Method for treatment and control of plant disease

Patent metadata

Field	Value
Publication number	US-11976265-B2
Application number	US-202117497582-A
Country	US
Kind code	B2
Filing date	Oct 8, 2021
Priority date	Oct 19, 2012
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

Methods and compositions are provided for preventing or reducing symptoms or disease associated with Xylella fastidiosa or Xanthomonas axonopodis in a plant. The invention provides novel bacteriophages virulent to Xylella fastidiosa or Xanthomonas axonopodis, including XfaMija and XfaMijo, and further provides methods for treating or preventing Pierce's Disease or Citrus Canker in plants.

First claim

What is claimed is:

1. A method of propagating a virulent bacteriophage that includes X. fastidiosa in its host range, comprising infecting a culture of Xanthomonas bacteria with said virulent bacteriophage, allowing said bacteriophage to propagate, and isolating virulent bacteriophage particles from the culture.

2. The method of claim 1 , wherein the bacteriophage infects the cell by binding to a cell surface feature.

3. The method of claim 1 , wherein said cell surface feature is a Type IV pilus.

4. The method of claim 1 , wherein said virulent bacteriophage comprises a tailed bacteriophage from the group consisting of a podophage, a siphophage, and a myophage.

5. The method of claim 1 , wherein said virulent bacteriophage is isolated from the environment.

6. The method of claim 1 , wherein the bacteriophage is isolated from a sewage treatment plant or effluent therefrom.

7. The method of claim 1 , wherein the bacteriophage is isolated from a plant or a surface thereof or from the surrounding soil.

8. The method of claim 1 , wherein the Xanthomonas bacteria is capable of replicating hourly.

9. The method of claim 1 , wherein the bacteriophage is virulent in Xylella fastidiosa.

10. The method of claim 1 , wherein allowing the bacteriophage to propagate comprises the use of agar overlaying for growth of the bacteriophage.

11. The method of claim 1 , wherein the culture of Xanthomonas bacteria comprises strain EC-12, a representative sample having been deposited under ATCC Accession Number PTA-13101.

12. The method of claim 1 , wherein the bacteriophage is selected from the group consisting of bacteriophages of the Xfas100 phage type, bacteriophages of the Xfas300 phage type, and bacteriophages of the Xfas500 type;
wherein the Xfas100 phage type displays the following characteristics:
(a) the bacteriophage is capable of lysing said Xylella fastidiosa;
(b) the bacteriophage infects a cell by binding to a Type IV pilus;
(c) the bacteriophage comprises a non-contractile tail and a capsid size ranging from 55-77 nm in diameter, with a morphology typical of the Siphoviridae family; and
(d) the genomic size of the bacteriophage is 55500 bp to 56200 bp;

wherein the Xfas300 phage type displays the following characteristics:
(e) the bacteriophage is capable of lysing said Xylella fastidiosa;
(f) the bacteriophage infects a cell by binding to a Type IV pilus;
(g) the bacteriophage comprises a morphology typical of the Podoviridae family characterized by a non-contractile tail with a capsid size ranging from 58-68 nm in diameter; and
(h) the genomic size of the bacteriophage is 43300 bp to 44600 bp; and further wherein the Xfas500 phage type displays the following characteristics:
(i) the bacteriophage is capable of lysing said Xylella fastidiosa;
(j) the bacteriophage infects a cell by binding to a Type IV pilus;
(k) the bacteriophage comprises a morphology typical of the Myoviridae family characterized by a contractile tail with a capsid size ranging from 85-95 nm in diameter; and
(l) the genomic size of the bacteriophage is about 190000 bp to about 230000 bp.

13. The method of claim 12 , wherein the Xfas100 phage type comprises a genome with a DNA sequence 90% or more identical to a sequence selected from the group consisting of SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, and SEQ ID NO:18; the Xfas300 phage type comprises a genome with a DNA sequence 90% or more identical to a sequence selected from the group consisting of SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID 22, SEQ ID NO:23, and SEQ ID NO:24; and wherein the Xfas500 phage type comprises a genome with a DNA sequence selected from the group consisting of SEQ ID NO:25-30.

14. The method of claim 1 , wherein representative samples of said bacteriophage have been deposited under ATCC Accession Numbers PTA-13096, PTA-13095, PTA-13098, PTA-13099, PTA-13100, and PTA-13097, respectively, for bacteriophages Xfas103, Xfas106, Xfas302, Xfas303, Xfas304, and Xfas306; and ATCC Accession Numbers ATCC PTA-122743, and ATCC PTA-122742, respectively, for bacteriophages Xfas501 and Xfas502.

15. The method of claim 1 , wherein the titer of a solution or a lysate of isolated virulent bacteriophage particles is about 1×10 1 to about 1×10 12 PFU/ml.

16. The method of claim 1 , wherein:
allowing said bacteriophage to propagate comprises growing a culture of bacteria infected with the bacteriophage on a soft agar overlay; or
isolating virulent bacteriophage particles from the culture comprises centrifugation, filtration, or dialysis to recover the bacteriophage particles.

Assignees

• Texas A & M Univ Sys
• The Texas A&MUniversity System

Inventors

• Gonzalez Carlos F
• Ahern Stephen J
• Das Mayukh
• Young Iii Ryland F
• Bhowmick Tushar Suvra

Classifications

• C12N1/00 Primary

  Microorganisms; Compositions thereof (medicinal preparations containing material from protozoa, bacteria or viruses A61K35/66, from algae A61K36/02, from fungi A61K36/06; preparing medicinal bacterial antigen or antibody compositions, e.g. bacterial vaccines, A61K39/00); Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor · CPC title

• A01N63/40

  Viruses, e.g. bacteriophages · CPC title

• C12N7/00 Primary

  Viruses; Bacteriophages; Compositions thereof; Preparation or purification thereof (preparing medicinal viral antigen or antibody compositions, e.g. virus vaccines, A61K39/00) · CPC title

• C12N15/8281

  for bacterial resistance · CPC title

• C12N2795/10121

  Viruses as such, e.g. new isolates, mutants or their genomic sequences · CPC title