Charcoal-free culture media for legionella

1. An in vitro method for culturing a Legionella bacterium, comprising incubating a Legionella bacterium on a charcoal-free solid agar medium comprising:

a) serum, wherein the serum is present at a concentration of 1%-35% (v/v);

b) a nitrogen source; and

c) an iron source.

2. A screening method for identifying an antibiotic suitable for suppressing the growth of a Legionella bacterium, comprising:

a. contacting a Legionella bacterium with a charcoal-free solid agar medium to provide a test sample, wherein the charcoal-free solid agar medium comprises:

i. serum, wherein the serum is present at a concentration of 1%-35% (v/v);

ii. a nitrogen source; and

iii. an iron source;

b. incubating the test sample in the presence of a candidate antibiotic; and

c. identifying said candidate antibiotic as suitable for suppressing the growth of the Legionella bacterium when the bacterial load of said Legionella bacterium in the test sample subsequent to incubation is lower than a bacterial load of said Legionella bacterium in a control sample, wherein the control sample is incubated in the absence of said candidate antibiotic; or

d. identifying said candidate antibiotic as unsuitable for suppressing the growth of the Legionella bacterium when the bacterial load of said Legionella bacterium in the test sample subsequent to incubation is the same as or greater than the bacterial load of said Legionella bacterium in a control sample, wherein the control sample is incubated in the absence of said candidate antibiotic.

3. A kit comprising a charcoal-free solid agar medium for culturing a Legionella bacterium, and/or reagents for preparing a charcoal-free solid agar medium for culturing the Legionella bacterium, wherein:

a. said charcoal-free solid agar medium comprises:

i. serum, wherein the serum is present at a concentration of 1%-35% (v/v);

ii. a nitrogen source; and

iii. an iron source; and/or

b. said reagents comprise:

i. agar;

ii. serum;

iii. a nitrogen source; and

iv. an iron source; and

wherein said kit further comprises instructions for culturing the Legionella bacterium on said charcoal-free solid agar medium.

4. The screening method according to claim 2 , wherein said method further comprises the step of recording data obtained in step (c) and/or step (d) on a suitable data carrier.

5. The method according to claim 1 , wherein said nitrogen source is one or more of yeast extract, beef extract, liver extract, casein hydrolysate, plant cell extract, soy bean extract or any combination thereof.

6. The method according to claim 1 , wherein the iron source is an iron chelate and/or ferric pyrophosphate.

7. The method according to claim 1 , wherein:

a. the agar is present at a concentration of 0.2%-5% (w/v);

b. the nitrogen source is present at a concentration of 0.2%-10% (w/v); and/or

c. the iron source is present at a concentration of 0.01%-0.1% (w/v).

8. The method according to claim 1 , wherein said charcoal-free solid agar medium further comprises one or more agent comprising:

a. a buffer;

b. alpha-ketoglutarate; and/or

c. cysteine.

9. The method according to claim 1 , wherein said charcoal-free solid agar medium further comprises one or more agent comprising:

a. a buffer that is present at a concentration of 1 mM-500 mM;

b. alpha-ketoglutarate that is present at a concentration of 0.001%-1% (w/v); and/or

c. cysteine that is present at a concentration of 1%-10% (w/v).

10. The method according to claim 1 , wherein said serum is one or more of horse serum, sheep serum, goat serum, bovine serum, fetal bovine serum, calf serum, mouse serum, rat serum, pig serum, guinea pig serum, porcine serum, or rabbit serum.

11. The method according to claim 1 , wherein said serum is horse serum.

12. The method according to claim 1 , wherein the Legionella bacterium is one or more of the following species: L. adelaidensis, L. anisa, L. beliardensis, L. birminghamensis, L. bozemanae, L. brunensis, L. busanensis, L. cherrii, L. cincinnatiensis, L. donaldonsii, L. dresdeniensis, L. dumoffii, L. erythra, L. fairfieldensis, L. feeleii, L. geestiana, L. gormanii, L. gratiana, L. gresilensis, L. hackeliae sg 1 , L. impletisoli, L. israelensis, L. jamestowniensis, L. jordanis, L. lansingensis, L. londiniensis, L. longbeachae, L. maceachernii, L. micdadei, L. micdadei, L. moravica, L. pneumophila, L. nagasakiensis, L. taurinensis, L. wadsworthii , or L. yabuuchiae.

13. The screening method according to claim 2 , wherein said nitrogen source is one or more of yeast extract, beef extract, liver extract, casein hydrolysate, plant cell extract, soy bean extract or any combination thereof.

14. The screening method according to claim 2 , wherein the iron source is an iron chelate and/or ferric pyrophosphate.

15. The screening method according to claim 2 , wherein:

a. the agar is present at a concentration of 0.2%-5% (w/v);

b. the nitrogen source is present at a concentration of 0.2%-10% (w/v); and/or

c. the iron source is present at a concentration of 0.01%-0.1% (w/v).

16. The screening method according to claim 2 , wherein said charcoal-free solid agar medium further comprises one or more agent comprising:

a. a buffer;

b. alpha-ketoglutarate; and/or

c. cysteine.

17. The screening method according to claim 2 , wherein said charcoal-free solid agar medium further comprises one or more agent comprising:

a. a buffer that is present at a concentration of 1 mM-500 mM;

b. alpha-ketoglutarate that is present at a concentration of 0.001%-1% (w/v); and/or

cysteine that is present at a concentration of 1%-10% (w/v).

18. The screening method according to claim 2 , wherein said serum is one or more of horse serum, sheep serum, goat serum, bovine serum, fetal bovine serum, calf serum, mouse serum, rat serum, pig serum, guinea pig serum, porcine serum, or rabbit serum.

19. The screening method according to claim 2 , wherein said serum is horse serum.

20. The screening method according to claim 2 , wherein the Legionella is one or more of the following species: L. adelaidensis, L. anisa, L. beliardensis, L. birminghamensis, L. bozemanae, L. brunensis, L. busanensis, L. cherrii, L. cincinnatiensis, L. donaldonsii, L. dresdeniensis, L. dumoffii, L. erythra, L. fairfieldensis, L. feeleii, L. geestiana, L. gormanii, L. gratiana, L. gresilensis, L. hackeliae sgl, L. impletisoli, L. israelensis, L. jamestowniensis, L. jordanis, L. lansingensis, L. londiniensis, L. longbeachae, L. maceachernii, L. micdadei, L. micdadei, L. moravica, L. pneumophila, L. nagasakiensis, L. taurinensis, L. wadsworthii , or L. yabuuchiae.