title: GENETIC MUTATIONS AFFECTING THE FIRST LINE ERADICATION THERAPY OF Helicobacter pylori-INFECTED EGYPTIAN PATIENTS.
abstract: Several genetic mutations affect the first-line triple therapy for Helicobacter pylori. We aimed to study the most common genetic mutations affecting the metronidazole and clarithromycin therapy for H. pylori-infected Egyptian patients.
  In our study, we included 100 successive dyspeptic patients scheduled for diagnosis through upper gastroscopy at Cairo's University Hospital, Egypt. Gastric biopsies were tested for the presence of H. pylori by detection of the 16S rRNA gene. Positive biopsies were further studied for the presence of the rdxA gene deletion by Polymerase Chain Reaction (PCR), while clarithromycin resistance was investigated by the presence of nucleotide substitutions within H. pylori 23S rRNA V domain using MboII and BsaI to carry out a Restricted Fragment Length Polymorphism (RFLP) assay.
  Among 70 H. pylori positive biopsies, the rdxA gene deletion was detected in 44/70 (62.9%) samples, while predominance of the A2142G mutations within the H. pylori 23S rRNA V domain was evidenced in 39/70 (55.7%) of the positive H. pylori cases. No statistically significant difference was found between the presence of gene mutations and different factors such as patients 'age, gender, geographic distribution, symptoms and endoscopic findings.
  Infection with mutated H. pylori strains is considerably high, a finding that imposes care in the use of the triple therapy to treat H. pylori in Egypt, since the guidelines recommend to abandon the standard triple therapy when the primary clarithromycin resistance rate is over 20%1.
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Iman
authors.initials: I
authors.lastname: Ramzy
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Hassan
authors.initials: H
authors.lastname: Elgarem
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Iman
authors.initials: I
authors.lastname: Hamza
authors.affiliation: Clinical and Chemical Pathology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mail: doaa.ghaith@kasralainy.edu.eg.
authors.forename: Doaa
authors.initials: D
authors.lastname: Ghaith
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Tamer
authors.initials: T
authors.lastname: Elbaz
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Waleed
authors.initials: W
authors.lastname: Elhosary
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Gehan
authors.initials: G
authors.lastname: Mostafa
authors.affiliation: Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. E-mails: hgarem@yahoo.cpm; Iman_hamza@hotmail.com; Iman_ramzy@hotmail.com; ma_mohey@kasralainy.edu.eg; Wh8609@gmail.com; gehan1511@gmail.com; tamerbaz@yahoo.com.
authors.forename: Mohammad A Mohey Eldin
authors.initials: MA
authors.lastname: Elzahry
mesh_terms: D000328:Adult; D017291:Clarithromycin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004534:Egypt; D005260:Female; D017353:Gene Deletion; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics*; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology*; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D008795:Metronidazole; D017291:Clarithromycin