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Cheung GYC, Lee JH, Liu R, Lawhon SD, Yang C, Otto M. Methicillin Resistance Elements in the Canine Pathogen Staphylococcus pseudintermedius and Their Association with the Peptide Toxin PSM-mec. Antibiotics (Basel) 2024; 13:130. [PMID: 38391516 PMCID: PMC10886032 DOI: 10.3390/antibiotics13020130] [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: 01/11/2024] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Staphylococcus pseudintermedius is a frequent cause of infections in dogs. Infectious isolates of this coagulase-positive staphylococcal species are often methicillin- and multidrug-resistant, which complicates therapy. In staphylococci, methicillin resistance is encoded by determinants found on mobile genetic elements called Staphylococcal Chromosome Cassette mec (SCCmec), which, in addition to methicillin resistance factors, sometimes encode additional genes, such as further resistance factors and, rarely, virulence determinants. In this study, we analyzed SCCmec in a collection of infectious methicillin-resistant S. pseudintermedius (MRSP) isolates from predominant lineages in the United States. We found that several lineages characteristically have specific types of SCCmec elements and Agr types and harbor additional factors in their SCCmec elements that may promote virulence or affect DNA uptake. All isolates had SCCmec-encoded restriction-modification (R-M) systems of types I or II, and sequence types (STs) ST84 and ST64 had one type II and one type I R-M system, although the latter lacked a complete methylation enzyme gene. ST68 isolates also had an SCCmec-encoded CRISPR system. ST71 isolates had a psm-mec gene, which, in all but apparently Agr-dysfunctional isolates, produced a PSM-mec peptide toxin, albeit at relatively small amounts. This study gives detailed insight into the composition of SCCmec elements in infectious isolates of S. pseudintermedius and lays the genetic foundation for further efforts directed at elucidating the contribution of identified accessory SCCmec factors in impacting SCCmec-encoded and thus methicillin resistance-associated virulence and resistance to DNA uptake in this leading canine pathogen.
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Affiliation(s)
- Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Ji Hyun Lee
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Sara D Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Ching Yang
- Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY 11548, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), Bethesda, MD 20892, USA
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Nakajima I, Fukuda K, Ishida W, Kishimoto T, Kuwana A, Suzuki T, Kaito C, Yamashiro K. Staphylococcus aureus-derived virulent phenol-soluble modulin α triggers alarmin release to drive IL-36-dependent corneal inflammation. Microbes Infect 2024; 26:105237. [PMID: 37805122 DOI: 10.1016/j.micinf.2023.105237] [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: 01/10/2023] [Revised: 08/22/2023] [Accepted: 10/02/2023] [Indexed: 10/09/2023]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients with keratitis produces substantial amounts of phenol-soluble modulin α (PSMα). However, the role of PSMα in S. aureus keratitis remains unclear. We observed that PSMα-producing and PSMα-deficient strains could infect the cornea in our experimental mouse keratitis model; however, only the PSMα-producing strain delayed epithelial wound healing and induced stromal inflammation. PSMα induced damage to the epithelium, the release of alarmins IL-1α and IL-36α, and the expression of inflammatory chemokines by resident corneal cells in the mouse corneal organ culture. The IL-36 (but not IL-1) receptor antagonist attenuated mouse keratitis induced by PSMα-containing bacterial culture supernatants, as well as by infection with PSMα-producing S. aureus, suggesting that the corneal inflammations were dependent on IL-36. Recombinant PSMα elicited IL-36-dependent corneal inflammation in mice. Thus, PSMα and the subsequently released IL-36 are critical factors triggering inflammation during S. aureus keratitis.
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Affiliation(s)
- Isana Nakajima
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan
| | - Ken Fukuda
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan.
| | - Waka Ishida
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan
| | - Tatsuma Kishimoto
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan
| | - Aozora Kuwana
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan
| | - Takashi Suzuki
- Department of Ophthalmology, Toho University, Tokyo, Japan
| | - Chikara Kaito
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kenji Yamashiro
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Kochi, Japan
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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [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] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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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.
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Affiliation(s)
| | - Peter Neubauer
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
| | - Matthias Gimpel
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
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In Silico Genome-Scale Analysis of Molecular Mechanisms Contributing to the Development of a Persistent Infection with Methicillin-Resistant Staphylococcus aureus (MRSA) ST239. Int J Mol Sci 2022; 23:ijms232416086. [PMID: 36555727 PMCID: PMC9781258 DOI: 10.3390/ijms232416086] [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: 10/30/2022] [Revised: 12/05/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The increasing frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) limits the chances for the effective antibacterial therapy of staphylococcal diseases and results in the development of persistent infection such as bacteremia and osteomyelitis. The aim of this study was to identify features of the MRSAST239 0943-1505-2016 (SA943) genome that contribute to the formation of both acute and chronic musculoskeletal infections. The analysis was performed using comparative genomics data of the dominant epidemic S. aureus lineages, namely ST1, ST8, ST30, ST36, and ST239. The SA943 genome encodes proteins that provide resistance to the host's immune system, suppress immunological memory, and form biofilms. The molecular mechanisms of adaptation responsible for the development of persistent infection were as follows: amino acid substitution in PBP2 and PBP2a, providing resistance to ceftaroline; loss of a large part of prophage DNA and restoration of the nucleotide sequence of beta-hemolysin, that greatly facilitates the escape of phagocytosed bacteria from the phagosome and formation of biofilms; dysfunction of the AgrA system due to the presence of psm-mec and several amino acid substitutions in the AgrC; partial deletion of the nucleotide sequence in genomic island vSAβ resulting in the loss of two proteases of Spl-operon; and deletion of SD repeats in the SdrE amino acid sequence.
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Nakano Y, Murata M, Matsumoto Y, Toyoda K, Ota A, Yamasaki S, Otakeno H, Yokoo K, Shimono N. Clinical characteristics and factors related to infection with SCCmec type II and IV Methicillin-resistant Staphylococcus aureus in a Japanese secondary care facility: a single-center retrospective study. J Glob Antimicrob Resist 2022; 31:355-362. [PMID: 36372183 DOI: 10.1016/j.jgar.2022.11.003] [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: 06/03/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Differences in virulence genes, including psm-mec, which is a phenol-soluble modulin-mec (PSM-mec) encoding gene, of predominant staphylococcal cassette chromosome mec (SCCmec) types II and IV Methicillin-resistant Staphylococcus aureus (MRSA) may contribute to the virulence and clinical features of MRSA in Japan. We aimed to clarify the clinical characteristics and risk factors of infection among SCCmec types II and IV MRSA isolates from a Japanese secondary acute care hospital. METHODS We analysed 58 SCCmec type II and 83 SCCmec type IV MRSA isolates collected from blood, central venous catheter tips, deep or superficial tissues, and sputum. RESULTS SCCmec type II MRSA risk factors for progression to infection were seb, enterotoxin gene cluster, psm-mec mutation, and vancomycin minimum inhibitory concentrations (MIC) of 1 or 2 mg/L as virulence factors (adjusted odds ratio [aOR] = 11.8; 95% confidence interval [CI]: 2.49-77.7; P = 0.004); solid tumour was a host factor (aOR = 25.9; 95% CI: 3.66-300; P = 0.003). SCCmec type IV MRSA risk factors were sea, cna, and vancomycin MIC of 1 or 2 mg/L as virulence factors (aOR = 3.14; 95% CI: 1.06-10.6; P = 0.049) and intravascular indwelling catheter as host factors (aOR = 3.78; 95% CI: 1.03-14.5; P = 0.045). Compared with SCCmec type II, SCCmec type IV MRSA resulted in more frequent bloodstream infections and higher Sequential Organ Failure Assessment scores. CONCLUSION We found that factors related to virulence genes and bacteriological and host characteristics are associated with SCCmec types II and IV MRSA infection and severity. These risk factors may be useful criteria for designing infection control programs.
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Affiliation(s)
- Yuki Nakano
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Higashi-Ku, Fukuoka, Japan; Department of Pharmacy, Saiseikai Futsukaichi Hospital, Chikushino, Fukuoka, Japan
| | - Masayuki Murata
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Higashi-Ku, Fukuoka, Japan; Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan; Center for the Study of Global Infection, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan.
