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penicillin v acylases from gram-negative bacteria degrade n-acylhomoserine lactones and attenuate virulence in pseudomonas aeruginosa.virulence pathways in gram-negative pathogenic bacteria are regulated by quorum sensing mechanisms, through the production and sensing of n-acylhomoserine lactone (ahl) signal molecules. enzymatic degradation of ahls leading to attenuation of virulence (quorum quenching) could pave the way for the development of new antibacterials. penicillin v acylases (pvas) belong to the ntn hydrolase superfamily, together with ahl acylases. pvas are exploited widely in the pharmaceutical industry, but their ...201727933456
growth of bacterial phytopathogens in animal manures.animal manures are routinely applied to agricultural lands to improve crop yield, but the possibility to spread bacterial phytopathogens through field fertilization has not been considered yet. we monitored 49 cattle, horse, swine, sheep or chicken manure samples collected in 14 polish voivodeships for the most important plant pathogenic bacteria - ralstonia solanacearum (rsol), xanthomonas campestris pv. campestris (xcc), pectobacterium carotovorum subsp. carotovorum (pcc), pectobacterium atros ...201728319994
evolution of pectobacterium bacteriophage φm1 to escape two bifunctional type iii toxin-antitoxin and abortive infection systems through mutations in a single viral gene.some bacteria, when infected by their viral parasites (bacteriophages), undergo a suicidal response that also terminates productive viral replication (abortive infection [abi]). this response can be viewed as an altruistic act protecting the uninfected bacterial clonal population. abortive infection can occur through the action of type iii protein-rna toxin-antitoxin (ta) systems, such as toxinpa from the phytopathogen pectobacterium atrosepticum rare spontaneous mutants evolved in the generaliz ...201728159786
biotransformation of penicillin v to 6-aminopenicillanic acid using immobilized whole cells of e. coli expressing a highly active penicillin v acylase.the production of 6-aminopenicillanic acid (6-apa) is a key step in the manufacture of semisynthetic antibiotics in the pharmaceutical industry. the penicillin g acylase from escherichia coli has long been utilized for this purpose. however, the use of penicillin v acylases (pva) presents some advantages including better stability and higher conversion rates. the industrial application of pvas has so far been limited due to the nonavailability of suitable bacterial strains and cost issues. in th ...201726986755
new clues on the regulation of the crispr-cas immune system.research into the crispr-cas immune system of prokaryotes is progressing at a tremendous pace given both its important biological function and its role as a source of new genetic tools. however, a few areas of the field have remained largely unaddressed. a recent report provides information on one such overlooked area: how the cell regulates the crispr-cas immune system. the processes, despite their importance, have remained illusive. in pectobacterium atrosepticum regulation is, perhaps surpris ...201726942048
global gene expression analysis of cross-protected phenotype of pectobacterium atrosepticum.the ability to adapt to adverse conditions permits many bacterial species to be virtually ubiquitous and survive in a variety of ecological niches. this ability is of particular importance for many plant pathogenic bacteria that should be able to exist, except for their host plants, in different environments e.g. soil, water, insect-vectors etc. under some of these conditions, bacteria encounter absence of nutrients and persist, acquiring new properties related to resistance to a variety of stre ...201728081189
spacer capture and integration by a type i-f cas1-cas2-3 crispr adaptation complex.crispr-cas adaptive immune systems capture dna fragments from invading bacteriophages and plasmids and integrate them as spacers into bacterial crispr arrays. in type i-e and ii-a crispr-cas systems, this adaptation process is driven by cas1-cas2 complexes. type i-f systems, however, contain a unique fusion of cas2, with the type i effector helicase and nuclease for invader destruction, cas3. by using biochemical, structural, and biophysical methods, we present a structural model of the 400-kda ...201728611213
interference-driven spacer acquisition is dominant over naive and primed adaptation in a native crispr-cas system.crispr-cas systems provide bacteria with adaptive immunity against foreign nucleic acids by acquiring short, invader-derived sequences called spacers. here, we use high-throughput sequencing to analyse millions of spacer acquisition events in wild-type populations of pectobacterium atrosepticum. plasmids not previously encountered, or plasmids that had escaped crispr-cas targeting via point mutation, are used to provoke naive or primed spacer acquisition, respectively. the origin, location and o ...201627694798
inactivation of crispr-cas systems by anti-crispr proteins in diverse bacterial species.crispr-cas systems provide sequence-specific adaptive immunity against foreign nucleic acids(1,2). they are present in approximately half of all sequenced prokaryotes(3) and are expected to constitute a major barrier to horizontal gene transfer. we previously described nine distinct families of proteins encoded in pseudomonas phage genomes that inhibit crispr-cas function(4,5). we have developed a bioinformatic approach that enabled us to discover additional anti-crispr proteins encoded in phage ...201627573108
sensitive and rapid detection of pectobacterium atrosepticum by targeting the gyrb gene using a real-time loop-mediated isothermal amplification assay.this study reports the development of a real-time, loop-mediated isothermal amplification (realamp) assay for the detection of pectobacterium atrosepticum (p. atrosepticum). a phylogenetic tree was constructed based on the gyrb gene of p. atrosepticum and related species. pectobacterium atrosepticum from different sources can be clustered in the same branch with 100% support rate. the realamp primers targeting the gyrb gene of p. atrosepticum worked most efficiently at 61·0°c. compared with 55 r ...201627450435
root exudate of solanum tuberosum is enriched in galactose-containing molecules and impacts the growth of pectobacterium atrosepticum.potato (solanum tuberosum) is an important food crop and is grown worldwide. it is, however, significantly sensitive to a number of soil-borne pathogens that affect roots and tubers, causing considerable economic losses. so far, most research on potato has been dedicated to tubers and hence little attention has been paid to root structure and function.201627390353
pathogen-induced conditioning of the primary xylem vessels - a prerequisite for the formation of bacterial emboli by pectobacterium atrosepticum.representatives of pectobacterium genus are some of the most harmful phytopathogens in the world. in the present study, we have elucidated novel aspects of plant-pectobacterium atrosepticum interactions. this bacterium was recently demonstrated to form specific 'multicellular' structures - bacterial emboli in the xylem vessels of infected plants. in our work, we showed that the process of formation of these structures includes the pathogen-induced reactions of the plant. the colonisation of the ...201626992469
