the major causes of bovine leptospirosis and is of economical importance because of the reproductive failure, still birth, abortion, and reduced productivity in cattle. It is also a zoonotic disease-causing infection in humans characterized by headaches, fever, chills, sweats and myalgia, lethargy, aching joints, pulmonary haemorrhages, and death in severe cases. Control of the disease involves antibiotic therapy, management and vaccination, of which immunization is the cheapest and effective means of disease prevention. The present study was developed to isolate and characterize the outer membrane vesicles of Leptospira interrogans serovar Hardjo and to evaluate their vaccine potential in guinea pig model. The OMVs were isolated from the culture by sonication and ultracentrifugation. In transmission electron microscopy, the isolated OMVs appeared as small spherical structures of 50-200 nm size. In Western blot and indirect ELISA, antibodies specific to OMVs were observed as indicative of a good humoral immune response elicited by L. interrogans serovar Hardjo OMV. The OMV-based Leptospira vaccine was able to prevent kidney lesions and renal colonization compared to the control and bacterin vaccinated group as proven by histopathology and PCR.

Pathogenic Leptospira contamination in the environment: a systematic review.

Background: The pathogenic Leptospira is maintained in renal tubules of certain animals, mostly rodents, and excreted in the urine which can contaminate the environment. It is necessary to detect pathogenic Leptospira in environmental samples. Knowing the survival of Leptospira in the environment (water and soil) can provide an overview of where and how they can be transmitted to humans. Objective: Therefore, this study aimed to provide a systematic overview of pathogenic Leptospira presence in water and soil environment, the various species of pathogenic Leptospira that are harmful for human, and the ability to survive using a systematic review method. Methods: The search process used four databases: PubMed, Science Direct, Scopus, and ProQuest. Furthermore, the articles sought were published from 2000 to July 2021, and 38 were analysed. Results: The pathogenic Leptospira contamination in water was higher in urban areas, while soil samples were higher in rural areas. Various pathogenic Leptospira detected in the environment were L. alstonii, L. kmetyi, L. noguchii, and L. interrogans. Those pathogenic Leptospira can survive in water at 4-30°C and at pH < 7; in soil, it can survive at a humidity of < 20% and a pH < 6. Conclusion: Urban and rural areas have the same risk for leptospirosis disease because pathogenic Leptospira (P1).

Genetic diversity of P1/pathogenic Leptospira species hosted by bats worldwide.

INTRODUCTION: Bats are a diverse group of mammals that have unique features allowing them to act as reservoir hosts for several zoonotic pathogens such as Leptospira. Leptospires have been classified into pathogenic, intermediate, and saprophytic groups and more recently into clades P1, P2, S1, and S2, being all the most important pathogenic species related to leptospirosis included within the P1/pathogenic clade. Leptospira has been detected from bats in several regions worldwide; however, the diversity of leptospires harboured by bats is still unknown. AIM: The aim of the present study was to determine the genetic diversity of Leptospira spp. harboured by bats worldwide. METHODS: A systematic review was conducted on four databases to retrieve studies in which Leptospira was detected from bats. All studies were screened to retrieve all available Leptospira spp. 16S rRNA sequences from the GenBank database and data regarding their origin. Sequences obtained were compared with each other and reference sequences of Leptospira species and analysed through phylogenetic analysis. RESULTS: A total of 418 Leptospira spp. 16S rRNA sequences isolated from 55 bat species from 14 countries were retrieved from 15 selected manuscripts. From these, 417 sequences clustered within the P1/pathogenic group, and only one sequence clustered within the P2/intermediate group. Six major clades of P1/pathogenic Leptospira spp. were identified, three of them composed exclusively of sequences obtained from bats. CONCLUSION: We identified that bats harbour a great genetic diversity of Leptospira spp. that form part of the P1/pathogenic clade, some of which are closely related to leptospirosis-associated species. This finding contributes to the knowledge of the diversity of leptospires hosted by bats worldwide and reinforces the role of bats as reservoirs of P1/pathogenic Leptospira spp.

Vector-Borne and Zoonotic Pathogens in Raccoon Dogs (Nyctereutes procyonoides) and Raccoons (Procyon lotor) from Schleswig-Holstein, Germany.