| | - Yuji Matsumoto
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Higashi-Ku, Fukuoka, Japan; Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan; Center for the Study of Global Infection, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan
| | - Kazuhiro Toyoda
- Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan; Center for the Study of Global Infection, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan
| | - Azusa Ota
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Higashi-Ku, Fukuoka, Japan; Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan; Center for the Study of Global Infection, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan
| | - Sho Yamasaki
- Department of Environmental Medicine and Infectious Disease, Kyushu University, Higashi-Ku, Fukuoka, Japan; Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan
| | - Hisao Otakeno
- Department of Pharmacy, Saiseikai Futsukaichi Hospital, Chikushino, Fukuoka, Japan
| | - Kenjo Yokoo
- Department of Pharmacy, Saiseikai Futsukaichi Hospital, Chikushino, Fukuoka, Japan
| | - Nobuyuki Shimono
- Department of General Internal Medicine, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan; Center for the Study of Global Infection, Kyushu University Hospital, Higashi-Ku, Fukuoka, Japan
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Maharjan S, Ansari M, Maharjan P, Rai KR, Sabina KC, Kattel HP, Rai G, Rai SK. Phenotypic detection of methicillin resistance, biofilm production, and inducible clindamycin resistance in Staphylococcus aureus clinical isolates in Kathmandu, Nepal. Trop Med Health 2022; 50:71. [PMID: 36131351 PMCID: PMC9490977 DOI: 10.1186/s41182-022-00460-1] [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: 06/10/2022] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Methicillin resistance, inducible clindamycin resistance (ICR), biofilm production, and increased minimum inhibitory concentration (MIC) of vancomycin in Staphylococcus aureus are major causes of antibiotic treatment failure and increased morbidity and mortality. The surveillance of such isolates and the study of their antimicrobial pattern are essential in managing the infections caused by these isolates. This study aimed to determine methicillin resistance, biofilm production, and ICR in S. aureus isolates from a tertiary care hospital in Kathmandu, Nepal. MATERIALS AND METHODS A total of 217 S. aureus isolated from different samples were processed following standard laboratory procedures. Antibiotic susceptibility testing was performed by the Kirby-Bauer disk diffusion technique. Methicillin-resistant S. aureus (MRSA) were identified by the cefoxitin disk diffusion test, and biofilm producers were examined using the microtiter plate technique. D-test and E-test were performed to determine inducible clindamycin resistance and minimum inhibitory concentration of vancomycin, respectively. RESULTS Among the 217 S. aureus isolates, 78.3% were multidrug-resistant (MDR), 47.0% were MRSA, 62.2% were biofilm producers, and 50.7% showed ICR. All MRSA isolates exhibited MIC levels of vancomycin within the susceptible range. Biofilm producers and MRSA isolates showed elevated antimicrobial resistance. MRSA was significantly associated with MDR. Biofilm-producing and multidrug-resistant MRSA isolates showed significantly higher MIC levels of vancomycin (p = 0.0013 and < 0.0001, respectively), while ICR was significantly higher in MDR (p = 0.0001) isolates. CONCLUSION High multidrug resistance, MRSA, and ICR in this study call for routine evaluation of antibiotic susceptibility patterns of S. aureus. Vancomycin can be used to treat serious staphylococcal infections. Clindamycin should be prescribed only after performing the D-test. Drugs like teicoplanin, chloramphenicol, doxycycline, amikacin, and levofloxacin can treat MRSA infections.
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Affiliation(s)
- Sujina Maharjan
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal
| | - Mehraj Ansari
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal.
| | - Pawan Maharjan
- Phect-Nepal Model Hospital School of Medical Laboratory Sciences, Kathmandu, Nepal
| | - Kul Raj Rai
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal.,Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - K C Sabina
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal
| | - Hari Prasad Kattel
- Department of Microbiology, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Ganesh Rai
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal
| | - Shiba Kumar Rai
- Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal.,Department of Microbiology, Nepal Medical College and Teaching Hospital, Kathmandu, Nepal
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Genotypes of Staphylococcus aureus Clinical Isolates Are Associated with Phenol-Soluble Modulin (PSM) Production. Toxins (Basel) 2022; 14:toxins14080556. [PMID: 36006218 PMCID: PMC9412541 DOI: 10.3390/toxins14080556] [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: 07/15/2022] [Revised: 08/06/2022] [Accepted: 08/12/2022] [Indexed: 12/01/2022] Open
Abstract
Phenol-soluble modulins (PSMs) are important S. aureus virulence factors that cause cytolysis, mast cell degranulation, and stimulate inflammatory responses. In this study, PSM production by S. aureus clinical isolates was measured by liquid chromatography/mass spectrometry (LC-MS) and correlated with staphylococcal protein A (spa) type and staphylococcal cassette chromosome mec (SCCmec) type. Of 106 S. aureus clinical isolates, 50 (47.2%) corresponded to methicillin-susceptible S. aureus (MSSA) and 56 (52.8%) to methicillin-resistant S. aureus (MRSA). LC-MS analysis revealed no significant difference in average PSMα3, PSMα4, PSMβ2, and δ-toxin production between MSSA and MRSA isolates, but PSMα1, PSMα2, and PSMβ1 production were higher in MSSA than MRSA. This study demonstrated that average PSMα1–α4, PSMβ1–β2, and δ-toxin production by SCCmec type II strains was significantly lower than the IV, IVA, and V strains. Most of the SCCmec type II strains (n = 17/25; 68.0%) did not produce δ-toxin, suggesting a dysfunctional Agr system. The spa type t111 (except one strain) and t2460 (except one strain producing PSM α1–α4) did not produce PSMα1–α4 and δ-toxin, while average PSM production was higher among the t126 and t1784 strains. This study showed that the genotype of S. aureus, specifically the spa and SCCmec types, is important in characterizing the production of PSMs.
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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.
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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
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Miyashita A, Mitsutomi S, Mizushima T, Sekimizu K. Repurposing the PDMA-approved drugs in Japan using an insect model of staphylococcal infection. FEMS MICROBES 2022. [DOI: 10.1093/femsmc/xtac014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
A thousand and two hundred fifty-three (1253) compounds approved as therapeutic drugs in Japan (PMDA-approved compounds) were screened for their therapeutic effects against Staphylococcus aureus infection using the silkworm infection model. In the first stage of screening with an index of prolonged survival, 80 compounds were identified as hits. Of these, 64 compounds were clinically used as antimicrobial agents, and the remaining 16 compounds were not. The 16 compounds were examined for their dose-dependent therapeutic effects on the silkworm model as a second screening step, and we obtained five compounds as a result. One of the compounds (capecitabine) had no documented in vitro minimum inhibitory concentration (MIC) value against S. aureus. The MIC value of capecitabine against S. aureus strains ranged from 125 to 250 µg/mL Capecitabine was therapeutically effective at a dose of 200 mg/kg in a murine model of S. aureus infection. These results suggest that silkworm-based drug repositioning studies are of potential value. Furthermore, the therapeutic effects of capecitabine demonstrated in this study provide an important scientific rationale for clinical observational studies examining the association between staphylococcal infection events and capecitabine administration in cancer chemotherapy patients.
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Affiliation(s)
| | | | | | - Kazuhisa Sekimizu
- School of Pharma-Science, Teikyo University, Tokyo, Japan
- Genome Pharmaceuticals Institute, Co., Ltd., Tokyo, Japan
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Jahantigh HR, Faezi S, Habibi M, Mahdavi M, Stufano A, Lovreglio P, Ahmadi K. The Candidate Antigens to Achieving an Effective Vaccine against Staphylococcus aureus. Vaccines (Basel) 2022; 10:vaccines10020199. [PMID: 35214658 PMCID: PMC8876328 DOI: 10.3390/vaccines10020199] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 01/20/2022] [Accepted: 01/26/2022] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is an opportunistic pathogen that causes various inflammatory local infections, from those of the skin to postinfectious glomerulonephritis. These infections could result in serious threats, putting the life of the patient in danger. Antibiotic-resistant S. aureus could lead to dramatic increases in human mortality. Antibiotic resistance would explicate the failure of current antibiotic therapies. So, it is obvious that an effective vaccine against S. aureus infections would significantly reduce costs related to care in hospitals. Bacterial vaccines have important impacts on morbidity and mortality caused by several common pathogens, however, a prophylactic vaccine against staphylococci has not yet been produced. During the last decades, the efforts to develop an S. aureus vaccine have faced two major failures in clinical trials. New strategies for vaccine development against S. aureus has supported the use of multiple antigens, the inclusion of adjuvants, and the focus on various virulence mechanisms. We aimed to present a compressive review of different antigens of S. aureus and also to introduce vaccine candidates undergoing clinical trials, from which can help us to choose a suitable and effective candidate for vaccine development against S. aureus.
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Affiliation(s)
- Hamid Reza Jahantigh
- Animal Health and Zoonosis, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy;
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
- Correspondence: (H.R.J.); (K.A.); Tel.: +39-3773827669 (H.R.J.)
| | - Sobhan Faezi
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht 41937, Iran;
| | - Mehri Habibi
- Department of Molecular Biology, Pasteur Institute of Iran, Pasteur Ave., Tehran 13164, Iran;
| | - Mehdi Mahdavi
- Advanced Therapy Medicinal Product (ATMP) Department, Breast Cancer Research Center, Motamed Cancer Institute, Academic Center for Education, Culture and Research (ACECR), Tehran 1517964311, Iran
- Recombinant Vaccine Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran 13164, Iran;
| | - Angela Stufano
- Animal Health and Zoonosis, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy;
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
| | - Piero Lovreglio
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
| | - Khadijeh Ahmadi
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas 79391, Iran
- Correspondence: (H.R.J.); (K.A.); Tel.: +39-3773827669 (H.R.J.)
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12
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Venkat K, Hoyos M, Haycocks JR, Cassidy L, Engelmann B, Rolle-Kampczyk U, von Bergen M, Tholey A, Grainger DC, Papenfort K. A dual-function RNA balances carbon uptake and central metabolism in Vibrio cholerae. EMBO J 2021; 40:e108542. [PMID: 34612526 PMCID: PMC8672173 DOI: 10.15252/embj.2021108542] [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: 04/26/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/22/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are well known to modulate gene expression by base pairing with trans‐encoded transcripts and are typically non‐coding. However, several sRNAs have been reported to also contain an open reading frame and thus are considered dual‐function RNAs. In this study, we discovered a dual‐function RNA from Vibrio cholerae, called VcdRP, harboring a 29 amino acid small protein (VcdP), as well as a base‐pairing sequence. Using a forward genetic screen, we identified VcdRP as a repressor of cholera toxin production and link this phenotype to the inhibition of carbon transport by the base‐pairing segment of the regulator. By contrast, we demonstrate that the VcdP small protein acts downstream of carbon transport by binding to citrate synthase (GltA), the first enzyme of the citric acid cycle. Interaction of VcdP with GltA results in increased enzyme activity and together VcdR and VcdP reroute carbon metabolism. We further show that transcription of vcdRP is repressed by CRP allowing us to provide a model in which VcdRP employs two different molecular mechanisms to synchronize central metabolism in V. cholerae.
