Leptospirosis is an invasive infectious and systemic inflammatory disease

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).

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.

Enhancing leptospirosis control with nanosensing technology: A critical analysis

Leptospirosis is a serious health problem in tropical areas; thus, animals shed leptospires in the environment. Humans are accidental hosts infected through exposure to contaminating bacteria in the environment. One health strategy can be applied to protect and eliminate leptospirosis because this cooperates and coordinates activities between doctors, veterinarians, and ecologists. However, conventional methods still have limitations. Therefore, the main challenges of leptospirosis control are the high sensing of detection methods to screen and control the pathogens. Interestingly, nano sensing combined with a leptospirosis detection approach can increase the sensitivity and eliminate some limitations. This article reviews nanomaterial development for an advanced leptospirosis detection method, e.g., latex beads-based agglutination test, magnetic nanoparticles enrichment, and gold-nanoparticles-based immunochromatographic assay. Thus, nanomaterials can be functionalized with biomolecules or sensing molecules utilized in various mechanisms such as biosensors. Over the last decade, many biosensors have been developed for Leptospira spp. pathogen and others. The evolution of biosensors for leptospirosis detection was designed for high efficiency and might be an alternative tool. In addition, the high-sensing fabrications are useful for leptospires screening in very low levels, for example, soil or water from the environment.

Beyond the bowel - chaos caused by leaky barriers

The current issue of the Biomedical Journal includes a study presenting a possible agent against gut aging, a review of recent results in the field of breath biomarkers, as well as the investigation of the relationship between kidney disease and leptospirosis. Furthermore, the advantages of 3D imaging in dental medicine are elucidated, the influence of afterhyperpolarization in regulating the circadian clock is discussed, and the effectiveness of apremilast against ARDS is demonstrated. A controversial factor involved in the complex process of bone homeostasis is reviewed, and prevalent non-SARS human coronavirus types in Taiwan are looked at in detail. Lastly, the impact family history has on type 2 diabetes for the identification of high risk groups is addressed, the link between postoperative delirium risk and frailty in elderly patients is examined, and elements involved in recovering walking ability after stroke are analyzed.

Use of an Integrated Multi-Omics Approach To Identify Molecular Mechanisms and Critical Factors Involved in the Pathogenesis of Leptospira

Leptospirosis, a bacterial zoonosis caused by pathogenic Leptospira spp., is prevalent worldwide and has become a serious threat in recent years. Limited understanding of Leptospira pathogenesis and host response has hampered the development of effective vaccine and diagnostics. Although Leptospira is phagocytosed by innate immune cells, it resists its destruction, and the evading mechanism involved is unclear. In the present study, we used an integrative multi-omics approach to identify the critical molecular factors of Leptospira involved in pathogenesis during interaction with human macrophages. Transcriptomic and proteomic analyses were performed at 24 h postinfection of human macrophages (phorbol-12-myristate-13-acetate differentiated THP-1 cells) with the pathogenic Leptospira interrogans serovar Icterohaemorrhagiae strain RGA (LEPIRGA). Our results identified a total of 1,528 transcripts and 871 proteins that were significantly expressed with an adjusted P value of <0.05. The correlations between the transcriptomic and proteomic data were above average (r = 0.844), suggesting the role of the posttranscriptional processes during host interaction. The conjoint analysis revealed the expression of several virulence-associated proteins such as adhesins, invasins, and secretory and chemotaxis proteins that might be involved in various processes of attachment and invasion and as effectors during pathogenesis in the host. Further, the interaction of bacteria with the host cell (macrophages) was a major factor in the differential expression of these proteins. Finally, eight common differentially expressed RNA-protein pairs, predicted as virulent, outer membrane/extracellular proteins were validated by quantitative PCR. This is the first report using integrated multi-omics approach to identify critical factors involved in Leptospira pathogenesis. Validation of these critical factors may lead to the identification of target antigens for the development of improved diagnostics and vaccines against leptospirosis. IMPORTANCE Leptospirosis is a zoonotic disease of global importance. It is caused by a Gram-negative bacterial spirochete of the genus Leptospira. The current challenge is to detect the infection at early stage for treatment or to develop potent vaccines that can induce cross-protection against various pathogenic serovars. Understanding host-pathogen interactions is important to identify the critical factors involved in pathogenesis and host defense for developing improved vaccines and diagnostics. Utilizing an integrated multi-omics approach, our study provides important insight into the interaction of Leptospira with human macrophages and identifies a few critical factors (such as virulence-associated proteins) involved in pathogenesis. These factors can be exploited for the development of novel tools for the detection, treatment, or prevention of leptospirosis.

