Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.1 (DNase)
 7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

About 60 characteristics have been investigated in 7 hemolyzing and 12 nonhemolyzing strains of L. monocytogenes. From these investigations resulted inter alia that the organism grows well under strictly anaerobic conditions, esculin is split at 45 degrees C,NH3 is produced from peptone, but not from arginin, and H2S can be traced by sufficiently sensitive methods. All strains possess a lipase, muramidase, and deoxyribonuclease, the hemolytic ones only also a lecithinase. Besides, the hemolytic strains only dispose of experimental virulence and of a CAMP factor-like agent. The experimental animal of choice seems to be the conjunctivally infected guinea pig in which a generalized infection develops.
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PMID:[Some properties of carrier strains of Listeria monocytogenes (author's transl)]. 81 65

The ATB 32 Staph system correctly identified 45 of 54 Staphylococcus hyicus cultures isolated from pigs and cattle. The biochemical profiles of the remaining nine cultures were not listed in the product data base. The 40 porcine and 14 bovine cultures resulted in three and seven different biochemical profiles, respectively. In parallel experiments, almost all S. hyicus cultures showed hemolytic reactions on chocolate agar, had CAMP-like reactivities in the zone of lysis of the staphylococcal beta-lysin, and had bacteriolytic properties on Micrococcus luteus cells. In addition, the S. hyicus cultures were unpigmented, were DNase positive, expressed an S. hyicus-specific teichoic acid, and were usually coagulase positive in porcine plasma. Most of the porcine strains were protein A positive, and two porcine cultures were clumping factor positive.
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PMID:Characterization of Staphylococcus hyicus with the ATB 32 Staph system and with conventional tests. 186 41

1215 strains of bacteria isolated from cows suffering from acute or chronic clinic mastitis were tested in the antibiogram according to the Kirby-Bauer method. The germ spectrum included: 304 DNase-positive strains of Staphylococci 304 DNase-negative strains of Staphylococci 304 CAMP-negative strains of Streptococci 303 Strains of Enterobacteriaceae The antibiotics selected were Penicillin, Cloxacillin, Neomycin und Gentamicin, then the combinations Penicillin/Neomycin, Cloxacillin/Gentamicin and Nafcillin/Penicillin/Dihydrostreptomycin. Gentamicin showed excellent action against Staphylococci and Enterobacteriaceae. Further on, the present investigations show, that the combination Cloxacillin/Gentamicin is fully effective in the gram-positive spectrum (against Streptococci and Staphylococci), as in the gram-negative spectrum (against E. coli).
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PMID:[Rates of resistance of mastitis pathogens from cows in Switzerland]. 239 50

The identification of 202 isolates of aerobically growing Gram-positive rods from clinical material was attempted by using a combination of "traditional" morphological and biochemical tests (Hollis & Weaver (20)) plus patterns of cellular and metabolic fatty acids. This system served as the "gold standard" for three others, i.e. API Coryne (Rapid Coryne), MIDI TSBA and MIDI CLIN Aerobic. In addition, several growth, biochemical and susceptibility tests (growth on cystine-tellurite blood agar, DNase, hippurate and starch hydrolysis, methanethiol formation, API ZYM, CAMP reaction, susceptibility to O/129 and to six antimicrobials) were done in order to check their usefulness for the identification of this group of bacteria. Our system, with the help of chemotaxonomic tests (m-DAP and mycolic acids), was able to identify 154/202 (76%) of the isolates by species and an additional 41/202 (21%) by genus only; 7 (3%) could not be identified. The API Coryne system identified to species or genus level 140/195 isolates (72%). Corresponding figures for the MIDI TSBA and CLIN systems were 63/195 (32%) and 88/195 (45%); further details of species and genus identification are presented in the text. The main drawback of the commercial systems is the extent and probably the numerical depth of the data base. We recommend the use of our multisystem approach for the identification of Gram-positive rods until commercial systems are based on a broader and numerically more extensive data base. The additional tests did not prove species- or genus-specific.
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PMID:Identification of coryneform and other gram-positive rods with several methods. 802 40

Antimicrobial peptides are part of the innate host defense system, and inactivation of these peptides is implicated in airway infections in cystic fibrosis (CF). The sputum of patients with CF contains anionic polyelectrolytes, including F-actin and DNA not found in normal airway fluid. These anionic filaments aggregate to contribute to the altered viscoelastic properties of CF sputum. We hypothesized that the airway components stabilizing bundles of F-actin and DNA are in part cationic antimicrobial agents, and that appropriate modification of diseased airway fluid of patients with CF might dissociate these bundles and restore antimicrobial activity. We demonstrate that the human cathelicidin peptide LL37 forms bundles with F-actin and DNA, which are dissolved by gelsolin and DNase, respectively. Coincident with bundle formation, antimicrobial activity of LL37 is inhibited by F-actin and DNA. Pseudomonas bacteria were killed by low concentrations of LL37, but killing was significantly reduced in the presence of F-actin. The actin filament-fragmenting protein gelsolin restored bactericidal activity nearly completely. In a growth inhibition assay, the effects of F-actin were confirmed, and DNA was also shown to inhibit the activity of LL37. When added to CF sputum, gelsolin significantly reduced the growth of bacteria, suggesting activation of endogenous antimicrobial factors. These findings may have therapeutic implications for treatments previously thought to alter only the viscoelastic properties of airway secretions and amplify the possible advantage of gelsolin in CF treatment.
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PMID:The antimicrobial activity of the cathelicidin LL37 is inhibited by F-actin bundles and restored by gelsolin. 1260 Aug 26