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Affiliation(s)
- Kavyaa Venkat
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Mona Hoyos
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - James Rj Haycocks
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Liam Cassidy
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | | | | | | | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | - David C Grainger
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany.,Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
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13
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Kanaida M, Kimishima A, Eguchi S, Iwatsuki M, Watanabe Y, Honsho M, Hirose T, Noguchi Y, Nonaka K, Sennari G, Matsui H, Kaito C, Hanaki H, Asami Y, Sunazuka T. Total Syntheses and Chemical Biology Studies of Hymeglusin and Fusarilactone A, Novel Circumventors of β-Lactam Drug Resistance in Methicillin-Resistant Staphylococcus aureus. ChemMedChem 2021; 16:2106-2111. [PMID: 33783142 DOI: 10.1002/cmdc.202100219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Indexed: 11/10/2022]
Abstract
Hymeglusin, a previously known eukaryotic hydroxymethylglutaryl-CoA (HMG-CoA) synthase inhibitor, was identified as circumventing the β-lactam drug resistance in methicillin-resistant Staphylococcus aureus (MRSA). We describe the concise total syntheses of a series of natural products, which enabled determination of the absolute configuration of fusarilactone A and provided structure-activity relationship information. Based on previous reports, we speculated that the target protein of this circumventing effect may be MRSA bacterial HMG-CoA synthase (mvaS). We found that this enzyme was dose-dependently inhibited by hymeglusin. Furthermore, overexpression of the MRSA mvaS gene and site-directed mutagenesis studies suggested its binding site and the mechanism of action.
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Affiliation(s)
- Masahiro Kanaida
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Aoi Kimishima
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Shuhei Eguchi
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Masato Iwatsuki
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Yoshihiro Watanabe
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Masako Honsho
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Tomoyasu Hirose
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Yoshihiko Noguchi
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Kenichi Nonaka
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Goh Sennari
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Hidehito Matsui
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Chikara Kaito
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530, Japan
| | - Hideaki Hanaki
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Yukihiro Asami
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
| | - Toshiaki Sunazuka
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
- Ōmura Satoshi Memorial Institute, Kitasato University, 5-9-1 Shirokane Minato-ku, Tokyo, 108-8641, Japan
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14
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Hsu BM, Chen JS, Lin IC, Hsu GJ, Koner S, Hussain B, Huang SW, Tsai HC. Molecular and Anti-Microbial Resistance (AMR) Profiling of Methicillin-Resistant Staphylococcus aureus (MRSA) from Hospital and Long-Term Care Facilities (LTCF) Environment. Antibiotics (Basel) 2021; 10:antibiotics10060748. [PMID: 34205552 PMCID: PMC8235027 DOI: 10.3390/antibiotics10060748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/17/2021] [Accepted: 06/17/2021] [Indexed: 11/16/2022] Open
Abstract
To provide evidence of the cross-contamination of emerging pathogenic microbes in a local network between long-term care facilities (LTCFs) and hospitals, this study emphasizes the molecular typing, the prevalence of virulence genes, and the antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus. MRSA isolates were characterized from 246 samples collected from LTCFs, medical tubes of LTCF residents, and hospital environments of two cities, Chiayi and Changhua. Species identification, molecular characterization, and drug resistance analysis were performed. Hospital environments had a higher MRSA detection rate than that of LTCF environments, where moist samples are a hotspot of MRSA habitats, including tube samples from LTCF residents. All MRSA isolates in this study carried the exfoliative toxin eta gene (100%). The majority of MRSA isolates were resistant to erythromycin (76.7%), gentamicin (60%), and ciprofloxacin (55%). The percentage of multidrug-resistant MRSA isolates was approximately 50%. The enterobacterial repetitive intergenic consensus polymerase chain reaction results showed that 18 MRSA isolates belonged to a specific cluster. This implied that genetically similar isolates were spread between hospitals and LTCFs in Changhua city. This study highlights the threat to the health of LTCFs’ residents posed by hospital contact with MRSA.
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Affiliation(s)
- Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County 621, Taiwan; (B.-M.H.); (S.K.); (B.H.)
- Center for Innovative on Aging Society, National Chung Cheng University, Chiayi County 621, Taiwan
| | - Jung-Sheng Chen
- Department of Medical Research, E-Da Hospital, Kaohsiung City 824, Taiwan;
| | - I-Ching Lin
- Department of Family Medicine, Asia University Hospital, Taichung City 413, Taiwan;
- Department of Kinesiology, Health and Leisure, Chienkuo Technology University, Chenghua County 500, Taiwan
| | - Gwo-Jong Hsu
- Division of Infectious Diseases, Ditmanson Medical Foundation, Chia-Yi Christian Hospital, Chiayi City 600, Taiwan;
| | - Suprokash Koner
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County 621, Taiwan; (B.-M.H.); (S.K.); (B.H.)
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi County 621, Taiwan
| | - Bashir Hussain
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County 621, Taiwan; (B.-M.H.); (S.K.); (B.H.)
- Department of Biomedical Sciences, National Chung Cheng University, Chiayi County 621, Taiwan
| | - Shih-Wei Huang
- Center for Environmental Toxin and Emerging Contaminant Research, Cheng Shiu University, Kaohsiung City 830, Taiwan;
- Super Micro Research and Technology Center, Cheng Shiu University, Kaohsiung City 830, Taiwan
| | - Hsin-Chi Tsai
- Department of Psychiatry, School of Medicine, Tzu Chi University, Hualien County 970, Taiwan
- Department of Psychiatry, Tzu-Chi General Hospital, Hualien County 970, Taiwan
- Correspondence: ; Tel.: +88-638-561-825
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15
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Shen W, Yang N, Teng D, Hao Y, Ma X, Mao R, Wang J. Design and High Expression of Non-glycosylated Lysostaphins in Pichia pastoris and Their Pharmacodynamic Study. Front Microbiol 2021; 12:637662. [PMID: 33815324 PMCID: PMC8012855 DOI: 10.3389/fmicb.2021.637662] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/26/2021] [Indexed: 01/21/2023] Open
Abstract
Lysostaphin is an effective antimicrobial agent to Staphylococcus, especially for the methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Staphylococcus aureus (MDRSA). In this study, the seven lysostaphin derived mutants (rLys) were designed to overcome the barrier of glycosylation during expression in Pichia pastoris. Among them, 127A and 127A232Q had highest antimicrobial activity (MIC values 0.07–0.3 μM) to S. aureus than others and the commercial lysostaphins (1–15.8 times). There was no glycosylation during the expression in 5-L fermenter level, with the high yield of 1315 mg/L (127A) and 1141 mg/L (127A232Q), respectively. Meanwhile, 127A and 127A232Q effectively killed 99.9% of S. aureus at low concentration (1 × MIC) within 30 min, without the regrowth of pathogen. They also showed low toxicity, high pH and temperature stability. The results of in vivo therapeutic effect of 127A and 127A232Q against high virulent S. aureus CVCC546 showed that 127A and 127A232Q increased the survival rate of infected mice up to 100% at the dose of 10 mg/kg than the untreated group, reduced the bacterial translocation by 5-7 log CFU (over 99%) in organs compared to the untreated group and alleviated multiple-organ injuries (liver, kidney and spleen). These data indicated that the non-glycosylated lysostaphin 127A and 127A232Q may be a promising therapeutic agent against MDR staphylococcal infections.
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Affiliation(s)
- Wenluan Shen
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Na Yang
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Da Teng
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Ya Hao
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Xuanxuan Ma
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Ruoyu Mao
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Jianhua Wang
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.,Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
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16
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Hamada M, Yamaguchi T, Sato A, Ono D, Aoki K, Kajiwara C, Kimura S, Maeda T, Sasaki M, Murakami H, Ishii Y, Tateda K. Increased Incidence and Plasma-Biofilm Formation Ability of SCC mec Type IV Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated From Patients With Bacteremia. Front Cell Infect Microbiol 2021; 11:602833. [PMID: 33842382 PMCID: PMC8032974 DOI: 10.3389/fcimb.2021.602833] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/12/2021] [Indexed: 12/15/2022] Open
Abstract
In Japan, Staphylococcal cassette chromosome mec (SCCmec) type IV methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly prominent cause of bacteremia, but the virulence of most of these strains is unclear. We aimed to investigate the relationship between the molecular characteristics and the ability to form biofilms in the presence of blood plasma (plasma-biofilms) of MRSA strains isolated from bloodstream infections. In this study, the molecular characteristics and biofilms of MRSA strains isolated from blood cultures between 2015 and 2017 were analyzed by PCR-based assays, crystal violet staining, and confocal reflection microscopy methods. Among the 90 MRSA isolates, the detection rate of SCCmec type II clones decreased from 60.7 to 20.6%. The SCCmec type IV clone replaced the SCCmec type II clone as the dominant clone, with a detection rate increasing from 32.1 to 73.5%. The plasma-biofilm formation ability of the SCCmec type IV clone was higher than the SCCmec type II clone and even higher in strains harboring the cna or arcA genes. Plasma-biofilms, mainly composed of proteins, were formed quickly and strongly. Our study demonstrated the increased plasma-biofilm formation ability of SCCmec type IV strains.
