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.

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.

scholarly journals PlmA, a New Member of the GntR Family, Has Plasmid Maintenance Functions in Anabaena sp. Strain PCC 7120

2003 ◽  
Vol 185 (15) ◽  
pp. 4315-4325 ◽  
Author(s):  
Martin H. Lee ◽  
Michael Scherer ◽  
Sébastien Rigali ◽  
James W. Golden
Keyword(s):  
Plasmid Copy Number ◽  
Filamentous Cyanobacterium ◽  
Wild Type ◽  
Plasmid Copy ◽  
Reading Frame ◽  
Plasmid Maintenance ◽  
Cyanobacterial Species ◽  
A Genome ◽  
Pcc 7120 ◽  
Gntr Family

ABSTRACT The filamentous cyanobacterium Anabaena (Nostoc) sp. strain PCC 7120 maintains a genome that is divided into a 6.4-Mb chromosome, three large plasmids of more that 100 kb, two medium-sized plasmids of 55 and 40 kb, and a 5.5-kb plasmid. Plasmid copy number can be dynamic in some cyanobacterial species, and the genes that regulate this process have not been characterized. Here we show that mutations in an open reading frame, all1076, reduce the numbers of copies per chromosome of several plasmids. In a mutant strain, plasmids pCC7120δ and pCC7120ζ are both reduced to less than 50% of their wild-type levels. The exogenous pDU1-based plasmid pAM1691 is reduced to less than 25% of its wild-type level, and the plasmid is rapidly lost. The peptide encoded by all1076 shows similarity to members of the GntR family of transcriptional regulators. Phylogenetic analysis reveals a new domain topology within the GntR family. PlmA homologs, all coming from cyanobacterial species, form a new subfamily that is distinct from the previously identified subfamilies. The all1076 locus, named plmA, regulates plasmid maintenance functions in Anabaena sp. strain PCC 7120.

scholarly journals RepB C-terminus mutation of an ori pRi vector affects plasmid copy number inAgrobacteriumand transgene copy number in plants

2018 ◽  
Author(s):  
Zarir Vaghchhipawala ◽  
Sharon Radke ◽  
Ervin Nagy ◽  
Mary L. Russell ◽  
Susan Johnson ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Copy Number ◽  
Binary Vector ◽  
Single Copy ◽  
Plasmid Copy Number ◽  
Plant Production ◽  
Silent Mutation ◽  
Wild Type ◽  
Plasmid Copy ◽  
C Terminus

AbstractA nativerepABCreplication origin, ori pRi, was previously reported as a single copy plasmid inAgrobacterium tumefaciensand can improve the production of transgenic plants with a single copy insertion of transgenes when it is used in binary vectors forAgrobacterium-mediatedtransformation. A high copy ori pRi variant plasmid, pTF::Ri, which does not improve the frequency of single copy transgenic plants, has been reported in the literature. Sequencing the high copy pTF::RirepABCoperon revealed the presence of two mutations: one silent mutation and one missense mutation that changes a tyrosine to a histidine (Y299H) in a highly conserved area of the C-terminus of the RepB protein (RepBY299H). Reproducing these mutations in the wild-type oriRi binary vector showed thatAgrobacteriumcells with the RepBY299Hmutation grow faster on both solidified and in liquid medium, and have higher plasmid copy number as determined by ddPCR. In order to investigate the impact of the RepBY299Hmutation on transformation and quality plant production, the RepBY299Hmutated ori pRi binary vector was compared with the original wild-type ori pRi binary vector and a multi-copy oriV binary vector in canola transformation. Molecular analyses of the canola transgenic plants demonstrated that the multi-copy ori pRi with the RepBY299Hmutation inAgrobacteriumcells lost the advantage of generating high frequency single copy, backbone-free transgenic plants compared to using the single copy wild-type ori pRi binary vector.

scholarly journals Restoration of wild-type motility to flagellin-knockout Escherichia coli

2019 ◽  
Author(s):  
Nicholas M. Thomson ◽  
Mark J. Pallen
Keyword(s):  
Escherichia Coli ◽  
Copy Number ◽  
Plasmid Copy Number ◽  
Major Constituent ◽  
Strongly Correlated ◽  
Wild Type ◽  
Plasmid Copy ◽  
Inducible Promoters ◽  
E Coli ◽  
Flagellar Filament