structural plasticity and in vivo activity of cas1 from the type i-f crispr-cas system.crispr-cas systems are adaptive immune systems in prokaryotes that provide protection against viruses and other foreign dna. in the adaptation stage, foreign dna is integrated into crispr (clustered regularly interspaced short palindromic repeat) arrays as new spacers. these spacers are used in the interference stage to guide effector crispr associated (cas) protein(s) to target complementary foreign invading dna. cas1 is the integrase enzyme that is central to the catalysis of spacer integratio ...201626929403
alternative scenarios of starvation-induced adaptation in pectobacterium atrosepticum.bacteria have high adaptive potential that ensures their survival during various environmental challenges. to adapt, bacteria activate a physiological program of stress response that makes them able to persist under adverse conditions. the present study sought to examine the ability of a particular bacterial species to induce a stress response in alternative scenarios. cells of the phytopathogenic microorganism pectobacterium atrosepticum were taken as a model. the cells were exposed to starvati ...201626912323
efficacies of quorum sensing inhibitors, piericidin a and glucopiericidin a, produced by streptomyces xanthocidicus kpp01532 for the control of potato soft rot caused by erwinia carotovora subsp. atroseptica.to discover potential inhibitors of the quorum sensing (qs) system, a library of microbial culture extracts was screened with chromobacterium violaceumcv026 strain. the culture extract of streptomyces xanthocidicus kpp01532 contained quorum-sensing inhibitors (qsis) of the cv026 strain. the active constituents of the culture extract of strain kpp01532 were purified using a series of chromatographic procedures, and based on data from nmr and mass spectroscopy, piericidin a and glucopiericidin a w ...201626856451
specific detection of pectobacterium carotovorum by loop-mediated isothermal amplification.potatoes are an important agroeconomic crop worldwide and maceration diseases caused by pectolytic bacterial pathogens result in significant pre- and post-harvest losses. pectobacterium carotovorum shares a common host range with other pectobacterium spp. and other members of the enterobacteriaceae, such as dickeya spp. as these pathogens cannot be clearly differentiated on the basis of the symptoms they cause, improved methods of identification are critical for the determination of sources of c ...201626833881
discovery and profiling of small rnas responsive to stress conditions in the plant pathogen pectobacterium atrosepticum.small rnas (srnas) have emerged as important regulatory molecules and have been studied in several bacteria. however, to date, there have been no whole-transcriptome studies on srnas in any of the soft rot enterobacteriaceae (sre) group of pathogens. although the main ecological niches for these pathogens are plants, a significant part of their life cycle is undertaken outside their host within adverse soil environment. however, the mechanisms of sre adaptation to this harsh nutrient-deficient e ...201626753530
structural analysis of a penicillin v acylase from pectobacterium atrosepticum confirms the importance of two trp residues for activity and specificity.penicillin v acylases (pva) catalyze the deacylation of the beta-lactam antibiotic phenoxymethylpenicillin (pen v). they are members of the ntn hydrolase family and possess an n-terminal cysteine as the main catalytic nucleophile residue. they form the evolutionarily related cholylglycine hydrolase (cgh) group which includes bile salt hydrolases (bsh) responsible for bile deconjugation. even though a few pva and bsh structures have been reported, no structure of a functional pva from gram-negati ...201626707624
ph-dependent dna distortion and repression of gene expression by pectobacterium atrosepticum pecs.transcriptional activity is exquisitely sensitive to changes in promoter dna topology. transcription factors may therefore control gene activity by modulating the relative positioning of -10 and -35 promoter elements. the plant pathogen pectobacterium atrosepticum, which causes soft rot in potatoes, must alter gene expression patterns to ensure growth in planta. in the related soft-rot enterobacterium dickeya dadantii, pecs functions as a master regulator of virulence gene expression. here, we r ...201627213700
two novel antimicrobial defensins from rice identified by gene coexpression network analyses.defensins form an antimicrobial peptides (amp) family, and have been widely studied in various plants because of their considerable inhibitory functions. however, their roles in rice (oryza sativa l.) have not been characterized, even though rice is one of the most important staple crops that is susceptible to damaging infections. additionally, a previous study identified 598 rice genes encoding cysteine-rich peptides, suggesting there are several uncharacterized amps in rice. we performed in si ...201627527801
pectobacterium atrosepticum and pectobacterium carotovorum harbor distinct, independently acquired integrative and conjugative elements encoding coronafacic acid that enhance virulence on potato stems.integrative and conjugative elements (ices) play a central role in the evolution of bacterial virulence, their transmission between bacteria often leading to the acquisition of virulence factors that alter host range or aggressiveness. much is known about the functions of the virulence determinants that ices harbor, but little is understood about the cryptic effects of ices on their host cell. in this study, the importance of horizontally acquired island 2 (hai2), an ice in the genome of pectoba ...201627065965
sigmoid: a user-friendly tool for improving bacterial genome annotation through analysis of transcription control signals.the majority of bacterial genome annotations are currently automated and based on a 'gene by gene' approach. regulatory signals and operon structures are rarely taken into account which often results in incomplete and even incorrect gene function assignments. here we present sigmoid, a cross-platform (os x, linux and windows) open-source application aiming at simplifying the identification of transcription regulatory sites (promoters, transcription factor binding sites and terminators) in bacter ...201627257541
a plasmid-transposon hybrid mutagenesis system effective in a broad range of enterobacteria.random transposon mutagenesis is a powerful technique used to generate libraries of genetic insertions in many different bacterial strains. here we develop a system facilitating random transposon mutagenesis in a range of different gram-negative bacterial strains, including pectobacterium atrosepticum, citrobacter rodentium, serratia sp. atcc39006, serratia plymuthica, dickeya dadantii, and many more. transposon mutagenesis was optimized in each of these strains and three studies are presented t ...201526733980
characterization of dickeya and pectobacterium species by capillary electrophoretic techniques and maldi-tof ms.dickeya and pectobacterium species represent an important group of broad-host-range phytopathogens responsible for blackleg and soft rot diseases on numerous plants including many economically important plants. although these species are commonly detected using cultural, serological, and molecular methods, these methods are sometimes insufficient to classify the bacteria correctly. on that account, this study was undertaken to investigate the feasibility of three individual analytical techniques ...201526229029
complete genome sequence of phytopathogenic pectobacterium atrosepticum bacteriophage peat1.pectobacterium atrosepticum is a common phytopathogen causing significant economic losses worldwide. to develop a biocontrol strategy for this blackleg pathogen of solanaceous plants, p. atrosepticum bacteriophage peat1 was isolated and its genome completely sequenced. interestingly, morphological and sequence analyses of the 45,633-bp genome revealed that phage peat1 is a member of the family podoviridae and most closely resembles the klebsiella pneumoniae bacteriophage kp34. this is the first ...201526272557