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Affiliation(s)
- Masakaze Hamada
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Tetsuo Yamaguchi
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Ayami Sato
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan.,Department of Surgery, Toho University Sakura Medical Center, Chiba, Japan
| | - Daisuke Ono
- Department of Infectious Diseases and Infection Control, Saitama Medical Center, Saitama Medical University, Saitama, Japan
| | - Kotaro Aoki
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Chiaki Kajiwara
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Soichiro Kimura
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Tadashi Maeda
- Department of General Medicine and Emergency Care, Toho University Omori Medical Center, Tokyo, Japan
| | - Masakazu Sasaki
- Department of Clinical Laboratories, Toho University Omori Medical Center, Tokyo, Japan
| | - Hinako Murakami
- Department of Clinical Laboratories, Toho University Omori Medical Center, Tokyo, Japan
| | - Yoshikazu Ishii
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Kazuhiro Tateda
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan.,Department of Clinical Laboratories, Toho University Omori Medical Center, Tokyo, Japan
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17
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Zaman M, Andreasen M. Modulating Kinetics of the Amyloid-Like Aggregation of S. aureus Phenol-Soluble Modulins by Changes in pH. Microorganisms 2021; 9:microorganisms9010117. [PMID: 33430169 PMCID: PMC7825627 DOI: 10.3390/microorganisms9010117] [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: 11/14/2020] [Revised: 12/30/2020] [Accepted: 01/04/2021] [Indexed: 11/26/2022] Open
Abstract
The pathogen Staphylococcus aureus is recognized as one of the most frequent causes of biofilm-associated infections. The recently identified phenol-soluble modulin (PSM) peptides act as the key molecular effectors of staphylococcal biofilm maturation and promote the formation of an aggregated fibril structure. The aim of this study was to evaluate the effect of various pH values on the formation of functional amyloids of individual PSM peptides. Here, we combined a range of biophysical, chemical kinetics and microscopic techniques to address the structure and aggregation mechanism of individual PSMs under different conditions. We established that there is a pH-induced switch in PSM aggregation kinetics. Different lag times and growth of fibrils were observed, which indicates that there was no clear correlation between the rates of fibril elongation among different PSMs. This finding confirms that pH can modulate the aggregation properties of these peptides and suggest a deeper understanding of the formation of aggregates, which represents an important basis for strategies to interfere and might help in reducing the risk of biofilm-related infections.
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18
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Bhowmik D, Chetri S, Pandey P, Das BJ, Wangkheimayum J, Choudhury NA, Singha KM, Chanda DD, Bhattacharjee A. Expressional Pattern of psm-mec System in Methicillin-Resistant Staphylococcus aureus Under Oxacillin Stress. Curr Microbiol 2021; 78:528-533. [PMID: 33388933 DOI: 10.1007/s00284-020-02336-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 12/14/2020] [Indexed: 11/28/2022]
Abstract
The psm-mec element and other regulatory factors such as sarA, agrA, and RNAIII are responsible for maintaining the genetic framework for enhanced virulence of MRSA. psm-mec is found predominantly in the staphylococcal cassette chromosome (SCCmec). sarA, agrA, and RNAIII control gene expression to facilitate adaptation in certain environment. Genome-wide approaches have shown that expression of virulence factors is frequently regulated at transcriptional, translational level, and mRNA degradation level. In this study, transcriptional responses of psm-mec gene in accordance with other regulatory factors sarA, agrA, and RNAIII were observed under normal conditions as well as when exposed to 2 μg/ml and 6 μg/ml of oxacillin stress. One-way t-test was carried out for analysing RQ values obtained through real-time PCR. This study showed downregulation of psm-mec gene and upregulation of other regulatory genes at lower concentration of oxacillin. However, this was reverse when exposed against higher concentration of oxacillin. It was observed from the study that the expression of virulence factors were dependent on each other under different concentration of oxacillin. Thus, this study highlights that psm-mec, sarA, agrA, and RNAIII gene are under direct control of antibiotic pressure in a concentration-dependent manner.
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Affiliation(s)
| | - Shiela Chetri
- Department of Microbiology, Assam University, Silchar, Assam, India
| | - Piyush Pandey
- Department of Microbiology, Assam University, Silchar, Assam, India
| | | | | | | | - K Melson Singha
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
| | - Debadatta Dhar Chanda
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
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19
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Mediati DG, Wu S, Wu W, Tree JJ. Networks of Resistance: Small RNA Control of Antibiotic Resistance. Trends Genet 2020; 37:35-45. [PMID: 32951948 DOI: 10.1016/j.tig.2020.08.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/13/2020] [Accepted: 08/20/2020] [Indexed: 12/20/2022]
Abstract
The golden age of antibiotics has passed, and the threat of untreatable antimicrobial resistant infections is now a reality for many individuals. Understanding how bacteria resist antimicrobial treatment and regulate gene expression in response to antibiotics is an important step towards combating resistance. In this review we focus on a ubiquitous class of bacterial gene regulators termed regulatory small RNAs (sRNAs) and how they contribute to antimicrobial resistance and tolerance. Small RNAs have notable roles in modulating the composition of the bacterial envelope, and through these functions control intrinsic antimicrobial resistance in many human pathogens. Recent technical advances that allow profiling of the 'sRNA interactome' have revealed a complex post-transcriptional network of sRNA interactions that can be used to identify network hubs and regulatory bottlenecks. Sequence-specific inhibition of these sRNAs with programmable RNA-targeting therapeutics may present avenues for treating antimicrobial resistant pathogens or resensitizing to our current antibiotics.
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Affiliation(s)
- Daniel G Mediati
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sylvania Wu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Winton Wu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
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20
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Song HS, Choi TR, Han YH, Park YL, Park JY, Yang SY, Bhatia SK, Gurav R, Kim YG, Kim JS, Joo HS, Yang YH. Increased resistance of a methicillin-resistant Staphylococcus aureus Δagr mutant with modified control in fatty acid metabolism. AMB Express 2020; 10:64. [PMID: 32266584 PMCID: PMC7138893 DOI: 10.1186/s13568-020-01000-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/28/2020] [Indexed: 02/08/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are distinct from general Staphylococcus strains with respect to the composition of the membrane, ability to form a thicker biofilm, and, importantly, ability to modify the target of antibiotics to evade their activity. The agr gene is an accessory global regulator of gram-positive bacteria that governs virulence or resistant mechanisms and therefore an important target for the control of resistant strains. However, the mechanism by which agr impacts resistance to β-lactam antibiotics remains unclear. In the present study, we found the Δagr mutant strain having higher resistance to high concentrations of β-lactam antibiotics such as oxacillin and ampicillin. To determine the influence of variation in the microenvironment of cells between the parental and mutant strains, fatty acid analysis of the supernatant, total lipids, and phospholipid fatty acids were compared. The Δagr mutant strain tended to produce fewer fatty acids and retained lower amounts of C16, C18 fatty acids in the supernatant. Phospholipid analysis showed a dramatic increase in the hydrophobic longer-chain fatty acids in the membrane. To target membrane, we applied several surfactants and found that sorbitan monolaurate (Span20) had a synergistic effect with oxacillin by decreasing biofilm formation and growth. These findings indicate that agr deletion allows for MRSA to resist antibiotics via several changes including constant expression of mecA, fatty acid metabolism, and biofilm thickening.
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21
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Liu CC, Lin MH. Involvement of Heme in Colony Spreading of Staphylococcus aureus. Front Microbiol 2020; 11:170. [PMID: 32117177 PMCID: PMC7026375 DOI: 10.3389/fmicb.2020.00170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/24/2020] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus spreads rapidly on the surface of soft agar medium. The spreading depends on the synthesis of biosurfactants, i.e., phenol soluble modulins (PSMs), which facilitate colony spreading of S. aureus. Our earlier study demonstrated that water accumulates in a colony is important to modulate colony spreading of S. aureus. The current study screened a transposon-based mutant library of S. aureus HG001 and obtained four non-spreading mutants with mutations in hemY and ctaA, which are involved in heme synthesis. The spreading ability of these mutants was restored when the mutants are transformed with a plasmid encoding hemY or ctaA, respectively. HemY mutants, which do not synthesize heme B, were able to spread on agar medium supplemented with hemin, a heme B derivative. By contrast, hemin supplementation did not rescue the spreading of the ctaA mutant, which lacks heme B and heme A, indicating that heme A is also critical for colony spreading. Moreover, mutations in hemY and ctaA had little effect on PSMs production but affect ATP production and water accumulation in the colony. In conclusion, this study sheds light on the role of heme synthesis and energy production in the regulation of S. aureus colony spreading, which is important for understanding the movement mechanisms of bacteria lacking a motor apparatus.
