Detection of Helicobacter pylori and determination of clarithromycin susceptibility using formalin-fixed, paraffin-embedded gastric biopsy specimens by fluorescence in situ hybridization.
BACKGROUND
Clarithromycin resistance and poor compliance to therapy are often responsible for Helicobacter pylori eradication therapy failure.


OBJECTIVE
To evaluate fluorescence in situ hybridization (FISH) as a nonculture method to simultaneously detect H. pylori and to identify clarithromycin resistance.


METHODS
Fifty-four patients with dyspepsia (17 male, 37 female subjects; mean age, 46.5; range, 21-78 years) were studied. Two antrum and corpus biopsies were taken from each patient. Positive rapid urease test (RUT) and histopathologic examinations defined H. pylori positivity. A total of 108 formalin-fixed paraffin-embedded gastric mucosal biopsies were examined retrospectively by the FISH (seaFAST H. pylori Combi-Kit) method.


RESULTS
Forty-five patients (83.3%) were H. pylori positive and 43 (95.5%) were also positive by FISH. There were two false-positive FISH results. Fourteen patients (31.1%) had clarithromycin-susceptible strains, 4 (8.9%) resistant strains, and 27 (60%) both susceptible and resistant strains.


CONCLUSIONS
FISH results correlated well with H. pylori infection and were able to identify clarithromycin-susceptible and -resistant strains. This technique will be helpful in determining the bacterial density and the success of treatment where clarithromycin has been widely used in populations to increase the efficacy of the treatment and to clarify the treatment failure in vitro.
Yilmaz
Ozlem
O
Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Dokuz Eylül University, Inciralti, Izmir, Turkey. ozlem.yilmaz@deu.edu.tr
Demiray
Ebru
E
Tümer
Sait
S
Altungöz
Oğuz
O
Yörükoğlu
Kutsal
K
Soytürk
Müjde
M
Simşek
Ilkay
I
D000328:Adult; D000368:Aged; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004415:Dyspepsia / Q000382:microbiology / Q000473:pathology; D005260:Female; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016612:Paraffin Embedding; D013270:Stomach / Q000382:microbiology*
D017291:Clarithromycin