The initiation of hyperinvasive disease in group A Streptococcus (GAS) serotype M1T1 occurs by mutation within the covRS two-component regulon (named covRS for control of virulence regulatory sensor kinase), which promotes resistance to neutrophil-mediated killing through the upregulation of bacteriophage-encoded Sda1 DNase. To determine whether other virulence factors contribute to this phase-switching phenomenon, we studied a panel of 10 isogenic GAS serotype M1T1 virulence gene knockout mutants. While loss of several individual virulence factors did not prevent GAS covRS switching in vivo, we found that M1 protein and hyaluronic acid capsule are indispensable for the switching phenotype, a phenomenon previously attributed uniquely to the Sda1 DNase. We demonstrate that like M1 protein and Sda1, capsule expression enhances survival of GAS serotype M1T1 within neutrophil extracellular traps. Furthermore, capsule shares with M1 protein a role in GAS resistance to human cathelicidin antimicrobial peptide LL-37. We conclude that a quorum of GAS serotype M1T1 virulence genes with cooperative roles in resistance to neutrophil extracellular killing is essential for the switch to a hyperinvasive phenotype in vivo.
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PMID:M protein and hyaluronic acid capsule are essential for in vivo selection of covRS mutations characteristic of invasive serotype M1T1 group A Streptococcus. 2082 73

The CsrRS (or CovRS) two component system controls expression of up to 15% of the genome of group A Streptococcus (GAS). While some studies have suggested that the sensor histidine kinase CsrS responds to membrane perturbations as a result of various environmental stresses, other data have implicated the human antimicrobial peptide LL-37 and extracellular Mg(2+) as specific signals. We now report that Mg(2+) and LL-37 have opposite effects on expression of multiple genes that are activated or repressed by the transcriptional regulator CsrR. Using a GAS isolate representative of the recently emerged and widely disseminated M1T1 clone implicated in severe invasive disease, we found marked up-regulation by CsrRS of multiple virulence factors including pyrogenic exotoxin A, DNase Sda1, streptolysin O, and the hyaluronic acid capsular polysaccharide, among others. Topology and surface protein labeling studies indicated that CsrS is associated with the bacterial cell membrane and has a surface-exposed extracellular domain accessible to environmental ligands. Replacement of a cluster of three acidic amino acids with uncharged residues in the extracellular domain of CsrS abrogated LL-37 signaling and conferred a hyporesponsive phenotype consistent with tonic activation of CsrS autokinase activity, an effect that could be overridden by mutation of the CsrS active site histidine. Both loss- and gain-of-function mutations of a conserved site in the receiver domain of CsrR established an essential role for lysine 102 in CsrS-to-CsrR signal transduction. These results provide strong evidence that Mg(2+) and LL-37 are specific signals that function by altering CsrS autokinase activity and downstream phosphotransfer to CsrR to modulate its activity as a transcriptional regulator. The representation of multiple antiphagocytic and cytotoxic factors in the CsrRS regulon together with results of in vitro phagocytic killing assays support the hypothesis that CsrRS mediates conversion of GAS from a colonizing to an invasive phenotype in response to signaling by host LL-37.
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PMID:Signal transduction through CsrRS confers an invasive phenotype in group A Streptococcus. 2204 38

Actin exists as a monomer (G-actin) which can be polymerized to filaments) F-actin) that under the influence of actin-binding proteins and polycations bundle and contribute to the formation of the cytoskeleton. Bundled actin from lysed cells increases the viscosity of sputum in lungs of cystic fibrosis patients. The human host defense peptide LL-37 was previously shown to induce actin bundling and was thus hypothesized to contribute to the pathogenicity of this disease. In this work, interactions between actin and the cationic LL-37 were studied by optical, proteolytic and surface plasmon resonance methods and compared to those obtained with scrambled LL-37 and with the cationic protein lysozyme. We show that LL-37 binds strongly to CaATP-G-actin while scrambled LL-37 does not. While LL-37, at superstoichiometric LL-37/actin concentrations polymerizes MgATP-G-actin, at lower non-polymerizing concentrations LL-37 inhibits actin polymerization by MgCl(2) or NaCl. LL-37 bundles Mg-F-actin filaments both at low and physiological ionic strength when in equimolar or higher concentrations than those of actin. The LL-37 induced bundles are significantly less sensitive to increase in ionic strength than those induced by scrambled LL-37 and lysozyme. LL-37 in concentrations lower than those needed for actin polymerization or bundling, accelerates cleavage of both monomer and polymer actin by subtilisin. Our results indicate that the LL-37-actin interaction is partially electrostatic and partially hydrophobic and that a specific actin binding sequence in the peptide is responsible for the hydrophobic interaction. LL-37-induced bundles, which may contribute to the accumulation of sputum in cystic fibrosis, are dissociated very efficiently by DNase-1 and also by cofilin.
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PMID:LL-37 induces polymerization and bundling of actin and affects actin structure. 2318 80

A medium which incorporates CAMP factor produced by Streptococcus agalactiae (group B) into sheep blood agar was used to culture and identify coagulase-positive staphylococci from bovine milk. Of 506 staphylococcal isolates from bovine milk, 92.5% of coagulase-positive organisms produced a wide zone of complete hemolysis, whereas 98.9% of coagulase-negative organisms did not. The agreement of this one-step culture and identification test with the standard tube coagulase test was higher than that of the deoxyribonuclease test medium, Baird-Parker egg yolk medium, tellurite glycine medium and slide coagulase tests.
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PMID:Medium to Culture and Differentiate Coagulase-Positive and -Negative Staphylococci from Bovine Milk. 3093 8