1
|
Barzkar N, Bunphueak P, Chamsodsai P, Muangrod P, Thumthanaruk B, Rungsardthong V, Tabtimmai L. Jellyfish protein hydrolysates: Multifunctional bioactivities unveiled in the battle against diabetes, inflammation, and bacterial pathogenesis. Microb Pathog 2024; 191:106648. [PMID: 38641070 DOI: 10.1016/j.micpath.2024.106648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/10/2024] [Accepted: 04/14/2024] [Indexed: 04/21/2024]
Abstract
This study investigates the multifunctional bioactivities of pepsin-hydrolyzed jellyfish by-products (Rhopilema hispidum and Lobonema smithii), focusing on their anti-α-glucosidase activity, anti-inflammatory effects, anti-bacterial properties, and ability to inhibit biofilm formation of Staphylococcus aureus. Our findings revealed that jellyfish protein hydrolysates, particularly from Rhopilema hispidum, exhibit significant anti-α-glucosidase activity, surpassing the well-known α-glucosidase inhibitor Acarbose. Furthermore, we demonstrated the anti-inflammatory capabilities of these hydrolysates in suppressing lipopolysaccharide (LPS)-induced nitric oxide production in murine macrophage cells. This effect was dose-dependent and non-cytotoxic, highlighting the hydrolysate potential in treating inflammation-related conditions. Regarding anti-bacterial activity, pepsin-hydrolyzed jellyfish selectively exhibited a potent effect against S. aureus, including Methicillin-susceptible and Methicillin-resistant strains. This activity was evident at minimum inhibitory concentrations (MIC) of 25 μg/mL for S. aureus ATCC10832, while a modest effect was observed against other Gram-positive strains. The hydrolysates effectively delayed bacterial growth dose-dependently, suggesting their use as alternative agents against bacterial infections. Most notably, pepsin-hydrolyzed jellyfish showed significant anti-biofilm activity against S. aureus. The umbrella section hydrolysate of Rhopilema hispidum was particularly effective, reducing biofilm formation through downregulating the icaA gene, crucial for biofilm development. Furthermore, the hydrolysates modulated the expression of the agrA gene, a key regulator in the pathogenesis of S. aureus. In conclusion, pepsin-hydrolyzed jellyfish protein hydrolysates exhibit promising multifunctional bioactivities, including anti-diabetic, anti-inflammatory, antibacterial, and anti-biofilm properties. These findings suggest their potential application in pharmaceutical and nutraceutical fields, particularly in managing diabetic risks, inflammation, bacterial infections, and combating the biofilm-associated pathogenicity of S. aureus.
Collapse
Affiliation(s)
- Noora Barzkar
- Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science King Mongkut's University of Technology North Bangkok, 10800, Thailand; Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand
| | - Pinchuta Bunphueak
- Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand; Department of Biotechnology, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, 10800, Thailand
| | - Phumin Chamsodsai
- Interdisciplinary Program in Genetic Engineering and Bioinformatics, Graduate School, Kasetsart University, Bangkok, 10800, Thailand
| | - Pratchaya Muangrod
- Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science King Mongkut's University of Technology North Bangkok, 10800, Thailand; Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand
| | - Benjawan Thumthanaruk
- Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science King Mongkut's University of Technology North Bangkok, 10800, Thailand; Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand
| | - Vilai Rungsardthong
- Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science King Mongkut's University of Technology North Bangkok, 10800, Thailand; Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand
| | - Lueacha Tabtimmai
- Food and Agro-Industrial Research Center, King Mongkut's University of Technology North Bangkok, 10800, Thailand; Department of Biotechnology, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, 10800, Thailand.
| |
Collapse
|
2
|
Hallier M, Bronsard J, Dréano S, Sassi M, Cattoir V, Felden B, Augagneur Y. RNAIII is linked with the pentose phosphate pathway through the activation of RpiRc in Staphylococcus aureus. mSphere 2024; 9:e0034823. [PMID: 38591898 DOI: 10.1128/msphere.00348-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Staphylococcus aureus RNAIII is a dual-function regulatory RNA that controls the expression of multiple virulence genes and especially the transition from adhesion to the production of exotoxins. However, its contribution to S. aureus central metabolism remains unclear. Using MS2-affinity purification coupled with RNA sequencing, we uncovered more than 50 novel RNAIII-mRNA interactions. Among them, we demonstrate that RNAIII is a major activator of the rpiRc gene, encoding a regulator of the pentose phosphate pathway (PPP). RNAIII binds the 5' UTR of rpiRc mRNA to favor ribosome loading, leading to an increased expression of RpiRc and, subsequently, of two PPP enzymes. Finally, we show that RNAIII and RpiRc are involved in S. aureus fitness in media supplemented with various carbohydrate sources related to PPP and glycolysis. Collectively, our data depict an unprecedented phenotype associated with the RNAIII regulon, especially the direct implication of RNAIII in central metabolic activity modulation. These findings show that the contribution of RNAIII in Staphylococcus aureus adaptation goes far beyond what was initially reported. IMPORTANCE Staphylococcus aureus is a major human pathogen involved in acute and chronic infections. Highly recalcitrant to antibiotic treatment, persistent infections are mostly associated with the loss of RNAIII expression, a master RNA regulator responsible for the switch from colonization to infection. Here, we used the MS2 affinity purification coupled with RNA sequencing approach to identify novel mRNA targets of RNAIII and uncover novel functions. We demonstrate that RNAIII is an activator of the expression of genes involved in the pentose phosphate pathway and is implicated in the adjustment of bacterial fitness as a function of carbohydrate sources. Taken together, our results demonstrate an unprecedented role of RNAIII that goes beyond the knowledge gained so far and contributes to a better understanding of the role of RNAIII in bacterial adaptation expression and the coordination of a complex regulatory network.
Collapse
Affiliation(s)
- Marc Hallier
- QCPS (Quality Control in Protein Synthesis), IGDR UMR CNRS 6290, Université de Rennes 1, Rennes, France
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Julie Bronsard
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Stéphane Dréano
- Molecular Bases of Tumorigenesis: VHL Disease Team, CNRS UMR 6290 IGDR, BIOSIT, Université de Rennes 1, Rennes, France
| | - Mohamed Sassi
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Vincent Cattoir
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Brice Felden
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Yoann Augagneur
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| |
Collapse
|
3
|
Vadakkan K, Sathishkumar K, Kuttiyachan Urumbil S, Ponnenkunnathu Govindankutty S, Kumar Ngangbam A, Devi Nongmaithem B. A review of chemical signaling mechanisms underlying quorum sensing and its inhibition in Staphylococcus aureus. Bioorg Chem 2024; 148:107465. [PMID: 38761705 DOI: 10.1016/j.bioorg.2024.107465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/29/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
Staphylococcus aureus is a significant bacterium responsible for multiple infections and is a primary cause of fatalities among patients in hospital environments. The advent of pathogenic bacteria such as methicillin-resistant S. aureus revealed the shortcomings of employing antibiotics to treat bacterial infectious diseases. Quorum sensing enhances S. aureus's survivability through signaling processes. Targeting the key components of quorum sensing has drawn much interest nowadays as a promising strategy for combating infections caused by bacteria. Concentrating on the accessory gene regulator quorum-sensing mechanism is the most commonly suggested anti-virulence approach for S.aureus. Quorum quenching is a common strategy for controlling illnesses triggered by microorganisms since it reduces the pathogenicity of bacteria and improves bacterial biofilm susceptibility to antibiotics, thus providing an intriguing prospect for drug discovery. Quorum sensing inhibition reduces selective stresses and constrains the emergence of antibiotic resistance while limiting bacterial pathogenicity. This review examines the quorum sensing mechanisms involved in S. aureus, quorum sensing targets and gene regulation, environmental factors affecting quorum sensing, quorum sensing inhibition, natural products as quorum sensing inhibitory agents and novel therapeutical strategies to target quorum sensing in S. aureus as drug developing technique to augment conventional antibiotic approaches.
Collapse
Affiliation(s)
- Kayeen Vadakkan
- Department of Biotechnology, St. Mary's College (Autonomous), Thrissur, Kerala 680020, India; Manipur International University, Imphal, Manipur 795140, India.
| | - Kuppusamy Sathishkumar
- Center for Global Health Research, Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Thandalam, Chennai, Tamil Nadu 602105, India
| | | | | | | | | |
Collapse
|
4
|
Guo X, Wang L, Zhang J, Liu Q, Wang B, Liu D, Gao F, Lanzi G, Zhao Y, Shi Y. Thwarting resistance: MgrA inhibition with methylophiopogonanone a unveils a new battlefront against S. aureus. NPJ Biofilms Microbiomes 2024; 10:15. [PMID: 38413623 PMCID: PMC10899606 DOI: 10.1038/s41522-024-00485-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
Limitations in the clinical treatment of Staphylococcus aureus (S. aureus) infections have arisen due to the advent of antibiotic-resistant strains. Given the immense potential of therapeutic strategies targeting bacterial virulence, the role of MgrA as a pivotal virulence determinant in S. aureus-orchestrating resistance, adherence, and hundreds of virulence targets-becomes indispensable. In this investigation, leveraging advanced virtual screening and fluorescence anisotropy assays, we discerned methylophiopogonanone A (Mo-A), a flavonoid derivative, as a potent disruptor of the MgrA-DNA interaction nexus. Subsequent analysis revealed that Mo-A effectively inhibits the expression of virulence factors such as Hla and Pvl in S. aureus and markedly reduces its adhesion capability to fibrinogen. On a cellular landscape, Mo-A exerts a mitigating influence on the deleterious effects inflicted by S. aureus USA300 on A549 cells. Furthermore, our data indicate that Mo-A downregulates the transcription of genes associated with immune evasion, such as nucleases (nuc), Staphylococcal Chemotaxis Inhibitory Protein (chips), and Staphylococcal Complement Inhibitor (scin), thereby undermining immune escape and amplifying neutrophil chemotaxis. Upon application in an in vivo setting, Mo-A assumes a protective persona in a murine model of S. aureus USA300-induced pneumonia and demonstrates efficacy in the Galleria mellonella infection model. Of note, S. aureus displayed no swift acquisition of resistance to Mo-A, and the effect was synergistically enhanced when used in combination with vancomycin. Our findings add substantive weight to the expanding field of virulence-targeted therapeutic strategies and set the stage for more comprehensive exploration of Mo-A potential in combating antibiotic-resistant S. aureus.
Collapse
Affiliation(s)
- Xuerui Guo
- School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Li Wang
- Clinical Medical College, Changchun University of Chinese Medicine, Changchun, China
| | - Jinlong Zhang
- School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Quan Liu
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China
| | - Bingmei Wang
- Clinical Medical College, Changchun University of Chinese Medicine, Changchun, China
| | - Da Liu
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Fei Gao
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, China
| | | | - Yicheng Zhao
- Clinical Medical College, Changchun University of Chinese Medicine, Changchun, China.
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China.