Distribution, frequency and clinical presentation of leptospirosis and coinfections: a systematic review protocol

INTRODUCTION

Leptospirosis is a zoonotic disease with high prevalence in low-income and middle-income countries and tropical and subtropical regions. The clinical symptoms of the disease are similar to symptoms presented by other endemic infectious diseases that could be present simultaneously. Thus, leptospirosis could be masked by similar infections like dengue, malaria, hantavirus, melioidosis and borreliosis, among others. Therefore, leptospirosis could present itself as an under-reported infection or as a coinfection with another pathogen, as has been reported in the literature. However, there is a lack of documented evidence about the specific risk factors of leptospirosis infection, the symptoms, the coinfection's mortality and the frequency of coinfection. Additionally, leptospirosis coinfections have not been considered a neglected public health concern. Therefore, this systematic review aims to evaluate published articles that show the risk factors associated with leptospirosis infection and coinfection with other pathogens.

METHODS AND ANALYSIS

The search process to identify eligible studies will be conducted including the LILACS, ProQuest, PubMed and Scopus databases with no restriction in terms of publication date. Also, grey literature will be included in the research. Authors will independently screen the title and abstracts of the articles identified from the search using Rayyan free software. Eligibility criteria include peer-reviewed research articles written in English or Spanish, including observational studies, cohorts, case-control, cross-sectional, ecological studies and report cases. The systematic review will include studies that report descriptions of leptospirosis cases with coinfection or co-occurrence. The search will be accomplished by articles from 1950 to May 2022. The data will be extracted in a standard extraction form using an Excel format.

ETHICS AND DISSEMINATION

Results will be published in a peer-reviewed journal. Also, findings will be disseminated through scientific meetings. Ethical approval will not be required as this is a systematic review and primary data will be not collected or included.

PROSPERO REGISTRATION NUMBER

CRD42021234754.

A novel biological sources consistency evaluation method reveals high level of biodiversity within wild natural medicine: A case study of Amynthas earthworms as “Guang Dilong”

For wild natural medicine, unanticipated biodiversity as species or varieties with similar morphological characteristics and sympatric distribution may co-exist in a single batch of medical materials, which affects the efficacy and safety of clinical medication. DNA barcoding as an effective species identification tool is limited by its low sample throughput nature. In this study, combining DNA mini-barcode, DNA metabarcoding and species delimitation method, a novel biological sources consistency evaluation strategy was proposed, and high level of interspecific and intraspecific variations were observed and validated among 5376 Amynthas samples from 19 sampling points regarded as "Guang Dilong" and 25 batches of proprietary Chinese medicines. Besides Amynthas aspergillum as the authentic source, 8 other Molecular Operational Taxonomic Units (MOTUs) were elucidated. Significantly, even the subgroups within A. aspergillum revealed here differ significantly on chemical compositions and biological activity. Fortunately, this biodiversity could be controlled when the collection was limited to designated areas, as proved by 2796 "decoction pieces" samples. This batch biological identification method should be introduced as a novel concept regarding natural medicine quality control, and to offer guidelines for in-situ conservation and breeding bases construction of wild natural medicine.

Internalization of Leptospira interrogans via diverse endocytosis mechanisms in human macrophages and vascular endothelial cells

Leptospirosis, one of the leading global causes of morbidity and mortality, is an emerging public health problem, particularly in large urban centers of developing countries. Leptospirosis results from infection with an organism belonging to the Leptospira genus L. interrogans. The extensive invasive ability has previously been documented, however a mechanism that describes how the organism is internalized by human macrophages and transmigrates through human blood vessel remains poorly understood. In the present study, we utilized a human macrophage and vascular endothelial cell line to study the diverse invasive mechanisms by which L. interrogans infections occur. We found that THP-1 and HUVEC had a diverse expression of cell receptors and L. interrogans entered THP-1 and HUVEC by different pathways. In the macrophage model cell line, ITGB1/FAK-signaling mediated microfilament dependent endocytosis with lysosome fusion, whereas ITGB1/CAV-1/PI3K-signaling mediated microfilament dependent endocytosis and transcytosis without lysosome fusion in the endothelial cell model. Shedding of pathogenic leptospires from HUVEC displayed higher viability than those from THP-1. The monolayer of HUVEC maintained integrity during the infection, while 3D imaging showed that leptospires were transmigrated both intra- and intercellularly. These results indicate that endocytosis of leptospires in human macrophages and human vascular endothelial cells are quite different, macrophages are responsible for eliminating leptospires in the human body during the infection while vascular endothelial cells facilitate dissemination of leptospires from blood vessels into target organs where they cause injury.

