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Pal A, Ghosh D, Thakur P, Nagpal P, Irulappan M, Maruthan K, Mukherjee S, Patil NG, Dutta T, Veeraraghavan B, Vivekanandan P. Clinically relevant mutations in regulatory regions of metabolic genes facilitate early adaptation to ciprofloxacin in Escherichia coli. Nucleic Acids Res 2024:gkae719. [PMID: 39180403 DOI: 10.1093/nar/gkae719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 07/31/2024] [Accepted: 08/09/2024] [Indexed: 08/26/2024] Open
Abstract
The genomic landscape associated with early adaptation to ciprofloxacin is poorly understood. Although the interplay between core metabolism and antimicrobial resistance is being increasingly recognized, mutations in metabolic genes and their biological role remain elusive. Here, we exposed Escherichia coli to increasing gradients of ciprofloxacin with intermittent transfer-bottlenecking and identified mutations in three non-canonical targets linked to metabolism including a deletion (tRNA-ArgΔ414-bp) and point mutations in the regulatory regions of argI (ARG box) and narU. Our findings suggest that these mutations modulate arginine and carbohydrate metabolism, facilitate anaerobiosis and increased ATP production during ciprofloxacin stress. Furthermore, mutations in the regulatory regions of argI and narU were detected in over 70% of sequences from clinical E. coli isolates and were overrepresented among ciprofloxacin-resistant isolates. In sum, we have identified clinically relevant mutations in the regulatory regions of metabolic genes as a central theme that drives physiological changes necessary for adaptation to ciprofloxacin stress.
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Affiliation(s)
- Arijit Pal
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Zoology, Raiganj Surendranath Mahavidyalaya, Sudarshanpur, Raiganj, Uttar Dinajpur, West Bengal733134, India
| | - Dipannita Ghosh
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Pratyusha Thakur
- RNA Biology Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Priya Nagpal
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Madhumathi Irulappan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Karthik Maruthan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sanket Mukherjee
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Nikita G Patil
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Amity Institute of Virology and Immunology, Amity University, Noida, Uttar Pradesh, India
| | - Tanmay Dutta
- RNA Biology Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Balaji Veeraraghavan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Perumal Vivekanandan
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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2
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Freiberg JA, Reyes Ruiz VM, Gimza BD, Murdoch CC, Green ER, Curry JM, Cassat JE, Skaar EP. Restriction of arginine induces antibiotic tolerance in Staphylococcus aureus. Nat Commun 2024; 15:6734. [PMID: 39112491 PMCID: PMC11306626 DOI: 10.1038/s41467-024-51144-9] [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: 11/14/2023] [Accepted: 07/31/2024] [Indexed: 08/10/2024] Open
Abstract
Staphylococcus aureus is responsible for a substantial number of invasive infections globally each year. These infections are problematic because they are frequently recalcitrant to antibiotic treatment. Antibiotic tolerance, the ability of bacteria to persist despite normally lethal doses of antibiotics, contributes to antibiotic treatment failure in S. aureus infections. To understand how antibiotic tolerance is induced, S. aureus biofilms exposed to multiple anti-staphylococcal antibiotics are examined using both quantitative proteomics and transposon sequencing. These screens indicate that arginine metabolism is involved in antibiotic tolerance within a biofilm and support the hypothesis that depletion of arginine within S. aureus communities can induce antibiotic tolerance. Consistent with this hypothesis, inactivation of argH, the final gene in the arginine synthesis pathway, induces antibiotic tolerance. Arginine restriction induces antibiotic tolerance via inhibition of protein synthesis. In murine skin and bone infection models, an argH mutant has enhanced ability to survive antibiotic treatment with vancomycin, highlighting the relationship between arginine metabolism and antibiotic tolerance during S. aureus infection. Uncovering this link between arginine metabolism and antibiotic tolerance has the potential to open new therapeutic avenues targeting previously recalcitrant S. aureus infections.