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China.
| | - Yan Shi
- School of Pharmaceutical Science, Jilin University, Changchun, China.
| |
Collapse
|
5
|
Oura Y, Shimamura Y, Kan T, Masuda S. Effect of Polyphenols on Inflammation Induced by Membrane Vesicles from Staphylococcus aureus. Cells 2024; 13:387. [PMID: 38474351 DOI: 10.3390/cells13050387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/07/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Staphylococcus aureus, a bacterium found on human skin, produces toxins and various virulence factors that can lead to skin infections such as atopic dermatitis. These toxins and virulence factors are carried in membrane vesicles (MVs), composed of the bacterium's own cell membranes, and are expected to reach host target cells in a concentrated form, inducing inflammation. This study investigated the effects of two polyphenols, (-)-epigallocatechin gallate (EGCG) and nobiletin (NOL), on the expression of S. aureus virulence factors and the inflammation induced by MVs. The study found that EGCG alone decreased the production of Staphylococcal Enterotoxin A (SEA), while both EGCG and NOL reduced biofilm formation and the expression of virulence factor-related genes. When S. aureus was cultured in a broth supplemented with these polyphenols, the resulting MVs showed a reduction in SEA content and several cargo proteins. These MVs also exhibited decreased levels of inflammation-related gene expression in immortalized human keratinocytes. These results suggest that EGCG and NOL are expected to inhibit inflammation in the skin by altering the properties of MVs derived from S. aureus.
Collapse
Affiliation(s)
- Yukino Oura
- School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Yuko Shimamura
- School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Toshiyuki Kan
- Department of Synthetic Organic & Medicinal Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Shuichi Masuda
- School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| |
Collapse
|
6
|
Fernández-Barat L, López-Aladid R, Vázquez N, Cabrera R, Vila J, Ferrer M, Torres A. Bacterial Adaptive Memory in Methicillin-Resistant Staphylococcus aureus from Endotracheal Tubes. Pathogens 2024; 13:144. [PMID: 38392882 PMCID: PMC10892081 DOI: 10.3390/pathogens13020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
OBJECTIVES To evaluate the expression dynamics of biofilm genes in methicillin-resistant Staphylococcus aureus (MRSA) retrieved from endotracheal tubes (ETT) and to determine how gene regulation is attenuated in vitro where host-environmental factors are no longer present. METHODS Biofilm was grown (24 h) in tryptic broth soy plus 0.25% glucose for a clinical MRSA isolate in planktonic state and after sessile growth named ETT-MRSA (S2, S3, S4, S5, S6, S7). Gene expression of five biofilm-related genes (icaC, clfB, ebps, fnbB, and RNA III) was assessed consecutively from day 1 to day 4 after ETT growth through real-time PCR. 16S rRNA was used as a control. RESULTS The MRSA isolates retrieved from ETT were capable of producing biofilms dependent on ica. The gene expression dynamics of ETT-MRSA changed progressively compared to planktonic MRSA gene expression under both ambient air (p < 0.001) and ambient air with 5% CO2 (p < 0.001). Dynamic assessment of icaC expression in both atmospheric conditions showed progressive downregulation in vitro compared to in vivo ETT biofilms. The expression patterns of clfB and ebps genes were similar to icaC. In contrast, the expression of the RNA III gene showed progressive upregulation from day 1 to day 4 (p < 0.001). CONCLUSIONS MRSA loses its biofilm gene expression in vitro, by adaptive features across multiple generations, as evidenced by the progressive downregulation of icaC and upregulation of RNA III. These findings underscore the significance of host-environment dependence in regulating bacterial biofilm genes, highlighting its importance in diagnostics. Bacterial strains lose their host-specific characteristics as they are cultured in vitro.
Collapse
Affiliation(s)
- Laia Fernández-Barat
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
| | - Ruben López-Aladid
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
| | - Nil Vázquez
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
| | - Roberto Cabrera
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
| | - Jordi Vila
- University of Barcelona, 08193 Barcelona, Spain;
- Microbiology Service at Hospital Clinic and Institute of Global Health (ISGlobal), 08036 Barcelona, Spain
| | - Miquel Ferrer
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
- Pulmonary and Critical Care Unit, Respiratory Institute, Hospital Clinic, 08036 Barcelona, Spain
| | - Antoni Torres
- Centro de Investigación Biomedica En Red-Enfermedades Respiratorias (CibeRes, CB06/06/0028) and Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; (R.L.-A.); (N.V.); (R.C.); (M.F.)
- University of Barcelona, 08193 Barcelona, Spain;
- Pulmonary and Critical Care Unit, Respiratory Institute, Hospital Clinic, 08036 Barcelona, Spain
| |
Collapse
|
7
|
Chauvier A, Walter NG. Regulation of bacterial gene expression by non-coding RNA: It is all about time! Cell Chem Biol 2024; 31:71-85. [PMID: 38211587 DOI: 10.1016/j.chembiol.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 01/13/2024]
Abstract
Commensal and pathogenic bacteria continuously evolve to survive in diverse ecological niches by efficiently coordinating gene expression levels in their ever-changing environments. Regulation through the RNA transcript itself offers a faster and more cost-effective way to adapt than protein-based mechanisms and can be leveraged for diagnostic or antimicrobial purposes. However, RNA can fold into numerous intricate, not always functional structures that both expand and obscure the plethora of roles that regulatory RNAs serve within the cell. Here, we review the current knowledge of bacterial non-coding RNAs in relation to their folding pathways and interactions. We posit that co-transcriptional folding of these transcripts ultimately dictates their downstream functions. Elucidating the spatiotemporal folding of non-coding RNAs during transcription therefore provides invaluable insights into bacterial pathogeneses and predictive disease diagnostics. Finally, we discuss the implications of co-transcriptional folding andapplications of RNAs for therapeutics and drug targets.
Collapse
Affiliation(s)
- Adrien Chauvier
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
8
|
Schnoor SB, Neubauer P, Gimpel M. Recent insights into the world of dual-function bacterial sRNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023:e1824. [PMID: 38039556 DOI: 10.1002/wrna.1824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 12/03/2023]
Abstract
Dual-function sRNAs refer to a small subgroup of small regulatory RNAs that merges base-pairing properties of antisense RNAs with peptide-encoding properties of mRNA. Both functions can be part of either same or in another metabolic pathway. Here, we want to update the knowledge of to the already known dual-function sRNAs and review the six new sRNAs found since 2017 regarding their structure, functional mechanisms, evolutionary conservation, and role in the regulation of distinct biological/physiological processes. The increasing identification of dual-function sRNAs through bioinformatics approaches, RNomics and RNA-sequencing and the associated increase in regulatory understanding will likely continue to increase at the same rate in the future. This may improve our understanding of the physiology, virulence and resistance of bacteria, as well as enable their use in technical applications. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
Collapse
Affiliation(s)
| | - Peter Neubauer
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
| | - Matthias Gimpel
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
| |
Collapse
|
9
|
Brandwein JN, Sculthorpe TS, Ridder MJ, Bose JL, Rice KC. Factors impacting the regulation of nos gene expression in Staphylococcus aureus. Microbiol Spectr 2023; 11:e0168823. [PMID: 37747881 PMCID: PMC10580903 DOI: 10.1128/spectrum.01688-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/29/2023] [Indexed: 09/27/2023] Open
Abstract
Staphylococcus aureus nitric oxide synthase (saNOS) contributes to oxidative stress resistance, antibiotic tolerance, virulence, and modulation of aerobic and nitrate-based cellular respiration. Despite its involvement in these essential processes, the genetic regulation of nos expression has not been well characterized. 5' rapid amplification of cDNA ends on nos RNA isolated from S. aureus UAMS-1 (USA200 strain) and AH1263 (USA300 strain) revealed that the nos transcriptional start site mapped to an adenine nucleotide in the predicted Shine-Dalgarno site located 11 bp upstream of the nos ATG start codon, suggesting that the nos transcript may have a leaderless organization or may be subject to processing. The SrrAB two-component system (TCS) was previously identified as a positive regulator of nos RNA levels, and experiments using a β-galactosidase reporter plasmid confirmed that SrrAB is a positive regulator of nos promoter activity. In addition, the quorum-sensing system Agr was identified as a negative regulator of low-oxygen nos expression in UAMS-1, with activity epistatic to SrrAB. Involvement of Agr was strain dependent, as nos expression remained unchanged in an AH1263 agr mutant, which has higher Agr activity compared to UAMS-1. Furthermore, nos promoter activity and RNA levels were significantly stronger in AH1263 relative to UAMS-1 during late-exponential low-oxygen growth, when nos expression is maximal. Global regulators Rex and MgrA were also implicated as negative regulators of low-oxygen nos promoter activity in UAMS-1. Collectively, these results provide new insight into factors that control nos expression.IMPORTANCEBacterial nitric oxide synthase (bNOS) has recently emerged in several species as a key player in resistance to stresses commonly encountered during infection. Although Staphylococcus aureus (sa)NOS has been suggested to be a promising drug target in S. aureus, an obstacle to this in practice is the existence of mammalian NOS, whose oxygenase domain is like bacterial NOS. Increased understanding of the nos regulatory network in S. aureus could allow targeting of saNOS through its regulators, bypassing the issue of also inhibiting mammalian NOS. Furthermore, the observed strain-dependent differences in S. aureus nos regulation presented in this study reinforce the importance of studying bacterial NOS regulation and function at both the strain and species levels.
Collapse
Affiliation(s)
- Jessica N. Brandwein
- Department of Microbiology & Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Tiffany S. Sculthorpe
- Department of Microbiology & Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Miranda J. Ridder
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jeffrey L. Bose
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Kelly C. Rice
- Department of Microbiology & Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
10
|
Sankhwar R, Kumar A, Yadav S, Singh V, Gupta RK. Emycin-E purified from Streptomyces sp. RG1011 from Himalayan soil has antibiofilm activity against Staphylococcus aureus. Microb Pathog 2023; 182:106256. [PMID: 37454942 DOI: 10.1016/j.micpath.2023.106256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/09/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND Staphylococcus aureus is an opportunistic pathogen that causes deadly infections in human as well as animals. The intricate network of virulence factors and biofilms are the major hindrance for the antibiotics in the successful treatment of the infection. The aim of this study is to isolate, identify and characterize natural antimicrobial agent against S. aureus from natural resources. METHODS Himalayan soils were subjected to primary, secondary and tertiary screening to isolate soil Actinobacteria. Identification and characterization of the isolate was done by various biochemical assays and 16s rDNA sequencing. Partial purification of the potent antimicrobial agent was done by n-butanol from the culture supernatant, TLC and HPLC were performed to purify the active component and subjected to FTIR and ESI-MS analysis. RESULTS The potent isolate RM-1(13) was confirmed as Streptomyces griseus strain RG1011 (NCBI accession no: 0M780275) by biochemical and molecular analysis. The partially purified antimicrobial agent was active against various Gram-positive and Gram-negative pathogens. The active component was purified by HPLC and identified as Emycin-E by ESI-MS analysis. The Emycin-E has calculated MIC of 0.31 μg/ml against S. aureus ATCC 25923. Emycin-E inhibits the biofilm formation of S. aureus in in vitro microtiter plate assay. CONCLUSIONS The identified antimicrobial agent was found active against various Gram-positive and Gram-negative pathogens. We have successfully identified the active compound as Emycin-E by FTIR and ESI-MS analysis. Our study suggests the role of Emycin-E in the inhibition of biofilm formation in S. aureus.
