The urea breath test involves breathing into a balloon-like bag. It's a safe and easy
way to detect H. pylori bacteria, diagnosis H. pylori infection, and determine if
treatment cured the infection. H. pylori infection is a major cause of peptic ulcer
disease. Its presence also increases your risk of gastritis and stomach cancer.
During the H. pylori breath test, you will be asked to exhale into a balloon-like
bag. The amount of carbon dioxide you exhale into this bag is measured to
provide a baseline level for comparison.
Next, you will be asked to drink a small amount of a pleasant lemon-flavored
solution. The solution contains a substance called urea. Fifteen minutes after
drinking the solution, you will exhale into a second bag. The amount of carbon
dioxide you exhale into the second bag is also measured.
If H. pylori is present in the stomach, the urea is broken up and turned into carbon
dioxide. The carbon dioxide is absorbed across the lining of the stomach and into
the blood. It then travels in the blood to the lungs where it is excreted in the
breath. So if the amount of carbon dioxide in your second sample is higher than
the amount in your first sample, you have a positive test for the presence of H.
pylori.
Mycoplasma
It’s cultured on on Eaton's agar with fried-egg" appearance except for M.
pneumoniae
(Eaton's agar) includes (v/v):[1]



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70% Difco PPLO (pleuropneumonia-like organism) agar or broth
base
20% unheated horse serum
10% fresh aqueous extract of baker's yeast
1000 units/ml Penicillin G
Mycoplasma have high nutritional demands and can grow on PPLO agar with
beef heart infusion and 10–20% horse serum. The serum provides Mycoplasma
with the cholesterol and long-chain fatty acids required for growth. The optimum
pH for Mycoplasma culture is pH 7.8–8.0. Cells may die when the pH drops
below pH 7.0.
Mycoplasma are aerobic or facultative anaerobic microorganisms, but they
usually grow better in aerobic environment. The best culture environment for
initial isolation is atmospheric conditions supplemented with 5% CO2 or
anaerobic conditions with 5% CO2 and 95% N2.