1
|
Chaurasia R, Marroquin AS, Vinetz JM, Matthias MA. Pathogenic Leptospira Evolved a Unique Gene Family Comprised of Ricin B-Like Lectin Domain-Containing Cytotoxins. Front Microbiol 2022; 13:859680. [PMID: 35422779 PMCID: PMC9002632 DOI: 10.3389/fmicb.2022.859680] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/08/2022] [Indexed: 12/29/2022] Open
Abstract
Leptospirosis is a globally important neglected zoonotic disease. Previous data suggest that a family of virulence-modifying (VM) proteins (PF07598) is a distinctive feature of group I pathogenic Leptospira that evolved as important virulence determinants. Here, we show that one such VM protein, LA3490 (also known as Q8F0K3), is expressed by Leptospira interrogans serovar Lai, as a secreted genotoxin that is potently cytotoxic to human cells. Structural homology searches using Phyre2 suggested that VM proteins are novel R-type lectins containing tandem N-terminal ricin B-chain-like β-trefoil domains. Recombinant LA3490 (rLA3490) and an N-terminal fragment, t3490, containing only the predicted ricin B domain, bound to the terminal galactose and N-acetyl-galactosamine residues, asialofetuin, and directly competed for asialofetuin-binding sites with recombinant ricin B chain. t3490 alone was sufficient for binding, both to immobilized asialofetuin and to the HeLa cell surface but was neither internalized nor cytotoxic. Treatment of HeLa cells with rLA3490 led to cytoskeleton disassembly, caspase-3 activation, and nuclear fragmentation, and was rapidly cytolethal. rLA3490 had DNase activity on mammalian and bacterial plasmid DNA. The combination of cell surface binding, internalization, nuclear translocation, and DNase functions indicate that LA3490 and other VM proteins evolved as novel forms of the bacterial AB domain-containing toxin paradigm.
Collapse
Affiliation(s)
- Reetika Chaurasia
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Alan S Marroquin
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Joseph M Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Michael A Matthias
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| |
Collapse
|
2
|
Extracellular Proteome Analysis Shows the Abundance of Histidine Kinase Sensor Protein, DNA Helicase, Putative Lipoprotein Containing Peptidase M75 Domain and Peptidase C39 Domain Protein in Leptospira interrogans Grown in EMJH Medium. Pathogens 2021; 10:pathogens10070852. [PMID: 34358002 PMCID: PMC8308593 DOI: 10.3390/pathogens10070852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 01/01/2023] Open
Abstract
Leptospirosis is a re-emerging form of zoonosis that is caused by the spirochete pathogen Leptospira. Extracellular proteins play critical roles in the pathogenicity and survival of this pathogen in the host and environment. Extraction and analysis of extracellular proteins is a difficult task due to the abundance of enrichments like serum and bovine serum albumin in the culture medium, as is distinguishing them from the cellular proteins that may reach the analyte during extraction. In this study, extracellular proteins were separated as secretory proteins from the culture supernatant and surface proteins were separated during the washing of the cell pellet. The proteins identified were sorted based on the proportion of the cellular fractions and the extracellular fractions. The results showed the identification of 56 extracellular proteins, out of which 19 were exclusively extracellular. For those proteins, the difference in quantity with respect to their presence within the cell was found to be up to 1770-fold. Further, bioinformatics analysis elucidated characteristics and functions of the identified proteins. Orthologs of extracellular proteins in various Leptospira species were found to be closely related among different pathogenic forms. In addition to the identification of extracellular proteins, this study put forward a method for the extraction and identification of extracellular proteins.
Collapse
|
3
|
Chaurasia R, Sritharan M. Cytotoxicity of the 42 kDa SMase C sphingomyelinase secreted by Leptospira interrogans serovar Pomona on Vero cells. MICROBIOLOGY-SGM 2020; 166:1065-1073. [PMID: 32985970 DOI: 10.1099/mic.0.000976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Sphingomyelinases produced by the pathogenic members of the genus Leptospira are implicated in the haemorrhagic manifestations seen in the severe form of leptospirosis. With multiple sphingomyelinase genes present in the genome of pathogenic Leptospira, much remains to be understood about these molecules. They include factors regulating their expression, post-translational modifications, and release of the biologically active forms of these molecules. In this study, serovar Pomona was chosen as it is reported to express high levels of sphingomyelinase that explained the haemolytic activity seen in experimental animals infected with this pathogen. Here, we demonstrate the cytotoxicity of a 42 kDa sphingomyelinase secreted by Leptospira interrogans serovar Pomona strain Pomona upon infecting Vero cells. This sphingomyelinase detected using specific anti-sphingomyelinase antibodies, exhibited haemolytic and sphingomyelinase activities that caused host-cell damage evident from the confocal images and scanning electron micrographs. The implications of these findings and the detection of a 42 kDa sphingomyelinase in the urine of human patients with leptospirosis in our earlier study is discussed with an emphasis on the potential of these sphingomyelinases as candidate markers for the early diagnosis of leptospirosis.