Collapse
Affiliation(s)
- Ruchi Sankhwar
- Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, 226025, Uttar Pradesh, India
| | - Abhishek Kumar
- Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, 226025, Uttar Pradesh, India
| | - Shilpi Yadav
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, 226025, Uttar Pradesh, India
| | - Vineeta Singh
- Department of Biotechnology, Institute of Engineering and Technology, Dr. A.P.J. Abdul Kalam Technical University, Lucknow, 226021, India
| | - Ravi Kr Gupta
- Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, 226025, Uttar Pradesh, India.
| |
Collapse
|
11
|
Li Q, Liu Q, Wang Z, Zhang X, Ma R, Hu X, Mei J, Su Z, Zhu W, Zhu C. Biofilm Homeostasis Interference Therapy via 1 O 2 -Sensitized Hyperthermia and Immune Microenvironment Re-Rousing for Biofilm-Associated Infections Elimination. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300592. [PMID: 36850031 DOI: 10.1002/smll.202300592] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/10/2023] [Indexed: 06/02/2023]
Abstract
The recurrence of biofilm-associated infections (BAIs) remains high after implant-associated surgery. Biofilms on the implant surface reportedly shelter bacteria from antibiotics and evade innate immune defenses. Moreover, little is currently known about eliminating residual bacteria that can induce biofilm reinfection. Herein, novel "interference-regulation strategy" based on bovine serum albumin-iridium oxide nanoparticles (BIONPs) as biofilm homeostasis interrupter and immunomodulator via singlet oxygen (1 O2 )-sensitized mild hyperthermia for combating BAIs is reported. The catalase-like BIONPs convert abundant H2 O2 inside the biofilm-microenvironment (BME) to sufficient oxygen gas (O2 ), which can efficiently enhance the generation of 1 O2 under near-infrared irradiation. The 1 O2 -induced biofilm homeostasis disturbance (e.g., sigB, groEL, agr-A, icaD, eDNA) can disrupt the sophisticated defense system of biofilm, further enhancing the sensitivity of biofilms to mild hyperthermia. Moreover, the mild hyperthermia-induced bacterial membrane disintegration results in protein leakage and 1 O2 penetration to kill bacteria inside the biofilm. Subsequently, BIONPs-induced immunosuppressive microenvironment re-rousing successfully re-polarizes macrophages to pro-inflammatory M1 phenotype in vivo to devour residual biofilm and prevent biofilm reconstruction. Collectively, this 1 O2 -sensitized mild hyperthermia can yield great refractory BAIs treatment via biofilm homeostasis interference, mild-hyperthermia, and immunotherapy, providing a novel and effective anti-biofilm strategy.
Collapse
Affiliation(s)
- Qianming Li
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Quan Liu
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Zhengxi Wang
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Xianzuo Zhang
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Ruixiang Ma
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Xianli Hu
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Jiawei Mei
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Zheng Su
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| | - Wanbo Zhu
- Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Chen Zhu
- Department of Orthopedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, P. R. China
| |
Collapse
|
12
|
Tan XY, Citartan M, Chinni SV, Ahmed SA, Tang TH. Biocomputational Identification of sRNAs in Leptospira interrogans Serovar Lai. Indian J Microbiol 2023; 63:33-41. [PMID: 37188232 PMCID: PMC10172424 DOI: 10.1007/s12088-022-01050-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Regulatory small RNAs (sRNA) are RNA transcripts that are not translated into proteins but act as functional RNAs. Pathogenic Leptospira cause an epidemic spirochaetal zoonosis, Leptospirosis. It is speculated that Leptospiral sRNAs are involved in orchestrating their pathogenicity. In this study, biocomputational approach was adopted to identify Leptospiral sRNAs. In this study, two sRNA prediction programs, i.e., RNAz and nocoRNAc, were employed to screen the reference genome of Leptospira interrogans serovar Lai. Out of 126 predicted sRNAs, there are 96 cis-antisense sRNAs, 28 trans-encoded sRNAs and 2 sRNAs that partially overlap with protein-coding genes in a sense orientation. To determine whether these candidates are expressed in the pathogen, they were compared with the coverage files generated from our RNA-seq datasets. It was found out that 7 predicted sRNAs are expressed in mid-log phase, stationary phase, serum stress, temperature stress and iron stress while 2 sRNAs are expressed in mid-log phase, stationary phase, serum stress, and temperature stress. Besides, their expressions were also confirmed experimentally via RT-PCR. These experimentally validated candidates were also subjected to mRNA target prediction using TargetRNA2. Taken together, our study demonstrated that biocomputational strategy can serve as an alternative or as a complementary strategy to the laborious and expensive deep sequencing methods not only to uncover putative sRNAs but also to predict their targets in bacteria. In fact, this is the first study that integrates computational approach to predict putative sRNAs in L. interrogans serovar Lai. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-022-01050-9.
Collapse
Affiliation(s)
- Xinq Yuan Tan
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Marimuthu Citartan
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Suresh Venkata Chinni
- Department of Biotechnology, Faculty of Applied Sciences, AIMST University, 08100 Bedong, Kedah Malaysia
| | - Siti Aminah Ahmed
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Thean-Hock Tang
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| |
Collapse
|
13
|
Zhang Y, Wu Q, Forsythe S, Liu C, Chen N, Li Y, Zhang J, Wang J, Ding Y. The cascade regulation of small RNA and quorum sensing system: Focusing on biofilm formation of foodborne pathogens in food industry. FOOD BIOSCI 2023. [DOI: 10.1016/j.fbio.2023.102472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
14
|
Krohmaly KI, Freishtat RJ, Hahn AL. Bioinformatic and experimental methods to identify and validate bacterial RNA-human RNA interactions. J Investig Med 2023; 71:23-31. [PMID: 36162901 DOI: 10.1136/jim-2022-002509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2022] [Indexed: 01/21/2023]
Abstract
Ample evidence supports the importance of the microbiota on human health and disease. Recent studies suggest that extracellular vesicles are an important means of bacterial-host communication, in part via the transport of small RNAs (sRNAs). Bacterial sRNAs have been shown to co-precipitate with human and mouse RNA-induced silencing complex, hinting that some may regulate gene expression as eukaryotic microRNAs do. Bioinformatic tools, including those that can incorporate an sRNA's secondary structure, can be used to predict interactions between bacterial sRNAs and human messenger RNAs (mRNAs). Validation of these potential interactions using reproducible experimental methods is essential to move the field forward. This review will cover the evidence of interspecies communication via sRNAs, bioinformatic tools currently available to identify potential bacterial sRNA-host (specifically, human) mRNA interactions, and experimental methods to identify and validate those interactions.
Collapse
Affiliation(s)
- Kylie I Krohmaly
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, District of Columbia, USA.,Institute for Biomedical Sciences, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Robert J Freishtat
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, District of Columbia, USA.,Division of Emergency Medicine, Children's National Hospital, Washington, District of Columbia, USA.,Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Andrea L Hahn
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, District of Columbia, USA.,Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.,Division of Infectious Diseases, Children's National Hospital, Washington, District of Columbia, USA
| |
Collapse
|
15
|
Huber C, Wolf SA, Ziebuhr W, Holmes MA, Assmann J, Lübke-Becker A, Thürmer A, Semmler T, Brombach J, Bethe A, Bischoff M, Wieler LH, Epping L, Walther B. How to survive pig farming: Mechanism of SCC mec element deletion and metabolic stress adaptation in livestock-associated MRSA. Front Microbiol 2022; 13:969961. [PMID: 36504815 PMCID: PMC9728531 DOI: 10.3389/fmicb.2022.969961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/04/2022] [Indexed: 11/24/2022] Open
Abstract
Previous research on methicillin susceptible Staphylococcus aureus (MSSA) belonging to livestock-associated (LA-) sequence type (ST) 398, isolated from pigs and their local surroundings, indicated that differences between these MSSA and their methicillin resistant predecessors (MRSA) are often limited to the absence of the staphylococcal cassette chromosome mec (SCCmec) and few single nucleotide polymorphisms. So far, our understanding on how LA-MRSA endure the environmental conditions associated with pig-farming as well as the putative impact of this particular environment on the mobilisation of SCCmec elements is limited. Thus, we performed in-depth genomic and transcriptomic analyses using the LA-MRSA ST398 strain IMT38951 and its methicillin susceptible descendant. We identified a mosaic-structured SCCmec region including a putative replicative SCCmecVc which is absent from the MSSA chromosome through homologous recombination. Based on our data, such events occur between short repetitive sequences identified within and adjacent to two distinct alleles of the large cassette recombinase genes C (ccrC). We further evaluated the global transcriptomic response of MRSA ST398 to particular pig-farm associated conditions, i.e., contact with host proteins (porcine serum) and a high ammonia concentration. Differential expression of global regulators involved in stress response control were identified, i.e., ammonia-induced alternative sigma factor B-depending activation of genes for the alkaline shock protein 23, the heat shock response and the accessory gene regulator (agr)-controlled transcription of virulence factors. Exposure to serum transiently induced the transcription of distinct virulence factor encoding genes. Transcription of genes reported for mediating the loss of methicillin resistance, especially ccrC, was not significantly different compared to the unchallenged controls. We concluded that, from an evolutionary perspective, bacteria may save energy by incidentally dismissing a fully replicative SCCmec element in contrast to the induction of ccr genes on a population scale. Since the genomic SCCmec integration site is a hot-spot of recombination, occasional losses of elements of 16 kb size may restore capacities for the uptake of foreign genetic material. Subsequent spread of resistance, on the other hand, might depend on the autonomous replication machinery of the deleted SCCmec elements that probably enhance chances for reintegration of SCCmec into susceptible genomes by mere multiplication.
Collapse
Affiliation(s)
- Charlotte Huber
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Silver A. Wolf
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Julia Assmann
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Antina Lübke-Becker
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Andrea Thürmer
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Torsten Semmler
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Julian Brombach
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Astrid Bethe
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany
| | - Lothar H. Wieler
- Methodology and Research Infrastructure, Robert Koch Institute, Berlin, Germany
| | - Lennard Epping
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Birgit Walther
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany,*Correspondence: Birgit Walther,
| |
Collapse
|
16
|
Developing New Tools to Fight Human Pathogens: A Journey through the Advances in RNA Technologies. Microorganisms 2022; 10:microorganisms10112303. [DOI: 10.3390/microorganisms10112303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
A long scientific journey has led to prominent technological advances in the RNA field, and several new types of molecules have been discovered, from non-coding RNAs (ncRNAs) to riboswitches, small interfering RNAs (siRNAs) and CRISPR systems. Such findings, together with the recognition of the advantages of RNA in terms of its functional performance, have attracted the attention of synthetic biologists to create potent RNA-based tools for biotechnological and medical applications. In this review, we have gathered the knowledge on the connection between RNA metabolism and pathogenesis in Gram-positive and Gram-negative bacteria. We further discuss how RNA techniques have contributed to the building of this knowledge and the development of new tools in synthetic biology for the diagnosis and treatment of diseases caused by pathogenic microorganisms. Infectious diseases are still a world-leading cause of death and morbidity, and RNA-based therapeutics have arisen as an alternative way to achieve success. There are still obstacles to overcome in its application, but much progress has been made in a fast and effective manner, paving the way for the solid establishment of RNA-based therapies in the future.
