Detection of Mutation of PBP1 Gene of Helicobacter pylori in Gastric Biopsies in Abidjan

Objectives: The purpose of this study is to determine the presence of mutations in the gene pbp1, conferring resistance to amoxicillin of Helicobacter pylori, from gastric biopsies in Abidjan (Côte d'Ivoire).

Place and Duration: Between August 2015 and February 2016, gastric biopsies were collected in the endoscopy room from adult patients in the Gastroenterology Department at the Hospital and University Center of Cocody (Abidjan) and then stored. From October to December 2016, laboratory tests were performed in the Bacteriology-virology department, the molecular biology platform of the Institute Pasteur of Côte d'Ivoire, and the sequencing platform Eurofins (Cochin, France).

Methodology: Helicobacter pylori DNA was extracted directly from the stored gastric biopsies. The detection of the gene pbp1 in Helicobacter pylori was done through conventional PCR and the DNA was quantified using a NanoDrop® spectrophotometer, Lite (Thermo Fischer Scientific, USA), followed by sequencing from Eurofins, MWG / operon (Cochin, France). The reference strains used for sequence comparison were selected from NCBI's Genbank database with accession numbers ranging from AY 743230.1 to AY 743236.1.

Results: Thirteen out of fifty-six pbp1 genes, conferring resistance to amoxicillin, were sequenced. The substitution of Lysine for Leucine at position 102 (K102L) was predominant in 7 of them, about 53.8%. A Substitution at position 62 of glycine by alanine (G62A) was also found in 6 of them (about 46.2%). In addition, 5 of the 13 strains (or 38.5%) all had Lysine substitutions. They are F45K, D54K, H60K, and I117K.

Conclusion: The presence of several mutations in the gene pbp1 of H. pylori might be a dominant factor in the resistance to amoxicillin of H. pylori, which needs further investigations.