Method for treatment and control of plant disease

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.