penicillin v acylase from pectobacterium atrosepticum exhibits high specific activity and unique kinetics.penicillin v acylases (pvas, e.c.3.5.11) belong to the ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin v). penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. pvas employ the n-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (bshs). here, we report the cloning and characterization of a ...201525931393
antibacterial activity of caffeine against plant pathogenic bacteria.the objective of the present study was to evaluate the antibacterial properties of a plant secondary metabolite - caffeine. caffeine is present in over 100 plant species. antibacterial activity of caffeine was examined against the following plant-pathogenic bacteria: ralstonia solanacearum (rsol), clavibacter michiganesis subsp. sepedonicus (cms), dickeya solani (dsol), pectobacterium atrosepticum (pba), pectobacterium carotovorum subsp. carotovorum (pcc), pseudomonas syringae pv. tomato (pst), ...201526307771
mobilization of horizontally acquired island 2 is induced in planta in the phytopathogen pectobacterium atrosepticum scri1043 and involves the putative relaxase eca0613 and quorum sensing.integrative and conjugative elements (ices) contribute to the rapid evolution of bacterial pathogens via horizontal gene transfer of virulence determinants. ices have common mechanisms for transmission, yet the cues triggering this process under natural environmental or physiological conditions are largely unknown. in this study, mobilization of the putative ice horizontally acquired island 2 (hai2), present in the chromosome of the phytopathogen pectobacterium atrosepticum scri1043, was examine ...201526271942
salicylic and jasmonic acid pathways are necessary for defence against dickeya solani as revealed by a novel method for blackleg disease screening of in vitro grown potato.potato is major crop ensuring food security in europe, and blackleg disease is increasingly causing losses in yield and during storage. recently, one blackleg pathogen, dickeya solani has been shown to be spreading in northern europe that causes aggressive disease development. currently, identification of tolerant commercial potato varieties has been unsuccessful; this is confounded by the complicated etiology of the disease and a strong environmental influence on disease development. there is c ...201525903921
[the effect of topology of quorum sensing-related genes in pectobacterium atrosepticumon their expression].in prokaryotic genomes, the neighboring genes are often located on the complementary dna strands and adjoin each other by their 5'- or 3'-ends or even overlap by their open reading frames. it was suggested that such gene topology hasfunctional purpose providing the regulation of their expression. for those genes that overlap by their coding 3'-termini this assumption has not been confirmed experimentally. in a broad group of bacteria that belong to proteobacteria such a convergent gene arrangeme ...201525842850
transcriptome of the quorum-sensing signal-degrading rhodococcus erythropolis responds differentially to virulent and avirulent pectobacterium atrosepticum.social bacteria use chemical communication to coordinate and synchronize gene expression via the quorum-sensing (qs) regulatory pathway. in pectobacterium, a causative agent of the blackleg and soft-rot diseases on potato plants and tubers, expression of the virulence factors is collectively controlled by the qs-signals n-acylhomoserine lactones (nahls). several soil bacteria, such as the actinobacterium rhodococcus erythropolis, are able to degrade nahls, hence quench the chemical communication ...201525585922
antibacterial activity of carob (ceratonia siliqua l.) extracts against phytopathogenic bacteria pectobacterium atrosepticum.acetone and ethanol extracts of carob (ceratonia siliqua l.) leaf and pods were evaluated for their in vitro inhibitory ability against the pectinolytic gram negative pectobacterium atrosepticum (pca, cfbp-5384) bacteria, the causal agent of potato soft rot. potato (solanum tuberosum, var nicola) tuber rot tissues obtained after 5 day bacterial inoculation was analyzed by lc-ms and gc-ms to study pca pathogenicity. trans/cis n-feruloylputrescine was identified in potato tuber after 5-day inocula ...201525489722
genomic overview of the phytopathogen pectobacterium wasabiae strain rns 08.42.1a suggests horizontal acquisition of quorum-sensing genes.the blackleg and soft-rot diseases caused by pectinolytic enterobacteria such as pectobacterium and dickeya are major causes of losses affecting potato crop in the field and upon storage. in this work, we report the isolation, characterization and genome analysis of the pectobacterium wasabiae (formerly identified as pectobacterium carotovorum subsp. carotovorum) strain rns 08.42.1a, that has been isolated from a solanum tuberosum host plant in france. comparative genomics with 3 other p. wasabi ...201525297844
regulation of the type i-f crispr-cas system by crp-camp and galm controls spacer acquisition and interference.the crispr-cas prokaryotic 'adaptive immune systems' represent a sophisticated defence strategy providing bacteria and archaea with protection from invading genetic elements, such as bacteriophages or plasmids. despite intensive research into their mechanism and application, how crispr-cas systems are regulated is less clear, and nothing is known about the regulation of type i-f systems. we used pectobacterium atrosepticum, a gram-negative phytopathogen, to study crispr-cas regulation, since it ...201526007654
deciphering the dual effect of lipopolysaccharides from plant pathogenic pectobacterium.lipopolysaccharides (lps) are a component of the outer cell surface of almost all gram-negative bacteria and play an essential role for bacterial growth and survival. lipopolysaccharides represent typical microbe-associated molecular pattern (mamp) molecules and have been reported to induce defense-related responses, including the expression of defense genes and the suppression of the hypersensitive response in plants. however, depending on their origin and the challenged plant, lps were shown t ...201525760034
microbial population dynamics in response to pectobacterium atrosepticum infection in potato tubers.endophytes are microbes and fungi that live inside plant tissues without damaging the host. herein we examine the dynamic changes in the endophytic bacterial community in potato (solanum tuberosum) tuber in response to pathogenic infection by pectobacterium atrosepticum, which causes soft rot in numerous economically important crops. we quantified community changes using both cultivation and next-generation sequencing of the 16s rrna gene and found that, despite observing significant variability ...201526118792
a type vi secretion system is involved in pseudomonas fluorescens bacterial competition.protein secretion systems are crucial mediators of bacterial interactions with other organisms. among them, the type vi secretion system (t6ss) is widespread in gram-negative bacteria and appears to inject toxins into competitor bacteria and/or eukaryotic cells. major human pathogens, such as vibrio cholerae, burkholderia and pseudomonas aeruginosa, express t6sss. bacteria prevent self-intoxication by their own t6ss toxins by producing immunity proteins, which interact with the cognate toxins. w ...201424551247