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Affiliation(s)
- Chao-Chin Liu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Mei-Hui Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- *Correspondence: Mei-Hui Lin,
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22
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Tabuchi F, Lulitanond A, Lulitanond V, Thunyaharn S, Kaito C. Epidemiological study on the relationship between toxin production and psm-mec mutations in MRSA isolates in Thailand. Microbiol Immunol 2020; 64:219-225. [PMID: 31808571 DOI: 10.1111/1348-0421.12764] [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: 10/09/2019] [Revised: 11/17/2019] [Accepted: 12/02/2019] [Indexed: 11/29/2022]
Abstract
In this present study, we investigated the phenol-soluble modulin (psm-mec) mutations, the staphylococcal cassette chromosome mec (SCCmec) types, and toxin production in 102 methicillin-resistant Staphylococcus aureus (MRSA) isolates from the northeast and central regions of Thailand. The MRSA isolates carrying -7T>C psm-mec in Type II SCCmec (n = 18) and the MRSA isolates carrying no psm-mec in Type IV (n = 8) or Type IX SCCmec (n = 4) had higher hemolytic activity against sheep erythrocytes than MRSA isolates carrying intact psm-mec in Type III SCCmec (n = 34), but MRSA isolates carrying no psm-mec in Type I SCCmec (n = 27) did not.
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Affiliation(s)
- Fumiaki Tabuchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Aroonlug Lulitanond
- Center for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Viraphong Lulitanond
- Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Sudaluck Thunyaharn
- Faculty of Medical Technology, Nakhonratchasima College, Nakhon Ratchasima, Thailand.,Department of Microbiology, Phramongkutklao College of Medicine, Bangkok, Thailand
| | - Chikara Kaito
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Comparative Transcriptomic and Functional Assessments of Linezolid-Responsive Small RNA Genes in Staphylococcus aureus. mSystems 2020; 5:5/1/e00665-19. [PMID: 31911464 PMCID: PMC6946794 DOI: 10.1128/msystems.00665-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are RNA molecules that can have important regulatory roles across gene expression networks. There is a growing understanding of the scope and potential breadth of impact of sRNAs on global gene expression patterns in Staphylococcus aureus, a major human pathogen. Here, transcriptome comparisons were used to examine the roles of sRNA genes with a potential role in the response of S. aureus to antibiotic exposure. Although no measurable impact on key bacterial phenotypes was observed after deleting each of 18 sRNAs identified by these comparisons, this research is significant because it underscores the subtle modes of action of these sometimes abundant molecules within the bacterium. Staphylococcus aureus contains a repertoire of at least 50 and possibly 500 small RNAs (sRNAs). The functions of most sRNAs are not understood, although some are known to respond to environmental changes, including the presence of antibiotics. Here, in an effort to better understand the roles of sRNAs in the context of antibiotic exposure, we took a clinical methicillin-resistant S. aureus (MRSA) isolate and separately deleted eight sRNAs that were significantly upregulated in response to the last-line antibiotic linezolid as revealed by transcriptome sequencing (RNA-seq) comparisons. We also deleted an additional 10 sRNAs that were either highly expressed or previously found to respond to antibiotic exposure. There were no significant changes for any of the 18 mutants in a variety of phenotypic screens, including MIC screens, growth competition assays in the presence of linezolid, biofilm formation, and resistance to whole-blood killing. These data suggest sRNA functional redundancy, because despite their high expression levels upon antibiotic exposure, individual sRNA genes do not affect readily observable bacterial phenotypes. The sRNA transcriptional changes we measured during antibiotic exposure might also reflect sRNA “indifference,” that is, a general stress response not specifically related to sRNA function. These data underscore the need for sensitive assays and new approaches to try and decipher the functions of sRNA genes in S. aureus. IMPORTANCE Bacterial small RNAs (sRNAs) are RNA molecules that can have important regulatory roles across gene expression networks. There is a growing understanding of the scope and potential breadth of impact of sRNAs on global gene expression patterns in Staphylococcus aureus, a major human pathogen. Here, transcriptome comparisons were used to examine the roles of sRNA genes with a potential role in the response of S. aureus to antibiotic exposure. Although no measurable impact on key bacterial phenotypes was observed after deleting each of 18 sRNAs identified by these comparisons, this research is significant because it underscores the subtle modes of action of these sometimes abundant molecules within the bacterium.
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24
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Sanson MA, Macias OR, Shah BJ, Hanson B, Vega LA, Alamarat Z, Flores AR. Unexpected relationships between frequency of antimicrobial resistance, disease phenotype and emm type in group A Streptococcus. Microb Genom 2019; 5:e000316. [PMID: 31755853 PMCID: PMC6927302 DOI: 10.1099/mgen.0.000316] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Despite universal susceptibility to β-lactams, resistance to second-line antimicrobials (e.g. erythromycin) is increasingly common among group A Streptococcus (GAS). To better understand the frequency of regional GAS antimicrobial resistance, we screened a previously described GAS strain collection from Houston, TX, USA, for resistance to commonly used antimicrobials. A total of 100/929 (10.8 %) showed resistance to at least one antimicrobial. Tetracycline resistance was identified in 52 (5.6 %) GAS strains. The cumulative frequency of erythromycin and clindamycin resistance [macrolide (M) and macrolide-lincosamide-streptogramin (MLS) phenotypes] was greatest among invasive GAS strains (9.9 %) compared to that of strains derived from any other infection type (5.9 %, P=0.045). We identified emm types 11, 75, 77 and 92 as the only emm types with high (e.g. >50 %) within-emm type resistance and contributing to the majority (24/26; 92 %) of erythromycin/clindamycin resistance in invasive GAS. High-frequency resistance emm types were also significantly overrepresented in invasive GAS strains as indicated by invasive index. We performed whole-genome sequencing to define genetic elements associated with resistance among emm types 11, 75, 77 and 92. Diverse mobile elements contributed to GAS resistance including transposons, integrative conjugative elements, prophage and a plasmid. Phylogenetic analysis suggests recent clonal emergence of emm92 GAS strains. Our findings indicate that less frequently encountered GAS emm types disproportionately contribute to resistance phenotypes, are defined by diverse mobile genetic elements and may favour invasive disease.
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Affiliation(s)
- Misu A. Sanson
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA
| | - Olga R. Macias
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA
| | - Brittany J. Shah
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA
| | - Blake Hanson
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Sciences Center at Houston, Houston, TX, USA
| | - Luis Alberto Vega
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA
| | - Zain Alamarat
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA
| | - Anthony R. Flores
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, Houston, TX, USA,Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Sciences Center at Houston, Houston, TX, USA,*Correspondence: Anthony R. Flores,
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25
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Abstract
Regulatory RNAs, present in many bacterial genomes and particularly in pathogenic bacteria such as Staphylococcus aureus, control the expression of genes encoding virulence factors or metabolic proteins. They are extremely diverse and include noncoding RNAs (sRNA), antisense RNAs, and some 5' or 3' untranslated regions of messenger RNAs that act as sensors for metabolites, tRNAs, or environmental conditions (e.g., temperature, pH). In this review we focus on specific examples of sRNAs of S. aureus that illustrate how numerous sRNAs and associated proteins are embedded in complex networks of regulation. In addition, we discuss the CRISPR-Cas systems defined as an RNA-interference-like mechanism, which also exist in staphylococcal strains.
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26
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Putnam NE, Fulbright LE, Curry JM, Ford CA, Petronglo JR, Hendrix AS, Cassat JE. MyD88 and IL-1R signaling drive antibacterial immunity and osteoclast-driven bone loss during Staphylococcus aureus osteomyelitis. PLoS Pathog 2019; 15:e1007744. [PMID: 30978245 PMCID: PMC6481883 DOI: 10.1371/journal.ppat.1007744] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/24/2019] [Accepted: 04/01/2019] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is able to infect virtually all organ systems and is a frequently isolated etiologic agent of osteomyelitis, a common and debilitating invasive infection of bone. Treatment of osteomyelitis requires invasive surgical procedures and prolonged antibiotic therapy, yet is frequently unsuccessful due to extensive pathogen-induced bone damage that can limit antibiotic penetration and immune cell influx to the infectious focus. We previously established that S. aureus triggers profound alterations in bone remodeling in a murine model of osteomyelitis, in part through the production of osteolytic toxins. However, staphylococcal strains lacking osteolytic toxins still incite significant bone destruction, suggesting that host immune responses are also major drivers of pathologic bone remodeling during osteomyelitis. The objective of this study was to identify host immune pathways that contribute to antibacterial immunity during S. aureus osteomyelitis, and to define how these immune responses alter bone homeostasis and contribute to bone destruction. We specifically focused on the interleukin-1 receptor (IL-1R) and downstream adapter protein MyD88 given the prominent role of this signaling pathway in both antibacterial immunity and osteo-immunologic crosstalk. We discovered that while IL-1R signaling is necessary for local control of bacterial replication during osteomyelitis, it also contributes to bone loss during infection. Mechanistically, we demonstrate that S. aureus enhances osteoclastogenesis of myeloid precursors in vitro, and increases the abundance of osteoclasts residing on bone surfaces in vivo. This enhanced osteoclast abundance translates to trabecular bone loss, and is dependent on intact IL-1R signaling. Collectively, these data define IL-1R signaling as a critical component of the host response to S. aureus osteomyelitis, but also demonstrate that IL-1R-dependent immune responses trigger collateral bone damage through activation of osteoclast-mediated bone resorption.
