Synergistic effects of novel penicillin-binding protein 1A amino acid substitutions contribute to high-level amoxicillin resistance of Helicobacter pylori

Authors

Alain Cimuanga-Mukanya, Oita University,Japan
Evariste Tshibangu-Kabamba, University of Mbujimayi, DRC
Patrick de Jesus Ngoma Kisoko, University of Kinshasa, DRC
Fabien Mbaya Tshibangu, Oita University, Japan
Antoine Tshimpi Wola, University of Kinshasa, DRC
Pascal Tshiamala Kashala, Astrid Clinics, DRC
Dieudonné Mumba Ngoyi, National Institute of Biomedical Research, DRC
Steve Ahuka-Mundeke, National Institute of Biomedical Research , DRC
Gunturu Revathi, Aga Khan UniversityFollow
Ghislain Disashi-Tumba, University of Mbujimayi, DRC

Document Type

Article

Department

Pathology (East Africa)

Abstract

The growing resistance to amoxicillin (AMX)—one of the main antibiotics used in Helicobacter pylori eradication therapy—is an increasing health concern. Several mutations of penicillin-binding protein 1A (PBP1A) are suspected of causing AMX resistance; however, only a limited set of these mutations have been experimentally explored. This study aimed to investigate four PBP1A mutations (i.e., T558S, N562H, T593A, and G595S) carried by strain KIN76, a high-level AMX-resistant clinical H. pylori isolate with an AMX minimal inhibition concentration (MIC) of 2 µg/mL. We transformed a recipient strain 26695 with the DNA containing one to four mutation allele combinations of the pbp1 gene from strain KIN76. Transformants were subjected to genomic exploration and antimicrobial susceptibility testing. The resistance was transformable, and the presence of two to four PBP1A mutations (T558S and N562H, or T593A and G595S), rather than separate single mutations, was necessary to synergistically increase the AMX MIC up to 16-fold compared with the wild-type (WT) strain 26695. An AMX binding assay of PBP1A was performed using these strains, and binding was visualized by chasing Bocillin, a fluorescent penicillin analog. This revealed that all four-mutation allele-transformed strains exhibited decreased affinity to AMX on PBP1A than the WT. Protein structure modeling indicated that functional modifications occur as a result of these amino acid substitutions. This study highlights a new synergistic AMX resistance mechanism and establishes new markers of AMX resistance in H. pylori.

Publication (Name of Journal)

Msphere

DOI

https://doi.org/10.1128/msphere.00089-24

Recommended Citation

Cimuanga-Mukanya, A., Tshibangu-Kabamba, E., Ngoma Kisoko, P. d., Tshibangu, F. M., Wola, A. T., Kashala, P. T., Ngoyi, D. M., Ahuka-Mundeke, S., Revathi, G., Disashi-Tumba, G. (2024). Synergistic effects of novel penicillin-binding protein 1A amino acid substitutions contribute to high-level amoxicillin resistance of Helicobacter pylori. Msphere, 9(8), 1-19.
Available at: https://ecommons.aku.edu/eastafrica_fhs_mc_pathol/296

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.