Collapse
|
17
|
Qi Y, Hou J, Zhao Y, Song W, Wang L, Chen H, Chen G. An inhibitory effect of schisandrone on α-hemolysin expression to combat methicillin-resistant staphylococcus aureus infections. World J Microbiol Biotechnol 2022; 39:3. [PMID: 36344903 DOI: 10.1007/s11274-022-03442-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
Due to increasing antibiotic resistance, targeting bacterial virulence factors is now gaining further interest as an alternative strategy to develop novel classes of anti-infective agents. The critical role of α-hemolysin (Hla), an indispensable virulence determinant, in the pathogenicity of Staphylococcus aureus renders this virulence factor an appealing target for effective therapeutic applications. Herein, we identified a natural compound schisandraone, as an effective Hla inhibitor, which could inhibit Hla production and thus hemolytic activity in a dose-dependent manner without affecting the growth of S. aureus. We also found that the addition of schisandrone could down-regulate the transcriptional levels of the hla, agrA and RNAIII and significantly alleviated Hla-mediated injury of A549 cells co-cultured with S. aureus. In vivo studies further suggested that schisandrone combined with antibiotic ceftiofur exhibited a significant therapeutic effect on S. aureus infection. These findings revealed the role of schisandrone in inhibiting the activity of Hla and we believe that it is a promising anti-virulence candidate to combat MRSA pneumonia.
Collapse
Affiliation(s)
- Yingxin Qi
- College of Life Science, Key Laboratory of Straw Biology and Utilization of the Ministry of Education Jilin Agricultural University, Changchun, China.,School of Biological and Food Engineering, Jilin Engineering Normal University, Changchun, China
| | - Juan Hou
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Yicheng Zhao
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China.,Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun, China
| | - Wu Song
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Li Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Huan Chen
- Jilin Agricultural University, Changchun, China
| | - Guang Chen
- College of Life Science, Key Laboratory of Straw Biology and Utilization of the Ministry of Education Jilin Agricultural University, Changchun, China. .,School of Biological and Food Engineering, Jilin Engineering Normal University, Changchun, China.
| |
Collapse
|
18
|
Role of RNAIII in Resistance to Antibiotics and Antimicrobial Agents in Staphylococcus epidermidis Biofilms. Int J Mol Sci 2022; 23:ijms231911094. [PMID: 36232391 PMCID: PMC9569910 DOI: 10.3390/ijms231911094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/29/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus epidermidis is a known opportunistic pathogen and is one of the leading causes of chronic biofilm-associated infections. Biofilm formation is considered as a main strategy to resist antibiotic treatment and help bacteria escape from the human immune system. Understanding the complex mechanisms in biofilm formation can help find new ways to treat resistant strains and lower the prevalence of nosocomial infections. In order to examine the role of RNAIII regulated by the agr quorum sensing system and to what extent it influences biofilm resistance to antimicrobial agents, deletion mutant S. epidermidis RP62a-ΔRNAIII deficient in repressor domains with a re-maining functional hld gene was created. A deletion strain was used to examine the influence of oxacillin in combination with vanillin on biofilm resistance and cell survival was determined. Utilizing real-time qPCR, confocal laser scanning microscopy (CLSM), and crystal violet staining analyses, we found that the RNAIII-independent controlled phenol soluble modulins (PSMs) and RNAIII effector molecule have a significant role in biofilm resistance to antibiotics and phenolic compounds, and it protects the integrity of biofilms. Moreover, a combination of antibiotic and antimicrobial agents can induce methicillin-resistant S. epidermidis biofilm formation and can lead to exceedingly difficult medical treatment.
Collapse
|
19
|
Manna AC, Leo S, Girel S, González-Ruiz V, Rudaz S, Francois P, Cheung AL. Teg58, a small regulatory RNA, is involved in regulating arginine biosynthesis and biofilm formation in Staphylococcus aureus. Sci Rep 2022; 12:14963. [PMID: 36056144 PMCID: PMC9440087 DOI: 10.1038/s41598-022-18815-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 08/19/2022] [Indexed: 12/02/2022] Open
Abstract
Staphylococcus aureus adapts to different environments by sensing and responding to diverse environmental cues. The responses are coordinately regulated by regulatory proteins, and small regulatory RNAs at the transcriptional and translational levels. Here, we characterized teg58, a SarA repressed sRNA, using ChIP-Seq and RNA-Seq analysis of a sarA mutant. Phenotypic and genetic analyses indicated that inactivation of teg58 led to reduced biofilm formation in a process that is independent of SarA, agr, PIA, and PSMs. RNA-Seq analysis of teg58 mutant revealed up-regulation of arginine biosynthesis genes (i.e., argGH) as well as the ability of the mutant to grow in a chemical defined medium (CDM) lacking L-arginine. Exogenous L-arginine or endogenous induction of argGH led to decreased biofilm formation in parental strains. Further analysis in vitro and in vivo demonstrated that the specific interaction between teg58 and the argGH occurred at the post-transcriptional level to repress arginine synthesis. Biochemical and genetic analyses of various arginine catabolic pathway genes demonstrated that the catabolic pathway did not play a significant role in reduced biofilm formation in the teg58 mutant. Overall, results suggest that teg58 is a regulatory sRNA that plays an important role in modulating arginine biosynthesis and biofilm formation in S. aureus.
Collapse
Affiliation(s)
- Adhar C Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA.
| | - Stefano Leo
- Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals and University Medical Center, Rue Michel-Servet 1, 1211, Geneva 4, Switzerland
| | - Sergey Girel
- Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
- University Medical Center, Rue Michel-Servet 1, 1211, Geneva 4, Switzerland
| | - Víctor González-Ruiz
- Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
- University Medical Center, Rue Michel-Servet 1, 1211, Geneva 4, Switzerland
| | - Serge Rudaz
- Institute of Pharmaceutical Sciences of Western Switzerland (ISPSO), School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
- University Medical Center, Rue Michel-Servet 1, 1211, Geneva 4, Switzerland
| | - Patrice Francois
- Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals and University Medical Center, Rue Michel-Servet 1, 1211, Geneva 4, Switzerland
| | - Ambrose L Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
| |
Collapse
|
20
|
Song W, Wang B, Sui L, Shi Y, Ren X, Wang X, Kong X, Hou J, Wang L, Wei L, Luan Y, Guan J, Zhao Y. Tamarixetin Attenuated the Virulence of Staphylococcus aureus by Directly Targeting Caseinolytic Protease P. JOURNAL OF NATURAL PRODUCTS 2022; 85:1936-1944. [PMID: 35833867 DOI: 10.1021/acs.jnatprod.2c00138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Staphylococcus aureus, especially drug-resistant S. aureus infections, is a worldwide healthcare challenge. There is a growing focus on antivirulence therapy against S. aureus. Caseinolytic protease p (ClpP) is a protein hydrolase essential for pathogenicity in S. aureus. A flavonoid compound, tamarixetin, which was screened in this work, was specifically able to inhibit the hydrolytic activity of ClpP on the fluorescent substrate Suc-LY-AMC with an IC50 of 49.73 μM, without affecting the growth of methicillin-resistant S. aureus strain USA300 and was without obvious cytotoxicity. Further assays found that tamarixetin inhibited the transcription of hla, agr, RNAIII, pvl, PSM-α, and spa genes as well as suppressed the protein expression levels of Hla and PVL. Moreover, tamarixetin was observed to dramatically inhibit the hemolytic activity of hla in S. aureus. Consistent with that of S. aureus USA300-ΔclpP, tamarixetin was shown to increase urease expression. The thermal shift and cellular thermal shift assays showed that tamarixetin markedly changed the thermal stability of ClpP. The dissociation constant (KD) value of tamarixetin with ClpP was 2.52 × 10-6 M measured by surface plasmon resonance. The molecular docking and ClpP point mutation results also demonstrated that tamarixetin had a strong interaction with ClpP. In vivo study showed that tamarixetin was effective in protecting mice from S. aureus pneumonia by increasing survival, reducing lung tissue load, and slowing down the infiltration of inflammatory factors. In addition, tamarixetin was able to enhance the antibacterial activity of cefotaxime in combination. In conclusion, tamarixetin was promising as a ClpP inhibitor for S. aureus infections.
Collapse
Affiliation(s)
- Wu Song
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Bingmei Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Liyan Sui
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun 130021, China
| | - Yan Shi
- School of Pharmacy, Jilin University, Changchun 130021, China
| | - Xinran Ren
- School of Pharmacy, Jilin University, Changchun 130021, China
| | - Xingye Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Xiangri Kong
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Juan Hou
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Li Wang
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Lin Wei
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
| | - Yanhe Luan
- Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130021, China
| | - Jiyu Guan
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yicheng Zhao
- College of Clinical Medicine, Changchun University of Chinese Medicine, Changchun 130017, China
- Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun 130021, China
| |
Collapse
|
21
|
Baur ST, Poehlein A, Renz NJ, Hollitzer SK, Montoya Solano JD, Schiel-Bengelsdorf B, Daniel R, Dürre P. Modulation of sol mRNA expression by the long non-coding RNA Assolrna in Clostridium saccharoperbutylacetonicum affects solvent formation. Front Genet 2022; 13:966643. [PMID: 36035128 PMCID: PMC9402939 DOI: 10.3389/fgene.2022.966643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 07/11/2022] [Indexed: 12/01/2022] Open
Abstract
Solvents such as butanol are important platform chemicals and are often produced from petrochemical sources. Production of butanol and other compounds from renewable and sustainable resources can be achieved by solventogenic bacteria, such as the hyper-butanol producer Clostridium saccharoperbutylacetonicum. Its sol operon consists of the genes encoding butyraldehyde dehydrogenase, CoA transferase, and acetoacetate decarboxylase (bld, ctfA, ctfB, adc) and the gene products are involved in butanol and acetone formation. It is important to understand its regulation to further optimize the solvent production. In this study, a new long non-coding antisense transcript complementary to the complete sol operon, now called Assolrna, was identified by transcriptomic analysis and the regulatory mechanism of Assolrna was investigated. For this purpose, the promoter-exchange strain C. saccharoperbutylacetonicum ΔPasr::Pasr** was constructed. Additionally, Assolrna was expressed plasmid-based under control of the native Pasr promoter and the lactose-inducible PbgaL promoter in both the wild type and the promoter-exchange strain. Solvent formation was strongly decreased for all strains based on C. saccharoperbutylacetonicum ΔPasr::Pasr** and growth could not be restored by plasmid-based complementation of the exchanged promoter. Interestingly, very little sol mRNA expression was detected in the strain C. saccharoperbutylacetonicum ΔPasr::Pasr** lacking Assolrna expression. Butanol titers were further increased for the overexpression strain C. saccharoperbutylacetonicum [pMTL83151_asr_PbgaL] compared to the wild type. These results suggest that Assolrna has a positive effect on sol operon expression. Therefore, a possible stabilization mechanism of the sol mRNA by Assolrna under physiological concentrations is proposed.
