scholarly journals A Novel Restriction-Modification System Is Responsible for Temperature-Dependent Phage Resistance in Listeria monocytogenes ECII

2012 ◽  
Vol 78 (6) ◽  
pp. 1995-2004 ◽  
Author(s):  
Jae-Won Kim ◽  
Vikrant Dutta ◽  
Driss Elhanafi ◽  
Sangmi Lee ◽  
Jason A. Osborne ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Low Temperatures ◽  
Phage Resistance ◽  
Type Ii ◽  
Temperature Dependent ◽  
Epidemic Clone ◽  
Modification System ◽  
Content Type ◽  
Restriction Modification System ◽  
Restriction Modification

ABSTRACTListeria monocytogenesepidemic clone II (ECII) strains are unusual in being completely resistant to phage when grown at low temperatures (≤30°C). In the current study we constructed and characterized amariner-based mutant (J46C) of the ECII strain H7550-CdSthat lacked temperature-dependent resistance to phage. The transposon was localized in LMOh7858_2753 (open reading frame [ORF] 2753), a member of a 12-ORF genomic island unique to ECII strains. ORF 2753 and ORF 2754 exhibited homologies to restriction endonucleases and methyltransferases associated with type II restriction-modification (RM) systems.In silico-based predictions of the recognition site for this putative RM system were supported by resistance of DNA from ECII strains to digestion by BfuI, a type II restriction enzyme specific for GTATCC (N6/5). Similarly to J46C, a mutant harboring an in-frame deletion of ORF 2753 was susceptible to phage regardless of temperature of growth (25°C or 37°C). Genetic complementation restored phage resistance in 25°C-grown cells of ORF 2753 mutants. Reverse transcription (RT) and quantitative real-time PCR data suggested enhanced transcription of ORF 2753 at low temperatures (≤25°C) compared to 37°C. In contrast, available transcriptional data suggested that the putative methyltransferase (ORF 2754) was constitutively expressed at all tested temperatures (4 to 37°C). Thus, temperature-dependent resistance ofL. monocytogenesECII to phage is mediated by temperature-dependent expression of the restriction endonuclease associated with a novel RM system (LmoH7) unique to this epidemic clone.

scholarly journals Epidemic Clone I-Specific Genetic Markers in Strains of Listeria monocytogenes Serotype 4b from Foods

2004 ◽  
Vol 70 (7) ◽  
pp. 4158-4164 ◽  
Author(s):  
Suleyman Yildirim ◽  
Wen Lin ◽  
Anthony D. Hitchins ◽  
Lee-Ann Jaykus ◽  
Eric Altermann ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Genetic Markers ◽  
Food Processing ◽  
Gene Cassette ◽  
Epidemic Clone ◽  
Modification System ◽  
Restriction Modification System ◽  
Food Borne ◽  
Serotype 4B ◽  
Restriction Modification

ABSTRACT Listeria monocytogenes contamination of ready-to-eat foods has been implicated in numerous outbreaks of food-borne listeriosis. However, the health hazards posed by L. monocytogenes detected in foods may vary, and speculations exist that strains actually implicated in illness may constitute only a fraction of those that contaminate foods. In this study, examination of 34 serogroup 4 (putative or confirmed serotype 4b) isolates of L. monocytogenes obtained from various foods and food-processing environments, without known implication in illness, revealed that many of these strains had methylation of cytosines at GATC sites in the genome, rendering their DNA resistant to digestion by the restriction endonuclease Sau3AI. These strains also harbored a gene cassette with putative restriction-modification system genes as well as other, genomically unlinked genetic markers characteristic of the major epidemic-associated lineage of L. monocytogenes (epidemic clone I), implicated in numerous outbreaks in Europe and North America. This may reflect a relatively high fitness of strains with these genetic markers in foods and food-related environments relative to other serotype 4b strains and may partially account for the repeated involvement of such strains in human food-borne listeriosis.

scholarly journals Lactococcal Plasmid pNP40 Encodes a Novel, Temperature-Sensitive Restriction-Modification System

2004 ◽  
Vol 70 (9) ◽  
pp. 5546-5556 ◽  
Author(s):  
Jonathan O'Driscoll ◽  
Frances Glynn ◽  
Oonagh Cahalane ◽  
Mary O'Connell-Motherway ◽  
Gerald F. Fitzgerald ◽  
...  
Keyword(s):  
Restriction Enzymes ◽  
Temperature Sensitive ◽  
Temperature Dependent ◽  
Modification System ◽  
Restriction Modification System ◽  
Naturally Occurring ◽  
Low Copy Number ◽  
Encoding Genes ◽  
Restriction Modification ◽  
Specific Mrna