Leptospirosis is a zoonotic bacterial disease which causes 1.03 million cases and 58,900 deaths each year. Human infections occur when the primary reservoir hosts, such as rodents, contaminate food and water with leptospires. Unlike other bacterial pathogens, leptospires invade the human body through mucosal barriers and enter the bloodstream, which can result in septicemia. Left untreated, leptospirosis can spread into multiple organs and tissues such as lungs, liver and kidneys. Pathological features of this disease include high fever, myalgia, lymphadenectasis, hemorrhaging and jaundice. Human macrophages and vascular endothelial cells play important roles in eliminating and preventing the transmission of this pathogen. We speculated that leptospires could be neutralized in macrophages and subsequently transported by vascular endothelial cells throughout the human body. In this research, the diverse mechanisms of human macrophages and vascular endothelial cells infected by leptospires were explored. Our findings can be used to improve the treatment, prevention, and supervision regarding leptospire transmission and infection.

The COVID-19 Mirage: A Young Biologist With an Atypical Presentation of a Zoonotic Disease During the COVID-19 Pandemic

COVID-19 has become one of the main causes of febrile illness among emergency department patients and is always a differential diagnosis to keep in mind. Nonetheless, some patients with a history of exposure, persistent fever, and suspicion of COVID-19 end up having entirely different etiologies. Here, we present the case of a 29-year-old male biologist with an uncommon presentation of a zoonotic disease, characterized by unspecific signs and symptoms, which led to a delayed diagnosis, causing significant emotional distress in the patient. We also coin the term “COVID-19 Mirage," to serve as a constant reminder for clinicians of the effect that COVID-19 has caused on the differential diagnosis of fever of unknown etiology.

Going Micro in Leptospirosis Kidney Disease

Leptospirosis is a zoonotic and waterborne disease worldwide. It is a neglected infectious disease caused by Leptospira spp., as well as a reemerging disease and global public health problem with respect to morbidity and mortality both in humans and animals. Leptospirosis emerges as a leading cause of acute febrile illness along with hepatorenal injury in many countries, including Thailand. While most affected persons are symptomatic in acute disease, which is always difficult to differentiate from other tropical diseases, there is growing evidence of subtle manifestations that cause unrecognized chronic symptoms. The kidney is one of the common organs affected by Leptospires. Although acute kidney injury in the spectrum of interstitial nephritis is a well-described characteristic in severe leptospirosis, chronic kidney disease from leptospirosis is widely discussed. Early recognition of severe leptospirosis leads to reduce morbidity and mortality. Thus, in this review, we highlight the spectrum of characteristics involved in leptospirosis kidney disease and the use of serologic and molecular methods, as well as the treatments of severe leptospirosis.

Ocular leptospirosis: a review of current state of art of a neglected disease

Introduction: Leptospirosis is a neglected and re-emerging zoonotic disease that may cause ocular involvement, uveitis being the main complication of the systemic disease. Aim: The purpose of this review was to raise awareness and update on uveitis caused by leptospirosis, which is a challenging pathology because it can mimic other types of uveitis. Materials and methods: An article review, was conducted by searching PubMed (MEDLINE), Scielo, Cochrane Library databases using the following MeSH and DeCS terms: "leptospirosis", "uveitis", "ocular", "eye" and "human". The inclusion criteria were articles between 2000 and 2021 in English, Spanish, French or Portuguese. Results and Discussion: A total of 49 articles were obtained with the mentioned inclusion criteria, and additionally 5 articles before the year 2000, which were considered due to their relevance and scarcity of articles on the pathology. Afterwards, a description of the disease was made. Conclusion: This literature review was steered to raise awareness and to apprise physicians and ophthalmologists about a pathology that is becoming increasingly relevant, but underdiagnosed, even in developed countries. Abbreviations: REU = recurrent equine uveitis, MAT = microagglutination.