Collapse
Affiliation(s)
- Saskia Tabea Baur
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
- *Correspondence: Saskia Tabea Baur,
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Niklas Jan Renz
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | | | | | | | - Rolf Daniel
- Department of Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Peter Dürre
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| |
Collapse
|
22
|
Kinney KJ, Stach JM, Kulhankova K, Brown M, Salgado-Pabón W. Vegetation Formation in Staphylococcus Aureus Endocarditis Inversely Correlates With RNAIII and sarA Expression in Invasive Clonal Complex 5 Isolates. Front Cell Infect Microbiol 2022; 12:925914. [PMID: 35860377 PMCID: PMC9289551 DOI: 10.3389/fcimb.2022.925914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/14/2022] [Indexed: 01/29/2023] Open
Abstract
Infective endocarditis (IE) is one of the most feared and lethal diseases caused by Staphylococcus aureus. Once established, the infection is fast-progressing and tissue destructive. S. aureus of the clonal complex 5 (CC5) commonly cause IE yet are severely understudied. IE results from bacterial colonization and formation of tissue biofilms (known as vegetations) on injured or inflamed cardiac endothelium. S. aureus IE is promoted by adhesins, coagulases, and superantigens, with the exotoxins and exoenzymes likely contributing to tissue destruction and dissemination. Expression of the large repertoire of virulence factors required for IE and sequelae is controlled by complex regulatory networks. We investigated the temporal expression of the global regulators agr (RNAIII), rot, sarS, sarA, sigB, and mgrA in 8 invasive CC5 isolates and established intrinsic expression patterns associated with IE outcomes. We show that vegetation formation, as tested in the rabbit model of IE, inversely correlates with RNAIII and sarA expression during growth in Todd-Hewitt broth (TH). Large vegetations with severe sequelae arise from strains with high-level expression of colonization factors but slower transition towards expression of the exotoxins. Overall, strains proficient in vegetation formation, a hallmark of IE, exhibit lower expression of RNAIII and sarA. Simultaneous high expression of RNAIII, sarA, sigB, and mgrA is the one phenotype assessed in this study that fails to promote IE. Thus, RNAIII and sarA expression that provides for rheostat control of colonization and virulence genes, rather than an on and off switch, promote both vegetation formation and lethal sepsis.
Collapse
Affiliation(s)
- Kyle J. Kinney
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jessica M. Stach
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Katarina Kulhankova
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Matthew Brown
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Wilmara Salgado-Pabón
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States,Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, United States,*Correspondence: Wilmara Salgado-Pabón,
| |
Collapse
|
23
|
Menard G, Silard C, Suriray M, Rouillon A, Augagneur Y. Thirty Years of sRNA-Mediated Regulation in Staphylococcus aureus: From Initial Discoveries to In Vivo Biological Implications. Int J Mol Sci 2022; 23:ijms23137346. [PMID: 35806357 PMCID: PMC9266662 DOI: 10.3390/ijms23137346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Staphylococcus aureus is a widespread livestock and human pathogen that colonizes diverse microenvironments within its host. Its adaptation to the environmental conditions encountered within humans relies on coordinated gene expression. This requires a sophisticated regulatory network, among which regulatory RNAs (usually called sRNAs) have emerged as key players over the last 30 years. In S. aureus, sRNAs regulate target genes at the post-transcriptional level through base–pair interactions. The functional characterization of a subset revealed that they participate in all biological processes, including virulence, metabolic adaptation, and antibiotic resistance. In this review, we report 30 years of S. aureus sRNA studies, from their discovery to the in-depth characterizations of some of them. We also discuss their actual in vivo contribution, which is still lagging behind, and their place within the complex regulatory network. These shall be key aspects to consider in order to clearly uncover their in vivo biological functions.
Collapse
Affiliation(s)
- Guillaume Menard
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Chloé Silard
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Marie Suriray
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Astrid Rouillon
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Yoann Augagneur
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
- Correspondence: ; Tel.: +33-223234631
| |
Collapse
|
24
|
McKellar SW, Ivanova I, Arede P, Zapf RL, Mercier N, Chu LC, Mediati DG, Pickering AC, Briaud P, Foster RG, Kudla G, Fitzgerald JR, Caldelari I, Carroll RK, Tree JJ, Granneman S. RNase III CLASH in MRSA uncovers sRNA regulatory networks coupling metabolism to toxin expression. Nat Commun 2022; 13:3560. [PMID: 35732654 PMCID: PMC9217828 DOI: 10.1038/s41467-022-31173-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/03/2022] [Indexed: 01/13/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen responsible for significant human morbidity and mortality. Post-transcriptional regulation by small RNAs (sRNAs) has emerged as an important mechanism for controlling virulence. However, the functionality of the majority of sRNAs during infection is unknown. To address this, we performed UV cross-linking, ligation, and sequencing of hybrids (CLASH) in MRSA to identify sRNA-RNA interactions under conditions that mimic the host environment. Using a double-stranded endoribonuclease III as bait, we uncovered hundreds of novel sRNA-RNA pairs. Strikingly, our results suggest that the production of small membrane-permeabilizing toxins is under extensive sRNA-mediated regulation and that their expression is intimately connected to metabolism. Additionally, we also uncover an sRNA sponging interaction between RsaE and RsaI. Taken together, we present a comprehensive analysis of sRNA-target interactions in MRSA and provide details on how these contribute to the control of virulence in response to changes in metabolism.
Collapse
Affiliation(s)
- Stuart W McKellar
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Ivayla Ivanova
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Pedro Arede
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Rachel L Zapf
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
| | - Noémie Mercier
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Liang-Cui Chu
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Daniel G Mediati
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, NSW, Australia
| | - Amy C Pickering
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, UK
| | - Paul Briaud
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
| | - Robert G Foster
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Grzegorz Kudla
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - J Ross Fitzgerald
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, UK
| | - Isabelle Caldelari
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
- The Infectious and Tropical Disease Institute, Ohio University, Athens, OH, 45701, USA
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, NSW, Australia
| | - Sander Granneman
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
25
|
Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
Collapse
|
26
|
Zhang M, Li H, Agyekumwaa AK, Yu Y, Xiao X. Effects of citronellal on growth and enterotoxins production in Staphylococcus aureus ATCC 29213. Toxicon 2022; 213:92-98. [PMID: 35489426 DOI: 10.1016/j.toxicon.2022.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus (S. aureus) is known to be one of the most common foodborne pathogens capable of secreting a wide range of exotoxins such as enterotoxin, which severely threatens the health of consumers. Over the past few years, the development of safe and effective strategies in inhibiting the growth and enterotoxins generation of S. aureus in food turns out to be the research focus and emphasis. This research explores citronellal (CIT), a native compound with extensive existence in spices, which could effectively inhibit the growth and enterotoxins generation of S. aureus (ATCC 29213). Results from minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill curves, showed that CIT could tremendously inhibit the growth of S. aureus. Analysis on hemolysin showed that CIT at sub-MIC could significantly (p < 0.05) inhibit the hemolytic activity of S. aureus. As revealed by the results of ELISA, the production of enterotoxins in the culture supernatant and pork meat decreased significantly (p < 0.05) after exposure to CIT at sub-MIC. Furthermore, a significant (p < 0.05) decrease in dose-dependent was found in the transcription levels of virulence-related genes. In all, CIT proved to be a possible inhibitor of the growth and enterotoxins production of S. aureus with highly promising application in the food industry.
Collapse
Affiliation(s)
- Mao Zhang
- Research Center of Food Safety and Detection, College of Food Science and Engineering, South China University of Technology, Guangzhou, 510006, PR China
| | - Hui Li
- Research Center of Food Safety and Detection, College of Food Science and Engineering, South China University of Technology, Guangzhou, 510006, PR China
| | - Addo Keren Agyekumwaa
- Research Center of Food Safety and Detection, College of Food Science and Engineering, South China University of Technology, Guangzhou, 510006, PR China
| | - Yigang Yu
- Research Center of Food Safety and Detection, College of Food Science and Engineering, South China University of Technology, Guangzhou, 510006, PR China.
| | - Xinglong Xiao
- Research Center of Food Safety and Detection, College of Food Science and Engineering, South China University of Technology, Guangzhou, 510006, PR China.
| |
Collapse
|
27
|
TMT proteomic analysis for molecular mechanism of Staphylococcus aureus in response to freezing stress. Appl Microbiol Biotechnol 2022; 106:3139-3152. [PMID: 35460349 DOI: 10.1007/s00253-022-11927-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/02/2022]
Abstract
The foodborne pathogen Staphylococcus aureus continues to challenge the food industry due to the pathogenicity and tolerance of the bacterium. As a common storage condition for frozen food during transportation, distribution, and storage, freezing does not seem to be entirely safe due to the cold tolerance of S. aureus. In addition, our study indicated that the biofilm formation ability of S. aureus was significantly increased in response to freezing stress. To explore the molecular mechanism regulating the response to freezing stress, the proteomics signature of S. aureus after freezing stress based on tandem mass tag (TMT) labeling and liquid chromatography tandem mass spectrometry (LC-MS/MS) was analyzed. Gene Ontology and pathway analysis revealed that ribosome function, metabolism, RNA repair, and stress response proteins were differentially regulated (P < 0.05). Furthermore, transpeptidase sortase A, biofilm operon icaADBC HTH-type negative transcriptional regulator IcaR, and HTH-type transcriptional regulator MgrA were involved in the modulation of increased biofilm formation in response to freezing stress (P < 0.05). Moreover, significant lysine acetylation and malonylation signals in the S. aureus response to freezing stress were observed. Collectively, the current work provides additional insight for comprehending the molecular mechanism of S. aureus in response to freezing stress and presents potential targets for developing strategies to control S. aureus. KEY POINTS: • TMT proteomic analysis was first used on S. aureus in response to freezing stress. • Ribosome-, metabolism-, and biofilm-related proteins change after freezing stress. • Increased biofilm formation in S. aureus responded to freezing stress.
Collapse
|
28
|
Roncarati D, Scarlato V, Vannini A. Targeting of Regulators as a Promising Approach in the Search for Novel Antimicrobial Agents. Microorganisms 2022; 10:microorganisms10010185. [PMID: 35056634 PMCID: PMC8777881 DOI: 10.3390/microorganisms10010185] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Since the discovery of penicillin in the first half of the last century, antibiotics have become the pillars of modern medicine for fighting bacterial infections. However, pathogens resistant to antibiotic treatment have increased in recent decades, and efforts to discover new antibiotics have decreased. As a result, it is becoming increasingly difficult to treat bacterial infections successfully, and we look forward to more significant efforts from both governments and the scientific community to research new antibacterial drugs. This perspective article highlights the high potential of bacterial transcriptional and posttranscriptional regulators as targets for developing new drugs. We highlight some recent advances in the search for new compounds that inhibit their biological activity and, as such, appear very promising for treating bacterial infections.
Collapse
Affiliation(s)
- Davide Roncarati
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
| | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
| | - Andrea Vannini
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40126 Bologna, Italy
- Correspondence: (D.R.); (V.S.); (A.V.)
| |
Collapse
|
29
|
Skeparnias I, Zhang J. Cooperativity and Interdependency between RNA Structure and RNA-RNA Interactions. Noncoding RNA 2021; 7:ncrna7040081. [PMID: 34940761 PMCID: PMC8704770 DOI: 10.3390/ncrna7040081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
Complex RNA–RNA interactions are increasingly known to play key roles in numerous biological processes from gene expression control to ribonucleoprotein granule formation. By contrast, the nature of these interactions and characteristics of their interfaces, especially those that involve partially or wholly structured RNAs, remain elusive. Herein, we discuss different modalities of RNA–RNA interactions with an emphasis on those that depend on secondary, tertiary, or quaternary structure. We dissect recently structurally elucidated RNA–RNA complexes including RNA triplexes, riboswitches, ribozymes, and reverse transcription complexes. These analyses highlight a reciprocal relationship that intimately links RNA structure formation with RNA–RNA interactions. The interactions not only shape and sculpt RNA structures but also are enabled and modulated by the structures they create. Understanding this two-way relationship between RNA structure and interactions provides mechanistic insights into the expanding repertoire of noncoding RNA functions, and may inform the design of novel therapeutics that target RNA structures or interactions.
