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Updated: Mar 3, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Broad-host-range Kayvirus phages preferentially infect Staphylocococcus aureus cells with β-glycosylated WTA, the
Andrea Jurado1, Carlos C Gómez-Cambronero2, Ana Rodríguez1
1Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Oviedo, Spain; DairySafe Group. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.
Objectives:
In Staphylococcus aureus, WTA glycosylation participates in the interaction with the immune system and bacteriophage adsorption. Indeed, virulent phages with podovirus morphology and some myoviruses require β-glycosylation (catalized by TarS), and are hindered by α-glycosylation (carried out by TarM) of WTA. In contrast, other myophages, like phiIPLA-RODI and phage K, exhibit a broad-host range and infect strains without either glycosylation according to the spot test. Here, we set out to determine the impact of glycosylation type on susceptibility to the Kayvirus phiIPLA-RODI.
Methods:
Phage susceptibility was tested through different assays and the impact of capsule production and WTA glycosylation was studied through genome and mutant analyses.
Results:
We demonstrate that phages K and phiIPLA-RODI, despite not requiring WTA glycosylation, are both significantly more efficient at infecting strains with tarS-mediated modifications. Moreover, presence of tarM correlates with decreased susceptibility to phiIPLA-RODI, especially in strains lacking an intact capsule. Besides confirming that mutations in the quorum-sensing system Agr confer reduced susceptibility to some phages, we also identified the alternative sigma factor SigB as an additional regulator of phage infectivity. While Agr controls transcription of tarM, SigB exerts this role by modulating tarS expression.
Conclusions:
Our results suggest that the majority of known virulent phages infecting S. aureus have evolved to maximize their chances of infecting this pathogen in the mammalian host. While this is good news from the perspective of phage therapy, the potential impact of altering the balance between phage and host by exposing cells to high doses of phages must be examined.
Insights
Staphylococcus aureus phage infection efficiency is influenced by wall teichoic acid (WTA) glycosylation. Phages show varied interactions with TarS and TarM modifications, with SigB also regulating infectivity.
Area of Science:
- Microbiology
- Virology
- Molecular Biology
Background:
- Wall teichoic acid (WTA) glycosylation in Staphylococcus aureus impacts host immune interactions and bacteriophage (phage) adsorption.
- Specific glycosylation patterns, like β-glycosylation (TarS) and α-glycosylation (TarM), differentially affect phage infectivity.
Purpose of the Study:
- To investigate the influence of WTA glycosylation, specifically TarS and TarM modifications, on the infectivity of broad-host-range phages phiIPLA-RODI and phage K.
- To identify additional regulatory factors involved in S. aureus phage infectivity.
Main Methods:
- Spot tests were used to assess phage infectivity on S. aureus strains with varying WTA glycosylation statuses.
- Genetic analysis was performed to identify regulatory elements controlling tarS and tarM expression.
- The role of quorum-sensing system Agr and alternative sigma factor SigB in phage infectivity was examined.
Main Results:
- Broad-host-range phages phiIPLA-RODI and phage K demonstrated enhanced infectivity on strains with TarS-mediated modifications, despite not requiring WTA glycosylation.
- TarM presence correlated with decreased susceptibility to phiIPLA-RODI, particularly in non-encapsulated strains.
- Mutations in the Agr system reduced phage susceptibility, and SigB was identified as a novel regulator of TarS expression, impacting phage infectivity.
Conclusions:
- S. aureus phages have evolved to optimize infection in mammalian hosts, with WTA glycosylation playing a complex role.
- The findings highlight the intricate interplay between phage, host genetics (Agr, SigB), and WTA modification in determining infection outcomes.
- While promising for phage therapy, the ecological impact of high-dose phage application warrants further investigation.
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