Collapse
Affiliation(s)
- Reetika Chaurasia
- Present address: Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT, USA
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Manjula Sritharan
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| |
Collapse
|
4
|
Sobroza ÂO, Pillat MM, Dorneles GL, Machado MS, Silva CB, Petry L, Schafer A, França RT, de Andrade CM, Antoniazzi AQ, Tonin AA, Lopes ST. Anti-erythrocyte IgG in hamsters with acute experimental infection by Leptospira interrogans serovar Canicola. Microb Pathog 2017. [DOI: 10.1016/j.micpath.2017.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Knöpfler S, Mayer-Scholl A, Luge E, Klopfleisch R, Gruber AD, Nöckler K, Kohn B. Evaluation of clinical, laboratory, imaging findings and outcome in 99 dogs with leptospirosis. J Small Anim Pract 2017; 58:582-588. [DOI: 10.1111/jsap.12718] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/01/2017] [Accepted: 05/29/2017] [Indexed: 11/28/2022]
Affiliation(s)
- S. Knöpfler
- Clinic for Small Animals; Freie Universität Berlin, Oertzenweg 19b; D-14163 Berlin
| | - A. Mayer-Scholl
- Federal Institute for Risk AssessmentDiedersdorfer Weg 1, D-12277 Berlin; Germany
| | - E. Luge
- Federal Institute for Risk AssessmentDiedersdorfer Weg 1, D-12277 Berlin; Germany
| | - R. Klopfleisch
- Institute for Veterinary Pathology; Freie Universität Berlin, Robert-von-Ostertag-Str. 15, D-14163 Berlin; Germany
| | - A. D. Gruber
- Institute for Veterinary Pathology; Freie Universität Berlin, Robert-von-Ostertag-Str. 15, D-14163 Berlin; Germany
| | - K. Nöckler
- Federal Institute for Risk AssessmentDiedersdorfer Weg 1, D-12277 Berlin; Germany
| | - B. Kohn
- Clinic for Small Animals; Freie Universität Berlin, Oertzenweg 19b; D-14163 Berlin
| |
Collapse
|
6
|
Narayanavari SA, Lourdault K, Sritharan M, Haake DA, Matsunaga J. Role of sph2 Gene Regulation in Hemolytic and Sphingomyelinase Activities Produced by Leptospira interrogans. PLoS Negl Trop Dis 2015; 9:e0003952. [PMID: 26274394 PMCID: PMC4537108 DOI: 10.1371/journal.pntd.0003952] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 07/06/2015] [Indexed: 12/19/2022] Open
Abstract
Pathogenic members of the genus Leptospira are the causative agents of leptospirosis, a neglected disease of public and veterinary health concern. Leptospirosis is a systemic disease that in its severest forms leads to renal insufficiency, hepatic dysfunction, and pulmonary failure. Many strains of Leptospira produce hemolytic and sphingomyelinase activities, and a number of candidate leptospiral hemolysins have been identified based on sequence similarity to well-characterized bacterial hemolysins. Five of the putative hemolysins are sphingomyelinase paralogs. Although recombinant forms of the sphingomyelinase Sph2 and other hemolysins lyse erythrocytes, none have been demonstrated to contribute to the hemolytic activity secreted by leptospiral cells. In this study, we examined the regulation of sph2 and its relationship to hemolytic and sphingomyelinase activities produced by several L. interrogans strains cultivated under the osmotic conditions found in the mammalian host. The sph2 gene was poorly expressed when the Fiocruz L1-130 (serovar Copenhageni), 56601 (sv. Lai), and L495 (sv. Manilae) strains were cultivated in the standard culture medium EMJH. Raising EMJH osmolarity to physiological levels with sodium chloride enhanced Sph2 production in all three strains. In addition, the Pomona subtype kennewicki strain LC82-25 produced substantially greater amounts of Sph2 during standard EMJH growth than the other strains, and sph2 expression increased further by addition of salt. When 10% rat serum was present in EMJH along with the sodium chloride supplement, Sph2 production increased further in all strains. Osmotic regulation and differences in basal Sph2 production in the Manilae L495 and Pomona strains correlated with the levels of secreted hemolysin and sphingomyelinase activities. Finally, a transposon insertion in sph2 dramatically reduced hemolytic and sphingomyelinase activities during incubation of L. interrogans at physiologic osmolarity. Complementation of the mutation with the sph2 gene partially restored production of hemolytic and sphingomyelinase activities. These results indicate that the sph2 gene product contributes to the hemolytic and sphingomyelinase activities secreted by L. interrogans and most likely dominates those functions under the culture condition tested. The spirochete Leptospira causes leptospirosis, a potentially deadly disease of humans and animals. Candidate factors that promote infection include hemolysins encoded by several leptospiral genes. Hemolysins rupture red blood cells in vitro. Some hemolysins are sphingomyelinases, which target sphingomyelin in the host cell membrane. Hemolysins have the potential to disrupt organ function during infection. It is not known which hemolysins and sphingomyelinases are responsible for the hemolytic and sphingomyelinase activities secreted by L. interrogans. We found that the production of hemolytic activity is regulated and is tied to expression of sph2, which encodes a hemolysin with sphingomyelinase, cytotoxic, and fibronectin-binding activities. Hemolytic and sphingomyelinase activities and sph2 expression were higher when the osmolarity of the culture medium was raised to the level found in the mammalian host. Similarly, sph2 expression was substantially higher in an L. interrogans strain that secreted large amounts of hemolytic and sphingomyelinase activities than in a strain that generated negligible amounts. Most importantly, disruption of the sph2 gene eliminated hemolysin production and yielded substantially less sphingomyelinase than the wild-type strain. Our findings indicate that sph2 is a major contributor to the hemolytic and sphingomyelinase activities secreted by L. interrogans and that the hemolytic and sphingomyelinase activities measured in standard L. interrogans cultures may underestimate the levels produced during infection.
