Characterization of hemolysis and hemoxidation activities by Treponema denticola

Chu, Lianrui; Kennell, W; Holt, Stanley C.

doi:10.1006/mpat.1994.1019

Cited by 23 publications

(38 citation statements)

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“…A genome-wide transcriptomics approach was used to determine the effects of growth as part of a The expression of several genes encoding known virulence factors, including cystalysin and the dentilisin complex, was found to be upregulated in the biofilm relative to planktonic cells, raising the possibility that T. denticola is more virulent when growing as a biofilm. Cystalysin is a pyridoxal 59-phosphate-dependent C b -S c lyase that catalyses the conversion of L-cysteine to pyruvate, ammonia and H 2 S, and was first described as a 46 kDa haemolysin that was able to agglutinate and lyse erythrocytes (Chu et al, 1994;Krupka et al, 2000). This lysis of red blood cells allows T. denticola to access iron-containing molecules such as haem and haemoglobin.…”

Section: Discussionmentioning

confidence: 99%

Treponema denticola biofilm-induced expression of a bacteriophage, toxin–antitoxin systems and transposases

et al. 2010

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Treponema denticola is an oral spirochaete that has been strongly associated with chronic periodontitis. The bacterium exists as part of a dense biofilm (subgingival dental plaque) accreted to the tooth. To determine T. denticola gene products important for persistence as a biofilm we developed a continuous-culture biofilm model and conducted a genome-wide transcriptomic analysis of biofilm and planktonic cells. A total of 126 genes were differentially expressed with a fold change of 1.5 or greater. This analysis identified the upregulation of putative prophage genes in the T. denticola 35405 genome. Intact bacteriophage particles were isolated from T. denticola and circular phage DNA was detected by PCR analysis. This represents the first, to our knowledge, functional bacteriophage isolated from T. denticola, which we have designated Qtd1. In biofilm cells there was also an upregulation of genes encoding several virulence factors, toxinantitoxin systems and a family of putative transposases. Together, these data indicate that there is a higher potential for genetic mobility in T. denticola when growing as a biofilm and that these systems are important for the biofilm persistence and therefore virulence of this bacterium.

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Section: Discussionmentioning

confidence: 99%

Treponema denticola biofilm-induced expression of a bacteriophage, toxin–antitoxin systems and transposases

et al. 2010

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“…To measure hemoxidation, defined as the oxidation of hemoglobin to methemoglobin, we added 0.4 ml of the same test preparations used for hemolytic activity to 1.6 ml of distilled water to lyse RBCs. Released methemoglobin was determined by measuring supernatant absorbance at 630 nm (6). Hydrogen peroxide (30%, wt/wt) and catalase were purchased from Sigma Chemical Co., St. Louis, Mo.…”

Section: Methodsmentioning

confidence: 99%

Hemolytic and Hemoxidative Activities inMycoplasma penetrans

Kannan

Baseman

2000

Infect Immun

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Mycoplasma penetrans is a newly isolated Mollicute from the urine of patients infected with human immunodeficiency virus that demonstrates the capacity to adhere to and invade human cells. A previous report, based on assays with mouse red blood cells (RBCs), indicated that M. penetrans lacked hemolytic activity. In our studies, we incubated different isolates of M. penetrans with various RBC species and observed hemolytic zones surrounding individual mycoplasma colonies. All M. penetrans strains displayed hemolysis after 2 to 3 days of incubation. Hemolytic activity diffused from single colonies, eventually causing complete lysis. Hemolysis was most pronounced with sheep RBCs, followed by horse, chicken, and human cells. Furthermore, hemolytic activity was demonstrable in both intact mycoplasma cell preparations and spent culture supernatant. However, unlike intact mycoplasmas, the hemolytic activity in the supernatant was dependent on the reducing agent, cysteine. In addition to hemolysis, a brown precipitate was closely associated with mycoplasma colonies, suggesting oxidation of hemoglobin. Absorption spectra indicated that hemoglobin was oxidized to methemoglobin, and the addition of catalase demonstrated H 2 O 2 -mediated hemoxidation. Other experiments suggested that hemoxidation enhanced total hemolysis, providing the first evidence of both hemolytic and hemoxidative activities in M. penetrans.Mycoplasmas, members of the cell wall-less Mollicutes and considered among the smallest self-replicating cells, have been detected in a wide range of hosts, including humans, other vertebrates, invertebrates, and plants (2,19,20,27). In previous studies of pathogenic mycoplasmas, hemadsorption and cytadherence activities were closely associated with virulence potential (2, 30). For example, hydrogen peroxide-mediated and membrane-associated hemolytic activities have been found in numerous Mycoplasma species (15,24,30), and analysis of mycoplasma genomic sequences revealed the presence of a hemolysin-like gene (VXpSPT7_orf424) in Mycoplasma pneumoniae (13) and a homologous gene (MG146) in Mycoplasma genitalium (10). It is well known that bacterial hemolysins lyse erythrocytes (RBCs) and a variety of other cell types, including mast cells, neutrophils, and polymorphonuclear cells, which enables hemolytic microorganisms to directly damage host tissues as well as induce inflammatory responses (5). However, a new species, Mycoplasma penetrans, which was isolated from the urine of patients infected with human immunodeficiency virus (22), was shown to actively invade mammalian cells in culture (21) and cause cytopathology in experimentally infected chicken embryos (12) but lack hemolytic activity (24). In this report we describe hemolytic activity in all isolates of M. penetrans and show that H 2 O 2 -mediated hemoxidative activity contributes to total mycoplasma-mediated hemolysis. MATERIALS AND METHODSBacterial strains and medium. M. penetrans cells (GTU-54 and isolates from France and Texas) (11) were obtained from J. T...

