A few phages in all three families showed apparently reduced progeny production in both mutant backgrounds, although the results were not statistically significant. Despite being a chemoautotroph, the bacterium is incapable of degrading plant tissue since it does not produce cellulolytic or pectinolytic enzymes Seemuller and Beer Phages were enriched by inoculating liquid bacterial cultures prepared in 0. Overexpression of amylovoran does decreased the amount of levansucrase secreted by the cell Bereswill et al. Here, a PCR-based one step deletion of chromosomal genes derived from the A phage RED system was used to generate amylovoran rcsB and levansucrase lsc- deficient mutants to remove potential surface receptors on E. R and Stewart, F. However, amylovoran produced by E.

After several attempts with several E. The host bacterium acts as a carrier by providing safe haven for phages that are currently in their lytic replication cycle within bacterial cells during biopesticide application. Example of PCR confirmation of homologous recombination to generate exopolysaccharide deficient mutants. For each isolate, three slices were placed on a sterile moist filter paper in a sterile plastic dish. But the overuse has led to the development of streptomycin-resistant E. Isolation trials were carried out from infected apples Malus domestica and pears Pyrus communis tissues blossoms, leaves, spurs and stem with cankers , as well as, twig pieces with well developed symptoms. The recovered putative lysogens were assayed from three cultures cultivated from frozen stocks.

Phage-mediated biological control of Erwinia amylovora: The role of CRISPRs and exopolysaccharide

The degree of plaque clearing was measured visually by ammylovora plaque turbidity in comparison to the surrounding bacterial lawn. The similar production on all hosts was consistent with clear plaque formation and strong EOPs for most isolates Table 2.


Furthermore, regulated synthesis of EPS may be advantageous for the bacteria to avoid unnecessary energy expenditures by overproducing EPS. Roach Another unique characteristic of an Abi system is that bacterial cell lysis follows inhibition of phage replication. The host erwibia ofthe five phages varied and one was able to infect all 52 E. The efficiency of plating EOP of several phages was also calculated Table Presence or absence of prophage was determined by phage gene detection and lytic induction.

The aim of my study was to design and validate rtPCR primers and probes that could detect, quantify, and discriminate between Erwinia spp.

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Phages have the capacity to alter bacterial adhesion, colonization, invasion, spread, resistance to host immune defenses and bacterial exotoxin production Bossi et al. Expert Opin Ther Pat 17, Despite the ability of each of the phages to infect E.

erwinia amylovora thesis

Geier G, Geider K. Mol Plant Microbe Int 23, This stage is less susceptible to infection by the pathogen.

Host Exopolysaccharide Quantity and Composition Impact Erwinia amylovora Bacteriophage Pathogenesis

Simultaneously, the same reactions were run but with the addition of a non-target DNA sample. This creates pores in the cell wall and allows phage DNA entry into the cell.

erwinia amylovora thesis

For induction of copious amounts ofEPS, 0. For Myoviridae phages, the opposite was found, EOP of around 1. Amylovoran production was almost undetectable in all mutants with rcsB gene deletions Fig. These latter sensitivities are equivalent to 1 virion per 2 JlI sample.

The only investigation of blossom blight control with trunk-injection of plant resistance inducer, evaluated PCA, the free acid of prohexadione-calcium Apogee, BASF Corp. Novel virulent and broad-host-range Erwinia amylovora bacteriophages reveal a high degree of mosaicism and a relationship to Enterobacteriaceae Phages.


Ann Appl Bioi 89, The majority of Abi systems are encoded erwiniw plasmids of Gram positive bacteria that include Bacillus licheniformis Tran et al. This article has been cited by other articles in PMC.

Roach Abstract It has been proposed that phages can be used commercially as a biopesticide for the control of fire blight caused by the phytopathogen Erwinia amylovora.

Can J Microbio 1 17, Abi systems often are highly effective once activated. Vanneste J L, editor. Department of Biological Sciences. This means that you will not need to remember your user name and password in the future and you will be able to login with the account you choose to sync, with the click of a button. Demonstrating whether potassium phosphites induce PR gene expression was of particular interest since previous studies lack this evidence, even though claiming plant resistance induction Gozzo and Faoro, Evolution 15, Addition of sorbitol and sucrose to the medium resulted in no statistical difference for EaR, Ea, and EaD-7 and modest increases in levansucrase activity for Ea, Ea, and EaG Mutants deficient in levansucrase synthesis still induce fire blight symptoms on pear shoots, but necrosis is slowed when compared to wild type isolates Geier and Geider Our study was carried out to investigate fire blight disease of apple and pear and its causal pathogen, Erwinia amylovora.

erwinia amylovora thesis

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