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Affiliation(s)
- Nicole E. Putnam
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Laura E. Fulbright
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jacob M. Curry
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Caleb A. Ford
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Jenna R. Petronglo
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Andrew S. Hendrix
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - James E. Cassat
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
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Maezawa Y, Nakaminami H, Takadama S, Hayashi M, Wajima T, Nakase K, Yamada T, Ikoshi H, Noguchi N. Tokiinshi, a traditional Japanese medicine (Kampo), suppresses Panton-Valentine leukocidin production in the methicillin-resistant Staphylococcus aureus USA300 clone. PLoS One 2019; 14:e0214470. [PMID: 30921402 PMCID: PMC6438529 DOI: 10.1371/journal.pone.0214470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 03/13/2019] [Indexed: 01/03/2023] Open
Abstract
It is necessary to develop agents other than antimicrobials for the treatment of Staphylococcus aureus infections to prevent the emergence of antimicrobial-resistant strains. Particularly, anti-virulence agents against the Panton-Valentine leukocidin (PVL)-positive methicillin-resistant S. aureus (MRSA), USA300 clone, is desired due to its high pathogenicity. Here, we investigated the potential anti-virulence effect of Tokiinshi, which is a traditional Japanese medicine (Kampo) used for skin diseases, against the USA300 clone. A growth inhibition assay showed that a conventional dose (20 mg/ml) of Tokiinshi has bactericidal effects against the clinical USA300 clones. Notably, the growth inhibition effects of Tokiinshi against S. epidermidis strains, which are the major constituents of the skin microbiome, was a bacteriostatic effect. The data suggested that Tokiinshi is unlikely to affect skin flora of S. epidermidis. Furthermore, PVL production and the expression of its gene were significantly suppressed in the USA300 clone by a lower concentration (5 mg/ml) of Tokiinshi. This did not affect the number of viable bacteria. Moreover, Tokiinshi significantly suppressed the expression of the agrA gene, which regulates PVL gene expression. For the first time, our findings strongly suggest that Tokiinshi has the potential to attenuate the virulence of the USA300 clone by suppressing PVL production via agrA gene suppression.
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Affiliation(s)
- Yuka Maezawa
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hidemasa Nakaminami
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
- * E-mail:
| | - Shunsuke Takadama
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Minami Hayashi
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Takeaki Wajima
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Keisuke Nakase
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Tetsuya Yamada
- Department of Traditional Chinese Medicine, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hideaki Ikoshi
- Department of Traditional Chinese Medicine, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Norihisa Noguchi
- Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
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28
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Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
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29
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Synthesis and structural characterization of antimicrobial binuclear copper(II) coordination compounds bridged by hydroxy- and/or thiodipropionic acid. J Inorg Biochem 2019; 191:8-20. [DOI: 10.1016/j.jinorgbio.2018.10.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/19/2018] [Accepted: 10/23/2018] [Indexed: 11/22/2022]
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30
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Raina M, King A, Bianco C, Vanderpool CK. Dual-Function RNAs. Microbiol Spectr 2018; 6:10.1128/microbiolspec.RWR-0032-2018. [PMID: 30191807 PMCID: PMC6130917 DOI: 10.1128/microbiolspec.rwr-0032-2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Indexed: 12/30/2022] Open
Abstract
Bacteria are known to use RNA, either as mRNAs encoding proteins or as noncoding small RNAs (sRNAs), to regulate numerous biological processes. However, a few sRNAs have two functions: they act as base-pairing RNAs and encode a small protein with additional regulatory functions. Thus, these so called "dual-function" sRNAs can serve as both a riboregulator and an mRNA. In some cases, these two functions can act independently within the same pathway, while in other cases, the base-pairing function and protein function act in different pathways. Here, we discuss the five known dual-function sRNAs-SgrS from enteric species, RNAIII and Psm-mec from Staphylococcus aureus, Pel RNA from Streptococcus pyogenes, and SR1 from Bacillus subtilis-and review their mechanisms of action and roles in regulating diverse biological processes. We also discuss the prospect of finding additional dual-function sRNAs and future challenges in studying the overlap and competition between the functions.
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Affiliation(s)
- Medha Raina
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892
| | - Alisa King
- Department of Microbiology, University of Illinois, Urbana, IL 61801
| | - Colleen Bianco
- Department of Microbiology, University of Illinois, Urbana, IL 61801
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Sonoda S, Yamaguchi T, Aoki K, Ono D, Sato A, Kajiwara C, Kimura S, Akasaka Y, Ishii Y, Miyazaki Y, Inase N, Tateda K. Evidence of latent molecular diversity determining the virulence of community-associated MRSA USA300 clones in mice. IMMUNITY INFLAMMATION AND DISEASE 2018; 6:402-412. [PMID: 30091216 PMCID: PMC6113770 DOI: 10.1002/iid3.234] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/10/2018] [Accepted: 07/13/2018] [Indexed: 01/26/2023]
Abstract
Introduction The USA300 clone of community‐associated MRSA is reported to be hypervirulent and epidemic in the United States. This clone causes a variety of diseases from lethal pneumonia to mild skin infections. We hypothesized that evolutionary diversity may exist among USA300 clones, which may link virulence traits with host responses and mortality rates. Methods USA300 isolates from severe pneumonia (IP) and skin infection (IS) were characterized by pulsed‐field gel electrophoresis (PFGE) and next‐generation sequencing. Their virulence traits and host responses were compared in a lung infection model. Results The two USA300 isolates were found to be identical in genomic analysis. Robust IL‐6 production, aggregation of bacteria, and hemorrhaging were observed in IP‐infected lungs, which were associated with a higher rate of mortality than that observed with strain IS. Few neutrophils were detected in the lungs infected with strain IP, even at high bacterial loads. Massive production of α‐toxin and coagulase were evident during the early phase of IP infection, and robust gene expression of hla (α‐toxin) and lukS‐PV (Panton–Valentine leukocidin), but not coa, agrA, or rnaIII, was confirmed in vitro. Strain IP also induced strong hemolysis in red blood cells. Conclusions The present data demonstrated latent diversity in the virulence of USA300 clones. Unknown regulatory mechanisms, probably involving a host factor(s) as a trigger, may govern the virulence expression and resultant high mortality in certain sub‐clones of USA300.
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Affiliation(s)
- Shiro Sonoda
- The Integrated Pulmonology, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan.,Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Tetsuo Yamaguchi
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Kotaro Aoki
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Daisuke Ono
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Ayami Sato
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan.,Department of Surgery, Toho University Sakura Medical Center, Chiba, 285-8741, Japan
| | - Chiaki Kajiwara
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Soichiro Kimura
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Yoshikiyo Akasaka
- Department of Pathology, Toho University. Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Yoshikazu Ishii
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
| | - Yasunari Miyazaki
- The Integrated Pulmonology, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| | - Naohiko Inase
- The Integrated Pulmonology, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| | - Kazuhiro Tateda
- Department of Microbiology and Infectious Disease, Toho University, Faculty of Medicine, Tokyo, 143-8540, Japan
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32
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Sritharadol R, Hamada M, Kimura S, Ishii Y, Srichana T, Tateda K. Mupirocin at Subinhibitory Concentrations Induces Biofilm Formation in Staphylococcus aureus. Microb Drug Resist 2018; 24:1249-1258. [PMID: 29653478 DOI: 10.1089/mdr.2017.0290] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Mupirocin is a useful antibiotic against superficial skin infections. We compared the impact of mupirocin with a cephalosporin, a fluoroquinolone, an aminoglycoside, and a macrolide on planktonic cell growth and biofilm formation of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). MATERIALS AND METHODS Minimum inhibitory concentration (MIC) of mupirocin was determined against S. aureus strains used in this study. Biofilm formation of S. aureus strains exposed to mupirocin was quantified by crystal violet staining assay. Moreover, biofilm structure and viability of the biofilm cells were visualized by Live/Dead staining assay. Biofilm-related gene expression was investigated by quantitative real-time PCR. RESULTS MRSA USA300 clone was resistant to mupirocin with MIC of 1,024 mg/L, while MRSA ATCC-43300 and MSSA ATCC-29213 were susceptible with MICs of 0.03 mg/L. Planktonic cell growth of the S. aureus strains was inhibited by mupirocin in a dose-dependent manner. However, some of the low concentrations of mupirocin less than the MICs promoted biofilm formation. Confocal laser scanning microscopy of the biofilm structures and cell viabilities showed established biofilms of slightly higher cell density in the mupirocin treated groups, especially in the MRSA USA300 clone. Gene expression of RNAIII in planktonic cells and biofilms of MRSA USA300 clone showed the highest upregulation after initial exposure to sub-MIC of mupirocin followed by downregulation, whereas the other antibiotics showed various fluctuations. CONCLUSION The results showed that subinhibitory concentrations of mupirocin promoted biofilm formation of S. aureus, in particular the MRSA USA300 clone.
