Methods for diagnosing bacterial infections
The present invention is directed to methods of determining the presence or absence of a bacterial infection in a patient using isotopically-labeled tyrosine and/or isotopically-labeled p-hydroxyphenylacetic acid.
1. A method for determining the presence or absence of a bacterial infection in a patient comprising:
administering to the patient a diagnostically effective amount of an isotopically-labeled compound that is
collecting one or more samples from the patient;
determining the amount of 13 CO 2 in said one or more samples; and
comparing the amount of 13 CO 2 in said one or more samples to an amount of 13 CO 2 in one or more samples obtained from the patient prior to the administration of the isotopically-labeled compound;
said amounts indicating the presence or absence of the bacterial infection in the patient;
wherein the bacteria has the enzyme p-hydroxyphenylacetate decarboxylase.
2. The method of claim 1 , wherein the bacteria of the bacterial infection is Clostridium difficile.
3. The method of claim 1 , wherein the isotopically-labeled compound is
4. The method of claim 1 , wherein the isotopically-labeled compound is
5. The method of claim 1 , wherein the samples are breath samples.
6. The method of claim 1 , wherein the isotopically labeled compound is
7. A method for determining the presence or absence of a bacterial infection in a patient comprising:
administering to the patient a diagnostically effective amount of an isotopically-labeled compound that is
collecting one or more samples from the patient;
determining the amount of 13 CO 2 in said one or more samples; and
comparing the amount of 13 CO 2 in said one or more samples to an amount of 13 CO 2 in one or more samples obtained from the patient prior to the administration of the isotopically-labeled compound,
said amounts indicating the presence or absence of the bacterial infection in the patient;
wherein the bacteria has the enzyme p-hydroxyphenylacetate decarboxylase.