Collapse
Affiliation(s)
| | - Kristel Lourdault
- Research Service, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America; Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Manjula Sritharan
- Department of Animal Biology, University of Hyderabad, Hyderabad, India
| | - David A Haake
- Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California, United States of America; Department of Urology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California, United States of America; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America; Division of Infectious Diseases, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
| | - James Matsunaga
- Research Service, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America; Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California, United States of America
| |
Collapse
|
7
|
Iron metabolism in hamsters experimentally infected with Leptospira interrogans serovar Pomona: influence on disease pathogenesis. Comp Immunol Microbiol Infect Dis 2014; 37:299-304. [PMID: 25449998 DOI: 10.1016/j.cimid.2014.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/10/2014] [Accepted: 09/26/2014] [Indexed: 11/23/2022]
Abstract
The aim of this study was to analyze the classic iron markers associated to the storage process in hamsters experimentally infected by Leptospira interrogans serovar Pomona. Four groups with six hamsters each were used; two were negative controls (C7 and C14) and two were composed by infected animals (T7 and T14). Blood samples were collected on the seventh (C7 and T7) and fourteenth days (C14 and T14) post-inoculation. Iron availability was determined in sera samples through the assessment of iron, ferritin, transferrin, and iron binding capacity, whereas the bone marrow was also evaluated for the presence of iron by Pearl's reaction. Additionally, the total antioxidant capacity (TAC) and total oxidant status (TOS) were assessed, along with hepcidin and IL-6 levels. Based on the results, it was possible to observe the onset of an anemic profile, predominantly hemolytic and regenerative. Also, The other parameters showed an increase in seric iron (P<0.01) and ferritin (P<0.01), and a positive Pearl's reaction in T7 and T14, when compared with the control groups. Transferrin levels decreased (P<0.05) in animals of T14 with saturation index. TAC was increased in both periods (P<0.01), while TOS was increased only on T14 (P<0.05). Hepcidin and IL-6 were increased on T7 and T14 (P<0.01). Therefore, it was observed that the serum profile from infected animals showed a strong hemolytic pattern, with some demonstration of ferric tissue sequestration when the infection tended to become chronic. The results show that iron metabolism is activated in hamsters infected by L. interrogans serovar Pomona.
Collapse
|
8
|
Narayanavari SA, Kishore NM, Sritharan M. Structural analysis of the Leptospiral sphingomyelinases: in silico and experimental evaluation of Sph2 as an Mg-dependent sphingomyelinase. J Mol Microbiol Biotechnol 2012; 22:24-34. [PMID: 22441407 DOI: 10.1159/000337013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Leptospiral sphingomyelinases are candidate virulence factors present only in pathogenic Leptospira spp. Leptospira interrogans serovar Lai encodes Sph1, Sph2, Sph3, Sph4 and SphH. Except for Sph4, they all possess the exo-endo-phosphatase domain that groups them under the DNase I superfamily. METHODS, RESULTS AND CONCLUSIONS Modeling of exo-endo-phosphatase domains reveals high-level structural similarity of Sph2 with the crystal structure of SmcL and BC SMase sphingomyelinases from Listeria ivanovii and Bacillus cereus, respectively. A β-hairpin loop, essential for host cell membrane interaction, is absent in leptospiral sphingomyelinases. Instead, several aromatic amino acids were oriented outward from the surface of these molecules and formed clusters of hydrophobic regions that possibly enables the anchoring of these molecules into the host cell membrane, as demonstrated in Sph2 and Sph3. Sph2 is unique and possesses the Mg(++)-binding Glu53 residue in the metal-binding site and two His residues (His151 and His286) in the catalytic site. We demonstrate experimentally the Mg(++)-dependent hemolysis of erythrocytes by rSph2 and its ability to cleave sphingomyelin to ceramide. Anti-Sph2 antibodies neutralized the hemolytic activity of Sph2. In conclusion, we provide evidence showing that Sph2 is a Mg(++)-dependent hemolysin with both sphingomyelinase and hemolytic activities.
Collapse
Affiliation(s)
- Suneel A Narayanavari
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | | | | |
Collapse
|
9
|
Narayanavari SA, Sritharan M, Haake DA, Matsunaga J. Multiple leptospiral sphingomyelinases (or are there?). MICROBIOLOGY-SGM 2012; 158:1137-1146. [PMID: 22422753 DOI: 10.1099/mic.0.057737-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Culture supernatants of leptospiral pathogens have long been known to haemolyse erythrocytes. This property is due, at least in part, to sphingomyelinase activity. Indeed, genome sequencing reveals that pathogenic Leptospira species are richly endowed with sphingomyelinase homologues: five genes have been annotated to encode sphingomyelinases in Leptospira interrogans. Such redundancy suggests that this class of genes is likely to benefit leptospiral pathogens in their interactions with the mammalian host. Surprisingly, sequence comparison with bacterial sphingomyelinases for which the crystal structures are known reveals that only one of the leptospiral homologues has the active site amino acid residues required for enzymic activity. Based on studies of other bacterial toxins, we propose that leptospiral sphingomyelinase homologues, irrespective of their catalytic activity, may possess additional molecular functions that benefit the spirochaete. Potential secretion pathways and roles in pathogenesis are discussed, including nutrient acquisition, dissemination, haemorrhage and immune evasion. Although leptospiral sphingomyelinase-like proteins are best known for their cytolytic properties, we believe that a better understanding of their biological role requires the examination of their sublytic properties as well.
Collapse
Affiliation(s)
| | - Manjula Sritharan
- Department of Animal Sciences, University of Hyderabad, Hyderabad, India
| | - David A Haake
- Department of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Department of Urology, University of California at Los Angeles, Los Angeles, CA, USA.,Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA, USA
| | - James Matsunaga
- Research Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
10
|
Recent progress on phospholipases: different sources, assay methods, industrial potential and pathogenicity. Appl Biochem Biotechnol 2011; 164:991-1022. [PMID: 21302142 DOI: 10.1007/s12010-011-9190-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
Abstract
Significant studies on phospholipases optimization, characterization, physiological role and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factor and major cause of pathophysiological effects. A general overview on phospholipase is needed for the identification of new reliable and efficient phospholipase, which would be potentially used in number of industrial and medical applications. Phospholipases catalyse the hydrolysis of one or more ester and phosphodiester bonds of glycerophospholipids. They vary in site of action on phospholipid which can be used industrially for modification/production of new phospholipids. Catalytically active phospholipase mainly use phosphatidylcholine as major substrate, but they can also show specificity with other phospholipids. Several accurate phospholipase assay methods are known, but a rapid and reliable method for high-throughput screening is still a challenge for efficient supply of superior phospholipases and their practical applications. Major application of phospholipase is in industries like oil refinery, health food manufacturing, dairy, cosmetics etc. All types of phospholipases can be involved as virulence factor. They can also be used as diagnostic markers for microbial infection. The importance of phospholipase in virulence is proven and inhibitors of the enzyme can be used as candidate for preventing the associated disease.