AbstractFlagellin is the major constituent of the flagellar filament and faithful restoration of wild-type motility to flagellin mutants may be beneficial for studies of flagellar biology and biotechnological exploitation of the flagellar system. Therefore, we explored the restoration of motility by flagellin expressed from a variety of combinations of promoter, plasmid copy number and induction strength. Motility was only partially restored using the tightly regulated rhamnose promoter, but wild-type motility was achieved with the T5 promoter, which, although leaky, allowed titration of induction strength. Motility was little affected by plasmid copy number when dependent on inducible promoters. However, plasmid copy number was important when expression was controlled by the native E. coli flagellin promoter. Motility was poorly correlated with flagellin transcription levels, but strongly correlated with the amount of flagellin associated with the flagellar filament, suggesting that excess monomers are either not exported or not assembled into filaments. This study provides a useful reference for further studies of flagellar function and a simple blueprint for similar studies with other proteins.

Protection against bleomycin-induced lung injury by IL-18 in mice

2005 ◽  
Vol 289 (2) ◽  
pp. L280-L287 ◽  
Author(s):  
Akemi Nakatani-Okuda ◽  
Haruyasu Ueda ◽  
Shin-ichiro Kashiwamura ◽  
Atsuo Sekiyama ◽  
Akira Kubota ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Messenger Rna ◽  
Lavage Fluid ◽  
Protective Role ◽  
Myeloperoxidase Activity ◽  
Wild Type ◽  
Sod Activity ◽  
Alveolar Epithelial ◽  
Lung Injuries ◽  
Macrophage Colony

The role of interleukin (IL)-18 in the protection from interstitial pneumonia and pulmonary fibrosis induced by bleomycin (BLM) was investigated by comparing the severity of BLM-induced lung injuries between wild-type and C57BL/6 mice with a targeted knockout mutation of the IL-18 gene (IL-18−/− mice). IL-18−/− mice showed much worse lung injuries than wild-type mice, as assessed by the survival rate, histological images, and leukocyte infiltration in the bronchoalveolar lavage fluid and myeloperoxidase activity. In wild-type mice, administration of IL-18 before BLM instillation resulted in suppression of lung injuries, increases in the hydroxyproline content, and decreases in the granulocyte-macrophage colony-stimulating factor content in the lung. Preadministration of IL-18 also resulted in prevention of the reduction of the lung IL-10 content caused by BLM-induced damage of alveolar epithelial. BLM instillation suppressed superoxide dismutase (SOD) activity in IL-18−/− mice to a greater extent than in wild-type mice. Pretreatment of IL-18 augmented Mn-containing superoxide dismutase (Mn-SOD) messenger RNA expression and SOD activity in the lung and prevented the reduction of SOD activity caused by BLM in both wild-type and IL-18−/− mice. These results suggest that IL-18 plays a protective role against BLM-induced lung injuries by upregulating a defensive molecule, Mn-SOD.

scholarly journals Evolutionary Rescue and Drug Resistance on Multicopy Plasmids

Genetics ◽  
2020 ◽  
Vol 215 (3) ◽  
pp. 847-868
Author(s):  
Mario Santer ◽  
Hildegard Uecker
Keyword(s):  
Copy Number ◽  
Gene Dosage ◽  
Branching Processes ◽  
Plasmid Copy Number ◽  
Wild Type ◽  
Plasmid Copy ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Evolutionary Rescue ◽  
Establishment Probability

Bacteria often carry “extra DNA” in the form of plasmids in addition to their chromosome. Many plasmids have a copy number greater than one such that the genes encoded on these plasmids are present in multiple copies per cell. This has evolutionary consequences by increasing the mutational target size, by prompting the (transitory) co-occurrence of mutant and wild-type alleles within the same cell, and by allowing for gene dosage effects. We develop and analyze a mathematical model for bacterial adaptation to harsh environmental change if adaptation is driven by beneficial alleles on multicopy plasmids. Successful adaptation depends on the availability of advantageous alleles and on their establishment probability. The establishment process involves the segregation of mutant and wild-type plasmids to the two daughter cells, allowing for the emergence of mutant homozygous cells over the course of several generations. To model this process, we use the theory of multitype branching processes, where a type is defined by the genetic composition of the cell. Both factors—the availability of advantageous alleles and their establishment probability—depend on the plasmid copy number, and they often do so antagonistically. We find that in the interplay of various effects, a lower or higher copy number may maximize the probability of evolutionary rescue. The decisive factor is the dominance relationship between mutant and wild-type plasmids and potential gene dosage effects. Results from a simple model of antibiotic degradation indicate that the optimal plasmid copy number may depend on the specific environment encountered by the population.