Collapse
|
30
|
Contribution of Coagulase and Its Regulator SaeRS to Lethality of CA-MRSA 923 Bacteremia. Pathogens 2021; 10:pathogens10111396. [PMID: 34832552 PMCID: PMC8623987 DOI: 10.3390/pathogens10111396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
Coagulase is a critical factor for distinguishing Staphylococcus aureus and coagulase-negative Staphylococcus. Our previous studies demonstrated that the null mutation of coagulase (coa) or its direct regulator, SaeRS, significantly enhanced the ability of S. aureus (CA-MRSA 923) to survive in human blood in vitro. This led us to further investigate the role of coagulase and its direct regulator, SaeRS, in the pathogenicity of CA-MRSA 923 in bacteremia during infection. In this study, we found that the null mutation of coa significantly decreased the mortality of CA-MRSA 923; moreover, the single null mutation of saeRS and the double deletion of coa/saeRS abolished the virulence of CA-MRSA 923. Moreover, the mice infected with either the saeRS knockout or the coa/saeRS double knockout mutant exhibited fewer histological lesions and less neutrophils infiltration in the infected kidneys compared to those infected with the coa knockout mutant or their parental control. Furthermore, we examined the impact of coa and saeRS on bacterial survival in vitro. The null mutation of coa had no impact on bacterial survival in mice blood, whereas the deletion mutation of saeRS or coa/saeRS significantly enhanced bacterial survival in mice blood. These data indicate that SaeRS plays a key role in the lethality of CA-MRSA 923 bacteremia, and that coagulase is one of the important virulence factors that is regulated by SaeRS and contributes to the pathogenicity of CA-MRSA 923.
Collapse
|
31
|
Abstract
SarA, a transcriptional regulator of Staphylococcus aureus, is a major global regulatory system that coordinates the expression of target genes involved in its pathogenicity. Various studies have identified a large number of SarA target genes, but an in-depth characterization of the sarA regulon, including small regulatory RNAs (sRNAs), has not yet been done. In this study, we utilized transcriptome sequencing (RNA-Seq) and chromatin immunoprecipitation sequencing (ChIP-Seq) to determine a comprehensive list of SarA-regulated targets, including both mRNAs and sRNAs. RNA-Seq analysis indicated 390 mRNAs and 51 sRNAs differentially expressed in a ΔsarA mutant, while ChIP-Seq revealed 354 mRNAs and 55 sRNA targets in the S. aureus genome. We confirmed the authenticity of several novel SarA targets by Northern blotting and electrophoretic mobility shift assays. Among them, we characterized repression of sprG2, a gene that encodes the toxin of a type I toxin-antitoxin system, indicating a multilayer lockdown of toxin expression by both SarA and its cognate antitoxin, SprF2. Finally, a novel SarA consensus DNA binding sequence was generated using the upstream promoter sequences of 15 novel SarA-regulated sRNA targets. A genome-wide scan with a deduced SarA motif enabled the discovery of new potential SarA target genes which were not identified in our RNA-Seq and ChIP-Seq analyses. The strength of this new consensus was confirmed with one predicted sRNA target. The RNA-Seq and ChIP-Seq combinatory analysis gives a snapshot of the regulation, whereas bioinformatic analysis reveals a permanent view of targets based on sequence. Altogether these experimental and in silico methodologies are effective to characterize transcriptional factor (TF) regulons and functions. IMPORTANCEStaphylococcus aureus, a commensal and opportunist pathogen, is responsible for a large number of human and animal infections, from benign to severe. Gene expression adaptation during infection requires a complex network of regulators, including transcriptional factors (TF) and sRNAs. TF SarA influences virulence, metabolism, biofilm formation, and resistance to some antibiotics. SarA directly regulates expression of around 20 mRNAs and a few sRNAs. Here, we combined high-throughput expression screening methods combined with binding assays and bioinformatics for an in-depth investigation of the SarA regulon. This combinatory approach allowed the identification of 85 unprecedented mRNAs and sRNAs targets, with at least 14 being primary. Among novel SarA direct targets, we characterized repression of sprG2, a gene that encodes the toxin of a toxin-antitoxin system, indicating a multilayer lockdown of toxin expression by both SarA and its cognate antitoxin, SprF2.
Collapse
|
32
|
Impact of Bicarbonate-β-Lactam Exposures on Methicillin-Resistant Staphylococcus aureus (MRSA) Gene Expression in Bicarbonate-β-Lactam-Responsive vs. Non-Responsive Strains. Genes (Basel) 2021; 12:genes12111650. [PMID: 34828256 PMCID: PMC8619011 DOI: 10.3390/genes12111650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 01/11/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections represent a difficult clinical treatment issue. Recently, a novel phenotype was discovered amongst selected MRSA which exhibited enhanced β-lactam susceptibility in vitro in the presence of NaHCO3 (termed ‘NaHCO3-responsiveness’). This increased β-lactam susceptibility phenotype has been verified in both ex vivo and in vivo models. Mechanistic studies to-date have implicated NaHCO3-mediated repression of genes involved in the production, as well as maturation, of the alternative penicillin-binding protein (PBP) 2a, a necessary component of MRSA β-lactam resistance. Herein, we utilized RNA-sequencing (RNA-seq) to identify genes that were differentially expressed in NaHCO3-responsive (MRSA 11/11) vs. non-responsive (COL) strains, in the presence vs. absence of NaHCO3-β-lactam co-exposures. These investigations revealed that NaHCO3 selectively repressed the expression of a cadre of genes in strain 11/11 known to be a part of the sigB-sarA-agr regulon, as well as a number of genes involved in the anchoring of cell wall proteins in MRSA. Moreover, several genes related to autolysis, cell division, and cell wall biosynthesis/remodeling, were also selectively impacted by NaHCO3-OXA exposure in the NaHCO3-responsive strain MRSA 11/11. These outcomes provide an important framework for further studies to mechanistically verify the functional relevance of these genetic perturbations to the NaHCO3-responsiveness phenotype in MRSA.
Collapse
|
33
|
Felden B, Augagneur Y. Diversity and Versatility in Small RNA-Mediated Regulation in Bacterial Pathogens. Front Microbiol 2021; 12:719977. [PMID: 34447363 PMCID: PMC8383071 DOI: 10.3389/fmicb.2021.719977] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial gene expression is under the control of a large set of molecules acting at multiple levels. In addition to the transcription factors (TFs) already known to be involved in global regulation of gene expression, small regulatory RNAs (sRNAs) are emerging as major players in gene regulatory networks, where they allow environmental adaptation and fitness. Developments in high-throughput screening have enabled their detection in the entire bacterial kingdom. These sRNAs influence a plethora of biological processes, including but not limited to outer membrane synthesis, metabolism, TF regulation, transcription termination, virulence, and antibiotic resistance and persistence. Almost always noncoding, they regulate target genes at the post-transcriptional level, usually through base-pair interactions with mRNAs, alone or with the help of dedicated chaperones. There is growing evidence that sRNA-mediated mechanisms of actions are far more diverse than initially thought, and that they go beyond the so-called cis- and trans-encoded classifications. These molecules can be derived and processed from 5' untranslated regions (UTRs), coding or non-coding sequences, and even from 3' UTRs. They usually act within the bacterial cytoplasm, but recent studies showed sRNAs in extracellular vesicles, where they influence host cell interactions. In this review, we highlight the various functions of sRNAs in bacterial pathogens, and focus on the increasing examples of widely diverse regulatory mechanisms that might compel us to reconsider what constitute the sRNA.
Collapse
Affiliation(s)
- Brice Felden
- Inserm, Bacterial Regulatory RNAs and Medicine (BRM) - UMR_S 1230, Rennes, France
| | - Yoann Augagneur
- Inserm, Bacterial Regulatory RNAs and Medicine (BRM) - UMR_S 1230, Rennes, France
| |
Collapse
|
34
|
Yi L, Dong X, Grenier D, Wang K, Wang Y. Research progress of bacterial quorum sensing receptors: Classification, structure, function and characteristics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:143031. [PMID: 33129525 DOI: 10.1016/j.scitotenv.2020.143031] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/16/2020] [Accepted: 10/10/2020] [Indexed: 06/11/2023]
Abstract
The microbial community is an important part of the natural ecosystem, and the quorum sensing system is a momentous communication tool for the microbial community to connect to the surrounding environment. Quorum sensing is a process of cell-cell communication that relies on the production, release, and detection of extracellular signaling molecules, which are called autoinducers. Quorum sensing systems in bacteria consist of two main components: a receptor protein and an autoinducer. The binding of autoinducer to its receptor activates the target gene, which then performs the corresponding function in bacteria. In a natural environment, different bacterial species possess quorum sensing receptors that are structurally and functionally different. So far, many bacterial quorum sensing receptors have been identified and the structure and function of some receptors have been characterized. There are many reviews about quorum sensing and quorum sensing receptors, but there are few reviews that describe various types of quorum sensing in different environments with receptors as the core. Therefore, we summarize the well-defined quorum sensing receptors involved in intra-species and inter-species cell-cell communication, and describe the structure, function, and characteristics of typical receptors for different types of quorum sensing. A systematic understanding of quorum sensing receptors will help researchers to further explore the signaling mechanism and regulation mechanism of quorum sensing system, provide help to clarify the role and function of quorum sensing in natural ecosystems, then provide theoretical basis for the discovery or synthesis of new targeted drugs that block quorum sensing.
Collapse
Affiliation(s)
- Li Yi
- College of Life Science, Luoyang Normal University, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Xiao Dong
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Daniel Grenier
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, QC, Canada
| | - Kaicheng Wang
- China Animal Health and Epidemiology Center, Qingdao, China
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China; Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China.
| |
Collapse
|
35
|
Menendez-Gil P, Toledo-Arana A. Bacterial 3'UTRs: A Useful Resource in Post-transcriptional Regulation. Front Mol Biosci 2021; 7:617633. [PMID: 33490108 PMCID: PMC7821165 DOI: 10.3389/fmolb.2020.617633] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022] Open
Abstract
Bacterial messenger RNAs (mRNAs) are composed of 5′ and 3′ untranslated regions (UTRs) that flank the coding sequences (CDSs). In eukaryotes, 3′UTRs play key roles in post-transcriptional regulatory mechanisms. Shortening or deregulation of these regions is associated with diseases such as cancer and metabolic disorders. Comparatively, little is known about the functions of 3′UTRs in bacteria. Over the past few years, 3′UTRs have emerged as important players in the regulation of relevant bacterial processes such as virulence, iron metabolism, and biofilm formation. This MiniReview is an update for the different 3′UTR-mediated mechanisms that regulate gene expression in bacteria. Some of these include 3′UTRs that interact with the 5′UTR of the same transcript to modulate translation, 3′UTRs that are targeted by specific ribonucleases, RNA-binding proteins and small RNAs (sRNAs), and 3′UTRs that act as reservoirs of trans-acting sRNAs, among others. In addition, recent findings regarding a differential evolution of bacterial 3′UTRs and its impact in the species-specific expression of orthologous genes are also discussed.
