Effect of treatment failure on the CagA EPIYA motif in Helicobacter pylori strains from Colombian subjects

• Published in: World journal of gastroenterology : WJG Vol. 23; no. 11; pp. 1980 - 1989
• Main Authors: Bustamante-Rengifo, Javier Andres, Matta, Andres Jenuer, Pazos, Alvaro Jairo, Bravo, Luis Eduardo
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 21.03.2017
• Subjects: Adult; Amino Acid Motifs; Amoxicillin - therapeutic use; Anti-Bacterial Agents - therapeutic use; Antigens, Bacterial - genetics; Antigens, Bacterial - isolation & purification; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Basic Study; Biopsy; Breath Tests; Clarithromycin - therapeutic use; Colombia - epidemiology; Drug Therapy, Combination; Endoscopy, Gastrointestinal; Female; Genotype; Helicobacter Infections - drug therapy; Helicobacter Infections - epidemiology; Helicobacter Infections - microbiology; Helicobacter Infections - pathology; Helicobacter pylori - classification; Helicobacter pylori - genetics; Helicobacter pylori - isolation & purification; Helicobacter pylori - pathogenicity; Humans; Male; Omeprazole - therapeutic use; Phylogeny; Prevalence; Proton Pump Inhibitors - therapeutic use; Random Amplified Polymorphic DNA Technique; Treatment Failure; Treatment Outcome; Virulence Factors - genetics; Virulence Factors - isolation & purification; RAPD-PCR; 3’ cagA variable region; Treatment failure; Helicobacter pylori; EPIYA motifs
• ISSN: 1007-9327; 2219-2840; 2219-2840
• DOI: 10.3748/wjg.v23.i11.1980

To evaluate effect of treatment failure on and genotypes in ( ) isolates from Colombia. One hundred and seventy-six participants infected with from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from isolates was amplified using primers specific for and genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA (RAPD) fingerprinting. Treatment effectiveness was at 74.6%. Of the participants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of post-treatment infection was 64% (16/25) and 40% (10/25) by histology and culture, respectively. Upon comparing the and genotypes found before and after therapy, multiple genotypes ( -positive and -negative) were found before treatment; in contrast, -negative genotypes decreased after treatment. genotype was highly prevalent in patients before and after therapy. The 3' region was successfully amplified in 95.5% (21/22) of the isolates obtained before and in 81.8% (18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7% (16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before treatment. Unsuccessful treatment limits colonization by low-virulence strains resulting in partial and selective eradication in mixed infections, and acts on the -positive strains inducing genetic rearrangements in variable region that produces a loss or gain of EPIYA repetitions.