Collapse
|
11
|
Evangelista KV, Coburn J. Leptospira as an emerging pathogen: a review of its biology, pathogenesis and host immune responses. Future Microbiol 2011; 5:1413-25. [PMID: 20860485 DOI: 10.2217/fmb.10.102] [Citation(s) in RCA: 196] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Leptospirosis, the most widespread zoonosis in the world, is an emerging public health problem, particularly in large urban centers of developing countries. Several pathogenic species of the genus Leptospira can cause a wide range of clinical manifestations, from a mild, flu-like illness to a severe disease form characterized by multiorgan system complications leading to death. However, the mechanisms of pathogenesis of Leptospira are largely unknown. This article will address the animal models of acute and chronic leptospire infections, and the recent developments in the genetic manipulation of the bacteria, which facilitate the identification of virulence factors involved in pathogenesis and the assessment of their potential values in the control and prevention of leptospirosis.
Collapse
Affiliation(s)
- Karen V Evangelista
- Department of Microbiology & Molecular Genetics, Medical College of Wisconsin, Milwaukee, USA
| | | |
Collapse
|
12
|
Monahan AM, Callanan JJ, Nally JE. Review paper: Host-pathogen interactions in the kidney during chronic leptospirosis. Vet Pathol 2009; 46:792-9. [PMID: 19429975 DOI: 10.1354/vp.08-vp-0265-n-rev] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pathogenic species of Leptospira cause leptospirosis, a global zoonotic disease. Leptospira colonize renal tubules of chronically infected maintenance hosts, from where they are shed in urine to the environment and survive in suitable moist conditions. Transmission of disease to new hosts is facilitated by contact with contaminated urine or water sources, because Leptospira can penetrate broken skin or mucosal surfaces of new hosts. Infection of new hosts may be asymptomatic, as with chronically infected maintenance hosts, or may result in an acute disease process in which clinical signs can include fever, jaundice, renal failure, and pulmonary hemorrhage. Those factors that determine if an animal will suffer an acute or a chronic infection are not fully understood but include host animal species, infecting serovar, and infecting dose. During chronic infection, renal colonization and leptospiruria persist despite cellular and humoral responses by the host. Tubulointerstitial nephritis is the most common lesion associated with chronic infection, and this may progress to fibrosis and subsequent renal failure. This review aims to address how Leptospira cause tubulointerstitial nephritis during chronic leptospirosis and to summarize the mechanisms by which Leptospira might evade host immune responses during chronic colonization of the renal tubule.
Collapse
Affiliation(s)
- A M Monahan
- Veterinary Sciences Centre, UCD School of Agriculture Food Science and Veterinary Medicine, UCD Conway Institute of Biomolecular and Biomedical Research, College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland
| | | | | |
Collapse
|
13
|
Yang J, Zhang Y, Xu J, Geng Y, Chen X, Yang H, Wang S, Wang H, Jiang X, Guo X, Zhao G. Serum activity of platelet-activating factor acetylhydrolase is a potential clinical marker for leptospirosis pulmonary hemorrhage. PLoS One 2009; 4:e4181. [PMID: 19145243 PMCID: PMC2615213 DOI: 10.1371/journal.pone.0004181] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 11/26/2008] [Indexed: 11/19/2022] Open
Abstract
Pulmonary hemorrhage has been recognized as a major, often lethal, manifestation of severe leptospirosis albeit the pathogenesis remains unclear. The Leptospira interrogans virulent serogroup Icterohaemorrhagiae serovar Lai encodes a protein (LA2144), which exhibited the platelet-activating factor acetylhydrolase (PAF-AH) activity in vitro similar to that of human serum with respect to its substrate affinity and specificity and thus designated L-PAF-AH. On the other hand, the primary amino acid sequence of L-PAF-AH is homologous to the alpha1-subunit of the bovine brain PAF-AH isoform I. The L-PAF-AH was proven to be an intracellular protein, which was encoded unanimously and expressed similarly in either pathogenic or saprophytic leptospires. Mongolian gerbil is an appropriate experimental model to study the PAF-AH level in serum with its basal activity level comparable to that of human while elevated directly associated with the course of pulmonary hemorrhage during severe leptospirosis. Mortality occurred around the peak of pulmonary hemorrhage, along with the transition of the PAF-AH activity level in serum, from the increasing phase to the final decreasing phase. Limited clinical data indicated that the serum activity of PAF-AH was likely to be elevated in the patients infected by L. interrogans serogroup Icterohaemorrhagiae, but not in those infected by other less severe serogroups. Although L-PAF-AH might be released into the micro-environment via cell lysis, its PAF-AH activity apparently contributed little to this elevation. Therefore, the change of PAF-AH in serum not only may be influential for pulmonary hemorrhage, but also seems suitable for disease monitoring to ensure prompt clinical treatment, which is critical for reducing the mortality of severe leptospirosis.