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Affiliation(s)
- Jeffrey A Freiberg
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Valeria M Reyes Ruiz
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Brittney D Gimza
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Caitlin C Murdoch
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Erin R Green
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Jacob M Curry
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - James E Cassat
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Eric P Skaar
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
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3
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Korshoj LE, Kielian T. Bacterial single-cell RNA sequencing captures biofilm transcriptional heterogeneity and differential responses to immune pressure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601229. [PMID: 38979200 PMCID: PMC11230364 DOI: 10.1101/2024.06.28.601229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display vast metabolic and transcriptional diversity along with high recalcitrance to antibiotics and host immune defenses. Investigating the complex heterogeneity within biofilm has been hindered by the lack of a sensitive and high-throughput method to assess stochastic transcriptional activity and regulation between bacterial subpopulations, which requires single-cell resolution. We have developed an optimized bacterial single-cell RNA sequencing method, BaSSSh-seq, to study Staphylococcus aureus diversity during biofilm growth and transcriptional adaptations following immune cell exposure. We validated the ability of BaSSSh-seq to capture extensive transcriptional heterogeneity during biofilm compared to planktonic growth. Application of new computational tools revealed transcriptional regulatory networks across the heterogeneous biofilm subpopulations and identification of gene sets that were associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq also detected alterations in biofilm metabolism, stress response, and virulence that were tailored to distinct immune cell populations. This work provides an innovative platform to explore biofilm dynamics at single-cell resolution, unlocking the potential for identifying biofilm adaptations to environmental signals and immune pressure.
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Zhou C, Pawline MB, Pironti A, Morales SM, Perault AI, Ulrich RJ, Podkowik M, Lejeune A, DuMont A, Stubbe FX, Korman A, Jones DR, Schluter J, Richardson AR, Fey PD, Drlica K, Cadwell K, Torres VJ, Shopsin B. Microbiota and metabolic adaptation shape Staphylococcus aureus virulence and antimicrobial resistance during intestinal colonization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.11.593044. [PMID: 38766195 PMCID: PMC11100824 DOI: 10.1101/2024.05.11.593044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Depletion of microbiota increases susceptibility to gastrointestinal colonization and subsequent infection by opportunistic pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). How the absence of gut microbiota impacts the evolution of MRSA is unknown. The present report used germ-free mice to investigate the evolutionary dynamics of MRSA in the absence of gut microbiota. Through genomic analyses and competition assays, we found that MRSA adapts to the microbiota-free gut through sequential genetic mutations and structural changes that enhance fitness. Initially, these adaptations increase carbohydrate transport; subsequently, evolutionary pathways largely diverge to enhance either arginine metabolism or cell wall biosynthesis. Increased fitness in arginine pathway mutants depended on arginine catabolic genes, especially nos and arcC, which promote microaerobic respiration and ATP generation, respectively. Thus, arginine adaptation likely improves redox balance and energy production in the oxygen-limited gut environment. Findings were supported by human gut metagenomic analyses, which suggest the influence of arginine metabolism on colonization. Surprisingly, these adaptive genetic changes often reduced MRSA's antimicrobial resistance and virulence. Furthermore, resistance mutation, typically associated with decreased virulence, also reduced colonization fitness, indicating evolutionary trade-offs among these traits. The presence of normal microbiota inhibited these adaptations, preserving MRSA's wild-type characteristics that effectively balance virulence, resistance, and colonization fitness. The results highlight the protective role of gut microbiota in preserving a balance of key MRSA traits for long-term ecological success in commensal populations, underscoring the potential consequences on MRSA's survival and fitness during and after host hospitalization and antimicrobial treatment.
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Affiliation(s)
- Chunyi Zhou
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Miranda B. Pawline
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
- Microbial Computational Genomic Core Lab, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Sabrina M. Morales
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Andrew I. Perault
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Robert J. Ulrich
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Magdalena Podkowik
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY 10016, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Alannah Lejeune
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ashley DuMont
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | | | - Aryeh Korman
- Metabolomics Core Resource Laboratory, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Drew R. Jones
- Metabolomics Core Resource Laboratory, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jonas Schluter
- Institute for Systems Genetics, Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Anthony R. Richardson
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Karl Drlica
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA
| | - Ken Cadwell
- Division of Gastroenterology and Hepatology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University, Grossman School of Medicine, New York, NY 10016, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY 10016, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. mBio 2024; 15:e0045324. [PMID: 38546267 PMCID: PMC11077960 DOI: 10.1128/mbio.00453-24] [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: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.
