Virulence of Listeria monocytogenes Propagated in NaCl Containing Media at 4, 25 and 37°C

1994 ◽  
Vol 57 (6) ◽  
pp. 475-478 ◽  
Author(s):  
ERIC R. MYERS ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Sodium Chloride ◽  
Mouse Model ◽  
Virulence Factor ◽  
Growth Temperature ◽  
Lethal Dose ◽  
Listeriolysin O ◽  
Sod Activity ◽  
Approximate Lethal Dose

Virulence, as determined in a mouse model, and virulence factor activities of catalase (CA), superoxide dismutase (SOD) and listeriolysin O (LLO), was examined in Listeria monocytogenes 10403S. Cells were propagated in media containing various concentrations of sodium chloride (NaCl) at 4, 25 and 37°C. Strain 10403S exhibited significant increases in CA activity and LLO when grown in media containing 428 mM of NaCl at 37°C. The CA activities at 4 and 25°C were significantly less, and the cells exhibited similar increases and decreases as cells grown at 37°C. When comparing the growth temperatures, the CA activity decreased as the growth temperature decreased. The SOD activity was significantly increased only when cells were propagated in media containing either 428 or 1,112 mM of NaCl. The SOD activity increased as the growth temperature decreased. No LLO activity was detected when cells were grown at 4 and 25°C. The production of these enzymes appeared to be thermoregulated. In addition, approximate lethal dose (ALD50) values were determined after intragastric (i.g.) and intraperitoneal (i.p.) infection. Each method of infection indicated that LLO was required for virulence, while growth in salt containing media, growth at 4°C, or the production of higher levels of CA, SOD and LLO did not appear to influence the virulence of L. monocytogenes.

Catalase, Superoxide Dismutase and Listeriolysin O Production by Listeria monocytogenes in Broth Containing Acetic and Hydrochloric Acids

1994 ◽  
Vol 57 (7) ◽  
pp. 626-628 ◽  
Author(s):  
LISA K. DIMMIG ◽  
ERIC R. MYERS ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Hydrochloric Acid ◽  
Enzyme Production ◽  
Growth Media ◽  
Listeriolysin O ◽  
Weak Acids ◽  
Sod Activity ◽  
Strong Acids

Cells of Listeria monocytogenes 10403S were propagated at 37°C in media acidified with either acetic or hydrochloric acid to determine the effect on the production of catalase (CA), superoxide dismutase (SOD) and listeriolysin O (LLO). The CA and LLO activities decreased while SOD activity increased as the pH of the growth media was decreased. Comparison of the acids indicated that neither acid caused significant differences in enzyme production except for SOD activity at pH 5.7. These results suggest that growth of L. monocytogenes in acid environments may influence the production of these enzymes, while growth in strong acids versus weak acids may not be significantly different.

Effects of Iron and Selenium on the Production of Catalase, Superoxide Dismutase, and Listeriolysin O in Listeria monocytogenes

1999 ◽  
Vol 62 (10) ◽  
pp. 1206-1209 ◽  
Author(s):  
CHRISTOPHER W. FISHER ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Listeriolysin O

Listeria monocytogenes 19112, Scott A, and 10403S were grown in tryptic soy broth (TSB) and TSB supplemented with 25 to 100 μg/ml of iron (Fe) and 0.5 to 2.5 μg/ml selenium (Se) to examine the effects on catalase (CA), superoxide dismutase (SOD), and listeriolysin O (LLO) activities. Growth in TSB supplemented with Fe resulted in significant increases in CA, SOD, and LLO activities in all three strains when compared to growth in TSB. The addition of 0.5 μg/ml Se to TSB resulted in significantly higher CA and LLO activities in L. monocytogenes 19112 but showed no effect on Scott A or 10403S. These results suggest that Fe plays a role in increasing the activities of CA, SOD, and LLO.

scholarly journals Listeria monocytogenes Phospholipase C-Dependent Calcium Signaling Modulates Bacterial Entry into J774 Macrophage-Like Cells