ABSTRACT A novel restriction-modification system, designated LlaJI, was identified on pNP40, a naturally occurring 65-kb plasmid from Lactococcus lactis. The system comprises four adjacent similarly oriented genes that are predicted to encode two m5C methylases and two restriction endonucleases. The LlaJI system, when cloned into a low-copy-number vector, was shown to confer resistance against representatives of the three most common lactococcal phage species. This phage resistance phenotype was found to be strongly temperature dependent, being most effective at 19°C. A functional analysis confirmed that the predicted methylase-encoding genes, llaJIM1 and llaJIM2, were both required to mediate complete methylation, while the assumed restriction enzymes, specified by llaJIR1 and llaJIR2, were both necessary for the complete restriction phenotype. A Northern blot analysis revealed that the four LlaJI genes are part of a 6-kb operon and that the relative abundance of the LlaJI-specific mRNA in the cells does not appear to contribute to the observed temperature-sensitive profile. This was substantiated by use of a LlaJI promoter-lacZ fusion, which further revealed that the LlaJI operon appears to be subject to transcriptional regulation by an as yet unidentified element(s) encoded by pNP40.

scholarly journals Temperature-Dependent Phage Resistance of Listeria monocytogenes Epidemic Clone II

2009 ◽  
Vol 75 (8) ◽  
pp. 2433-2438 ◽  
Author(s):  
Jae-Won Kim ◽  
Sophia Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
The United States ◽  
Phage Resistance ◽  
Processing Plant ◽  
Broad Host Range ◽  
Temperature Dependent ◽  
Cadmium Resistance ◽  
Epidemic Clone ◽  
Plant Environment ◽  
Serotype 4B

ABSTRACT Listeria monocytogenes epidemic clone II (ECII) has been responsible for two multistate outbreaks in the United States in 1998-1999 and in 2002, in which contaminated ready-to-eat meat products (hot dogs and turkey deli meats, respectively) were implicated. However, ecological adaptations of ECII strains in the food-processing plant environment remain unidentified. In this study, we found that broad-host-range phages, including phages isolated from the processing plant environment, produced plaques on ECII strains grown at 37°C but not when the bacteria were grown at lower temperatures (30°C or below). ECII strains grown at lower temperatures were resistant to phage regardless of the temperature during infection and subsequent incubation. In contrast, the phage susceptibility of all other tested strains of serotype 4b (including epidemic clone I) and of strains of other serotypes and Listeria species was independent of the growth temperature of the bacteria. This temperature-dependent phage susceptibility of ECII bacteria was consistently observed with all surveyed ECII strains from outbreaks or from processing plants, regardless of the presence or absence of cadmium resistance plasmids. Phages adsorbed similarly on ECII bacteria grown at 25°C and at 37°C, suggesting that resistance of ECII strains grown at 25°C was not due to failure of the phage to adsorb. Even though the underlying mechanisms remain to be elucidated, temperature-dependent phage resistance may represent an important ecological adaptation of L. monocytogenes ECII in processed, cold-stored foods and in the processing plant environment, where relatively low temperatures prevail.

scholarly journals Low-level expression of the Type II restriction–modification system confers potent bacteriophage resistance in Escherichia coli

DNA Research ◽  
2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Karolina Wilkowska ◽  
Iwona Mruk ◽  
Beata Furmanek-Blaszk ◽  
Marian Sektas
Keyword(s):  
Dna Methyltransferase ◽  
Host Bacterium ◽  
Type Ii ◽  
Potential Conflict ◽  
Modification System ◽  
Biological Assays ◽  
Restriction Modification System ◽  
Highly Sensitive ◽  
System Maintenance ◽  
Restriction Modification

Abstract Restriction–modification systems (R–M) are one of the antiviral defense tools used by bacteria, and those of the Type II family are composed of a restriction endonuclease (REase) and a DNA methyltransferase (MTase). Most entering DNA molecules are usually cleaved by the REase before they can be methylated by MTase, although the observed level of fragmented DNA may vary significantly. Using a model EcoRI R–M system, we report that the balance between DNA methylation and cleavage may be severely affected by transcriptional signals coming from outside the R–M operon. By modulating the activity of the promoter, we obtained a broad range of restriction phenotypes for the EcoRI R–M system that differed by up to 4 orders of magnitude in our biological assays. Surprisingly, we found that high expression levels of the R–M proteins were associated with reduced restriction of invading bacteriophage DNA. Our results suggested that the regulatory balance of cleavage and methylation was highly sensitive to fluctuations in transcriptional signals both up- and downstream of the R–M operon. Our data provided further insights into Type II R–M system maintenance and the potential conflict within the host bacterium.

