Having your cake and eating it - Staphylococcus aureus small colony variants can evolve faster growth rate without losing their antibiotic resistance

Staphylococcus aureus can produce small colony variants (SCVs) during infections. These cause significant clinical problems because they are difficult to detect in standard microbiological screening and are associated with persistent infections. The major causes of the SCV phenotype are mutations that inhibit respiration by inactivation of genes of the menadione or hemin biosynthesis pathways. This reduces the production of ATP required to support fast growth. Importantly, it also decreases cross-membrane potential in SCVs, resulting in decreased uptake of cationic compounds, with reduced susceptibility to aminoglycoside antibiotics as a consequence. Because SCVs are slow-growing (mutations in men genes are associated with growth rates in rich medium ~30% of the wild-type growth rate) bacterial cultures are very susceptible to rapid takeover by faster-growing mutants (revertants or suppressors). In the case of reversion, the resulting fast growth is obviously associated with the loss of antibiotic resistance. However, direct reversion is relatively rare due to the very small genetic target size for such mutations. We explored the phenotypic consequences of SCVs evolving faster growth by routes other than direct reversion, and in particular whether any of those routes allowed for the maintenance of antibiotic resistance. In a recent paper (mBio 8: e00358-17) we demonstrated the existence of several different routes of SCV evolution to faster growth, one of which maintained the antibiotic resistance phenotype. This discovery suggests that SCVs might be more adaptable and problematic that previously thought. They are capable of surviving as a slow-growing persistent form, before evolving into a significantly faster-growing form without sacrificing their antibiotic resistance phenotype.

Errataetall:

CommentOn: MBio. 2017 Jun 20;8(3):. - PMID 28634236

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:4

Enthalten in:

Microbial cell (Graz, Austria) - 4(2017), 8 vom: 01. Aug., Seite 275-277

Sprache:

Englisch

Beteiligte Personen:

Brandis, Gerrit [VerfasserIn]
Cao, Sha [VerfasserIn]
Huseby, Douglas L [VerfasserIn]
Hughes, Diarmaid [VerfasserIn]

Links:

Volltext

Themen:

ATP generation
Comment
Extragenic suppressor
Intragenic suppressor
Journal Article
SCV (small colony variant)
SrrAB
Suppressors
TRNA mutations

Anmerkungen:

Date Revised 29.09.2020

published: Electronic

CommentOn: MBio. 2017 Jun 20;8(3):. - PMID 28634236

Citation Status PubMed-not-MEDLINE

doi:

10.15698/mic2017.08.587

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM275181596