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Affiliation(s)
- Flavia G. Costa
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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6
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Reslane I, Handke LD, Watson GF, Shinde D, Ahn JS, Endres JL, Razvi F, Gilbert EA, Bayles KW, Thomas VC, Lehman MK, Fey PD. Glutamate -dependent arginine biosynthesis requires the inactivation of spoVG, sarA, and ahrC in Staphylococcus aureus. J Bacteriol 2024; 206:e0033723. [PMID: 38299858 PMCID: PMC10883023 DOI: 10.1128/jb.00337-23] [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: 10/13/2023] [Accepted: 01/09/2024] [Indexed: 02/02/2024] Open
Abstract
Genome sequencing has demonstrated that Staphylococcus aureus encodes arginine biosynthetic genes argDCJBFGH synthesizing proteins that mediate arginine biosynthesis using glutamate as a substrate. Paradoxically, however, S. aureus does not grow in a defined, glutamate-replete medium lacking arginine and glucose (CDM-R). Studies from our laboratory have found that specific mutations are selected by S. aureus that facilitate growth in CDM-R. However, these selected mutants synthesize arginine utilizing proline as a substrate rather than glutamate. In this study, we demonstrate that the ectopic expression of the argDCJB operon supports the growth of S. aureus in CDM-R, thus documenting the functionality of this pathway. Furthermore, suppressor mutants of S. aureus JE2 putA::Tn, which is defective in synthesizing arginine from proline, were selected on CDM-R agar. Genome sequencing revealed that these mutants had compensatory mutations within both spoVG, encoding an ortholog of the Bacillus subtilis stage V sporulation protein, and sarA, encoding the staphylococcal accessory regulator. Transcriptional studies document that argD expression is significantly increased when JE2 spoVG sarA was grown in CDM-R. Lastly, we found that a mutation in ahrC was required to induce argD expression in JE2 spoVG sarA when grown in an arginine-replete medium (CDM), suggesting that AhrC also functions to repress argDCJB in an arginine-dependent manner. In conclusion, these data indicate that the argDCJB operon is functional when transcribed in vitro and that SNPs within potential putative regulatory proteins are required to alleviate the repression.IMPORTANCEAlthough Staphylococcus aureus has the capability to synthesize all 20 amino acids, it is phenotypically auxotrophic for several amino acids including arginine. This work identifies putative regulatory proteins, including SpoVG, SarA, and AhrC, that function to inhibit the arginine biosynthetic pathways using glutamate as a substrate. Understanding the ultimate mechanisms of why S. aureus is selected to repress arginine biosynthetic pathways even in the absence of arginine will add to the growing body of work assessing the interactions between metabolism and S. aureus pathogenesis.
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Affiliation(s)
- Itidal Reslane
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Luke D. Handke
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Gabrielle F. Watson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Dhananjay Shinde
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jong-Sam Ahn
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jennifer L. Endres
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Fareha Razvi
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Emily A. Gilbert
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Kenneth W. Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Vinai C. Thomas
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - McKenzie K. Lehman
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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7
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Solar Venero EC, Galeano MB, Luqman A, Ricardi MM, Serral F, Fernandez Do Porto D, Robaldi SA, Ashari BAZ, Munif TH, Egoburo DE, Nemirovsky S, Escalante J, Nishimura B, Ramirez MS, Götz F, Tribelli PM. Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo. BMC Biol 2024; 22:27. [PMID: 38317219 PMCID: PMC10845740 DOI: 10.1186/s12915-024-01830-3] [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: 07/31/2023] [Accepted: 01/18/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39 °C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37 °C, by using RNAseq and physiological assays including in vivo experiments. RESULTS In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes in both species. Altered metabolic features at 39 °C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39 °C, they upregulated ethanol oxidation-related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα, and pmsβ genes at 39 °C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphyloxantin production, and a decrease in biofilm formation at 39 °C. On the side of PA monocultures, we observed an increase in extracellular lipase and protease and biofilm formation at 39 °C along with a decrease in the motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in vitro and in vivo. S. aureus monocultured at 39οC showed a decrease in cellular invasion and an increase in IL-8-but not in IL-6-production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39 °C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37 and 39 °C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39 °C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39 °C comparing with 37 °C. CONCLUSIONS Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.