Collapse
Affiliation(s)
- Pilar Menendez-Gil
- Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas (CSIC) - Gobierno de Navarra, Navarra, Spain
| | - Alejandro Toledo-Arana
- Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas (CSIC) - Gobierno de Navarra, Navarra, Spain
| |
Collapse
|
36
|
MgrA Activates Staphylococcal Capsule via SigA-Dependent Promoter. J Bacteriol 2020; 203:JB.00495-20. [PMID: 33077637 DOI: 10.1128/jb.00495-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/14/2020] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus capsule polysaccharide is an important antiphagocytic virulence factor. The cap genes are regulated at the promoter element (Pcap) upstream of the cap operon. Pcap, which consists of a dominant SigB-dependent promoter and a weaker upstream SigA-dependent promoter, is activated by global regulator MgrA. How MgrA activates capsule is unclear. Here, we showed that MgrA directly bound to the Pcap region and affected the SigA-dependent promoter. Interestingly, an electrophoretic mobility shift assay showed that MgrA bound to a large region of Pcap, mainly downstream of the SigA-dependent promoter. We further showed that the ArlRS two-component system and the Agr quorum sensing system activated capsule primarily through MgrA in the early growth phases.IMPORTANCE The virulence of Staphylococcus aureus depends on the expression of various virulence factors, which is governed by a complex regulatory network. We have been using capsule as a model virulence factor to study virulence gene regulation in S. aureus MgrA is one of the regulators of capsule and has a major effect on capsule production. However, how MgrA regulates capsule genes is not understood. In this study, we were able to define the mechanism involving MgrA regulation of capsule. In addition, we also delineated the role of MgrA in capsule regulatory pathways involving the key virulence regulators Agr and Arl. This study further advances our understanding of virulence gene regulation in S. aureus, an important human pathogen.
Collapse
|
37
|
Karatzas KAG, Lemmens-den Toom NA, Tassou CC, van Leeuwen W, van Belkum A. Molecular characterization of piezotolerant and stress-resistant mutants of Staphylococcus aureus. J Appl Microbiol 2020; 130:901-912. [PMID: 32871628 DOI: 10.1111/jam.14832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/08/2020] [Accepted: 08/04/2020] [Indexed: 11/29/2022]
Abstract
AIMS In the previous work, following a pressure treatment with wild-type Staphylococcus aureus, we obtained piezotolerant isolates showing altered phenotypic characteristics. This work focuses on understanding the genetic background of their altered phenotype. METHODS AND RESULTS AK23, a representative piezotolerant isolate was subjected to DNA microarrays, corroborated by PCR product sequencing and revealed 10-gene deletion. All other piezotolerant isolates possessed the mutation encompassing the region from SAR0665 to SAR0674 genes (9351 bp) which was most likely the result of recombination between two homologous loci (ATTGCGGGTG) present in both genes. RNA microarray transcriptomic analysis showed that due to partial deletion of the low-affinity phosphate transporter pitA, the high-affinity PhoU-PstABCS operon was upregulated in AK23 which could be the reason for piezotolerance. Furthermore, AK23 showed low levels of the virulence gene regulator rnaIII resulting in the downregulation of several agr system genes explaining the impaired virulence characteristics of the mutant. CONCLUSIONS Naturally occurring mutations can result in piezotolerance which can be of a concern for high hydrostatic pressure-treated foods. SIGNIFICANCE AND IMPACT OF THE STUDY A locus has been identified in piezotolerant S. aureus mutants providing insight into possible mechanisms associated with phenotypic characteristics of S. aureus. Further work should study each individual gene of the locus.
Collapse
Affiliation(s)
- K A G Karatzas
- Department of Food and Nutritional Sciences, University of Reading, Reading, UK
| | - N A Lemmens-den Toom
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, GD Rotterdam, The Netherlands
| | - C C Tassou
- Hellenic Agricultural Organisation 'DEMETER', Institute of Technology of Agricultural Products, Attikis, Greece
| | - W van Leeuwen
- Leiden Centre for Applied Bioscience, University of Applied Science Leiden, Leiden, The Netherlands
| | - A van Belkum
- BioMérieux, Open Innovation & Partnerships, La Balme Les Grottes, France
| |
Collapse
|
38
|
Butrico CE, Cassat JE. Quorum Sensing and Toxin Production in Staphylococcus aureus Osteomyelitis: Pathogenesis and Paradox. Toxins (Basel) 2020; 12:toxins12080516. [PMID: 32806558 PMCID: PMC7471978 DOI: 10.3390/toxins12080516] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen capable of infecting nearly every vertebrate organ. Among these tissues, invasive infection of bone (osteomyelitis) is particularly common and induces high morbidity. Treatment of osteomyelitis is notoriously difficult and often requires debridement of diseased bone in conjunction with prolonged antibiotic treatment to resolve infection. During osteomyelitis, S. aureus forms characteristic multicellular microcolonies in distinct niches within bone. Virulence and metabolic responses within these multicellular microcolonies are coordinated, in part, by quorum sensing via the accessory gene regulator (agr) locus, which allows staphylococcal populations to produce toxins and adapt in response to bacterial density. During osteomyelitis, the Agr system significantly contributes to dysregulation of skeletal homeostasis and disease severity but may also paradoxically inhibit persistence in the host. Moreover, the Agr system is subject to complex crosstalk with other S. aureus regulatory systems, including SaeRS and SrrAB, which can significantly impact the progression of osteomyelitis. The objective of this review is to highlight Agr regulation, its implications on toxin production, factors that affect Agr activation, and the potential paradoxical influences of Agr regulation on disease progression during osteomyelitis.
Collapse
Affiliation(s)
- Casey E. Butrico
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - James E. Cassat
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence: ; Tel.: +1-615-936-6494
| |
Collapse
|
39
|
Park KH, Jung M, Kim DY, Lee YM, Lee MS, Ryu BH, Hong SI, Hong KW, Bae IG, Cho OH. Effects of subinhibitory concentrations of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus. J Hosp Infect 2020; 106:295-302. [PMID: 32679053 DOI: 10.1016/j.jhin.2020.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/06/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study. AIM To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates. METHODS MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet. FINDINGS Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin). CONCLUSION Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.
Collapse
Affiliation(s)
- K-H Park
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - M Jung
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - D Y Kim
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Y-M Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - M S Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - B-H Ryu
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - S I Hong
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - K-W Hong
- Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea
| | - I-G Bae
- Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea; Gyeongsang Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, Republic of Korea
| | - O-H Cho
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea; Gyeongsang Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, Republic of Korea.
| |
Collapse
|
40
|
Lalaouna D, Baude J, Wu Z, Tomasini A, Chicher J, Marzi S, Vandenesch F, Romby P, Caldelari I, Moreau K. RsaC sRNA modulates the oxidative stress response of Staphylococcus aureus during manganese starvation. Nucleic Acids Res 2019; 47:9871-9887. [PMID: 31504767 PMCID: PMC6765141 DOI: 10.1093/nar/gkz728] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/22/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023] Open
Abstract
The human opportunistic pathogen Staphylococcus aureus produces numerous small regulatory RNAs (sRNAs) for which functions are still poorly understood. Here, we focused on an atypical and large sRNA called RsaC. Its length varies between different isolates due to the presence of repeated sequences at the 5′ end while its 3′ part is structurally independent and highly conserved. Using MS2-affinity purification coupled with RNA sequencing (MAPS) and quantitative differential proteomics, sodA mRNA was identified as a primary target of RsaC sRNA. SodA is a Mn-dependent superoxide dismutase involved in oxidative stress response. Remarkably, rsaC gene is co-transcribed with the major manganese ABC transporter MntABC and, consequently, RsaC is mainly produced in response to Mn starvation. This 3′UTR-derived sRNA is released from mntABC-RsaC precursor after cleavage by RNase III. The mature and stable form of RsaC inhibits the synthesis of the Mn-containing enzyme SodA synthesis and favors the oxidative stress response mediated by SodM, an alternative SOD enzyme using either Mn or Fe as co-factor. In addition, other putative targets of RsaC are involved in oxidative stress (ROS and NOS) and metal homeostasis (Fe and Zn). Consequently, RsaC may balance two interconnected defensive responses, i.e. oxidative stress and metal-dependent nutritional immunity.
Collapse
Affiliation(s)
- David Lalaouna
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Jessica Baude
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Arnaud Tomasini
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg-Esplanade, IBMC-CNRS, Strasbourg, France
| | - Stefano Marzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France.,Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
| | - Pascale Romby
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Isabelle Caldelari
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Karen Moreau
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France
| |
Collapse
|
41
|
MgrA Negatively Impacts Staphylococcus aureus Invasion by Regulating Capsule and FnbA. Infect Immun 2019; 87:IAI.00590-19. [PMID: 31591167 DOI: 10.1128/iai.00590-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/27/2019] [Indexed: 01/19/2023] Open
Abstract
Virulence genes are regulated by a complex regulatory network in Staphylococcus aureus Some of the regulators are global in nature and affect many downstream genes. MgrA is a multiple-gene regulator that has been shown to activate genes involved in capsule biosynthesis and repress surface protein genes. The goal of this study was to demonstrate the biological significance of MgrA regulation of capsule and surface proteins. We found that strain Becker possessed one fibronectin-binding protein, FnbA, and that FnbA was the predominant protein involved in invasion of nonphagocytic HeLa cells. By genetic analysis of strains with different amounts of capsule, we demonstrated that capsule impeded invasion of HeLa cells by masking the bacterial cell wall-anchored protein FnbA. Using variants with different levels of mgrA transcription, we further demonstrated that MgrA negatively impacted invasion by activating the cap genes involved in capsule biosynthesis and repressing the fnbA gene. Thus, we conclude that MgrA negatively impacts cell invasion of S. aureus Becker by promoting capsule and repressing FnbA.
Collapse
|
42
|
Contribution of hla Regulation by SaeR to Staphylococcus aureus USA300 Pathogenesis. Infect Immun 2019; 87:IAI.00231-19. [PMID: 31209148 DOI: 10.1128/iai.00231-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/11/2019] [Indexed: 02/08/2023] Open
Abstract
The SaeRS two-component system in Staphylococcus aureus is critical for regulation of many virulence genes, including hla, which encodes alpha-toxin. However, the impact of regulation of alpha-toxin by Sae on S. aureus pathogenesis has not been directly addressed. Here, we mutated the SaeR-binding sequences in the hla regulatory region and determined the contribution of this mutation to hla expression and pathogenesis in strain USA300 JE2. Western blot analyses revealed drastic reduction of alpha-toxin levels in the culture supernatants of SaeR-binding mutant in contrast to the marked alpha-toxin production in the wild type. The SaeR-binding mutation had no significant effect on alpha-toxin regulation by Agr, MgrA, and CcpA. In animal studies, we found that the SaeR-binding mutation did not contribute to USA300 JE2 pathogenesis using a rat infective endocarditis model. However, in a rat skin and soft tissue infection model, the abscesses on rats infected with the mutant were significantly smaller than the abscesses on those infected with the wild type but similar to the abscesses on those infected with a saeR mutant. These studies indicated that there is a direct effect of hla regulation by SaeR on pathogenesis but that the effect depends on the animal model used.