Raccoon dogs (Nyctereutes procyonoides) and raccoons (Procyon lotor) are invasive alien species originating from East Asia and North America, respectively. They are discussed as vectors and reservoirs for various infectious diseases, including vector-borne and zoonotic pathogens, and are therefore a potential threat to human and domestic animal health, as well as to biodiversity and conservation. In the years 2021 and 2022, 110 raccoon dogs (Nyctereutes procyonoides) and 30 raccoons (Procyon lotor) were screened via qPCR for the presence of Leptospira spp., Rickettsia spp. and Borreliella spp. in the German federal state of Schleswig-Holstein as part of a health and risk assessment study. Borreliella spp. were confirmed in one raccoon dog and one raccoon, identified as Borreliella afzelii in the raccoon. Leptospira spp. were found in 21 (19.44%) raccoon dogs and 2 (6.90%) raccoons. In five raccoon dogs, Leptospira spp. were identified as Leptospira borgpetersenii, Leptospira kirschneri and Leptospira interrogans.

Exploring Leptospira interrogans FDAARGOS_203: Insights into AMR and Anti-Phage Defense.

Leptospira, which are known to be important disease-causing agents transmitted between animals and humans, result in significant illness and, in some cases, significant death in human populations. This purpose of this study was to examine the genomic structure of Leptospira interrogans serovar Copenhageni strain FDAARGOS_203 to identify the specific genetic factors that contribute to antimicrobial resistance (AMR) and defense against phages. The genome, consisting of two contigs totaling 4,630,574 base pairs, underwent thorough examination for protein-coding sequences, transfer RNA genes, and ribosomal RNA genes. A total of twenty-two antibiotic resistance genes that specifically target essential cellular processes such as cell wall synthesis, DNA replication, and protein synthesis have been identified. Significant among these were gidB, gdpD, and ggsA, each involved in separate aspects of antibiotic resistance. In addition, the investigation explored the defense mechanisms of bacteriophages, revealing the presence of defense islands that contain a range of anti-phage systems, including RM_Type_IV, PrrC, Borvo, CAS_Class1-Subtype-IC, and CAS_Class1-Subtype-IB. This comprehensive genomic analysis enhances our understanding of the molecular mechanisms that determine Leptospira's ability to adapt to various environments. The identified genetic factors linked to AMR and defense against phages not only enhance our scientific comprehension, but also provide a basis for focused interventions to reduce the impact of leptospirosis.

Global distribution of Leptospira serovar isolations and detections from animal host species: A systematic review and online database.

OBJECTIVES: Leptospira, the spirochaete causing leptospirosis, can be classified into >250 antigenically distinct serovars. Although knowledge of the animal host species and geographic distribution of Leptospira serovars is critical to understand the human and animal epidemiology of leptospirosis, current data are fragmented. We aimed to systematically review, the literature on animal host species and geographic distribution of Leptospira serovars to examine associations between serovars with animal host species and regions and to identify geographic regions in need of study. METHODS: Nine library databases were searched from inception through 9 March 2023 using keywords including Leptospira, animal, and a list of serovars. We sought reports of detection of Leptospira, from any animal, characterised by cross agglutinin absorption test, monoclonal antibody typing, serum factor analysis, or pulsed-field gel electrophoresis to identify the serovar. RESULTS: We included 409 reports, published from 1927 through 2022, yielding data on 154 Leptospira serovars. The reports included data from 66 (26.5%) of 249 countries. Detections were from 144 animal host species including 135 (93.8%) from the class Mammalia, 5 (3.5%) from Amphibia, 3 (2.1%) from Reptilia, and 1 (0.7%) from Arachnida. Across the animal host species, Leptospira serovars that were detected in the largest number of animal species included Grippotyphosa (n = 39), Icterohaemorrhagiae (n = 29), Pomona (n = 28), Australis (n = 25), and Ballum (n = 25). Of serovars, 76 were detected in a single animal host species. We created an online database to identify animal host species for each serovar by country. CONCLUSIONS: We found that many countries have few or no Leptospira serovars detected from animal host species and that many serovars were detected from a single animal species. Our study highlights the importance of efforts to identify animal host species of leptospirosis, especially in places with a high incidence of human leptospirosis. We provide an updated resource for leptospirosis researchers.

Seroprevalence and associated risk factors for bovine leptospirosis in Egypt.

Leptospirosis is caused by pathogenic bacteria of the genus Leptospira and is one of causative agents of reproductive problems leading to negative economic impact on bovine worldwide. The goal of this study was to investigate the seroprevalence of Leptospira spp. in cattle in some governorates of Egypt's Nile Delta and assess the risk factors for infection. A total of 410 serum samples were collected from cattle and examined using microscopic agglutination test. The overall seroprevalence was 10.2% and the most prevalent serovars were Icterohaemorrhagiae, Pomona and Canicola. In addition, the potential risk factors were associated Leptospira spp. infection were age, herd size, history of abortion, presence of dogs and rodent control. Thus, leptospirosis is common in dairy cattle in the Nile Delta and  the presence of rodents in feed and dog-accessible pastures increases the risk of Leptospira spp. infection among animals.