Collapse
Affiliation(s)
- Junwei Yang
- Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yixuan Zhang
- School of Life Science and Biopharmaceutical, Shenyang Pharmaceutical University, Shenyang, China
| | - Jing Xu
- Department of Medical Microbiology and Parasitology, Department of Pathology and Department of Animal Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Institute of Health Sciences, Shanghai, China
| | - Yan Geng
- School of Life Science and Biopharmaceutical, Shenyang Pharmaceutical University, Shenyang, China
| | - Xiaoying Chen
- School of Life Science and Biopharmaceutical, Shenyang Pharmaceutical University, Shenyang, China
| | - Hongliang Yang
- Department of Medical Microbiology and Parasitology, Department of Pathology and Department of Animal Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Shengnian Wang
- National Engineering Center for Biochip at Shanghai, Shanghai, China
| | - Hengan Wang
- Department of Medical Microbiology and Parasitology, Department of Pathology and Department of Animal Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xucheng Jiang
- Department of Medical Microbiology and Parasitology, Department of Pathology and Department of Animal Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaokui Guo
- Department of Medical Microbiology and Parasitology, Department of Pathology and Department of Animal Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Guoping Zhao
- Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- National Engineering Center for Biochip at Shanghai, Shanghai, China
- Shanghai-MOST Key Laboratory for Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
- Department of Microbiology and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
- * E-mail:
| |
Collapse
|
14
|
Tomita M, Taguchi R, Ikezawa H. Sphingomyelinase ofBacillus Cereusas a Bacterial Hemolysin. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569549109077272] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
15
|
Bharti AR, Nally JE, Ricaldi JN, Matthias MA, Diaz MM, Lovett MA, Levett PN, Gilman RH, Willig MR, Gotuzzo E, Vinetz JM. Leptospirosis: a zoonotic disease of global importance. THE LANCET. INFECTIOUS DISEASES 2004; 3:757-71. [PMID: 14652202 DOI: 10.1016/s1473-3099(03)00830-2] [Citation(s) in RCA: 1397] [Impact Index Per Article: 69.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In the past decade, leptospirosis has emerged as a globally important infectious disease. It occurs in urban environments of industrialised and developing countries, as well as in rural regions worldwide. Mortality remains significant, related both to delays in diagnosis due to lack of infrastructure and adequate clinical suspicion, and to other poorly understood reasons that may include inherent pathogenicity of some leptospiral strains or genetically determined host immunopathological responses. Pulmonary haemorrhage is recognised increasingly as a major, often lethal, manifestation of leptospirosis, the pathogenesis of which remains unclear. The completion of the genome sequence of Leptospira interrogans serovar lai, and other continuing leptospiral genome sequencing projects, promise to guide future work on the disease. Mainstays of treatment are still tetracyclines and beta-lactam/cephalosporins. No vaccine is available. Prevention is largely dependent on sanitation measures that may be difficult to implement, especially in developing countries.
Collapse
Affiliation(s)
- Ajay R Bharti
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Okazaki N, Osawa R, Suzuki R, Nikkawa T, Whiley RA. Novel observation of hot-cold-hot hemolysis exhibited by group B streptococci. J Clin Microbiol 2003; 41:877-9. [PMID: 12574305 PMCID: PMC149725 DOI: 10.1128/jcm.41.2.877-879.2003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Six human isolates of group B streptococci (GBS) were cultured on blood agar anaerobically at 37 degrees C for 18 h and then at 4 degrees C for 6 h and reincubated anaerobically at 37 degrees C for 6 h. Three of the strains showed a marked enlargement of the hemolysis zone compared with that obtained after hot-only (37 degrees C for 18 h) or hot-cold (37 degrees C for 18 h and then 4 degrees C for 6 h) treatment. Subsequent broth culture experiments revealed that enhanced hemolytic activity due to hot-cold-hot treatment was observed in all 6 GBS strains when cultured in the presence of starch.
Collapse
Affiliation(s)
- Norio Okazaki
- Department of Bacteriology and Pathology, Kanagawa Prefectural Public Health Laboratory, Nakao 1-1-1, Asahi-ku, Yokohama 241-0815, Japan
| | | | | | | | | |
Collapse
|
17
|
Lee SH, Kim S, Park SC, Kim MJ. Cytotoxic activities of Leptospira interrogans hemolysin SphH as a pore-forming protein on mammalian cells. Infect Immun 2002; 70:315-22. [PMID: 11748197 PMCID: PMC127624 DOI: 10.1128/iai.70.1.315-322.2002] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2001] [Revised: 08/21/2001] [Accepted: 09/25/2001] [Indexed: 11/20/2022] Open
Abstract
Leptospirosis is a spirochetal zoonosis that causes an acute febrile systemic illness in humans. Leptospira sp. hemolysins have been shown to be virulence factors for the pathogenesis of leptospirosis. Previously, we cloned a hemolysin SphH of Leptospira interrogans serovar lai, a homologue of L. borgpetersenii sphingomyelinase (SphA), from a genomic library (S. H. Lee, K. A. Kim, Y. K. Kim, I. W. Seong, M. J. Kim, and Y. J. Lee, Gene 254:19-28, 2000). Escherichia coli lysate harboring the sphH showed high hemolytic activities on sheep erythrocytes. However, it neither showed sphingomyelinase nor phospholipase activities, in contrast to SphA which was known to have sphingomyelinase activity. Interestingly, the SphH-mediated hemolysis on erythrocytes was osmotically protected by PEG 5000, suggesting that the SphH might have caused pore formation on the erythrocyte membrane. In the present study, we have prepared the Leptospira hemolysin SphH and investigated its hemolytic and cytotoxic activities on mammalian cells. SphH was shown to be a pore-forming protein on several mammalian cells: When treated with the SphH, the sheep erythrocyte membranes formed pores, which were morphologically confirmed by transmission electron microscopy. Furthermore, the SphH-mediated cytotoxicities on mammalian cells were demonstrated by the release of LDH and by inverted microscopic examinations. Finally, the immune serum against the full-length hemolysin could effectively neutralize the SphH-mediated hemolytic and cytotoxic activities. In conclusion, these results suggest that the virulence of Leptospira SphH was due to the pore formation on mammalian cell membranes.
Collapse
Affiliation(s)
- Seoung Hoon Lee
- Division of Infectious Diseases, Department of Internal Medicine, Graduate School of Biomedical Sciences, College of Medicine, Korea University, Seoul 136-705, Republic of Korea
| | | | | | | |
Collapse
|
18
|
Abstract
Leptospirosis is a worldwide zoonotic infection with a much greater incidence in tropical regions and has now been identified as one of the emerging infectious diseases. The epidemiology of leptospirosis has been modified by changes in animal husbandry, climate, and human behavior. Resurgent interest in leptospirosis has resulted from large outbreaks that have received significant publicity. The development of simpler, rapid assays for diagnosis has been based largely on the recognition that early initiation of antibiotic therapy is important in acute disease but also on the need for assays which can be used more widely. In this review, the complex taxonomy of leptospires, previously based on serology and recently modified by a genotypic classification, is discussed, and the clinical and epidemiological value of molecular diagnosis and typing is also evaluated.