Collapse
|
43
|
Kalvari I, Argasinska J, Quinones-Olvera N, Nawrocki EP, Rivas E, Eddy SR, Bateman A, Finn RD, Petrov AI. Rfam 13.0: shifting to a genome-centric resource for non-coding RNA families. Nucleic Acids Res 2019; 46:D335-D342. [PMID: 29112718 PMCID: PMC5753348 DOI: 10.1093/nar/gkx1038] [Citation(s) in RCA: 584] [Impact Index Per Article: 116.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
The Rfam database is a collection of RNA families in which each family is represented by a multiple sequence alignment, a consensus secondary structure, and a covariance model. In this paper we introduce Rfam release 13.0, which switches to a new genome-centric approach that annotates a non-redundant set of reference genomes with RNA families. We describe new web interface features including faceted text search and R-scape secondary structure visualizations. We discuss a new literature curation workflow and a pipeline for building families based on RNAcentral. There are 236 new families in release 13.0, bringing the total number of families to 2687. The Rfam website is http://rfam.org.
Collapse
Affiliation(s)
- Ioanna Kalvari
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Joanna Argasinska
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | | | - Eric P Nawrocki
- National Center for Biotechnology Information; National Institutes of Health; Department of Health and Human Services; Bethesda, MD 20894, USA
| | - Elena Rivas
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Sean R Eddy
- Howard Hughes Medical Institute, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Robert D Finn
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Anton I Petrov
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| |
Collapse
|
44
|
Tuffs SW, Herfst CA, Baroja ML, Podskalniy VA, DeJong EN, Coleman CEM, McCormick JK. Regulation of toxic shock syndrome toxin‐1 by the accessory gene regulator inStaphylococcus aureusis mediated by the repressor of toxins. Mol Microbiol 2019; 112:1163-1177. [DOI: 10.1111/mmi.14353] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Stephen W. Tuffs
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
| | - Christine A. Herfst
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
- Lawson Health Research Institute London Ontario Canada
| | - Miren L. Baroja
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
- Lawson Health Research Institute London Ontario Canada
| | - Vladyslav A. Podskalniy
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
| | - Erica N. DeJong
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
| | - Charlotte E. M. Coleman
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
| | - John K. McCormick
- Department of Microbiology and Immunology University of Western Ontario London Ontario Canada
- Lawson Health Research Institute London Ontario Canada
| |
Collapse
|
45
|
Bezar IF, Mashruwala AA, Boyd JM, Stock AM. Drug-like Fragments Inhibit agr-Mediated Virulence Expression in Staphylococcus aureus. Sci Rep 2019; 9:6786. [PMID: 31043623 PMCID: PMC6494831 DOI: 10.1038/s41598-019-42853-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 04/01/2019] [Indexed: 11/23/2022] Open
Abstract
In response to the increasingly problematic emergence of antibiotic resistance, novel strategies for combating pathogenic bacteria are being investigated. Targeting the agr quorum sensing system, which regulates expression of virulence in Staphylococcus aureus, is one potentially useful approach for combating drug-resistant pathogens that has not yet been fully explored. A previously published study of a fragment screen resulted in the identification of five compound fragments that interact with the DNA-binding domain of the response regulator AgrA from S. aureus. We have analyzed the ability of these compounds to affect agr-mediated virulence gene expression in cultured S. aureus cells. Three of the compounds demonstrated the ability to reduce agr-driven transcription at the P2 and P3 promoters of the agr operon and increase biofilm formation, and two of these compounds also showed the ability to reduce levels of secreted toxins. The finding that the compounds tested were able to reduce agr activity suggests that they could be useful tools for probing the effects of agr inhibition. Furthermore, the characteristics of compound fragments make them good starting materials for the development of compound libraries to iteratively improve the inhibitors.
Collapse
Affiliation(s)
- Ian F Bezar
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
- Graduate School of Biomedical Sciences at Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA
| | - Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Graduate School-New Brunswick, Rutgers University, New Brunswick, New Jersey, 08901, USA
- Department of Molecular Biology, Princeton University, Princeton, 08544, New Jersey, USA
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, 08901, USA
| | - Ann M Stock
- Department of Biochemistry and Molecular Biology, Center for Advanced Biotechnology and Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854, USA.
| |
Collapse
|
46
|
Abstract
Staphylococcus aureus is a Gram-positive opportunistic pathogen that has evolved a complex regulatory network to control virulence. One of the main functions of this interconnected network is to sense various environmental cues and respond by altering the production of virulence factors necessary for survival in the host, including cell surface adhesins and extracellular enzymes and toxins. Of these S. aureus regulatory systems, one of the best studied is the accessory gene regulator (agr), which is a quorum-sensing system that senses the local concentration of a cyclic peptide signaling molecule. This system allows S. aureus to sense its own population density and translate this information into a specific gene expression pattern. Besides agr, this pathogen uses other two-component systems to sense specific cues and coordinates responses with cytoplasmic regulators of the SarA protein family and alternative sigma factors. These divergent regulatory systems integrate the various environmental and host-derived signals into a network that ensures optimal pathogen response to the changing conditions. This article gives an overview of the most important and best-studied S. aureus regulatory systems and summarizes the functions of these regulators during host interactions. The regulatory systems discussed include the agr quorum-sensing system; the SaeRS, SrrAB, and ArlRS two-component systems, the cytoplasmic SarA-family regulators (SarA, Rot, and MgrA); and the alternative sigma factors (SigB and SigH).
Collapse
|
47
|
Botelho AMN, Cerqueira e Costa MO, Moustafa AM, Beltrame CO, Ferreira FA, Côrtes MF, Costa BSS, Silva DNS, Bandeira PT, Lima NCB, Souza RC, de Almeida LGP, Vasconcelos ATR, Narechania A, Ryan C, O’Brien K, Kolokotronis SO, Planet PJ, Nicolás MF, Figueiredo AMS. Local Diversification of Methicillin- Resistant Staphylococcus aureus ST239 in South America After Its Rapid Worldwide Dissemination. Front Microbiol 2019; 10:82. [PMID: 30873127 PMCID: PMC6400870 DOI: 10.3389/fmicb.2019.00082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 01/16/2019] [Indexed: 12/18/2022] Open
Abstract
The global spread of specific clones of methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health problem, and understanding the dynamics of geographical spread requires worldwide surveillance. Over the past 20 years, the ST239 lineage of MRSA has been recognized as an emerging clone across the globe, with detailed studies focusing on isolates from Europe and Asia. Less is known about this lineage in South America, and, particularly, Brazil where it was the predominant lineage of MRSA in the early 1990s to 2000s. To gain a better understanding about the introduction and spread of ST239 MRSA in Brazil we undertook a comparative phylogenomic analysis of ST239 genomes, adding seven completed, closed Brazilian genomes. Brazilian ST239 isolates grouped in a subtree with those from South American, and Western, romance-language-speaking, European countries, here designated the South American clade. After an initial worldwide radiation in the 1960s and 1970s, we estimate that ST239 began to spread in South America and Brazil in approximately 1988. This clone demonstrates specific genomic changes that are suggestive of local divergence and adaptational change including agrC single-nucleotide polymorphisms variants, and a distinct pattern of virulence-associated genes (mainly the presence of the chp and the absence of sea and sasX). A survey of a geographically and chronologically diverse set of 100 Brazilian ST239 isolates identified this virulence genotype as the predominant pattern in Brazil, and uncovered an unexpectedly high prevalence of agr-dysfunction (30%). ST239 isolates from Brazil also appear to have undergone transposon (IS256) insertions in or near global regulatory genes (agr and mgr) that likely led to rapid reprogramming of bacterial traits. In general, the overall pattern observed in phylogenomic analyses of ST239 is of a rapid initial global radiation, with subsequent local spread and adaptation in multiple different geographic locations. Most ST239 isolates harbor the ardA gene, which we show here to have in vivo anti-restriction activity. We hypothesize that this gene may have improved the ability of this lineage to acquire multiple resistance genes and distinct virulence-associated genes in each local context. The allopatric divergence pattern of ST239 also may suggest strong selective pressures for specific traits in different geographical locations.
Collapse
Affiliation(s)
- Ana Maria Nunes Botelho
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Ahmed M. Moustafa
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, United States
| | - Cristiana Ossaille Beltrame
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabienne Antunes Ferreira
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marina Farrel Côrtes
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno Souza Scramignon Costa
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Deborah Nascimento Santos Silva
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paula Terra Bandeira
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Rangel Celso Souza
- Laboratório Nacional de Computação Científica, Petrópolis, Rio de Janeiro, Brazil
| | | | | | - Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, United States
| | - Chanelle Ryan
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, United States
| | - Kelsey O’Brien
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, United States
| | - Sergios-Orestis Kolokotronis
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, United States
- Department of Epidemiology and Biostatistics, School of Public Health, SUNY Downstate Medical Center, Brooklyn, NY, United States
| | - Paul J. Planet
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Children’s Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, United States
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, United States
| | | | - Agnes Marie Sá Figueiredo
- Laboratório de Biologia Molecular de Bactérias, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
48
|
Abstract
Quorum sensing is a vital property of bacteria that enables community-wide coordination of collective behaviors. A key example of such a behavior is biofilm formation, in which groups of bacteria invest in synthesizing a protective, joint extracellular matrix. Quorum sensing involves the production, release, and subsequent detection of extracellular signaling molecules called autoinducers. The architecture of quorum-sensing signal transduction pathways is highly variable among different species of bacteria, but frequently involves posttranscriptional regulation carried out by small regulatory RNA molecules. This review illustrates the diverse roles small trans-acting regulatory RNAs can play, from constituting a network's core to auxiliary roles in adjusting the rate of autoinducer synthesis, mediating cross talk among different parts of a network, or integrating different regulatory inputs to trigger appropriate changes in gene expression. The emphasis is on describing how the study of small RNA-based regulation in quorum sensing and biofilm formation has uncovered new general properties or expanded our understanding of bacterial riboregulation.
Collapse
|
49
|
Abstract
Bacterial regulatory RNAs are key players in adaptation to changing environmental conditions and response to diverse cellular stresses. However, while regulatory RNAs of bacterial pathogens have been intensely studied under defined conditions in vitro, characterization of their role during the infection of eukaryotic host organisms is lagging behind. This review summarizes our current understanding of the contribution of the different classes of regulatory RNAs and RNA-binding proteins to bacterial virulence and illustrates their role in infection by reviewing the mechanisms of some prominent representatives of each class. Emerging technologies are described that bear great potential for global, unbiased studies of virulence-related RNAs in bacterial model and nonmodel pathogens in the future. The review concludes by deducing common principles of RNA-mediated gene expression control of virulence programs in different pathogens, and by defining important open questions for upcoming research in the field.
Collapse
|
50
|
Abstract
Small regulatory RNAs are now recognized as key regulators of gene expression in bacteria. They accumulate under specific conditions, most often because their synthesis is directly controlled by transcriptional regulators, including but not limited to alternative sigma factors and response regulators of two-component systems. In turn, small RNAs regulate, mostly at the posttranscriptional level, expression of multiple genes, among which are genes encoding transcriptional regulators. Small RNAs are thus embedded in mixed regulatory circuits combining transcriptional and posttranscriptional controls, and whose properties are discussed here.
Collapse
|