Global proteome of the saprophytic strain Leptospira biflexa and comparative analysis with pathogenic strain Leptospira interrogans uncover new pathogenesis mechanisms.

Leptospira is a genus of bacteria that includes free-living saprophytic species found in water or soil, and pathogenic species, which are the etiologic agents of leptospirosis. Besides all the efforts, there are only a few proteins described as virulence factors in the pathogenic strain L. interrogans. This work aims to perform L. biflexa serovar Patoc1 strain Paris global proteome and to compare with the proteome database of pathogenic L. interrogans serovar Copenhageni strain Fiocruz L1-130. We identified a total of 2327 expressed proteins of L. biflexa by mass spectrometry. Using the Get Homologues software with the global proteome of L. biflexa and L. interrogans, we found orthologous proteins classified into conserved, low conserved, and specific proteins. Comparative bioinformatic analyses were performed to understand the biological functions of the proteins, subcellular localization, the presence of signal peptide, structural domains, and motifs using public softwares. These results lead to the selection of 182 low conserved within the saprophyte, and 176 specific proteins of L. interrogans. It is anticipated that these findings will indicate further studies to uncover virulence factors in the pathogenic strain. This work presents for the first time the global proteome of saprophytic strain L. biflexa serovar Patoc, strain Patoc1. SIGNIFICANCE: The comparative analysis established an array of specific proteins in pathogenic strain that will narrow down the identification of immune protective proteins that will help fight leptospirosis.

High Exposure to Livestock Pathogens in Southern Pudu (Pudu puda) from Chile.

A significant gap in exposure data for most livestock and zoonotic pathogens is common for several Latin America deer species. This study examined the seroprevalence against 13 pathogens in 164 wild and captive southern pudu from Chile between 2011 and 2023. Livestock and zoonotic pathogen antibodies were detected in 22 of 109 wild pudus (20.18%; 95% CI: 13.34-29.18) and 17 of 55 captive pudus (30.91%; 95% CI: 19.52-44.96), including five Leptospira interrogans serovars (15.38% and 10.71%), Toxoplasma gondii (8.57% and 37.50%), Chlamydia abortus (3.03% and 12.82%), Neospora caninum (0.00% and 9.52%), and Pestivirus (8.00% and 6.67%). Risk factors were detected for Leptospira spp., showing that fawn pudu have statistically significantly higher risk of positivity than adults. In the case of T. gondii, pudu living in "free-range" have a lower risk of being positive for this parasite. In under-human-care pudu, a Pestivirus outbreak is the most strongly suspected as the cause of abortions in a zoo in the past. This study presents the first evidence of Chlamydia abortus in wildlife in South America and exposure to T. gondii, L. interrogans, and N. caninum in wild ungulate species in Chile. High seroprevalence of livestock pathogens such as Pestivirus and Leptospira Hardjo in wild animals suggests a livestock transmission in Chilean template forest.

Detection of Antibodies for Pathogenic Leptospira in Wild Mammals and Birds from Southern Chile-First Record of Seropositivity in a Guiña (Leopardus guigna).

Leptospirosis is a neglected bacterial zoonotic disease of worldwide distribution that is present in different animal species. This epidemiological study determined the seroprevalence of pathogenic Leptospira spp. in animals at a wildlife rehabilitation center in Puerto Montt, southern Chile, by sampling 60 animals belonging to three classes (birds, mammals, and reptiles). Diagnosis was performed using the microscopic agglutination test with a panel of eight serovars and serogroups. The results showed that 15 animals had anti-Leptospira antibodies, obtaining a seroprevalence of 25.00%, with Leptospira borgpetersenii serogroup Tarassovi presenting reactivity in 13 of the seropositive animals. Among the classes of mammals, chilla foxes (Lycalopex griseus) and pudus (Pudu puda) were seropositive. A guiña (Leopardus guigna) was also seropositive, which was described for the first time in mammals. Among the classes of birds, choroy parrots (Enicognathus leptorhynchus), bandurrias (Theristicus melanopis), and Magellanic penguins (Spheniscus magellanicus) were seropositive. Routine examinations to diagnose leptospirosis, perform epidemiological surveillance, and apply prevention and control measures are necessary, and additional research focusing on the One Health approach to explore the epidemiological role of different wild animal species in the maintenance and transmission of leptospirosis at the local and global levels are recommended.