simultaneous detection of major blackleg and soft rot bacterial pathogens in potato by multiplex polymerase chain reaction.a multiplex polymerase chain reaction (pcr) assay for simultaneous, fast and reliable detection of the main soft rot and blackleg potato pathogens in europe has been developed. it utilises three pairs of primers and enables detection of three groups of pectinolytic bacteria frequently found in potato, namely: pectobacterium atrosepticum, pectobacterium carotovorum subsp. carotovorum together with pectobacterium wasabiae and dickeya spp. in a multiplex pcr assay. in studies with axenic cultures o ...201425506085
identification of three elicitins and a galactan-based complex polysaccharide from a concentrated culture filtrate of phytophthora infestans efficient against pectobacterium atrosepticum.the induction of plant immunity by pathogen associated molecular patterns (pamps) constitutes a powerful strategy for crop protection. pamps indeed induce general defense responses in plants and thus increase plant resistance to pathogens. phytophthora infestans culture filtrates (ccfs) are known to induce defense responses and decrease the severity of soft rot due to pectobacterium atrosepticum in potato tubers. the aim of this study was to identify and characterize the active compounds from p. ...201425264828
genome sequence of pectobacterium atrosepticum strain 21a.we report the annotated genome sequence of the enterobacterial plant pathogen pectobacterium atrosepticum strain 21a, isolated in belarus from potato stem with blackleg symptoms.201425237028
priming in the type i-f crispr-cas system triggers strand-independent spacer acquisition, bi-directionally from the primed protospacer.clustered regularly interspaced short palindromic repeats (crispr), in combination with crispr associated (cas) genes, constitute crispr-cas bacterial adaptive immune systems. to generate immunity, these systems acquire short sequences of nucleic acids from foreign invaders and incorporate these into their crispr arrays as spacers. this adaptation process is the least characterized step in crispr-cas immunity. here, we used pectobacterium atrosepticum to investigate adaptation in type i-f crispr ...201424990370
comprehensive overexpression analysis of cyclic-di-gmp signalling proteins in the phytopathogen pectobacterium atrosepticum reveals diverse effects on motility and virulence phenotypes.bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-gmp) is a ubiquitous bacterial signalling molecule produced by diguanylate cyclases of the ggdef-domain family. elevated c-di-gmp levels or increased ggdef protein expression is frequently associated with the onset of sessility and biofilm formation in numerous bacterial species. conversely, phosphodiesterase-dependent diminution of c-di-gmp levels by eal- and hd-gyp-domain proteins is often accompanied by increased motility and virulence. ...201424760967
gsl2 over-expression confers resistance to pectobacterium atrosepticum in potato.over-expression of the potato gibberellin stimulated-like 2 ( gsl2 ) gene in transgenic potato confers resistance to blackleg disease incited by pectobacterium atrosepticum and confirms a role for gsl2 in plant defence. the gibberellin stimulated-like 2 (gsl2) gene (also known as snakin 2) encodes a cysteine-rich, low-molecular weight antimicrobial peptide produced in potato plants. this protein is thought to play important roles in the innate defence against invading microbes. over-expression o ...201424370960
stress response in pectobacterium atrosepticum scri1043 under starvation conditions: adaptive reactions at a low population density.the adaptive reactions of plant pathogenic bacterium pectobacterium atrosepticum scri1043 under starvation conditions were studied. the main emphasis was given to the peculiarities of stress responses depending on the bacterial population densities. when bacteria were subjected to starvation at high population densities (10(7)-10(9) cfu ml(-1)), their adaptive reactions conformed to the conventional conception of bacterial adaptation related to autolysis of part of the population, specific modif ...201424300393
group iii alcohol dehydrogenase from pectobacterium atrosepticum: insights into enzymatic activity and organization of the metal ion-containing region.nad(p)(+)-dependent alcohol dehydrogenases (adh) are widely distributed in all phyla. these proteins can be assigned to three nonhomologous groups of isozymes, with group iii being highly diverse with regards to catalytic activity and primary structure. members of group iii adhs share a conserved stretch of amino acid residues important for cofactor binding and metal ion coordination, while sequence identities for complete proteins are highly diverse (<20 to >90 %). a putative group iii adh payq ...201424265029
dissociation of a population of pectobacterium atrosepticum scri1043 in tobacco plants: formation of bacterial emboli and dormant cells.the population dynamics of pectobacterium atrosepticum scri1043 (pba) within tobacco plants was monitored from the time of inoculation until after long-term preservation of microorganisms in the remnants of dead plants. we found and characterised peculiar structures that totally occlude xylem vessels, which we have named bacterial emboli. viable but non-culturable (vbn) pba cells were identified in the remnants of dead plants, and the conditions for resuscitation of these vbn cells were establis ...201423990131
virulence in pectobacterium atrosepticum is regulated by a coincidence circuit involving quorum sensing and the stress alarmone, (p)ppgpp.pectobacterium atrosepticum (pca) is a gram-negative phytopathogen which causes disease by secreting plant cell wall degrading exoenzymes (pcwdes). previous studies have shown that pcwde production is regulated by (i) the intercellular quorum sensing (qs) signal molecule, 3-oxo-hexanoyl-l-homoserine lactone (ohhl), and (ii) the intracellular 'alarmone', (p)ppgpp, which reports on nutrient limitation. here we show that these two signals form an integrated coincidence circuit which ensures that me ...201323957692
structural modelling of substrate binding and inhibition in penicillin v acylase from pectobacterium atrosepticum.penicillin v acylases (pvas) and bile salt hydrolases (bshs) have considerable sequence and structural similarity; however, they vary significantly in their substrate specificity. we have identified a pva from a gram-negative organism, pectobacterium atrosepticum (papva) that turned out to be a remote homolog of the pvas and bshs reported earlier. even though the active site residues were conserved in papva it showed high specificity towards penv and interestingly the penv acylase activity was i ...201323850621
genome sequence of the pectobacterium atrosepticum strain cfbp6276, causing blackleg and soft rot diseases on potato plants and tubers.pectobacterium atrosepticum strain cfbp6276 is a pectinolytic enterobacterium causing blackleg and soft rot of the stem and tuber of solanum tuberosum. its virulence is under the control of quorum sensing, with n-acylhomoserine lactones as communication signals. here, we report the genome sequence of p. atrosepticum strain cfbp6276.201323788545
the endophytic lifestyle of escherichia coli o157:h7: quantification and internal localization in roots.the foodborne pathogen escherichia coli o157:h7 is increasingly associated with fresh produce (fruit and vegetables). bacterial colonization of fresh produce plants can occur to high levels on the external tissue but bacteria have also been detected within plant tissue. however, questions remain about the extent of internalization, its molecular basis, and internal location of the bacteria. we have determined the extent of internalization of e. coli o157:h7 in live spinach and lettuce plants and ...201323506361
