Mutations in Helicobacter pylori porD and oorD genes may contribute to furazolidone resistance.

Abstract

AIM: To determine the rate of furazolidone resistance of Helicobacter pylori (H. pylori) isolated from gastric biopsy specimens and to explore the relationship between genetic mutations in porD and oorD genes of H. pylori and its resistance to the antibiotic. METHODS: Gastric biopsy was performed in 83 adult patients aged 31-77 years with gastric complaints. H. pylori was isolated from biopsy specimens of 46 patients. E-test and 2-fold agar dilution method were used to determine the rate of H. pylori resistance to furazolidone. The genes porD and oorD from susceptible and resistant isolates were amplified by polymerase chain reaction (PCR), and their PCR products were sequenced. RESULTS: Resistance to furazolidone was found in 8.7% of H. pylori isolates and 6 mutations were detected in porD and oorD genes of the resistant isolates. Three mutations--G353A, A356G, and C357T--occurred in porD and the other mutations--A041G, A122G, C349A(G)--occurred in oorD genes. CONCLUSIONS: Changes in 6 amino acids may be associated with the resistance of H. pylori to furazolidone.