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“…denticola exhibits a broad repertoire of adhesive and cytopathic properties. Bacteria adhere to extracellular matrix components such as fibronectin, laminin, and collagen (15,20,31), and erythrocytes exposed to T. denticola become hemagglutinated, hemoxidized, and hemolyzed (11,12). The adherence of T. denticola to epithelial cells or gingival fibroblasts results in the occurrence of profound morphological changes, cell detachment from surfaces, cytoskeletal rearrangement, and the inhibition of propagation (1,3,7,16,40,59).…”

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The Chymotrypsin-Like Protease Complex ofTreponema denticolaATCC 35405 Mediates Fibrinogen Adherence and Degradation

et al. 2007

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Treponema denticola is an anaerobic spirochete strongly associated with human periodontal disease. T. denticola bacteria interact with a range of host tissue proteins, including fibronectin, laminin, and fibrinogen. The latter localizes in the extracellular matrix where tissue damage has occurred, and interactions with fibrinogen may play a key role in T. denticola colonization of the damaged sites. T. denticola ATCC 35405 showed saturable binding of fluid-phase fibrinogen to the cell surface and saturable adherence to immobilized fibrinogen. Levels of fibrinogen binding were enhanced in the presence of the serine protease inhibitor phenylmethylsulfonyl fluoride. The A␣ and B␤ chains of fibrinogen, but not the ␥ chains, were specifically recognized by T. denticola. Following fibrinogen affinity chromatography analysis of cell surface extracts, a major fibrinogen-binding component (polypeptide molecular mass, ϳ100 kDa), which also degraded fibrinogen, was purified. Upon heating at 100°C, the polypeptide was dissociated into three components (apparent molecular masses, 80, 48, and 45 kDa) that did not individually bind or degrade fibrinogen. The native 100-kDa polypeptide complex was identified as chymotrypsin-like protease (CTLP), or dentilisin. In an isogenic CTLP ؊ mutant strain, CKE, chymotrypsin-like activity was reduced >90% compared to that in the wild type and fibrinogen binding and hydrolysis were ablated. Isogenic mutant strain MHE, deficient in the production of Msp (major surface protein), showed levels of CTLP reduced 40% relative to those in the wild type and exhibited correspondingly reduced levels of fibrinogen binding and proteolysis. Thrombin clotting times in the presence of wild-type T. denticola cells, but not strain CKE (CTLP ؊ ) cells, were extended. These results suggest that interactions of T. denticola with fibrinogen, which may promote colonization and modulate hemostasis, are mediated principally by CTLP.

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Characterization of hemolysis and hemoxidation activities by Treponema denticola

Cited by 23 publications

References 0 publications

Treponema denticola biofilm-induced expression of a bacteriophage, toxin–antitoxin systems and transposases

Treponema denticola biofilm-induced expression of a bacteriophage, toxin–antitoxin systems and transposases

Hemolytic and Hemoxidative Activities inMycoplasma penetrans

The Chymotrypsin-Like Protease Complex ofTreponema denticolaATCC 35405 Mediates Fibrinogen Adherence and Degradation

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