differential induction of oxylipin pathway in potato and tobacco cells by bacterial and oomycete elicitors.potato and tobacco cells are differentially suited to study oxylipin pathway and elicitor-induced responses. synthesis of oxylipins via the lipoxygenase (lox) pathway provides plant cells with an important class of signaling molecules, related to plant stress responses and innate immunity. the aim of this study was to evaluate the induction of lox pathway in tobacco and potato cells induced by a concentrated culture filtrate (ccf) from phytophthora infestans and lipopolysaccharide (lps) from pec ...201323479199
potato signal molecules that activate pectate lyase synthesis in pectobacterium atrosepticum scri1043.a new type of plant-derived signal molecules that activate extracellular pectate lyase activity in phytopathogenic bacterium pectobacterium atrosepticum scri1043 was revealed. these compounds were characterized and partially purified by means of several approaches including rt-pcr analysis, luminescence bioassay and hplc fractionation. they were smaller than 1 kda, thermoresistant, nonproteinaceous, hydrophilic, and slightly negatively charged molecules. using gene expression analysis and bacter ...201323413022
a metabolic regulator modulates virulence and quorum sensing signal production in pectobacterium atrosepticum.plant cell wall-degrading enzymes (pcwde) are key virulence determinants in the pathogenesis of the potato pathogen pectobacterium atrosepticum. in this study, we report the impact on virulence of a transposon insertion mutation in the metj gene that codes for the repressor of the methionine biosynthesis regulon. in a mutant strain defective for the small regulatory rna rsmb, pcwde are not produced and virulence in potato tubers is almost totally abolished. however, when the metj gene is disrupt ...201323113713
identification of genes in the virr regulon of pectobacterium atrosepticum and characterization of their roles in quorum sensing-dependent virulence.in the economically important phytopathogen, pectobacterium atrosepticum, expression of plant cell wall degrading enzymes and other virulence determinants is controlled in a cell density-dependent fashion, termed quorum sensing (qs). canonical qs systems in gram-negative bacteria contain a luxi-type protein, synthesizing a signalling molecule, and a luxr-type regulator, responding to the signalling molecule above threshold concentrations. in p. atrosepticum, the central luxr-type repressor of vi ...201322788996
in planta biocontrol of pectobacterium atrosepticum by rhodococcus erythropolis involves silencing of pathogen communication by the rhodococcal gamma-lactone catabolic pathway.the virulence of numerous gram-negative bacteria is under the control of a quorum sensing process based on synthesis and perception of n-acyl homoserine lactones. rhodococcus erythropolis, a gram-positive bacterium, has recently been proposed as a biocontrol agent for plant protection against soft-rot bacteria, including pectobacterium. here, we show that the γ-lactone catabolic pathway of r. erythropolis disrupts pectobacterium communication and prevents plant soft-rot. we report the first char ...201323805254
cytotoxic chromosomal targeting by crispr/cas systems can reshape bacterial genomes and expel or remodel pathogenicity islands.in prokaryotes, clustered regularly interspaced short palindromic repeats (crisprs) and their associated (cas) proteins constitute a defence system against bacteriophages and plasmids. crispr/cas systems acquire short spacer sequences from foreign genetic elements and incorporate these into their crispr arrays, generating a memory of past invaders. defence is provided by short non-coding rnas that guide cas proteins to cleave complementary nucleic acids. while most spacers are acquired from phag ...201323637624
the subtype i-f crispr-cas system influences pathogenicity island retention in pectobacterium atrosepticum via crrna generation and csy complex formation.crispr (clustered regularly interspaced short palindromic repeats) arrays and cas (crispr-associated) proteins confer acquired resistance against mobile genetic elements in a wide range of bacteria and archaea. the phytopathogen pectobacterium atrosepticum scri1043 encodes a single subtype i-f crispr system, which is composed of three crispr arrays and the cas operon encoding cas1, cas3 (a cas2-cas3 fusion), csy1, csy2, csy3 and cas6f (csy4). the crispr arrays are transcribed into pre-crrna (cri ...201324256239
n,n'-alkylated imidazolium-derivatives act as quorum-sensing inhibitors targeting the pectobacterium atrosepticum-induced symptoms on potato tubers.bacteria belonging to the pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. in pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (qs) and n-acylhomoserine lactones (ahls). in this work, we screened a chemical library of qs-inhibitors (qsis) and ahl-analogs to find novel qsis targeting the virulence of pectobacterium. four n,n'-bisalkylated imidazolium salts were identified as qsi ...201324108370
isolation and structure elucidation of linolipins c and d, complex oxylipins from flax leaves.two complex oxylipins (linolipins c and d) were isolated from the leaves of flax plants inoculated with phytopathogenic bacteria pectobacterium atrosepticum. their structures were elucidated based on uv, ms and nmr spectroscopic data. both oxylipins were identified as digalactosyldiacylglycerol (dgdg) molecular species. linolipin c contains one residue of divinyl ether (ω5z)-etherolenic acid and one α-linolenate residue at sn-1 and sn-2 positions, respectively. linolipin d possesses two (ω5z)-et ...201324042063
surface swarming motility by pectobacterium atrosepticum is a latent phenotype that requires o antigen and is regulated by quorum sensing.we describe a previously cryptic phenotype associated with the opportunistic phytopathogen pectobacterium atrosepticum (pca): surface swarming. we found that when pca was spotted onto plates containing <0.5% (w/v) agar, the culture produced copious amounts of extracellular matrix material containing highly motile cells. once produced, this 'slime layer' spread rapidly across the plate either as an advancing front or as tendrils. transposon mutagenesis was used to identify mutants that were affec ...201324025601
role and regulation of the flp/tad pilus in the virulence of pectobacterium atrosepticum scri1043 and pectobacterium wasabiae scc3193.in this study, we characterized a putative flp/tad pilus-encoding gene cluster, and we examined its regulation at the transcriptional level and its role in the virulence of potato pathogenic enterobacteria of the genus pectobacterium. the flp/tad pilus-encoding gene clusters in pectobacterium atrosepticum, pectobacterium wasabiae and pectobacterium aroidearum were compared to previously characterized flp/tad gene clusters, including that of the well-studied flp/tad pilus model organism aggregati ...201324040039
ferredoxin containing bacteriocins suggest a novel mechanism of iron uptake in pectobacterium spp.in order to kill competing strains of the same or closely related bacterial species, many bacteria produce potent narrow-spectrum protein antibiotics known as bacteriocins. two sequenced strains of the phytopathogenic bacterium pectobacterium carotovorum carry genes encoding putative bacteriocins which have seemingly evolved through a recombination event to encode proteins containing an n-terminal domain with extensive similarity to a [2fe-2s] plant ferredoxin and a c-terminal colicin m-like cat ...201222427936