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Affiliation(s)
- E C Solar Venero
- Instituto De Química Biológica de La Facultad de Ciencias Exactas y Naturales-CONICET, Buenos Aires, Argentina
- Present addressDepartment of BiochemistrySchool of Medicine, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas Alberto Sols (Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas), Madrid, Spain
| | - M B Galeano
- Instituto De Química Biológica de La Facultad de Ciencias Exactas y Naturales-CONICET, Buenos Aires, Argentina
| | - A Luqman
- Department of Biology, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - M M Ricardi
- IFIBYNE (UBA-CONICET), FBMC, FCEyN-UBA, Buenos Aires, Argentina
| | - F Serral
- Instituto del Calculo-UBA-CONICET, Buenos Aires, Argentina
| | | | - S A Robaldi
- Departamento de Química Biológica, FCEyN-UBA, Buenos Aires, Argentina
| | - B A Z Ashari
- Department of Biology, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - T H Munif
- Department of Biology, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - D E Egoburo
- Departamento de Química Biológica, FCEyN-UBA, Buenos Aires, Argentina
| | - S Nemirovsky
- Instituto De Química Biológica de La Facultad de Ciencias Exactas y Naturales-CONICET, Buenos Aires, Argentina
| | - J Escalante
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, USA
| | - B Nishimura
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, USA
| | - M S Ramirez
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, USA
| | - F Götz
- Department of Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - P M Tribelli
- Instituto De Química Biológica de La Facultad de Ciencias Exactas y Naturales-CONICET, Buenos Aires, Argentina.
- Departamento de Química Biológica, FCEyN-UBA, Buenos Aires, Argentina.
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8
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Bhavana VH, Hillebrand GH, Gopalakrishna KP, Rapp RA, Ratner AJ, Tettelin H, Hooven TA. A group B Streptococcus indexed transposon mutant library to accelerate genetic research on an important perinatal pathogen. Microbiol Spectr 2023; 11:e0204623. [PMID: 37933989 PMCID: PMC10714824 DOI: 10.1128/spectrum.02046-23] [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: 05/18/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
IMPORTANCE Group B Streptococcus (GBS) is a significant global cause of serious infections, most of which affect pregnant women, newborns, and infants. Studying GBS genetic mutant strains is a valuable approach for learning more about how these infections are caused and is a key step toward developing more effective preventative and treatment strategies. In this resource report, we describe a newly created library of defined GBS genetic mutants, containing over 1,900 genetic variants, each with a unique disruption to its chromosome. An indexed library of this scale is unprecedented in the GBS field; it includes strains with mutations in hundreds of genes whose potential functions in human disease remain unknown. We have made this resource freely available to the broader research community through deposition in a publicly funded bacterial maintenance and distribution repository.
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Affiliation(s)
- Venkata H. Bhavana
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Gideon H. Hillebrand
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
| | | | - Rebekah A. Rapp
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- The Ellis School, Pittsburgh, Pennsylvania, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University, New York, New York, USA
- Department of Microbiology, New York University, New York, New York, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA
- UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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9
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Ou J, Dong H, Luan X, Wang X, Liu Q, Chen H, Cao M, Xu Z, Liu Y, Zhao W. iTRAQ-based differential proteomic analysis of high- and low-virulence strains of Spiroplasma eriocheiris. Microb Pathog 2023; 184:106365. [PMID: 37741306 DOI: 10.1016/j.micpath.2023.106365] [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: 08/08/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023]
Abstract
Spiroplasma eriocheiris is one of the major pathogenic bacteria in crustaceans, featuring high infectivity, rapid transmission, and an absence of effective control strategies, resulting in significant economic losses to the aquaculture industry. Research into virulence-related factors provides an important perspective to clarify how Spiroplasma eriocheiris is pathogenic to shrimps and crabs. Therefore, in this study, isobaric tags for relative and absolute quantitation (iTRAQ) technology was utilized to undertake a differential proteomic analysis of high- and low-virulence Spiroplasma eriocheiris strains at different growth phases. A total of 868 differentially expressed proteins (DEPs) were obtained, of which 31 novel proteins were identified by proteogenomic analysis. There were 62, 61, 175, and 235 DEPs between the log phase (YD) and non-log phase (YFD) of the high-virulence strain, between the log phase (CD) and non-log phase (CFD) of the low-virulence strain, between YD and CD, and between CFD and YFD, respectively. All the DEPs were compared with virulence protein databases (MvirDB and VFDB), and 68 virulence proteins of Spiroplasma eriocheiris were identified, of which 12 were involved in a total of 21 metabolic pathways, including motility, chemotaxis, growth, metabolism and virulence of the bacteria. The results of this study form the basis for further research into the molecular mechanism of virulence and physiological differences between high- and low-virulence strains of Spiroplasma eriocheiris, and provide a scientific basis for a detailed understanding of its pathogenesis.
