Molecular identification of giardia intestinalis in patients with dyspepsia.

BACKGROUND/AIMS: Giardia intestinalis triggers symptoms of functional dyspepsia. The aim of this study was to distinguish genotypes of G. intestinalis isolated from dyspeptic patients to evaluate their correlation with dyspeptic symptoms.

METHODS: In total, 120 dyspeptic subjects were investigated by upper endoscopy, including gastric and duodenal biopsies for histopathological examination, and parasitological examination of their stools and duodenal aspirates was performed. The patients were classified into five groups: group I (G. intestinalis) included 19 patients, group II (Helicobacter pylori) included 36 patients, group III (coeliac disease) included 3 patients, group IV (mixed G. intestinalis and H. pylori infection) included 4 patients, and group V (unexplained aetiology) included 58 patients. Genotyping of G. intestinalis was performed for groups I and IV using PCR-RFLP. The urease test was performed for H. pylori. Serum anti-gliadin, anti-endomysial and anti-transglutaminase antibody estimation was performed for the diagnosis of coeliac disease.

RESULTS: Genotype A of G. intestinalis was detected in the stool samples of 68.42% (13/19) and the duodenal aspirates of 42.1% (8/19) of dyspeptic patients harbouring the parasite. Genotype B was detected in 31.58% (6/19) of cases in stool samples and in 3 cases in duodenal aspirates.

CONCLUSIONS: H. pylori, G. intestinalis and coeliac disease are common causes of dyspepsia. G. intestinalis genotype A demonstrated a greater association with dyspeptic symptoms.