Brucella ovis Cysteine Biosynthesis Contributes to Peroxide Stress Survival and Fitness in the Intracellular Niche

Copyright © 2021 American Society for Microbiology..

Brucella ovis is an ovine intracellular pathogen with tropism for the male genital tract. To establish and maintain infection, B. ovis must survive stressful conditions inside host cells, including low pH, nutrient limitation, and reactive oxygen species. The same conditions are often encountered in axenic cultures during stationary phase. Studies of stationary phase may thus inform our understanding of Brucella infection biology, yet the genes and pathways that are important in Brucella stationary-phase physiology remain poorly defined. We measured fitness of a barcoded pool of B. ovis Tn-himar mutants as a function of growth phase and identified cysE as a determinant of fitness in stationary phase. CysE catalyzes the first step in cysteine biosynthesis from serine, and we provide genetic evidence that two related enzymes, CysK1 and CysK2, function redundantly to catalyze cysteine synthesis at steps downstream of CysE. Deleting cysE (ΔcysE) or both cysK1 and cysK2 (ΔcysK1 ΔcysK2) results in premature entry into stationary phase, reduced culture yield, and sensitivity to exogenous hydrogen peroxide. These phenotypes can be chemically complemented by cysteine or glutathione. ΔcysE and ΔcysK1 ΔcysK2 strains have no defect in host cell entry in vitro but have significantly diminished intracellular fitness between 2 and 24 h postinfection. Our study has uncovered unexpected redundancy at the CysK step of cysteine biosynthesis in B. ovis and demonstrates that cysteine anabolism is a determinant of peroxide stress survival and fitness in the intracellular niche.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:89

Enthalten in:

Infection and immunity - 89(2021), 6 vom: 17. Mai

Sprache:

Englisch

Beteiligte Personen:

Varesio, Lydia M [VerfasserIn]
Fiebig, Aretha [VerfasserIn]
Crosson, Sean [VerfasserIn]

Links:

Volltext

Themen:

70FD1KFU70
Bacterial Proteins
Brucella
Cysteine
Epithelial cells
Glutathione
Intracellular pathogen
Journal Article
K848JZ4886
Macrophages
Metabolism
Peroxides
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Sulfur

Anmerkungen:

Date Completed 20.09.2021

Date Revised 26.02.2022

published: Electronic-Print

Citation Status MEDLINE

doi:

10.1128/IAI.00808-20

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM323097294