in vivo protein interactions and complex formation in the pectobacterium atrosepticum subtype i-f crispr/cas system.clustered regularly interspaced short palindromic repeats (crispr) and their associated proteins (cas; crispr associated) are a bacterial defense mechanism against extra-chromosomal elements. crispr/cas systems are distinct from other known defense mechanisms insofar as they provide acquired and heritable immunity. resistance is accomplished in multiple stages in which the cas proteins provide the enzymatic machinery. importantly, subtype-specific proteins have been shown to form complexes in co ...201223226499
methylobacterium-induced endophyte community changes correspond with protection of plants against pathogen attack.plant inoculation with endophytic bacteria that normally live inside the plant without harming the host is a highly promising approach for biological disease control. the mechanism of resistance induction by beneficial bacteria is poorly understood, because pathways are only partly known and systemic responses are typically not seen. the innate endophytic community structures change in response to external factors such as inoculation, and bacterial endophytes can exhibit direct or indirect antag ...201223056459
selectivity and self-assembly in the control of a bacterial toxin by an antitoxic noncoding rna pseudoknot.bacterial small rnas perform numerous regulatory roles, including acting as antitoxic components in toxin-antitoxin systems. in type iii toxin-antitoxin systems, small processed rnas directly antagonize their toxin protein partners, and in the systems characterized the toxin and antitoxin components together form a trimeric assembly. in the present study, we sought to define how the rna antitoxin, toxi, inhibits its potentially lethal protein partner, toxn. we show through cross-inhibition exper ...201223267117
viral molecular mimicry circumvents abortive infection and suppresses bacterial suicide to make hosts permissive for replication.the global interplay between bacteria and bacteriophages has generated many macromolecules useful in biotechnology, through the co-evolutionary see-saw of bacterial defense and viral counter-attack measures. bacteria can protect themselves using abortive infection systems, which induce altruistic suicide in an infected cell and therefore protect the clonal population at the expense of the infected individual. our recent paper describes how bacteriophage φte successfully subverted the activity of ...201223739522
molecular characterization of spoilage bacteria as a means to observe the microbiological quality of carrot.this study characterized the bacteria causing decay of carrots during storage and marketing. spoilage strains were identified by 16s-amplified rdna restriction analysis and intergenic transcribed spacer-pcr-restriction fragment length polymorphism (its-pcr-rflp). genotypic fingerprinting by rflp-pulsed-field gel electrophoresis was used to assess the genetic diversity of the isolates. a total of 252 pseudomonas isolates from carrots were identified and classified into eight separate groups. most ...201222410227
top 10 plant pathogenic bacteria in molecular plant pathology.many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. however, to our knowledge, no such list exists. the aim of this review was to survey all bacterial pathologists with an association with the journal molecular plant pathology and ask them to nominate the bacterial pathogens they would place in a 'top 10' based on scientific/economic importance. the survey generated 458 votes from the international ...201222672649
evolution of the metabolic and regulatory networks associated with oxygen availability in two phytopathogenic enterobacteria.dickeya dadantii and pectobacterium atrosepticum are phytopathogenic enterobacteria capable of facultative anaerobic growth in a wide range of o2 concentrations found in plant and natural environments. the transcriptional response to o2 remains under-explored for these and other phytopathogenic enterobacteria although it has been well characterized for animal-associated genera including escherichia coli and salmonella enterica. knowledge of the extent of conservation of the transcriptional respo ...201222439737
pectobacterium spp. associated with bacterial stem rot syndrome of potato in canada.pectobacterium atrosepticum, p. carotovorum subsp. brasiliensis, p. carotovorum subsp. carotovorum, and p. wasabiae were detected in potato stems with blackleg symptoms using species- and subspecies-specific polymerase chain reaction (pcr). the tests included a new assay for p. wasabiae based on the phytase gene sequence. identification of isolates from diseased stems by biochemical or physiological characterization, pcr, and multi-locus sequence typing (mlst) largely confirmed the pcr detection ...201222713077
nicotiflorin, rutin and chlorogenic acid: phenylpropanoids involved differently in quantitative resistance of potato tubers to biotrophic and necrotrophic pathogens.physiological and molecular mechanisms underlying quantitative resistance of plants to pathogens are still poorly understood, but could depend upon differences in the intensity or timing of general defense responses. this may be the case for the biosynthesis of phenolics which are known to increase after elicitation by pathogens. we thus tested the hypothesis that differences in quantitative resistance were related to differential induction of phenolics by pathogen-derived elicitors. five potato ...201222677447
inactivation of pbtopo iiiβ causes hyper-excision of the pathogenicity island hai2 resulting in reduced virulence of pectobacterium atrosepticum.topoisomerase iii enzymes are present only in a limited set of bacteria and their physiological role remains unclear. here, we show that pbtopo iiiβ, a homologue of topoisomerase iii encoded on the chromosome of pectobacterium atrosepticum strain scri1043 (pba scri1043), is involved in excision of hai2, a discrete ~100 kb region, from the pba scri1043 chromosome. hai2 is a pathogenicity island (pai) that encodes coronafacic acid (cfa), a major virulence determinant required for infection of pota ...201222524709
microbial conversion of tomato by a plant pathogenic bacterium pectobacterium atrosepticum: a plant-microbial approach to control pathogenic candida species.this study was carried out to produce bioconverted products by microbial fermentation of tomato using a plant pathogenic bacterium pectobacterium atrosepticum and to evaluate their in vitro antimycotic effect against pathogenic candida species. the bioconverted products (500 microg/disc) provoked promising antimycotic effects against pathogenic isolates of candida species as shown by the diameters of zones of inhibition (9 +/- 0.6 to 14 +/- 0.4 mm), along with their respective minimum inhibitory ...201222428249
calcium- and ros-mediated defence responses in by2 tobacco cells by nonpathogenic streptomyces sp.the early molecular events underlying the elicitation of plant defence reactions by gram-positive bacteria are relatively unknown. in plants, calcium and reactive oxygen species are commonly involved as cellular messengers of a wide range of biotic stimuli from pathogenic to symbiotic bacteria. in the present work, we checked whether nonpathogenic streptomyces sp. strains could induce early signalling events leading to defence responses in by2 tobacco cell suspensions.201222292528
viral evasion of a bacterial suicide system by rna-based molecular mimicry enables infectious altruism.abortive infection, during which an infected bacterial cell commits altruistic suicide to destroy the replicating bacteriophage and protect the clonal population, can be mediated by toxin-antitoxin systems such as the type iii protein-rna toxin-antitoxin system, toxin. a flagellum-dependent bacteriophage of the myoviridae, φte, evolved rare mutants that "escaped" toxin-mediated abortive infection within pectobacterium atrosepticum. wild-type φte encoded a short sequence similar to the repetitive ...201223109916