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.

scholarly journals The impairment of superoxide dismutase coordinates the derepression of the PerR regulon in the response of Staphylococcus aureus to HOCl stress

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 855-861 ◽  
Author(s):  
Sami Maalej ◽  
Ines Dammak ◽  
Sam Dukan
Keyword(s):  
Staphylococcus Aureus ◽  
Superoxide Dismutase ◽  
Hypochlorous Acid ◽  
Antioxidant Properties ◽  
Exponential Phase ◽  
Dependent Manner ◽  
Wild Type ◽  
Sod Activity ◽  
Striking Result ◽  
Phosphoglycerate Dehydrogenase

The response of Staphylococcus aureus to hypochlorous acid (HOCl) exposure was investigated. HOCl challenges were performed on cultures interrupted in the exponential phase. Pretreatment with HOCl conferred resistance to hydrogen peroxide in a PerR-dependent manner. Derepression of the PerR regulon was observed at low HOCl concentration (survival >50 %), using several fusions of different stress promoters to lacZ reporter genes. At least four members of the PerR regulon (katA, mrgA, bcp and trxA) encoding proteins with antioxidant properties were strongly induced following exposure to various HOCl concentrations. A striking result was the link between the derepression of the PerR regulon and the decreased superoxide dismutase (SOD) activity following exposure to increased HOCl concentrations. The sodA mutant was more resistant than the wild-type and also had a higher level of 3-phosphoglycerate dehydrogenase (a measure of PerR regulon activity) without exposure to HOCl. Together, these results imply that derepression of PerR by HOCl is dependent on the level of SOD and protects exponentially arrested cells against HOCl stress.

scholarly journals The Pathway-Specific Regulator ClaR of Streptomyces clavuligerus Has a Global Effect on the Expression of Genes for Secondary Metabolism and Differentiation

2015 ◽  
Vol 81 (19) ◽  
pp. 6637-6648 ◽  
Author(s):  
Yolanda Martínez-Burgo ◽  
Rubén Álvarez-Álvarez ◽  
Antonio Rodríguez-García ◽  
Paloma Liras
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Aerial Mycelium ◽  
Gene Clusters ◽  
Streptomyces Clavuligerus ◽  
Plasmid Copy Number ◽  
Wild Type ◽  
Plasmid Copy ◽  
Content Type ◽  
Expression Of Genes

ABSTRACTStreptomyces clavuligerusclaR::aphis aclaR-defective mutant, but in addition to itsclaRdefect it also carries fewer copies of the resident linear plasmids pSCL2 and pSCL4 (on the order of 4 × 105-fold lower than the wild-type strain), as shown by qPCR. To determine the function of ClaR without potential interference due to plasmid copy number, a new strain,S. clavuligerusΔclaR::aac, withclaRdeleted and carrying the wild-type level of plasmids, was constructed. Transcriptomic analyses were performed inS. clavuligerusΔclaR::aacandS. clavuligerusATCC 27064 as the control strain. The new ΔclaRmutant did not produce clavulanic acid (CA) and showed a partial expression of genes for the early steps of the CA biosynthesis pathway and a very poor expression (1 to 8%) of the genes for the late steps of the CA pathway. Genes for cephamycin C biosynthesis were weakly upregulated (1.7-fold at 22.5 h of culture) in the ΔclaRmutant, but genes for holomycin biosynthesis were expressed at levels from 3- to 572-fold higher than in the wild-type strain, supporting the observed overproduction of holomycin byS. clavuligerusΔclaR::aac. Interestingly, three secondary metabolites produced by gene clusters SMCp20, SMCp22, and SMCp24, encoding still-cryptic compounds, had partially or totally downregulated their genes in the mutant, suggesting a regulatory role for ClaR wider than previously reported. In addition, theamfRgene was downregulated, and consequently, the mutant did not produce aerial mycelium. Expression levels of about 100 genes in the genome were partially up- or downregulated in the ΔclaRmutant, many of them related to the upregulation of the sigma factor-encodingrpoEgene.

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.

Sign in / Sign up

Export Citation Format

Share Document