Collapse
Affiliation(s)
- P N Levett
- University of the West Indies, School of Clinical Medicine & Research, and Leptospira Laboratory, Ministry of Health, Barbados.
| |
Collapse
|
19
|
Lee SH, Kim KA, Park YG, Seong IW, Kim MJ, Lee YJ. Identification and partial characterization of a novel hemolysin from Leptospira interrogans serovar lai. Gene 2000; 254:19-28. [PMID: 10974532 DOI: 10.1016/s0378-1119(00)00293-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
It has been suggested that leptospiral hemolysins are important in the virulence and pathogenesis of leptospirosis. We have isolated an Escherichia coli clone carrying the 7.8kb DNA insert from a genomic library of Leptospira interrogans serovar lai by plaque hybridization using a sequence derived from the sphingomyelinase C gene (sphA) of L. borgpetersenii. The clone showed a clear beta-hemolytic zone on sheep blood agar and high hemolytic activities on both human and sheep erythrocytes in liquid assays. The clone carried at least two genes responsible for the hemolytic activities, encoded by two open reading frames of 1662 and 816 nucleotides, which are named sphH and hap-1 (hemolysis associated protein-1), respectively. The SphH showed 75% homology to the SphA at the amino acid level, and the Hap-1 showed no significant homology in major databases. Interestingly, however, E. coli cells harboring sphH did not show sphingomyelinase or phospholipase activities. Moreover, SphH-mediated hemolysis was osmotically protected by polyethylene glycol 5000, suggesting that the hemolysis is likely to be caused by pore formation on the membrane. The SphH was successfully expressed in E. coli as a histidine (His)-SphH fusion protein. Both sphH and hap-1 were highly conserved among the Leptospira species, except for the absence of sphH in non-pathogenic L. biflexa serovar patoc. We concluded that the SphH is a novel hemolysin of a pathogenic Leptospira species, which may be a putative pore-forming protein.
Collapse
Affiliation(s)
- S H Lee
- Department of Life Science and Biotechnology, Graduate School of Biotechnology, Korea University, 136-705, Seoul, South Korea
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
Microbial pathogens use a number of genetic strategies to invade the host and cause infection. These common themes are found throughout microbial systems. Secretion of enzymes, such as phospholipase, has been proposed as one of these themes that are used by bacteria, parasites, and pathogenic fungi. The role of extracellular phospholipase as a potential virulence factor in pathogenic fungi, including Candida albicans, Cryptococcus neoformans, and Aspergillus, has gained credence recently. In this review, data implicating phospholipase as a virulence factor in C. albicans, Candida glabrata, C. neoformans, and A. fumigatus are presented. A detailed description of the molecular and biochemical approaches used to more definitively delineate the role of phospholipase in the virulence of C. albicans is also covered. These approaches resulted in cloning of three genes encoding candidal phospholipases (caPLP1, caPLB2, and PLD). By using targeted gene disruption, C. albicans null mutants that failed to secrete phospholipase B, encoded by caPLB1, were constructed. When these isogenic strain pairs were tested in two clinically relevant murine models of candidiasis, deletion of caPLB1 was shown to lead to attenuation of candidal virulence. Importantly, immunogold electron microscopy studies showed that C. albicans secretes this enzyme during the infectious process. These data indicate that phospholipase B is essential for candidal virulence. Although the mechanism(s) through which phospholipase modulates fungal virulence is still under investigations, early data suggest that direct host cell damage and lysis are the main mechanisms contributing to fungal virulence. Since the importance of phospholipases in fungal virulence is already known, the next challenge will be to utilize these lytic enzymes as therapeutic and diagnostic targets.
Collapse
|
21
|
Ghannoum MA. Potential role of phospholipases in virulence and fungal pathogenesis. Clin Microbiol Rev 2000; 13:122-43, table of contents. [PMID: 10627494 PMCID: PMC88936 DOI: 10.1128/cmr.13.1.122] [Citation(s) in RCA: 333] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Microbial pathogens use a number of genetic strategies to invade the host and cause infection. These common themes are found throughout microbial systems. Secretion of enzymes, such as phospholipase, has been proposed as one of these themes that are used by bacteria, parasites, and pathogenic fungi. The role of extracellular phospholipase as a potential virulence factor in pathogenic fungi, including Candida albicans, Cryptococcus neoformans, and Aspergillus, has gained credence recently. In this review, data implicating phospholipase as a virulence factor in C. albicans, Candida glabrata, C. neoformans, and A. fumigatus are presented. A detailed description of the molecular and biochemical approaches used to more definitively delineate the role of phospholipase in the virulence of C. albicans is also covered. These approaches resulted in cloning of three genes encoding candidal phospholipases (caPLP1, caPLB2, and PLD). By using targeted gene disruption, C. albicans null mutants that failed to secrete phospholipase B, encoded by caPLB1, were constructed. When these isogenic strain pairs were tested in two clinically relevant murine models of candidiasis, deletion of caPLB1 was shown to lead to attenuation of candidal virulence. Importantly, immunogold electron microscopy studies showed that C. albicans secretes this enzyme during the infectious process. These data indicate that phospholipase B is essential for candidal virulence. Although the mechanism(s) through which phospholipase modulates fungal virulence is still under investigations, early data suggest that direct host cell damage and lysis are the main mechanisms contributing to fungal virulence. Since the importance of phospholipases in fungal virulence is already known, the next challenge will be to utilize these lytic enzymes as therapeutic and diagnostic targets.