a processed noncoding rna regulates an altruistic bacterial antiviral system.the ≥ 10³⁰ bacteriophages on earth relentlessly drive adaptive coevolution, forcing the generation of protective mechanisms in their bacterial hosts. one such bacterial phage-resistance system, toxin, consists of a protein toxin (toxn) that is inhibited in vivo by a specific rna antitoxin (toxi); however, the mechanisms for this toxicity and inhibition have not been defined. here we present the crystal structure of the toxn-toxi complex from pectobacterium atrosepticum, determined to 2.75-å reso ...201121240270
regulation of type vi secretion gene clusters by sigma54 and cognate enhancer binding proteins.type vi secretion systems (t6ss) are bacteriophage-derived macromolecular machines responsible for the release of at least two proteins in the milieu, which are thought to form an extracellular appendage. although several t6ss have been shown to be involved in the virulence of animal and plant pathogens, clusters encoding these machines are found in the genomes of most species of gram-negative bacteria, including soil, marine, and environmental isolates. t6ss have been associated with several ph ...201121378190
csy4 is responsible for crispr rna processing in pectobacterium atrosepticum.crispr/cas systems provide bacteria and archaea with small rna-based adaptive immunity against foreign elements such as phages and plasmids. an important step in the resistance mechanism involves the generation of small guide rnas (crrnas) that, in combination with cas proteins, recognize and inhibit foreign nucleic acids in a sequence specific manner. the generation of crrnas requires processing of the primary crispr rna by an endoribonuclease. in this study we have characterized the ypest subt ...201121519197
lpxc and yafs are the most suitable internal controls to normalize real time rt-qpcr expression in the phytopathogenic bacteria dickeya dadantii.quantitative rt-pcr is the method of choice for studying, with both sensitivity and accuracy, the expression of genes. a reliable normalization of the data, using several reference genes, is critical for an accurate quantification of gene expression. here, we propose a set of reference genes, of the phytopathogenic bacteria dickeya dadantii and pectobacterium atrosepticum, which are stable in a wide range of growth conditions.201121637857
n-acetylglucosamine-dependent biofilm formation in pectobacterium atrosepticum is cryptic and activated by elevated c-di-gmp levels.the phytopathogenic bacterium pectobacterium atrosepticum (pba) strain scri1043 does not exhibit appreciable biofilm formation under standard laboratory conditions. here we show that a biofilm-forming phenotype in this strain could be activated from a cryptic state by increasing intracellular levels of c-di-gmp, through overexpression of a constitutively active diguanylate cyclase (pled*) from caulobacter crescentus. randomly obtained pba transposon mutants defective in the pga operon, involved ...201121948048
quantitative resistance of potato to pectobacterium atrosepticum and phytophthora infestans: integrating pamp-triggered response and pathogen growth.while the mechanisms underlying quantitative resistance of plants to pathogens are still not fully elucidated, the pathogen-associated molecular patterns (pamps)-triggered response model suggests that such resistance depends on a dynamic interplay between the plant and the pathogen. in this model, the pathogens themselves or elicitors they produce would induce general defense pathways, which in turn limit pathogen growth and host colonisation. it therefore suggests that quantitative resistance i ...201121853112
Chemical structure of the O-polysaccharide isolated from Pectobacterium atrosepticum SCRI 1039.The lipopolysaccharide (LPS) of the bacterium Pectobacterium atrosepticum SCRI 1039 was hydrolyzed and the products were separated. A study of the obtained O-polysaccharide by means of chemical methods, GLC, GLC-MS, and NMR spectroscopy allowed us to identify a branched polymer with a pentasaccharide repeating unit of the structure shown below, in which the fucose residue was partially O-acetylated at C-2, C-3 or C-4.201122074675
a multi-repeat adhesin of the phytopathogen, pectobacterium atrosepticum, is secreted by a type i pathway and is subject to complex regulation involving a non-canonical diguanylate cyclase.cyclic diguanylate (c-di-gmp) is a second messenger controlling many important bacterial processes. the phytopathogen pectobacterium atrosepticum scri1043 (pba1043) possesses a type i secretion system (t1ss) essential for the secretion of a proteinaceous multi-repeat adhesin (mrp) required for binding to the host plant. the genes encoding the mrp and the t1ss are tightly linked to genes encoding several putative c-di-gmp regulatory components. we show that c-di-gmp regulates secreted mrp levels ...201121992096
microbial fermentation of cabbage by a bacterial strain of pectobacterium atrosepticum for the production of bioactive material against candida species.the objective of this study was to produce the bioactive fermented product by the microbial fermentation of cabbage (brassica oleracea) using a bacterial strain pectobacterium atrosepticum which was assessed for its antimycotic efficacy against pathogenic isolates of candida species.201123177810
control of potato soft rot caused by pectobacterium carotovorum and pectobacterium atrosepticum by moroccan actinobacteria isolates.pectobacterium carotovorum and pectobacterium atrosepticum are dreadful causal agents of potato soft rot. actually, there are no efficient bactericides used to protect potato against pectobacterium spp. biological control using actinobacteria could be an interesting approach to manage this disease. thus, two hundred actinobacteria isolated from moroccan habitats were tested for their ability to inhibit in vitro 4 environmental pectobacterium strains and the two reference strains (p. carotovorum ...201122806806
phage-selected lipopolysaccharide mutants of pectobacterium atrosepticum exhibit different impacts on virulence.to positively select pectobacterium atrosepticum (pa) mutants with cell surface defects and to assess the impact of these mutations on phytopathogenesis.201020132374
two mobile pectobacterium atrosepticum prophages modulate virulence.the pectobacterium atrosepticum strain scri1043 genome contains two complete prophage sequences. one, eca41, is mu-like and is able to integrate into, and excise from, various genomic locations. the other, eca29, is a p2 family prophage, and is also able to excise from the genome. excision of both prophages is rare and we were unable to induce lysis of cultures. deletion of the entire prophages, both separately and in combination, did not affect the growth rate or the secretion of plant cell wal ...201020146746
quorum sensing-controlled evr regulates a conserved cryptic pigment biosynthetic cluster and a novel phenomycin-like locus in the plant pathogen, pectobacterium carotovorum.pectobacterium carotovorum scri193 is a phytopathogenic gram-negative bacterium. in this study, we have identified a novel cryptic pigment biosynthetic locus in p. carotovorum scri193 which we have called the pectobacterium orange pigment (pop) cluster. the pop cluster is flanked by two trna genes and contains genes that encode non-ribosomal peptide synthases and polyketide synthase and produces a negatively charged polar orange pigment. orange pigment production is activated when an adjacent tr ...201020192973
