Growth phase-dependent regulation of the global virulence regulator Rot in clinical isolates of Staphylococcus aureus

Jelsbak, Lotte; Hemmingsen, Lene; Donat, Stefanie; Ohlsen, Knut; Boye, Kasper; Westh, Henrik; Ingmer, Hanne; Frees, Dorte

doi:10.1016/j.ijmm.2009.07.003

Cited by 28 publications

(33 citation statements)

References 29 publications

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“…The vast majority of clinical isolates from acute infections express RNAIII (Traber et al, 2008), but the level of RNAIII expression varies among isolates (Jelsbak et al, 2010). However, agr-mutant strains, which most probably arose during infection, were isolated from patients (Traber et al, 2008).…”

Section: Expression Of Srnas In S Aureus During Infectionmentioning

confidence: 99%

The importance of regulatory RNAs in Staphylococcus aureus

Tomasini

François

Howden

et al. 2014

Infection, Genetics and Evolution

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a b s t r a c t RNA molecules with regulatory functions in pathogenic bacteria have benefited from a renewed interest these two last decades. In Staphylococcus aureus, recent genome-wide approaches have led to the discovery that almost 10-20% of genes code for RNAs with critical regulatory roles in adaptive processes. These RNAs include trans-acting RNAs, which mostly act through binding to target mRNAs, and cis-acting RNAs, which include regulatory regions of mRNAs responding to various metabolic signals. Besides recent analysis of S. aureus transcriptome has revealed an unprecedented existence of pervasive transcription generating a high number of weakly expressed antisense RNAs along the genome as well as numerous mRNAs with overlapped regions. Here, we will illustrate the diversity of trans-acting RNAs and illustrate how they are integrated into complex regulatory circuits, which link metabolism, stress response and virulence.

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Section: Expression Of Srnas In S Aureus During Infectionmentioning

confidence: 99%

The importance of regulatory RNAs in Staphylococcus aureus

Tomasini

François

Howden

et al. 2014

Infection, Genetics and Evolution

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“…Given that the difference in genome sequence is as high as 22 % in S. aureus (Jelsbak et al, 2010), different clones may have variable virulence. The analysis of the global population structure and expansion of pathogenic clones of S. aureus revealed that certain clones are more virulent than others (Layer et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Staphylococcus aureus ST121: a globally disseminated hypervirulent clone

Rao

Shang

et al. 2015

Journal of Medical Microbiology

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Staphylococcus aureus is a leading cause of bacterial infections in hospitals and communities worldwide. With the development of typing methods, several pandemic clones have been well characterized, including the extensively spreading hospital-associated meticillin-resistant S. aureus (HA-MRSA) clone ST239 and the emerging hypervirulent community-associated (CA) MRSA clone USA300. The multilocus sequence typing method was set up based on seven housekeeping genes; S. aureus groups were defined by the sharing of alleles at $5 of the seven loci. In many cases, the predicted founder of a group would also be the most prevalent ST within the group. As a predicted founder of major S. aureus groups, approximately 90 % of ST121 strains was meticillin-susceptible S. aureus (MSSA). The majority of ST121 strains carry accessory gene regulator type IV, whereas staphylococcal protein A gene types for ST121 are exceptionally diverse. More than 90 % of S. aureus ST121 strains have Panton-Valentine leukocidin; other enterotoxins, haemolysins, leukocidins and exfoliative toxins also contribute to the high virulence of ST121 strains. Patients suffering from S. aureus ST121 infections often need longer hospitalization and prolonged antimicrobial therapy. In this review, we tried to summarize the epidemiology of the S. aureus clone ST121 and focused on the molecular types, toxin carriage and disease spectrum of this globally disseminated clone.

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“…For instance, the opportunistic pathogen Staphylococcus aureus, which produces a plethora of secreted and cell wall-associated pathogenicity factors, can sense and respond to environmental cues to optimize the expression of virulence genes. Indeed, the synthesis of staphylococcal pathogenicity factors changes in response to variations in growth phase (1)(2)(3), cell population density (4), pH (5,6), glucose availability (7,8), NaCl concentration (9), and exposure to antibiotics (10).…”

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confidence: 99%

CodY-Mediated Regulation of the Staphylococcus aureus Agr System Integrates Nutritional and Population Density Signals

et al. 2014

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bThe Staphylococcus aureus Agr system regulates virulence gene expression by responding to cell population density (quorum sensing). When an extracellular peptide signal (AIP-III in strain UAMS-1, used for these experiments) reaches a concentration threshold, the AgrC-AgrA two-component regulatory system is activated through a cascade of phosphorylation events, leading to induction of the divergently transcribed agrBDCA operon and the RNAIII gene. RNAIII is a posttranscriptional regulator of numerous metabolic and pathogenesis genes. CodY, a global regulatory protein, is known to repress agrBDCA and RNAIII transcription during exponential growth in rich medium, but the mechanism of this regulation has remained elusive. Here we report that phosphorylation of AgrA by the AgrC protein kinase is required for the overexpression of the agrBDCA operon and the RNAIII gene in a codY mutant during the exponential-growth phase, suggesting that the quorum-sensing system, which normally controls AgrC activation, is active even in exponential-phase cells in the absence of CodY. In part, such premature expression of RNAIII was attributable to higher-than-normal accumulation of AIP-III in a codY mutant strain, as determined using ultrahigh-performance liquid chromatography coupled to mass spectrometry. Although CodY is a strong repressor of the agr locus, CodY bound only weakly to the agrBDCA-RNAIII promoter region, suggesting that direct regulation by CodY is unlikely to be the principal mechanism by which CodY regulates agr and RNAIII expression. Taken together, these results strongly suggest that cell population density signals inducing virulence gene expression can be overridden by nutrient availability, a condition monitored by CodY.

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Growth phase-dependent regulation of the global virulence regulator Rot in clinical isolates of Staphylococcus aureus

Cited by 28 publications

References 29 publications

The importance of regulatory RNAs in Staphylococcus aureus

The importance of regulatory RNAs in Staphylococcus aureus

Staphylococcus aureus ST121: a globally disseminated hypervirulent clone

CodY-Mediated Regulation of the Staphylococcus aureus Agr System Integrates Nutritional and Population Density Signals

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