Methods of identifying an organism
This disclosure features methods of identifying an organism. In certain embodiments, the invention provides methods of distinguishing virulent and non-virulent strains of Listeria monocytogenes.
1. A method of distinguishing virulent and low- or non-violent strains of Listeria monocytogenes , the method comprising:
obtaining a nucleic acid from L. monocytogenes;
preparing an optical map of one or more restriction digests of the obtained nucleic acid; and
detecting an insertion that is at least 48.3 kb in size in a clpP gene of a genome of L. monocytogenes , wherein presence of the insertion is indicative of a low- or non-virulent strain of L. monocytogenes.
2. The method according to claim 1 , wherein the nucleic acid is obtained from at least one sample type selected from the group consisting of: a food sample, an environmental sample, and a human tissue or body fluid sample.
3. The method according to claim 2 , wherein the environmental sample is selected from the group consisting of water, soil, sewage, and decaying vegetable matter.
4. The method according to claim 2 , wherein the tissue or body fluid is from a human having a disease selected from the group consisting of meningitis, gastroenteritis, and septicemia.
5. The method according to claim 1 , wherein the L. monocytogenes is classified as a serotype 4b strain.
6. The method according to claim 1 , wherein the L. monocytogenes is classified as a serotype 1/2a strain.
7. The method according to claim 1 , wherein the L. monocytogenes low- or non-virulent strain is selected from the group consisting of L. monocytogenes BO43 or L. monocytogenes 416.
8. The method according to claim 1 , wherein the L. monocytogenes virulent strain is selected from the group consisting of L. monocytogenes strain 4b F2365 , L. monocytogenes strain EGD-e, L. monocytogenes strain A23 , L. monocytogenes Clip81459 ‘4b CLIP80459’.