Collapse
Affiliation(s)
- M A Ghannoum
- Center for Medical Mycology, Mycology Reference Laboratory, University Hospitals of Cleveland, and Department of Dermatology, Case Western Reserve University, Cleveland, Ohio 44106-5028, USA.
| |
Collapse
|
22
|
Burth P, Younes-Ibrahim M, Gonçalez FH, Costa ER, Faria MV. Purification and characterization of a Na+, K+ ATPase inhibitor found in an endotoxin of Leptospira interrogans. Infect Immun 1997; 65:1557-60. [PMID: 9119504 PMCID: PMC175170 DOI: 10.1128/iai.65.4.1557-1560.1997] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We showed previously that the glycolipoprotein fraction prepared from Leptospira interrogans inhibited the Na+,K+ ATPase enzyme purified from brain or kidney and in isolated nephron segments (M. Younes-Ibrahim, P. Burth, M. V. Castro Faria, B. Buffin-Meyer, S. Marsy, C. Barlet-Bas, L. Cheval, and A. Doucet, C. R. Acad. Sci. Paris Ser. III 318:619-625, 1995). In the present communication, we have demonstrated that unsaturated fatty acids such as oleic and palmitoleic acids, which are adsorbed to this fraction, are effective inhibitors of the enzyme.
Collapse
Affiliation(s)
- P Burth
- Departamento de Biologia Celular e Genética, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Brazil
| | | | | | | | | |
Collapse
|
23
|
Merien F, Baranton G, Perolat P. Invasion of Vero cells and induction of apoptosis in macrophages by pathogenic Leptospira interrogans are correlated with virulence. Infect Immun 1997; 65:729-38. [PMID: 9009336 PMCID: PMC176119 DOI: 10.1128/iai.65.2.729-738.1997] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Interactions of virulent Leptospira interrogans serovar icterohaemorrhagiae strain Verdun with Vero cells (African green monkey kidney fibroblasts) and a monocyte-macrophage-like cell line (J774A.1) were assayed by a double-fluorescence immunolabelling method. Infectivity profiles were investigated according to (i) the duration of contact between leptospires and eukaryotic cells and (ii) the number of in vitro passages after primary isolation from lethally infected guinea pigs. Comparative experiments were conducted with the corresponding high-passage avirulent variant and the saprophytic leptospire Leptospira biflexa Patoc I. In Vero cells, virulent leptospires were quickly internalized from 20 min postinfection, whereas avirulent and saprophytic strains remained extracellularly located. In addition, the virulent strain demonstrated an ability to actively invade the monocyte-macrophage-like J774A.1 cells during the early stages of contact and to induce programmed cell death, as shown by the detection of oligonucleosomes in a quantitative sandwich enzyme immunoassay. In both cellular systems, subsequent in vitro subcultures demonstrated a progressive decrease of the invasiveness, pointing out the necessity of using primocultures of Leptospira for virulence studies. Invasiveness of virulent leptospires was significantly inhibited with monodansylcadaverine, indicating that internalization was dependent on receptor-mediated endocytosis. Invasion of epithelial cells and induction of apoptosis in macrophages may be related to the pathogenicity of Leptospira, and both could contribute to its ability to survive in the host and to escape from the immune response.
Collapse
Affiliation(s)
- F Merien
- Laboratoire des Leptospires, Institut Pasteur, Nouméa, New Caledonia, France
| | | | | |
Collapse
|
24
|
Santoro ML, Kogika MM, Hagiwara MK, Mirandola RM, Castelar IL. Decreased erythrocyte osmotic fragility during canine leptospirosis. Rev Inst Med Trop Sao Paulo 1994; 36:1-5. [PMID: 7997768 DOI: 10.1590/s0036-46651994000100001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Erythrocyte osmotic fragility (EOF) was carried out in nineteen dogs naturally infected by Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. A decreased EOF was observed, suggesting a modification of erythrocyte components secondary to disturbances that occur during canine leptospirosis, such as renal damage and hepatic disease.
Collapse
Affiliation(s)
- M L Santoro
- Laboratory of Pathophysiology-Institute Butantan, São Paulo, Brazil
| | | | | | | | | |
Collapse
|
25
|
Abstract
A variety of pathogenic bacteria produce phospholipases C, and since the discovery in 1944 that a bacterial toxin (Clostridium perfringens alpha-toxin) possessed an enzymatic activity, there has been considerable interest in this class of proteins. Initial speculation that all phospholipases C would have lethal properties has not been substantiated. Most of the characterized enzymes fall into one of four groups of structurally related proteins: the zinc-metallophospholipases C, the sphingomyelinases, the phosphatidylinositol-hydrolyzing enzymes, and the pseudomonad phospholipases C. The zinc-metallophospholipases C have been most intensively studied, and lethal toxins within this group possess an additional domain. The toxic phospholipases C can interact with eukaryotic cell membranes and hydrolyze phosphatidylcholine and sphingomyelin, leading to cell lysis. However, measurement of the cytolytic potential or lethality of phospholipases C may not accurately indicate their roles in the pathogenesis of disease. Subcytolytic concentrations of phospholipase C can perturb host cells by activating the arachidonic acid cascade or protein kinase C. Nonlethal phospholipases C, such as the Listeria monocytogenes PLC-A, appear to enhance the release of the organism from the host cell phagosome. Since some phospholipases C play important roles in the pathogenesis of disease, they could form components of vaccines. A greater understanding of the modes of action and structure-function relationships of phospholipases C will facilitate the interpretation of studies in which these enzymes are used as membrane probes and will enhance the use of these proteins as models for eukaryotic phospholipases C.
Collapse
Affiliation(s)
- R W Titball
- Chemical and Biological Defence Establishment, Porton Down, Salisbury, United Kingdom
| |
Collapse
|
26
|
Abstract
Zones of beta-hemolysis occurred around colonies of Borrelia burgdorferi grown on Barbour-Stoenner-Kelly medium containing agarose and horse blood. Blood plates were inoculated with either the infective strain Sh-2-82 or noninfective strain B-31 in an overlay and incubated in a candle jar. Both strains of B. burgdorferi displayed beta-hemolysis after 1 to 2 weeks of incubation. The hemolytic activity diffused out from the borrelial colonies, eventually resulting in lysis of the entire blood plate. Hemolysis was most pronounced with horse blood and was less intense with bovine, sheep, and rabbit blood. Hemolysis was enhanced by hot-cold incubation, which is typical of phospholipase-like activities in other bacteria. Further characterization of the borrelial hemolysin by using a spectrophotometric assay revealed its presence in the supernatant fluids of stationary-phase cultures. Detection of the borrelial hemolytic activity was dependent on activation of the hemolysin by the reducing agent cysteine. This study provides the first evidence of hemolytic activity associated with B. burgdorferi.