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Affiliation(s)
- Jiangtao Ou
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China.
| | - Huizi Dong
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Xiaoqi Luan
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China; Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Xiang Wang
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Qiao Liu
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Hao Chen
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Miao Cao
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Zheqi Xu
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Yang Liu
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
| | - Weihong Zhao
- Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland, School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224051, Province Jiangsu, China
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563767. [PMID: 37961268 PMCID: PMC10634794 DOI: 10.1101/2023.10.24.563767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like media (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several Staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant S. aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted qRT-PCR experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. These results support the potential utility of SLM as an in vitro model for assessing Staphylococcal physiology and metabolism on human skin. Importance Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed media that strives to replicate the human skin surface environment, and demonstrates roles for adhesins ClfA, SraP, and Fnbps in human corneocyte adherence.
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Freiberg JA, Ruiz VMR, Green ER, Skaar EP. Restriction of Arginine Induces Antibiotic Tolerance in Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.12.561972. [PMID: 37873095 PMCID: PMC10592767 DOI: 10.1101/2023.10.12.561972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Staphylococcus aureus is responsible for a substantial number of invasive infections globally each year. These infections are problematic because they are frequently recalcitrant to antibiotic treatment, particularly when they are caused by Methicillin-Resistant Staphylococcus aureus (MRSA). Antibiotic tolerance, the ability for bacteria to persist despite normally lethal doses of antibiotics, is responsible for most antibiotic treatment failure in MRSA infections. To understand how antibiotic tolerance is induced, S. aureus biofilms exposed to multiple anti-MRSA antibiotics (vancomycin, ceftaroline, delafloxacin, and linezolid) were examined using both quantitative proteomics and transposon sequencing. These screens indicated that arginine metabolism is involved in antibiotic tolerance within a biofilm and led to the hypothesis that depletion of arginine within S. aureus communities can induce antibiotic tolerance. Consistent with this hypothesis, inactivation of argH, the final gene in the arginine synthesis pathway, induces antibiotic tolerance under conditions in which the parental strain is susceptible to antibiotics. Arginine restriction was found to induce antibiotic tolerance via inhibition of protein synthesis. Finally, although S. aureus fitness in a mouse skin infection model is decreased in an argH mutant, its ability to survive in vivo during antibiotic treatment with vancomycin is enhanced, highlighting the relationship between arginine metabolism and antibiotic tolerance during S. aureus infection. Uncovering this link between arginine metabolism and antibiotic tolerance has the potential to open new therapeutic avenues targeting previously recalcitrant S. aureus infections.
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Affiliation(s)
- Jeffrey A. Freiberg
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Valeria M. Reyes Ruiz
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Erin R. Green
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Microbiology, University of Chicago, Chicago, IL 60637
| | - Eric P. Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
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Solar Venero EC, Galeano MB, Luqman A, Ricardi MM, Serral F, Fernandez Do Porto D, Robaldi SA, Ashari B, Munif TH, Egoburo DE, Nemirovsky S, Escalante J, Nishimura B, Ramirez MS, Götz F, Tribelli PM. Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.529514. [PMID: 36993402 PMCID: PMC10055263 DOI: 10.1101/2023.03.21.529514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Background Staphylococcus aureus and Pseudomonas aeruginosa cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39°C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37°C, by using RNAseq and physiological assays including in-vivo experiments. Results In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes on both species. Altered metabolic features at 39°C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39°C they upregulated ethanol oxidation related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα and pmsβ genes at 39°C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphylxantin production and a decrease in biofilm formation at 39°C. On the side of PA monocultures, we observed increase in extracellular lipase and protease and biofilm formation at 39°C along with a decrease in motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in-vitro and in-vivo . S. aureus monocultured at 39°C showed a decrease in cellular invasion and an increase in IL-8 -but not in IL-6- production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39°C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37°C and 39°C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39°C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39°C comparing with 37°C. Conclusion Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.