Retrospective evaluation of 22 dogs with leptospirosis treated with extracorporeal renal replacement therapies (2018-2021).

BACKGROUND: Outcomes of dogs with acute kidney injury secondary to leptospirosis (AKI-L) treated using renal replacement therapies (RRT) are poorly characterized. HYPOTHESIS/OBJECTIVES: Describe survival to discharge, short (≤30 days) and long-term (≥6 months) outcomes of AKI-L dogs receiving RRT and determine if there is a significant difference in maximum blood urea nitrogen (maxBUN), maximum creatinine (maxCr), maximum bilirubin (maxBili) and the number of body systems affected between survivors and non-survivors. ANIMALS: Twenty-two client-owned dogs with AKI-L receiving RRT. METHODS: Retrospective medical record review of dogs with AKI-L that received RRT between 2018 and 2021. RESULTS: Sixteen of 22 (73%) dogs survived to discharge. Of the survivors, 13 (81%) were alive >30 days from discharge and 12 (75%) were alive at 6 months from discharge. Factors significantly higher in non-survivors included number of body systems affected (survivors: 1 (19%), 2 (50%), 3 (25%) and 4 (6%) vs non-survivors: 3 (33.3%), and 4 (66.7%); P = .01) and median maxBili (survivors: 1.9 mg/dL; range, 0.1-41.6 vs non-survivors: 21.0 mg/dL; range, 12.3-38.9; P = .02). There was no significant difference in median maxBUN (survivors: 153.0 mg/dL; range, 67-257 vs non-survivors: 185.5 mg/dL; range, 102-218; P = .44) and median maxCr (survivors: 9.8 mg/dL; range, 6.2-15.9 vs non-survivors: 9.8 mg/dL; range, 8.4-13.5; P = .69) between survivors and non-survivors. CONCLUSIONS AND CLINICAL IMPORTANCE: Regardless of azotemia severity, dogs with AKI-L receiving RRT have a good survival rate to discharge. The number of body systems affected and hyperbilirubinemia might be associated with worse outcomes.

A Cross Sectional Study on the Bidirectional Interactions Between Leptospirosis and HIV Infection Among Patients from Maputo Central Hospital, Mozambique.

Introduction: This study aims to determine the baseline seroprevalence of leptospirosis, a zoonotic and neglected disease, in people living with HIV (PWH) in Maputo, Mozambique, and to evaluate the relationship between selected HIV-related factors that might influence risk of coinfection with leptospirosis, such as degree of immunosuppression, as assessed by CD4 cell count, World Health Organization (WHO) HIV/AIDS clinical stage and antiretroviral therapy (ART) intake. Methods: This was a descriptive cross-sectional analysis of 157 PWH, aged over 18 years old, admitted to the Maputo Central Hospital, in Maputo, Mozambique, between March 2020 and October 2021. The study participants were recruited as a convenience sample regardless of the reasons for their admission. We collected sociodemographic and clinical data, including ART and WHO HIV/AIDS clinical stage, and blood for CD4 cell count and detection of Leptospira IgG antibodies using a commercial Kit ab247199 Leptospira IgG ELISA (www.abcam.com/ab247199) with sensitivity and specificity of 100% and 97.3%, respectively. Laboratory testing was performed at the Faculty of Medicine, Eduardo Mondlane University and Laboratory of Clinical Analysis, in Maputo. Results: Participants were aged 18 to 72 years (median age 39 years; SD ± 10.5), the majority were female 100 (63.7%), from urban areas 138 (87.9%), with secondary-level education 80 (51%). The overall seroprevalence of Leptospira IgG antibodies was 40.1%. The median CD4 cell count was 385 cells/µl (02 to 2297; SD ± 378.47). Higher seroprevalence of Leptospira antibodies was found among participants with CD4 cell counts <250 cells/µl (54.8%), WHO HIV/AIDS stage IV (70.2%) and those on ART (92%), though there were no statistically significant differences between groups with and without Leptospira antibodies. Conclusion: Our study confirmed that Leptospira antibodies are highly prevalent in PWH in Maputo; however, Leptospira infection was not associated with the degree of immunosuppression, WHO HIV/AIDS clinical stage, or the use of ART. Our data support the need for routine screening for leptospirosis in PWH in Mozambique. Future studies are warranted to characterize the incidence and outcomes of symptomatic leptospirosis in this patient population and to identify circulating serovars and species in the country and region, as well as the implicated reservoirs.