Collapse
Affiliation(s)
- L R Williams
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Kentucky 40292
| | | |
Collapse
|
27
|
Segers RP, van Gestel JA, van Eys GJ, van der Zeijst BA, Gaastra W. Presence of putative sphingomyelinase genes among members of the family Leptospiraceae. Infect Immun 1992; 60:1707-10. [PMID: 1548095 PMCID: PMC257053 DOI: 10.1128/iai.60.4.1707-1710.1992] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The presence of multiple DNA elements in pathogenic members of the family Leptospiraceae, similar to the sphA sphingomyelinase gene from Leptospira borgpetersenii, was demonstrated by low-stringency hybridization experiments. These DNA elements were designated putative sphingomyelinase genes. Grouping of strains by similarity of hybridization patterns corresponds to the species subdivision of the family Leptospiraceae on the basis of genetic characteristics. Therefore, hybridization with the sphA gene can be used as a taxonomic tool. These hybridization experiments indicate the presence of two groups of genetically related pathogenic Leptospira species.
Collapse
Affiliation(s)
- R P Segers
- Department of Bacteriology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
28
|
Khisamov GZ, Morozova NK. Phospholipid catabolism enzymes of leptospires. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1992; 276:347-55. [PMID: 1576404 DOI: 10.1016/s0934-8840(11)80541-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phospholipase A2, C, D activities of pathogenic (VGNCI-3, HS-26) and saprophytic (K-1028, G-80) strains of leptospires were determined. The strains used synthesized intracellular and extracellular forms of these esterases. To a considerable degree the endophospholipase activity was associated with the membrane structures. Differences in substrate specificity, Km, Vmax pH optimum values between exophospholipases of pathogenic and saprophytic leptospires used in the experiments are demonstrated.
Collapse
Affiliation(s)
- G Z Khisamov
- Microbiology Laboratory, Medical Faculty, Patrice Lumumba Friendship University, Moscow, Russia
| | | |
Collapse
|
29
|
Rottini G, Dobrina A, Forgiarini O, Nardon E, Amirante GA, Patriarca P. Identification and partial characterization of a cytolytic toxin produced by Gardnerella vaginalis. Infect Immun 1990; 58:3751-8. [PMID: 2228246 PMCID: PMC313724 DOI: 10.1128/iai.58.11.3751-3758.1990] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Generation and release into the culture medium of a cytolytic toxin by Gardnerella vaginalis has been demonstrated. Addition of starch and of the nonionic detergent Tween 80 to the culture medium was essential to recover cytolytic activity. A protein with an apparent molecular mass of 61 to 63 kDa was purified from the culture supernatants showing lytic activity towards erythrocytes and nucleated cells, such as human endothelial cells and human neutrophils. The protein had marked selectivity for human erythrocytes, while erythrocytes from other species were not lysed or were lysed at much higher concentrations of the protein than those needed for human erythrocytes. The cytolytic activity was remarkably unstable in polar media, but was stabilized by nonionic detergents, by binding, or by insertion into the target cell membrane, suggesting its amphiphilic nature.
Collapse
Affiliation(s)
- G Rottini
- Institute of General Pathology, University of Trieste, Italy
| | | | | | | | | | | |
Collapse
|
30
|
Segers RP, van der Drift A, de Nijs A, Corcione P, van der Zeijst BA, Gaastra W. Molecular analysis of a sphingomyelinase C gene from Leptospira interrogans serovar hardjo. Infect Immun 1990; 58:2177-85. [PMID: 2163985 PMCID: PMC258794 DOI: 10.1128/iai.58.7.2177-2185.1990] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A thermolabile hemolysin from Leptospira interrogans serovar hardjo, strain Sponselee, was shown to specifically degrade sphingomyelin. Nucleotide sequence determination revealed that sphingomyelinase activity was encoded by an open reading frame of 1,668 nucleotides. Although a putative signal sequence could be identified, no evidence for protein export in either L. interrogans or Escherichia coli was obtained. The apparent molecular mass of the expression product in E. coli minicells was 41.2 kilodaltons, whereas open reading frame 1 encoded a protein of 63,268 daltons. The observed difference may be explained by processing at the carboxy-terminal part of the hemolysin in E. coli. A high degree of similarity on the DNA and protein levels with Staphylococcus aureus beta-hemolysin and sphingomyelinase C from three Bacillus cereus strains was observed. The presence of various sphingomyelinase genes within the L. interrogans species is demonstrated.
Collapse
Affiliation(s)
- R P Segers
- Department of Bacteriology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
| | | | | | | | | | | |
Collapse
|
31
|
del Real G, Segers RP, van der Zeijst BA, Gaastra W. Cloning of a hemolysin gene from Leptospira interrogans serovar hardjo. Infect Immun 1989; 57:2588-90. [PMID: 2744864 PMCID: PMC313494 DOI: 10.1128/iai.57.8.2588-2590.1989] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A DNA fragment encoding both hemolysin and sphingomyelinase C activity was cloned from the pathogenic bacterium Leptospira interrogans serovar hardjo. Initial clones were obtained by screening a genomic library in EMBL3 for hemolytic activity. Both hemolytic and sphingomyelinase C activities were coded for by a 3.9-kilobase BamHI fragment. The hemolysin was expressed from its own promoter in Escherichia coli K-12. Similar DNA sequences were also present in the serovars tarassovi and ballum.
Collapse
Affiliation(s)
- G del Real
- Department of Bacteriology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
| | | | | | | |
Collapse
|