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Wen X, Zhou Y, Liang X, Li J, Huang Y, Li Q. A novel carbon-nitrogen coupled metabolic pathway promotes the recyclability of nitrogen in composting habitats. BIORESOURCE TECHNOLOGY 2023; 381:129134. [PMID: 37164230 DOI: 10.1016/j.biortech.2023.129134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/12/2023]
Abstract
This study revealed a novel carbon-nitrogen coupled metabolic pathway. Results showed that the addition of inorganic carbon sources slowed down the decomposition of urea and conserved more nutrients in composting. Metagenomic analysis showed that the main bacteria involved in this new pathway were Actinobacteria, Proteobacteria and Firmicutes. During the late composting period, the dominant genus Microbacteium involved in denitrification accounted for 22.18% in control (CP) and only 0.12% in treatment group (T). Moreover, ureC, rocF, argF, argI, argG were key genes involved in urea cycle. The abundance of functional gene ureC and denitrification genes decreased in thermophilic and cooling phases, respectively. The genes hao, nosZ, ureA and nifH were more closely associated with Chloroflexi_bacterium and Bacillus_paralichenformis. In conclusion, composting habitats with additional inorganic carbon sources could not only weaken denitrification but also allow more nitrogen to be conserved through slow-release urea to improve resource utilization and decrease the environmental risk.
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Affiliation(s)
- Xiaoli Wen
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Yucheng Zhou
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Xueling Liang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Jixuan Li
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Yite Huang
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Qunliang Li
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
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Carrilero L, Urwin L, Ward E, Choudhury NR, Monk IR, Turner CE, Stinear TP, Corrigan RM. Stringent Response-Mediated Control of GTP Homeostasis Is Required for Long-Term Viability of Staphylococcus aureus. Microbiol Spectr 2023; 11:e0044723. [PMID: 36877013 PMCID: PMC10101089 DOI: 10.1128/spectrum.00447-23] [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: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 03/07/2023] Open
Abstract
Staphylococcus aureus is an opportunistic bacterial pathogen that often results in difficult-to-treat infections. One mechanism used by S. aureus to enhance survival during infection is the stringent response. This is a stress survival pathway that utilizes the nucleotides (p)ppGpp to reallocate bacterial resources, shutting down growth until conditions improve. Small colony variants (SCVs) of S. aureus are frequently associated with chronic infections, and this phenotype has previously been linked to a hyperactive stringent response. Here, we examine the role of (p)ppGpp in the long-term survival of S. aureus under nutrient-restricted conditions. When starved, a (p)ppGpp-null S. aureus mutant strain ((p)ppGpp0) initially had decreased viability. However, after 3 days we observed the presence and dominance of a population of small colonies. Similar to SCVs, these small colony isolates (p0-SCIs) had reduced growth but remained hemolytic and sensitive to gentamicin, phenotypes that have been tied to SCVs previously. Genomic analysis of the p0-SCIs revealed mutations arising within gmk, encoding an enzyme in the GTP synthesis pathway. We show that a (p)ppGpp0 strain has elevated levels of GTP, and that the mutations in the p0-SCIs all lower Gmk enzyme activity and consequently cellular GTP levels. We further show that in the absence of (p)ppGpp, cell viability can be rescued using the GuaA inhibitor decoyinine, which artificially lowers the intracellular GTP concentration. Our study highlights the role of (p)ppGpp in GTP homeostasis and underscores the importance of nucleotide signaling for long-term survival of S. aureus in nutrient-limiting conditions, such as those encountered during infections. IMPORTANCE Staphylococcus aureus is a human pathogen that upon invasion of a host encounters stresses, such as nutritional restriction. The bacteria respond by switching on a signaling cascade controlled by the nucleotides (p)ppGpp. These nucleotides function to shut down bacterial growth until conditions improve. Therefore, (p)ppGpp are important for bacterial survival and have been implicated in promoting chronic infections. Here, we investigate the importance of (p)ppGpp for long-term survival of bacteria in nutrient-limiting conditions similar to those in a human host. We discovered that in the absence of (p)ppGpp, bacterial viability decreases due to dysregulation of GTP homeostasis. However, the (p)ppGpp-null bacteria were able to compensate by introducing mutations in the GTP synthesis pathway that led to a reduction in GTP build-up and a rescue of viability. This study therefore highlights the importance of (p)ppGpp for the regulation of GTP levels and for long-term survival of S. aureus in restricted environments.
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Affiliation(s)
- Laura Carrilero
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Lucy Urwin
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Ezra Ward
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Naznin R. Choudhury
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Ian R. Monk
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Claire E. Turner
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
| | - Rebecca M. Corrigan
- The Florey Institute, School of Biosciences, University of Sheffield, Sheffield, United Kingdom
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