scholarly journals To Defend or Not To Defend: That’s the Question

mSphere ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Sriram Varahan ◽  
Lynn E. Hancock
Keyword(s):  
Antibiotic Resistance Genes ◽  
Adaptive Immune System ◽  
Opportunistic Pathogen ◽  
Modification System ◽  
Content Type ◽  
Adaptive Immune ◽  
Restriction Modification System ◽  
Short Palindromic Repeat ◽  
Evolution Of Resistance ◽  
Restriction Modification

ABSTRACT Enterococcus faecalis is an opportunistic pathogen and is one of the leading causes of nosocomial infections. E. faecalis harbors a number of antibiotic resistance genes, and most of these are present on mobile genetic elements (MGEs) that can be disseminated within the species, as well as to other members of the human microflora. In an article by Price and colleagues [V. J. Price et al., mSphere 1(3):e00064-16, 2016, http://dx.doi.org/10.1128/mSphere.00064-16 ], the authors demonstrated how E. faecalis uses a restriction-modification system along with a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas to function as a bacterial innate and adaptive immune system to regulate the influx of MGEs. The absence of these systems in high-risk hospital-adapted lineages of E. faecalis, including the prototypical V583 strain, appears to allow the ready acquisition of new traits that aid in the adaptation to new environmental stresses, including the evolution of resistance to many of our best antibiotics.

scholarly journals The EcoKI Type I Restriction-Modification System in Escherichia coli Affects but Is Not an Absolute Barrier for Conjugation

2014 ◽  
Vol 197 (2) ◽  
pp. 337-342 ◽  
Author(s):  
Louise Roer ◽  
Frank M. Aarestrup ◽  
Henrik Hasman
Keyword(s):  
Escherichia Coli ◽  
Rapid Evolution ◽  
Type I ◽  
Modification System ◽  
Major Barrier ◽  
Exogenous Dna ◽  
Content Type ◽  
Restriction Modification System ◽  
K 12 ◽  
Restriction Modification

The rapid evolution of bacteria is crucial to their survival and is caused by exchange, transfer, and uptake of DNA, among other things. Conjugation is one of the main mechanisms by which bacteria share their DNA, and it is thought to be controlled by varied bacterial immune systems. Contradictory results about restriction-modification systems based on phenotypic studies have been presented as reasons for a barrier to conjugation with and other means of uptake of exogenous DNA. In this study, we show that inactivation of the R.EcoKI restriction enzyme in strainEscherichia coliK-12 strain MG1655 increases the conjugational transfer of plasmid pOLA52, which carriers two EcoKI recognition sites. Interestingly, the results were not absolute, and uptake of unmethylated pOLA52 was still observed in the wild-type strain (with an intacthsdRgene) but at a reduction of 85% compared to the uptake of the mutant recipient with a disruptedhsdRgene. This leads to the conclusion that EcoKI restriction-modification affects the uptake of DNA by conjugation but is not a major barrier to plasmid transfer.

scholarly journals Species-Specific Type II Restriction-Modification System of Xylella fastidiosa Temecula1

2010 ◽  
Vol 76 (12) ◽  
pp. 4092-4095 ◽  
Author(s):  
Ayumi Matsumoto ◽  
Michele M. Igo
Keyword(s):  
Escherichia Coli ◽  
Transformation Efficiency ◽  
Xylella Fastidiosa ◽  
Type Ii ◽  
Modification System ◽  
Restriction Modification System ◽  
Species Specific ◽  
Restriction Modification

ABSTRACT The transformation efficiency of Xylella fastidiosa can be increased by interfering with restriction by the strain-specific type II system encoded by the PD1607 and PD1608 genes. Here, we report results for two strategies: in vitro methylation using M.SssI and isolation of DNA from an Escherichia coli strain expressing the methylase PD1607.

scholarly journals MmeI: a minimal Type II restriction-modification system that only modifies one DNA strand for host protection

2008 ◽  
Vol 36 (20) ◽  
pp. 6558-6570 ◽  
Author(s):  
Richard D. Morgan ◽  
Tanya K. Bhatia ◽  
Lindsay Lovasco ◽  
Theodore B. Davis
Keyword(s):  
Type Ii ◽  
Modification System ◽  
Host Protection ◽  
Restriction Modification System ◽  
Minimal Type ◽  
Dna Strand ◽  
Restriction Modification
Sign in / Sign up

Export Citation Format

Share Document