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Affiliation(s)
- Rutthapol Sritharadol
- 1 Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University , Hat Yai, Songkhla, Thailand .,2 Department of Microbiology and Infectious Diseases, Toho University School of Medicine , Tokyo, Japan
| | - Masakaze Hamada
- 2 Department of Microbiology and Infectious Diseases, Toho University School of Medicine , Tokyo, Japan
| | - Soichiro Kimura
- 2 Department of Microbiology and Infectious Diseases, Toho University School of Medicine , Tokyo, Japan
| | - Yoshikazu Ishii
- 2 Department of Microbiology and Infectious Diseases, Toho University School of Medicine , Tokyo, Japan
| | - Teerapol Srichana
- 1 Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Prince of Songkla University , Hat Yai, Songkhla, Thailand
| | - Kazuhiro Tateda
- 2 Department of Microbiology and Infectious Diseases, Toho University School of Medicine , Tokyo, Japan
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33
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Kane TL, Carothers KE, Lee SW. Virulence Factor Targeting of the Bacterial Pathogen Staphylococcus aureus for Vaccine and Therapeutics. Curr Drug Targets 2018; 19:111-127. [PMID: 27894236 PMCID: PMC5957279 DOI: 10.2174/1389450117666161128123536] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Staphylococcus aureus is a major bacterial pathogen capable of causing a range of infections in humans from gastrointestinal disease, skin and soft tissue infections, to severe outcomes such as sepsis. Staphylococcal infections in humans can be frequent and recurring, with treatments becoming less effective due to the growing persistence of antibiotic resistant S. aureus strains. Due to the prevalence of antibiotic resistance, and the current limitations on antibiotic development, an active and highly promising avenue of research has been to develop strategies to specifically inhibit the activity of virulence factors produced S. aureus as an alternative means to treat disease. OBJECTIVE In this review we specifically highlight several major virulence factors produced by S. aureus for which recent advances in antivirulence approaches may hold promise as an alternative means to treating diseases caused by this pathogen. Strategies to inhibit virulence factors can range from small molecule inhibitors, to antibodies, to mutant and toxoid forms of the virulence proteins. CONCLUSION The major prevalence of antibiotic resistant strains of S. aureus combined with the lack of new antibiotic discoveries highlight the need for vigorous research into alternative strategies to combat diseases caused by this highly successful pathogen. Current efforts to develop specific antivirulence strategies, vaccine approaches, and alternative therapies for treating severe disease caused by S. aureus have the potential to stem the tide against the limitations that we face in the post-antibiotic era.
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Affiliation(s)
- Trevor L. Kane
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Katelyn E. Carothers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA
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34
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Pollitt EJG, Diggle SP. Defining motility in the Staphylococci. Cell Mol Life Sci 2017; 74:2943-2958. [PMID: 28378043 PMCID: PMC5501909 DOI: 10.1007/s00018-017-2507-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/16/2017] [Accepted: 03/14/2017] [Indexed: 01/17/2023]
Abstract
The ability of bacteria to move is critical for their survival in diverse environments and multiple ways have evolved to achieve this. Two forms of motility have recently been described for Staphylococcus aureus, an organism previously considered to be non-motile. One form is called spreading, which is a type of sliding motility and the second form involves comet formation, which has many observable characteristics associated with gliding motility. Darting motility has also been observed in Staphylococcus epidermidis. This review describes how motility is defined and how we distinguish between passive and active motility. We discuss the characteristics of the various forms of Staphylococci motility, the molecular mechanisms involved and the potential future research directions.
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Affiliation(s)
- Eric J G Pollitt
- Department of Biomedical Science, Western Bank, University of Sheffield, Sheffield, UK
| | - Stephen P Diggle
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
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Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract. Microbiol Spectr 2017; 4. [PMID: 27227294 DOI: 10.1128/microbiolspec.uti-0012-2012] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.
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Geisinger E, Isberg RR. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria. J Infect Dis 2017; 215:S9-S17. [PMID: 28375515 DOI: 10.1093/infdis/jiw402] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance.
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Affiliation(s)
- Edward Geisinger
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| | - Ralph R Isberg
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
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37
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Sekimizu K. The Usefulness of Silkworms as a Model Animal for Evaluating the Effectiveness of Medicine and Food. YAKUGAKU ZASSHI 2017; 137:551-562. [DOI: 10.1248/yakushi.16-00249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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38
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Figueiredo AMS, Ferreira FA, Beltrame CO, Côrtes MF. The role of biofilms in persistent infections and factors involved in ica-independent biofilm development and gene regulation in Staphylococcus aureus. Crit Rev Microbiol 2017; 43:602-620. [PMID: 28581360 DOI: 10.1080/1040841x.2017.1282941] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Staphylococcus aureus biofilms represent a unique micro-environment that directly contribute to the bacterial fitness within hospital settings. The accumulation of this structure on implanted medical devices has frequently caused the development of persistent and chronic S. aureus-associated infections, which represent an important social and economic burden worldwide. ica-independent biofilms are composed of an assortment of bacterial products and modulated by a multifaceted and overlapping regulatory network; therefore, biofilm composition can vary among S. aureus strains. In the microniches formed by biofilms-produced by a number of bacterial species and composed by different structural components-drug refractory cell subpopulations with distinct physiological characteristics can emerge and result in therapeutic failures in patients with recalcitrant bacterial infections. In this review, we highlight the importance of biofilms in the development of persistence and chronicity in some S. aureus diseases, the main molecules associated with ica-independent biofilm development and the regulatory mechanisms that modulate ica-independent biofilm production, accumulation, and dispersion.
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Affiliation(s)
- Agnes Marie Sá Figueiredo
- a Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Fabienne Antunes Ferreira
- b Departamento de Microbiologia, Imunologia e Parasitologia , Campus Universitário Setor F, Bloco A. Florianópolis, Universidade Federal de Santa Catarina , Florianopolis , Brazil
| | - Cristiana Ossaille Beltrame
- a Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Marina Farrel Côrtes
- a Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
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Qin L, Da F, Fisher EL, Tan DCS, Nguyen TH, Fu CL, Tan VY, McCausland JW, Sturdevant DE, Joo HS, Queck SY, Cheung GYC, Otto M. Toxin Mediates Sepsis Caused by Methicillin-Resistant Staphylococcus epidermidis. PLoS Pathog 2017; 13:e1006153. [PMID: 28151994 PMCID: PMC5289634 DOI: 10.1371/journal.ppat.1006153] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/27/2016] [Indexed: 01/03/2023] Open
Abstract
Bacterial sepsis is a major killer in hospitalized patients. Coagulase-negative staphylococci (CNS) with the leading species Staphylococcus epidermidis are the most frequent causes of nosocomial sepsis, with most infectious isolates being methicillin-resistant. However, which bacterial factors underlie the pathogenesis of CNS sepsis is unknown. While it has been commonly believed that invariant structures on the surface of CNS trigger sepsis by causing an over-reaction of the immune system, we show here that sepsis caused by methicillin-resistant S. epidermidis is to a large extent mediated by the methicillin resistance island-encoded peptide toxin, PSM-mec. PSM-mec contributed to bacterial survival in whole human blood and resistance to neutrophil-mediated killing, and caused significantly increased mortality and cytokine expression in a mouse sepsis model. Furthermore, we show that the PSM-mec peptide itself, rather than the regulatory RNA in which its gene is embedded, is responsible for the observed virulence phenotype. This finding is of particular importance given the contrasting roles of the psm-mec locus that have been reported in S. aureus strains, inasmuch as our findings suggest that the psm-mec locus may exert effects in the background of S. aureus strains that differ from its original role in the CNS environment due to originally “unintended” interferences. Notably, while toxins have never been clearly implied in CNS infections, our tissue culture and mouse infection model data indicate that an important type of infection caused by the predominant CNS species is mediated to a large extent by a toxin. These findings suggest that CNS infections may be amenable to virulence-targeted drug development approaches. Coagulase-negative staphylococci (CNS) are the leading cause of sepsis in hospitalized patients, causing a significant number of deaths. This situation is further worsened by a limitation of therapeutic options due to the fact that most CNS infectious isolates are resistant to methicillin. CNS sepsis has been assumed to be due to on over-reacting immune response triggered by invariant bacterial surface structures. By using tissue culture and animal infection model-based evidence, we here show that in contrast to that notion, the PSM-mec toxin produced by methicillin-resistant strains of the leading CNS species Staphylococcus epidermidis has a strong impact on the severity of sepsis and its outcome. This is the first report to link a toxin to the pathogenesis of the most frequent bacterial cause of sepsis. Notably, these findings pave the way for anti-virulence strategies against this widespread and deadly type of infection.
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Affiliation(s)
- Li Qin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Dermatology, Wuhan No.1 Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Fei Da
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, China
| | - Emilie L. Fisher
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel C. S. Tan
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thuan H. Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Chih-Lung Fu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Vee Y. Tan
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Joshua W. McCausland
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel E. Sturdevant
- Research Technology Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Hamilton, Montana, United States of America
| | - Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Shu Y. Queck
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Gimpel M, Brantl S. Dual-function small regulatory RNAs in bacteria. Mol Microbiol 2016; 103:387-397. [PMID: 27750368 DOI: 10.1111/mmi.13558] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/10/2016] [Accepted: 10/11/2016] [Indexed: 12/31/2022]
Abstract
Dual-function sRNAs are a subgroup of small regulatory RNAs that act on the one hand as base-pairing sRNAs to inhibit or activate target gene expression and on the other hand as peptide-encoding mRNAs that function either in the same or in another metabolic pathway. Here, we review and compare the five currently known and intensively characterized dual-function sRNAs with regard to their two functions, their biological role, their evolutionary conservation and their requirements for RNA chaperones. Furthermore, we summarize the data available on five potential dual-function sRNAs, whose base-pairing function is well established whereas the role of their encoded peptides has not yet been elucidated. In addition, we provide three examples for RNAs with more than one function that do not fall into the above-mentioned category. With the application of RNAseq, peptidomics and transcriptomics it can be expected that the number of dual-function sRNAs will considerably increase within the next years, thus enhancing our knowledge on the regulatory potential of these RNAs.