1999 ◽  
Vol 67 (4) ◽  
pp. 1770-1778 ◽  
Author(s):  
Sandra J. Wadsworth ◽  
Howard Goldfine
Keyword(s):  
Listeria Monocytogenes ◽  
Calcium Signaling ◽  
Phospholipase C ◽  
Virulence Factors ◽  
Intracellular Signaling ◽  
Lethal Dose ◽  
Listeriolysin O ◽  
Wild Type ◽  
J774 Macrophage ◽  
Kinetics Of

ABSTRACT Listeria monocytogenes secretes several proteins that have been shown to contribute to virulence. Among these is listeriolysin O (LLO), a pore-forming hemolysin that is absolutely required for virulence. Two other virulence factors are phospholipases: a phosphatidylinositol-specific phospholipase C (PI-PLC [plcA]) and a broad-range PLC (plcB). Although mutations in plcA or plcB resulted in small increases in mouse 50% lethal dose (LD50), deletions in both genes resulted in a 500-fold increase in LD50. We have examined the role of these secreted proteins in host intracellular signaling in the J774 macrophage-like cell line. Measurements of cytosolic free calcium ([Ca2+]i) have revealed a rapid spike upon exposure of these cells to wild-typeL. monocytogenes. This is followed by a second peak at 5 min and a third prolonged peak with a maximal [Ca2+]i of 800 to 1,000 nM. The pattern of calcium changes was greatly altered by deletion of any of the three virulence factors. An LLO mutant produced none of these elevations in [Ca2+]i; however, a transient elevation was observed whenever these bacteria entered the cell. A PI-PLC mutant produced a diminished single elevation in [Ca2+]i at 15 to 30 min. A broad-range PLC mutant produced only the first calcium spike. Studies with inhibitors suggested that the first elevation arises from influx of calcium from the extracellular medium through plasma membrane channels and that the second and third elevations come from release of Ca2+ from intracellular stores. We observed that internalization of wild-type bacteria and the broad-range PLC mutant was delayed for 5 to 10 min, but the LLO and PI-PLC mutants were internalized rapidly upon infection. Inhibitors that affected calcium signaling changed the kinetics of association of wild-type bacteria with J774 cells, the kinetics of entry, and the efficiency of escape from the primary phagosome.

Influence of Plasmids on Catalase and Superoxide Dismutase Activities in Listeria monocytogenes

1995 ◽  
Vol 58 (9) ◽  
pp. 955-959 ◽  
Author(s):  
LOWELL L. ISOM ◽  
ALI H. AHMED ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Gradient Centrifugation ◽  
Plasmid Copy Number ◽  
Activity Levels ◽  
Wild Type ◽  
Cadmium Resistance ◽  
Sod Activity ◽  
Plasmid Copy ◽  
Cscl Density Gradient

Two of nine strains of Listeria monocytogenes examined were found to contain plasmid DNA. Strain 19112 contained a 31.1 kb plasmid and strain 7644 contained a 49.4 kb plasmid. Each of the strains was cured of its plasmid by heat treatment at 46°C. Both the wild-type and plasmid-negative forms of each strain were screened for cadmium resistance. The 31.1 kb plasmid of L. monocytogenes 19112 was shown to confer resistance to cadmium. Listeria monocytogenes 7644 did not show resistance to cadmium. The plasmids for both strains were isolated and purified by CsCl density-gradient centrifugation. Each plasmid was electroporated back into the respective plasmid-negative strain. The catalase (CA) and superoxide dismutase (SOD) activities were determined for the wild type, plasmid-negative and electroporated strains. There was a significant decrease in CA and SOD activities upon loss of the plasmid from each strain of L. monocytogenes. Strain 19112 showed a 36% decrease in CA activity and an 81% decrease in SOD activity as a result of plasmid removal. Strain 7644 showed a 22% decrease in both CA and SOD activities following plasmid loss. Catalase and SOD activity levels increased for both strains following reinsertion of the plasmid through electroporation. Catalase and SOD activity levels of L. monocytogenes 7644 were higher for the transformed strain than those of the wild type. Catalase and SOD activity levels of transformed L. monocytogenes 19112 were less than in the corresponding wild type. It appears that plasmids in L. monocytogenes strains 19112 and 7644 may be involved in influencing the regulation of the production of CA and SOD. Plasmid copy number may influence the level of activity of these enzymes.