Oral immunization of rat with chromosomal expression LipL32 in attenuated Salmonella vaccine induces immune respond against pathogenic Leptospira

Purpose

Leptospirosis caused by Leptospira spp. remains a global health problem. Available commercial leptospiral vaccines have shown an ineffective prevention for leptospiral infection. The aim of this study was to develop leptospirosis vaccine using recombinant attenuated Salmonella vaccine (RASV) as a platform. We expected that this vaccine has ability to continuous and strongly stimulate immune systems including protective mucosal, humoral, and cell mediated immunity in rat model.

Materials and Methods

In this study, we engineered RASV, NRSL32 strain containing chromosomal fusion between nucleotides encoding secretion signal of SPI-2 effector protein, SspH2 and gene encoding major pathogenic leptospiral outer membrane lipoprotein, LipL32. Subsequently, our modified RASV was oral vaccination to rat and blood samples were taken for assessment of immune responses.

Results

Our Salmonella NRSL32 strain showed expression and secretion of SspH2_1-215-LipL32 recombinant protein via SPI-2 T3SS. After oral administration of NRSL32 strain to rats, significant titers of total immunoglobulin G (IgG) and immunoglobulin A against rLipL32 were observed in long period up to 77 days after vaccination. The stimulated antibody showed ability to specific bind with LipL32 protein on surface of pathogenic Leptospira spp. Additionally, the balance level of IgG2a/IgG1 ratio and level of interferon-γ and interleukin-4 secretion were detected.

Conclusion

The results showed that our RASV platform with chromosomal expression elicited effective immune responses to leptospiral antigen. Moreover, this platform was capable for simultaneous stimulation of Th1 and Th2-biased responses. Further investigation is necessary study of protective efficacy against leptospiral infection in animal models.

Leptospirosis and Coinfection: Should We Be Concerned?

Pathogenic Leptospira is the causative agent of leptospirosis, an emerging zoonotic disease affecting animals and humans worldwide. The risk of host infection following interaction with environmental sources depends on the ability of Leptospira to persist, survive, and infect the new host to continue the transmission chain. Leptospira may coexist with other pathogens, thus providing a suitable condition for the development of other pathogens, resulting in multi-pathogen infection in humans. Therefore, it is important to better understand the dynamics of transmission by these pathogens. We conducted Boolean searches of several databases, including Google Scholar, PubMed, SciELO, and ScienceDirect, to identify relevant published data on Leptospira and coinfection with other pathogenic bacteria. We review the role of the host-microbiota in determining the synanthropic interaction of Leptospira sp. with other bacteria, thus creating a suitable condition for the leptospira to survive and persist successfully. We also discuss the biotic and abiotic factors that amplify the viability of Leptospira in the environment. The coinfection of leptospira with pathogenic bacteria has rarely been reported, potentially contributing to a lack of awareness. Therefore, the occurrence of leptospirosis coinfection may complicate diagnosis, long-lasting examination, and mistreatment that could lead to mortality. Identifying the presence of leptospirosis with other bacteria through metagenomic analysis could reveal possible coinfection. In conclusion, the occurrence of leptospirosis with other diseases should be of concern and may depend on the success of the transmission and severity of individual infections. Medical practitioners may misdiagnose the presence of multiple infections and should be made aware of and receive adequate training on appropriate treatment for leptospirosis patients. Physicians could undertake a more targeted approach for leptospirosis diagnosis by considering other symptoms caused by the coinfected bacteria; thus, more specific treatment could be given.

Pathology and One Health implications of fatal Leptospira interrogans infection in an urbanized, free-ranging, black-tufted marmoset (Callithrix penicillata) in Brazil

Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary haemorrhage, interstitial nephritis, and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species (L. interrogans species) were important for better understanding the pathogenesis of the disease. One Health-related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.

