Genetic mutations in adaptive evolution of growth-independent vancomycin-tolerant Staphylococcus aureus

© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissionsoup.com..

BACKGROUND: Antibiotic tolerance allows bacteria to overcome antibiotic treatment transiently and potentially accelerates the emergence of resistance. However, our understanding of antibiotic tolerance at the genetic level during adaptive evolution of Staphylococcus aureus remains incomplete. We sought to identify the mutated genes and verify the role of these genes in the formation of vancomycin tolerance in S. aureus.

METHODS: Vancomycin-susceptible S. aureus strain Newman was used to induce vancomycin-tolerant isolates in vitro by cyclic exposure under a high concentration of vancomycin (20× MIC). WGS and Sanger sequencing were performed to identify the genetic mutations. The function of mutated genes in vancomycin-tolerant isolates were verified by gene complementation. Other phenotypes of vancomycin-tolerant isolates were also determined, including mutation frequency, autolysis, lysostaphin susceptibility, cell wall thickness and cross-tolerance.

RESULTS: A series of vancomycin-tolerant S. aureus (VTSA) strains were isolated and 18 mutated genes were identified by WGS. Among these genes, pbp4, htrA, stp1, pth and NWMN_1068 were confirmed to play roles in VTSA formation. Mutation of mutL promoted the emergence of VTSA. All VTSA showed no changes in growth phenotype. Instead, they exhibited reduced autolysis, decreased lysostaphin susceptibility and thickened cell walls. In addition, all VTSA strains were cross-tolerant to antibiotics targeting cell wall synthesis but not to quinolones and lipopeptides.

CONCLUSIONS: Our results demonstrate that genetic mutations are responsible for emergence of phenotypic tolerance and formation of vancomycin tolerance may lie in cell wall changes in S. aureus.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:76

Enthalten in:

The Journal of antimicrobial chemotherapy - 76(2021), 11 vom: 11. Okt., Seite 2765-2773

Sprache:

Englisch

Beteiligte Personen:

Liu, Pilong [VerfasserIn]
Hao, Zehua [VerfasserIn]
Liu, Miaomiao [VerfasserIn]
Niu, Mingze [VerfasserIn]
Sun, Peng [VerfasserIn]
Yan, Shunhua [VerfasserIn]
Zhao, Lixiu [VerfasserIn]
Zhao, Xin [VerfasserIn]

Links:

Volltext

Themen:

6Q205EH1VU
Journal Article
Research Support, Non-U.S. Gov't
Vancomycin

Anmerkungen:

Date Completed 03.12.2021

Date Revised 14.12.2021

published: Print

Citation Status MEDLINE

doi:

10.1093/jac/dkab260

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM328470104