Fernando for his help in the isolation of phages in An overnight nutrient broth culture of isolate was centrifuged at 12, x g for 4 min. Roach stability varied widely and constantly generated large numbers of cured cells that had lost their lysogenic status. Centrifugation at x g for 25 min removed bacterial debris and agar. Author information Article notes Copyright and License information Disclaimer. The disease and its causative agent, Erwinia amylovora ed.

The lysogen therefore demonstrated homo-infection immunity to similar phages. All mutants were grown in NB. Streptomycin is an aminoglycoside that inhibits protein synthesis, disrupting normal bacterial cell function that eventually leads to cell death Psallidas and Tsiantos ; Norelli et al. Excellent control of shoot blight severity by injected OTC implies that this compound in injectable formulation most likely limits systemic spread of E. Management of fire blight:

The driver of this effect was probably the high transpiration rate of shoots which hold the largest leaf area in the apple canopy.

(PDF) Erwinia amylovora Bacteriophage Resistance | Dwayne Roach –

The aim of these studies was to investigate two common bacterial resistance mechanisms, lysogeny and exopolysaccharide production and their influence erwina phage pathogenesis.

The pathogen eventually gains entry into the natural openings nectaries on the hypanthium. One of the common modes of adsorption interference for phage is through mutation or recombination of bacterial genes.

Over the course of selected treatments, Lehman used multiplex real-time peR to follow population sizes of the phage, carrier and pathogen simultaneously. He conducted several phage therapy studies to control avian typhosis, bovine hemorrhagic septicemia, rhesis dysentery, and bubonic plague Summers ; ; A modified PCR deletion method 2448 was used to generate E.


Roach Acknowledgements I would like to thank my supervisory committee members, Drs. Biopesticides are derived from natural materials as animals, plants, bacteria, and certain minerals. Ann Appl Bioi 89, Targeting specifIc phage family genes with qPCR was able to distinguish an isolates family identity with ease. Genetics of sorbitol metabolism erwiniw Erwinia amylovora and its influence on bacterial virulence.

Please review our privacy policy. The only prophage genes that eriwnia transcribed are those that maintain a repressed state.

erwinia amylovora thesis

Prophage screening of environmental samples of E. Assay host refers to the tested host, and isolation host refers to the E. Its role in inhibition of Erw in ia amylovora and partial characterization of antibiotic biosynthesis genes. The probability of specialized transduction or lysogenic conversion seems to be low for E.

The primers specific to the sequences upstream and downstream of the gene target site and coding region of the antibiotic resistance expression cassette insert were used to confirm gene deletion Fig.

It is unknown if RcsA or RcsB are involved in lse gene expression since res-mutants produce the same amount of levan as the non-mutant strain.

All pear varieties grown worldwide are moderately to highly susceptible to fire blight. In the resulting mutants, a section of the coding region of each target gene was replaced by the CmR or KmR insert marker and mutants are listed in Table 1. Dynamics of the pseudolysogenic response in slowly growing cells of Pseudomonas aeruginos a.

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Pseudolysogenic conversions have been shown to confer host phenotypic changes such as pigment production, nutritional changes, toxin production, and superinfection immunity Ripp and Miller ; Williamson et al.


I would like to include my gratitude to the Agriculture and Agri-Food Canada staff at Vineland Station for their insightful commentary and support which made my time there enjoyable. The recovered putative lysogens were assayed from three cultures cultivated from frozen stocks. A detailed thseis of amylovroa first step in the infection process will provide strategies to construct a cocktail of phages, each utilizing different cell surface receptors.

Restriction analysis of DNA from Erwinia spp. I would like thank the past and present members of the Svircev and Castle labs, for their guidance and indispensable assistance during my time in the lab: Springer, Heidelberg, Germany [ Google Scholar ].

Single colonies from MMS were subcultured on nutrient agar NA, Difco for 72 h and bacterial lawn was aseptically scraped into storage medium. The profile was consistent and considered to be the result of nucleotide variability in the target sequence rather then from non-specific amplification of a non-target sequence.

erwinia amylovora thesis

Each strain was mixed with 10 3 PFU of each phage and plated using the double-layer agar technique. Bacterial isolates and bacteriophages.

The natural spontaneous induction of prophage’s lytic cycle was not observed in any of the E.