Tests for H. Pylori and chloromycetin

Dear Dr:

What are your thoughts on urea breath tests to detect H. Pylori? Are they reliable and if positive would you recommend treatment to erradicate the bacteria when symptoms are present (burning in the stomach, dyspepsia, etc.), or is it better to do an endoscopy?

If, for example Clarithromycin (which is one of the antibiotics to treat H. Pylori) has been used in someone several times to treat upper respiratory infections, would this make H. Pylori resistant to this antibiotic? Or, how can I be sure that I don't have a resistant strain of H. Pylori, or which antibiotic will kill this bacteria?

Also, what are your thoughts on using chloromycetin to treat stomach/intestinal infections, when other antibiotics are found to be ineffective?

Thanks for your help,
Roberto