scholarly journals Cytolysin-Dependent Escape of the Bacterium from the Phagosome Is Required but Not Sufficient for Induction of the Th1 Immune Response against Listeria monocytogenes Infection: Distinct Role of Listeriolysin O Determined by Cytolysin Gene Replacement

2007 ◽  
Vol 75 (8) ◽  
pp. 3791-3801 ◽  
Author(s):  
Hideki Hara ◽  
Ikuo Kawamura ◽  
Takamasa Nomura ◽  
Takanari Tominaga ◽  
Kohsuke Tsuchiya ◽  
...  
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Virulence Factor ◽  
Protective Immunity ◽  
Gene Replacement ◽  
Listeriolysin O ◽  
Listeria Ivanovii ◽  
Ifn Γ

ABSTRACT Listeria monocytogenes evades the antimicrobial mechanisms of macrophages by escaping from the phagosome into the cytosolic space via a unique cytolysin that targets the phagosomal membrane, listeriolysin O (LLO), encoded by hly. Gamma interferon (IFN-γ), which is known to play a pivotal role in the induction of Th1-dependent protective immunity in mice, appears to be produced, depending on the bacterial virulence factor. To determine whether the LLO molecule (the major virulence factor of L. monocytogenes) is indispensable or the escape of bacteria from the phagosome is sufficient to induce IFN-γ production, we first constructed an hly-deleted mutant of L. monocytogenes and then established isogenic L. monocytogenes mutants expressing LLO or ivanolysin O (ILO), encoded by ilo from Listeria ivanovii. LLO-expressing L. monocytogenes was highly capable of inducing IFN-γ production and Listeria-specific protective immunity, while the hly-deleted mutant was not. In contrast, the level of IFN-γ induced by ILO-expressing L. monocytogenes was significantly lower both in vitro and in vivo, despite the ability of this strain to escape the phagosome and the intracellular multiplication at a level equivalent to that of LLO-expressing L. monocytogenes. Only a negligible level of protective immunity was induced in mice against challenge with LLO- and ILO-expressing L. monocytogenes. These results clearly show that escape of the bacterium from the phagosome is a prerequisite but is not sufficient for the IFN-γ-dependent Th1 response against L. monocytogenes, and some distinct molecular nature of LLO is indispensable for the final induction of IFN-γ that is essentially required to generate a Th1-dependent immune response.

scholarly journals Toxic Effect of Glyphosate-Pesticide on Lipid Peroxidation Superoxide Dismutase and Catalase of Clarias Gariepinus

2020 ◽  
pp. 23-27
Author(s):  
Helen Nwamba Ogochukwu ◽  
Cosmas Ezekaibeya Achikanu
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Superoxide Dismutase ◽  
Catalase Activity ◽  
Lethal Dose ◽  
Clarias Gariepinus ◽  
Average Weight ◽  
Colorimetric Analysis ◽  
Sod Activity ◽  
Stress Indices

The oxidative stress indices lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) in juvenile Clarias gariepinus (average weight 200.15 g) exposed to sub - lethal dose 2.40mg/L and 4.98mg/L of glyphosate was investigated over a period of days 1,5,10 and 15 in three replicates. The colorimetric analysis showed increase in lipid peroxidation from 4.55 ±2.14a1 to 12.12± 10.00a1at 2.40mg/L but remain the same at 4.98mg/L (4.55±2.14a1) compared with control (3.03±0.01a1 to 1.51±2.14b1) from day 1 to 15. The SOD activity decreased significantly with time and concentration compared with control. The Catalase activity at day 15 decreased to 0.17±0.05a1 in 2.40mg/L but further increased to 0.28±0.05b1 in 4.98mg/L compared to 0.28±0.02a1 catalase activity as control. The result suggests that glyphosate induce oxidative stress that may overwhelm the antioxidant system in juvenile catfish especially at higher concentrations with long exposure.

