microbiology specialists inc.
Helicobacter pylori

Helicobacter pylori

Helicobacter pylori is recognized as the main cause of peptic ulcer disease and a major risk factor for gastric cancer.  The prevalence of Helicobacter pylori infection worldwide is approximately 50%, as high as 80%–90% in developing countries, and ≈35%–40% in the United States. Approximately 20% of persons infected with H. pylori develop related gastroduodenal disorders during their lifetime. Initially non-invasive methods for the diagnosis of H. pylori are used to diagnose infection.  These include serology, urea breath test, and the detection of H. pylori antigen in stool specimens.  A positive non-invasive test in conjunction with patient history of gastrointestinal distress constitute current empiric therapies.


For the last two decades, the recommended treatment for H. pylori eradication is the standard triple therapy using a proton pump inhibitor or ranitidine bismuth citrate, combined with clarithromycin and amoxicillin or metronidazole.  Up to 20% of patients with H. pylori infection are not cured after completing their first course of treatment and a second treatment regimen is usually suggested.


After one or more treatment failures, it may be necessary to have an endoscopy to obtain a culture and identify exactly which antibiotics will kill the bacteria.  During the endoscopy biopsies are collected from the antrum and fundus of the stomach lining.  Maintaining sample integrity prior to receipt by the laboratory for culture is paramount for the isolation of H. pylori.


Cultures for H. pylori requires the use of specialized transport media, selective culture media and the expertise to isolate and identify H. pylori.  Once H. pylori is isolated susceptibilities to a battery of antibiotics can be performed by e-test for the minimum inhibitory concentrations (mic) to ascertain the best antibiotic combination for treatment.  Our current panel tested by e-test is amoxicillin, clarithromycin, tetracycline and levofloxacin.  Metronidazole can be performed by request using the agar dilution method.


Culture turn-around time is 3-14 days.  Turn-around time for susceptibilities is 3-7 days.


Contact a msi representative at msi@microbiologyspecialists.com or by phone at 713-663-6888 for collection and transportation information.