Clinical Manifestations in a Fatal Case of Probable Rickettsia and Leptospira Coinfection in Yucatan, Mexico

Clinical or serological coinfections of Rickettsia and Leptospira are uncommon but should be included in differential diagnosis when poor sanitation and cohabitation with infected animals may converge. Rickettsial and leptospiral infections have been continuously increasing throughout the past decade in Yucatan, Mexico. Leptospirosis is a zoonotic disease caused by aerobic spirochetes, while rickettsiosis is an arthropod-borne disease. In 2020, 16% of all rickettsiosis cases and 10% of leptospirosis in the country originated in Yucatan. The objective of the present case report was to document an unusual case of probable coinfection with Rickettsia and Leptospira with emphasis on clinical manifestations and the epidemiological context that may orient future multidisciplinary measures. Here, we presented the case of a 12-year-old female whose mother had recently recovered from a rickettsial infection. The patient presented with fever and developed unspecific signs and symptoms of infection; however, her condition quickly deteriorated with gastrointestinal, hepatic, renal, and neurological dysfunction. After discounting rabies and identifying infection with Rickettsia and Leptospira, antibiotic treatment was indicated, but it was too late to prevent death. Simultaneous infections of Rickettsia and Leptospira may be considered in endemic regions when environmental, epidemiological, and clinical conditions converge.

M16-Type Metallopeptidases Are Involved in Virulence for Invasiveness and Diffusion of Leptospira interrogans and Transmission of Leptospirosis

BACKGROUND

Leptospirosis is a global zoonotic infectious disease caused by Leptospira interrogans. The pathogen rapidly invades into hosts and diffuses from bloodstream into internal organs and excretes from urine to cause transmission of leptospirosis. However, the mechanism of leptospiral invasiveness remains poorly understood.

METHODS

Proteolytic activity of M16-type metallopeptidases (Lep-MP1/2/3) of L. interrogans was determined by spectrophotometry. Expression and secretion of Lep-MP1/2/3 during infection of cells were detected by quantitative reverse-transcription polymerase chain reaction, Western blot assay, and confocal microscopy. Deletion and complementation mutants of the genes encoding Lep-MP1/2/3 were generated to determine the roles of Lep-MP1/2/3 in invasiveness using transwell assay and virulence in hamsters.

RESULTS

Leptospira interrogans but not saprophytic Leptospira biflexa strains were detectable for Lep-MP-1/2/3-encoding genes. rLep-MP1/2/3 hydrolyzed extracellular matrix proteins, but rLep-MP1/3 displayed stronger proteolysis than rLep-MP2, with 123.179/340.136 μmol/L Km and 0.154/0.159 s-1 Kcat values. Expression, secretion and translocation of Lep-MP1/2/3 during infection of cells were increased. ΔMP1/3 but not ΔMP2 mutant presented attenuated transmigration through cell monolayers, decreased leptospiral loading in the blood, lungs, liver, kidneys, and urine, and 10/13-fold decreased 50% lethal dose and milder histopathologic injury in hamsters.

CONCLUSIONS

Lep-MP1 and 3 are involved in virulence of L. interrogans in invasion into hosts and diffusion in vivo, and transmission of leptospirosis.

Don't sugar coat the COVID (only the vasculature)

This issue of the Biomedical Journal acquaints us with the compelling hypothesis that the vascular glycocalyx lies at the intersection of severe COVID-19 risk factors and damages, and the ways used by artificial intelligence to predict interactions between SARS-CoV-2 and human proteins. Furthermore, we explore the antiviral potential of valinomycin and the long list of COVID-19-related clinical trials, and learn how (not) to fix a broken femoral head. Last but not least, we get to enjoy the tale of the cellular oxygen-sensing system as well as the role of the host complement system during Leptospira infection, and learn that SARS-CoV-2 can sometimes come with a pathogenic plus one.

Tumour travel tours - Why circulating cancer cells value company

Welcome to the New Year and a new issue of the Biomedical Journal, where we learn that travelling with company boosts the metastatic potential of circulating tumour cells, as well as that a worm could be an excellent model to study antidiabetic drugs. In addition, we discover another pair of molecular scissors for genetic engineering, how exactly Leptospira wreaks havoc on its run through the host organism, and that hyperparathyroidism brings its own risks, but does not worsen the outcome of papillary thyroid carcinoma. Furthermore, the importance of taking into account differing beauty ideals for aesthetic surgery surveys is discussed, alongside the question how bad isolated local recurrence is in the case of HR + breast cancer. Finally, we find out that virtual colonoscopy deserves more credit, that the first medical experiment in space was all about the H-reflex, and that it is possible to survive advanced necrotising fasciitis of the face and neck.