Modification of the signal sequence cleavage site of listeriolysin O does not affect protein secretion but impairs the virulence of Listeria monocytogenes

Microbiology ◽  
2003 ◽  
Vol 149 (5) ◽  
pp. 1249-1255 ◽  
Author(s):  
Marie-Annick Lety ◽  
Claude Frehel ◽  
Jean-luc Beretti ◽  
Patrick Berche ◽  
Alain Charbit
Keyword(s):  
Bone Marrow ◽  
Listeria Monocytogenes ◽  
Mouse Model ◽  
Cleavage Site ◽  
Culture Supernatant ◽  
Signal Sequence ◽  
Bacterial Pathogen ◽  
Listeriolysin O ◽  
Major Virulence Factor ◽  
Signal Sequence Cleavage Site

Listeriolysin O (LLO, hly-encoded), a major virulence factor secreted by the bacterial pathogen Listeria monocytogenes, is synthesized as a precursor of 529 residues. To impair LLO secretion, the four residues of the predicted signal sequence cleavage site (EA-KD) were deleted and the mutant LLO protein was expressed in a hly-negative derivative of L. monocytogenes. Unexpectedly, the mutant protein was secreted in normal amounts in the culture supernatant and was fully haemolytic. N-terminal sequencing of the secreted LLO molecule revealed that N-terminal processing of the preprotein occurred three residues downstream of the natural cleavage site. L. monocytogenes expressing this truncated LLO showed a reduced capacity to disrupt the phagosomal membranes of bone marrow macrophages and of hepatocytes; and the mutant strain showed a 100-fold decrease in virulence in the mouse model. These results suggest that the first N-terminal residues of mature LLO participate directly in phagosomal escape and bacterial infection.

scholarly journals Superoxide Dismutase-Deficient Mutants ofHelicobacter pylori Are Hypersensitive to Oxidative Stress and Defective in Host Colonization

2001 ◽  
Vol 69 (6) ◽  
pp. 4034-4040 ◽  
Author(s):  
Richard W. Seyler ◽  
Jonathan W. Olson ◽  
Robert J. Maier
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Virulence Factor ◽  
Type Strain ◽  
Wild Type Strain ◽  
Spontaneous Mutation ◽  
Wild Type ◽  
Sod Activity ◽  
Cell Extracts ◽  
H Pylori

ABSTRACT Superoxide dismutase (SOD) is a nearly ubiquitous enzyme among organisms that are exposed to oxic environments. The single SOD ofHelicobacter pylori, encoded by the sodB gene, has been suspected to be a virulence factor for this pathogenic microaerophile, but mutations in this gene have not been reported previously. We have isolated mutants with interruptions in thesodB gene and have characterized them with respect to their response to oxidative stress and ability to colonize the mouse stomach. The sodB mutants are devoid of SOD activity, based on activity staining in nondenaturing gels and quantitative assays of cell extracts. Though wild-type H. pylori is microaerophilic, the mutants are even more sensitive to O2 for both growth and viability. While the wild-type strain is routinely grown at 12% O2, growth of the mutant strains is severely inhibited at above 5 to 6% O2. The effect of O2 on viability was determined by subjecting nongrowing cells to atmospheric levels of O2 and plating for survivors at 2-h time intervals. Wild-type cell viability dropped by about 1 order of magnitude after 6 h, while viability of the sodBmutant decreased by more than 6 orders of magnitude at the same time point. The mutants are also more sensitive to H2O2, and this sensitivity is exacerbated by increased O2 concentrations. Since oxidative stress has been correlated with DNA damage, the frequency of spontaneous mutation to rifampin resistance was studied. The frequency of mutagenesis of ansodB mutant strain is about 15-fold greater than that of the wild-type strain. In the mouse colonization model, only 1 out of 23 mice inoculated with an SOD-deficient mutant of a mouse-adapted strain became H. pylori positive, while 15 out of 17 mice inoculated with the wild-type strain were shown to harbor the organism. Therefore, SOD is a virulence factor which affects the ability of this organism to colonize the mouse stomach and is important for the growth and survival of H. pylori under conditions of oxidative stress.

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