Clarithromycin resistance of helicobacter pylori infections in Gaza Strip, Palestine

Abstract EN

Clarithromycin is a key component of most treatment protocols of Helicobacter pylori, and clarithromycin resistance is a key factor in the failure of eradication therapy and recurrence of infection.

Clarithromycin resistance rates vary throughout the world.

Therefore, this cross sectional study aimed at determining clarithromycin resistance of H.

pylori in infected patients in Gaza strip.

Biopsies were randomly collected from 87 patients subjected to gastric endoscopy for exploration based on clinical symptoms suggesting H.

pylori infection.

The biopsies were collected from different sites of the antrum and then formalin-fixed and paraffin-embedded.

Four-μm thick slides were prepared and used for fluorescent in situ hybridization detection of the 3 common mutations (2143A>G, 2144A>G and 2143A>C) in the 23S rRNA gene leading to clarithromycin resistance.

The results of the study showed that 58.6% of the examined samples were positive for H.

pylori infection, among them 3.9% were positive for the 2143A>G mutation, 3.9% for 2144A>G while none of the samples were positive for the 2143A>C.

A number of positive samples (25.5%) did not hybridize to any of the probes specific for either the wild type or the three mutations, indicating the possible existence of mutations in other nucleotides in the probes binding sites.

Thus, the extent of resistance to clarithromycin may be much higher.

In conclusion, H.

pylori infections in Gaza strip have high resistance rate for clarithromycin compared to other populations in and outside the area, probably because of the uncontrolled, abuse and misuse of antibiotics.