effect of water activity on the production of volatile organic compounds by muscodor albus and their effect on three pathogens in stored potato.muscodor albus (xylariaceae, ascomycetes) isolate cz-620 produces antimicrobial volatile organic compounds (voc), which appear to have potential for the control of various postharvest diseases. the effect of water activity (aw) on the production of voc by m. albus culture, and their inhibitory effects on the growth of three pathogens of potato tuber (fusarium sambucinum, helminthosporium solani, and pectobacterium atrosepticum) and the development of diseases caused by the three pathogens (dry r ...201021354528
aepa of pectobacterium is not involved in the regulation of extracellular plant cell wall degrading enzymes production.plant cell wall degrading enzymes (pcwde) are the major virulence determinants in phytopathogenic pectobacterium, and their production is controlled by many regulatory factors. in this study, we focus on the role of the aepa protein, which was previously described to be a global regulator of pcwde production in pectobacterium carotovorum (murata et al. in mol plant microbe interact 4:239-246, 1991). our results show that neither inactivation nor overexpression of aepa affects pcwde production in ...201020386924
comparison of specificity and sensitivity of immunochemical and molecular techniques for determination of clavibacter michiganensis subsp. michiganensis.detection of clavibacter michiganensis subsp. michiganensis (cmm), causing bacterial canker of tomato, was verified using pta-elisa and ifas with pabs of neogen europe ltd. (uk), and with published and also laboratory-generated pcr primers from the cmm tomatinase gene. the specificity of this technique was determined with 15 plant-pathogenic and 4 common, saprophytic bacteria. with ifas, crossreactions were found for pantoea dispersa, p. agglomerans and rahnella aquatilis, and with pta-elisa for ...201020526836
reverse engineering gene regulatory networks related to quorum sensing in the plant pathogen pectobacterium atrosepticum.the objective of the project reported in the present chapter was the reverse engineering of gene regulatory networks related to quorum sensing in the plant pathogen pectobacterium atrosepticum from micorarray gene expression profiles, obtained from the wild-type and eight knockout strains. to this end, we have applied various recent methods from multivariate statistics and machine learning: graphical gaussian models, sparse bayesian regression, lasso (least absolute shrinkage and selection opera ...201020835805
occurrence of pectobacterium carotovorum strains isolated from potato soft rot in morocco.pectobacterium carotovorum subsp. carotovorum, pectobacterium astrosepticum and pectobacterium chrysanthemi are the soft rot tuber of potatoes pathogens (solanum tuberosum). the aim of this study was to determine the occurrence of these pathogens in moroccan regions producing potatoes. fifty three isolates of pectobacterium were isolated on medium crystal violet pectate. the comparison of their bacteriological characteristics with standard strains allowed us to conclude that all the isolates bel ...201020937219
specific maceration and induction of pr-3 gene in potato tuber tissue by pectobacterium carotovorum subsp. atrosepticum type iii secretion system mutants.the exact function of type iii secretion system in some phytopathogenes including pectobacterium carotovorum subsp. atrosepticum (pca) is not understood and is a matter of debate. the aim of this study were to determine specific effect of type iii secretion system on potato tubers and to reveal the connection of this system with potato resistant genes such as pr-3. a pca hrpw fragment was subcloned into a low-copy-number cloning vector (pzh448). the resulting plasmid (pas19) was then conjugated ...200920334119
the r1162 mob proteins can promote conjugative transfer from cryptic origins in the bacterial chromosome.the mobilization proteins of the broad-host-range plasmid r1162 can initiate conjugative transfer of a plasmid from a 19-bp locus that is partially degenerate in sequence. such loci are likely to appear by chance in the bacterial chromosome and could act as cryptic sites for transfer of chromosomal dna when r1162 is present. the r1162-dependent transfer of chromosomal dna, initiated from one such potential site in pectobacterium atrosepticum, is shown here. a second active site was identified in ...200919074386
physicochemical basis for the inhibitory effects of organic and inorganic salts on the growth of pectobacterium carotovorum subsp. carotovorum and pectobacterium atrosepticum.twenty-one salts were tested for their effects on the growth of pectobacterium carotovorum subsp. carotovorum and pectobacterium atrosepticum. in liquid medium, 11 salts (0.2 m) exhibited strong inhibition of bacterial growth. the inhibitory action of salts relates to the water-ionizing capacity and the lipophilicity of their constituent ions.200919114504
lines of evidence for horizontal gene transfer of a phenazine producing operon into multiple bacterial species.phenazines are secondary metabolites with broad-spectrum antibiotic activity against bacteria, fungi, and eukaryotes. in pseudomonad species, a conserved seven-gene phenazine operon (phzabcdefg) is required for the conversion of chorismic acid to the broad-spectrum antibiotic phenazine-1-carboxylate. previous analyses of genes involved in phenazine production from nonpseudomonad species uncovered a high degree of sequence similarity to pseudomonad homologues. the analyses undertaken in this stud ...200919189039
small rna identification in enterobacteriaceae using synteny and genomic backbone retention ii.small rnas are bacterial counterparts of noncoding rnas. increasing evidence being added in the literature indicates that these small rnas play major roles in prokaryotes both at the transcriptome and proteome levels. based on comparative genomic studies, we present manually curated small rna regions in 25 recently completed genomes from enterobacteriaceae. the study is a continuation of our earlier work that uses the presence of small rnas sandwiched between specific conserved flanking genes re ...200919445646
mutagenesis and functional characterization of the rna and protein components of the toxin abortive infection and toxin-antitoxin locus of erwinia.bacteria are constantly challenged by bacteriophage (phage) infection and have developed multiple adaptive resistance mechanisms. these mechanisms include the abortive infection systems, which promote "altruistic suicide" of an infected cell, protecting the clonal population. a cryptic plasmid of erwinia carotovora subsp. atroseptica, peca1039, has been shown to encode an abortive infection system. this highly effective system is active across multiple genera of gram-negative bacteria and agains ...200919633081
microarray comparative genomic hybridisation analysis incorporating genomic organisation, and application to enterobacterial plant pathogens.microarray comparative genomic hybridisation (acgh) provides an estimate of the relative abundance of genomic dna (gdna) taken from comparator and reference organisms by hybridisation to a microarray containing probes that represent sequences from the reference organism. the experimental method is used in a number of biological applications, including the detection of human chromosomal aberrations, and in comparative genomic analysis of bacterial strains, but optimisation of the analysis is desi ...200919696881
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