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Affiliation(s)
- Matthias Gimpel
- Biologisch-Pharmazeutische Fakultät, Lehrstuhl für Genetik, Friedrich-Schiller-Universität Jena, AG Bakteriengenetik, Philosophenweg 12, Jena, D-07743, Germany
| | - Sabine Brantl
- Biologisch-Pharmazeutische Fakultät, Lehrstuhl für Genetik, Friedrich-Schiller-Universität Jena, AG Bakteriengenetik, Philosophenweg 12, Jena, D-07743, Germany
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The presence of a single MALDI-TOF mass spectral peak predicts methicillin resistance in staphylococci. Diagn Microbiol Infect Dis 2016; 86:257-261. [DOI: 10.1016/j.diagmicrobio.2016.08.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/26/2016] [Accepted: 08/02/2016] [Indexed: 11/18/2022]
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Kizaki H, Omae Y, Tabuchi F, Saito Y, Sekimizu K, Kaito C. Cell-Surface Phenol Soluble Modulins Regulate Staphylococcus aureus Colony Spreading. PLoS One 2016; 11:e0164523. [PMID: 27723838 PMCID: PMC5056675 DOI: 10.1371/journal.pone.0164523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 09/27/2016] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus produces phenol-soluble modulins (PSMs), which are amphipathic small peptides with lytic activity against mammalian cells. We previously reported that PSMα1-4 stimulate S. aureus colony spreading, the phenomenon of S. aureus colony expansion on the surface of soft agar plates, whereas δ-toxin (Hld, PSMγ) inhibits colony-spreading activity. In this study, we revealed the underlying mechanism of the opposing effects of PSMα1-4 and δ-toxin in S. aureus colony spreading. PSMα1-4 and δ-toxin are abundant on the S. aureus cell surface, and account for 18% and 8.5% of the total amount of PSMα1-4 and δ-toxin, respectively, in S. aureus overnight cultures. Knockout of PSMα1-4 did not affect the amount of cell surface δ-toxin. In contrast, knockout of δ-toxin increased the amount of cell surface PSMα1-4, and decreased the amount of culture supernatant PSMα1-4. The δ-toxin inhibited PSMα3 and PSMα2 binding to the S. aureus cell surface in vitro. A double knockout strain of PSMα1-4 and δ-toxin exhibited decreased colony spreading compared with the parent strain. Expression of cell surface PSMα1-4, but not culture supernatant PSMα1-4, restored the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. Expression of δ-toxin on the cell surface or in the culture supernatant did not restore the colony-spreading activity of the PSMα1-4/δ-toxin double knockout strain. These findings suggest that cell surface PSMα1-4 promote S. aureus colony spreading, whereas δ-toxin suppresses colony-spreading activity by inhibiting PSMα1-4 binding to the S. aureus cell surface.
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Affiliation(s)
- Hayato Kizaki
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yosuke Omae
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Fumiaki Tabuchi
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuki Saito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kazuhisa Sekimizu
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Chikara Kaito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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43
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Suzuki T, Yamamoto T, Kaito C, Miyamoto H, Ohashi Y. Impact ofpsm-mecin Methicillin-ResistantStaphylococcus aureus(ST764) Strains Isolated from Keratitis Patients. Microb Drug Resist 2016; 22:589-597. [DOI: 10.1089/mdr.2015.0315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Takashi Suzuki
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Toshihiro Yamamoto
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan
| | - Chikara Kaito
- Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Hitoshi Miyamoto
- Department of Clinical Laboratory, Ehime University Hospital, Toon, Japan
| | - Yuichi Ohashi
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan
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Qin L, McCausland JW, Cheung GYC, Otto M. PSM-Mec-A Virulence Determinant that Connects Transcriptional Regulation, Virulence, and Antibiotic Resistance in Staphylococci. Front Microbiol 2016; 7:1293. [PMID: 27597849 PMCID: PMC4992726 DOI: 10.3389/fmicb.2016.01293] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 08/05/2016] [Indexed: 11/24/2022] Open
Abstract
PSM-mec is a secreted virulence factor that belongs to the phenol-soluble modulin (PSM) family of amphipathic, alpha-helical peptide toxins produced by Staphylococcus species. All known PSMs are core genome-encoded with the exception of PSM-mec, whose gene is found in specific sub-types of SCCmec methicillin resistance mobile genetic elements present in methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci. In addition to the cytolytic translational product, PSM-mec, the psm-mec locus encodes a regulatory RNA. In S. aureus, the psm-mec locus influences cytolytic capacity, methicillin resistance, biofilm formation, cell spreading, and the expression of other virulence factors, such as other PSMs, which results in a significant impact on immune evasion and disease. However, these effects are highly strain-dependent, which is possibly due to differences in PSM-mec peptide vs. psm-mec RNA-controlled effects. Here, we summarize the functional properties of PSM-mec and the psm-mec RNA molecule and their roles in staphylococcal pathogenesis and physiology.
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Affiliation(s)
- Li Qin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA; Department of Dermatology, Wuhan No. 1 Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Joshua W McCausland
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA
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SCCmec-associated psm-mec mRNA promotes Staphylococcus epidermidis biofilm formation. Antonie van Leeuwenhoek 2016; 109:1403-15. [PMID: 27502022 DOI: 10.1007/s10482-016-0741-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/15/2016] [Indexed: 10/21/2022]
Abstract
Biofilm formation is considered the major pathogenic mechanism of Staphylococcus epidermidis-associated nosocomial infections. Reports have shown that SCCmec-associated psm-mec regulated methicillin-resistant Staphylococcus aureus virulence and biofilm formation. However, the role of psm-mec in S. epidermidis remains unclear. To this purpose, we analysed 165 clinical isolates of S. epidermidis to study the distribution, mutation and expression of psm-mec and the relationship between this gene and biofilm formation. Next, we constructed three psm-mec deletion mutants, one psm-mec transgene expression strain (p221) and two psm-mec point mutant strains (pM, pAG) to explore its effects on S. epidermidis biofilm formation. Then, the amount of biofilm formation, extracellular DNA (eDNA) and Triton X-100-induced autolysis of the constructed strains was measured. Results of psm-mec deletion and transgene expression showed that the gene regulated S. epidermidis biofilm formation. Compared with the control strains, the ability to form biofilm, Triton X-100-induced autolysis and the amount of eDNA increased in the p221 strain and the two psm-mec mutants pM and pAG expressed psm-mec mRNA without its protein, whereas no differences were observed among the three constructed strains, illustrating that psm-mec mRNA promoted S. epidermidis biofilm formation through up-regulation of bacterial autolysis and the release of eDNA. Our results reveal that acquisition of psm-mec promotes S. epidermidis biofilm formation.
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Imae K, Saito Y, Kizaki H, Ryuno H, Mao H, Miyashita A, Suzuki Y, Sekimizu K, Kaito C. Novel Nucleoside Diphosphatase Contributes to Staphylococcus aureus Virulence. J Biol Chem 2016; 291:18608-18619. [PMID: 27422825 DOI: 10.1074/jbc.m116.721845] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 11/06/2022] Open
Abstract
We identified SA1684 as a Staphylococcus aureus virulence gene using a silkworm infection model. The SA1684 gene product carried the DUF402 domain, which is found in RNA-binding proteins, and had amino acid sequence similarity with a nucleoside diphosphatase, Streptomyces coelicolor SC4828 protein. The SA1684-deletion mutant exhibited drastically decreased virulence, in which the LD50 against silkworms was more than 10 times that of the parent strain. The SA1684-deletion mutant also exhibited decreased exotoxin production and colony-spreading ability. Purified SA1684 protein had Mn(2+)- or Co(2+)-dependent hydrolyzing activity against nucleoside diphosphates. Alanine substitutions of Tyr-88, Asp-106, and Asp-123/Glu-124, which are conserved between SA1684 and SC4828, diminished the nucleoside diphosphatase activity. Introduction of the wild-type SA1684 gene restored the hemolysin production of the SA1684-deletion mutant, whereas none of the alanine-substituted SA1684 mutant genes restored the hemolysin production. RNA sequence analysis revealed that SA1684 is required for the expression of the virulence regulatory genes agr, sarZ, and sarX, as well as metabolic genes involved in glycolysis and fermentation pathways. These findings suggest that the novel nucleoside diphosphatase SA1684 links metabolic pathways and virulence gene expression and plays an important role in S. aureus virulence.
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Affiliation(s)
- Kenta Imae
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Yuki Saito
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Hayato Kizaki
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Hiroki Ryuno
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Han Mao
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Atsushi Miyashita
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Yutaka Suzuki
- the Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Kazuhisa Sekimizu
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
| | - Chikara Kaito
- From the Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033 and
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Hong X, Qin J, Li T, Dai Y, Wang Y, Liu Q, He L, Lu H, Gao Q, Lin Y, Li M. Staphylococcal Protein A Promotes Colonization and Immune Evasion of the Epidemic Healthcare-Associated MRSA ST239. Front Microbiol 2016; 7:951. [PMID: 27446000 PMCID: PMC4922140 DOI: 10.3389/fmicb.2016.00951] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/02/2016] [Indexed: 11/19/2022] Open
Abstract
The highly successful epidemic of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) ST239 is a growing concern worldwide, due to its progressive adaptation to the highly selective environment of the healthcare system. HA-MRSA ST239 display the reduced virulence and successfully colonize in hospital settings, while the emergent community-associated MRSA (CA-MRSA) maintain full virulence and cause infections in the community environment. Our aim was to investigate what enables S. aureus ST239 to be highly adaptive under hospital circumstances and gradually progress to a series of widespread invasive infections. We found that spa expression of HA-MRSA ST239 is much higher than that of CA-SA ST398. And we discovered that the highly production of staphylococcal protein A (SpA), having no concern with spa gene structure, enhances nasal colonization and cell adhesion in ST239. S. aureus ST239 defends against the adaptive immune response by resisting phagocytosis and inducing apoptosis of B cells through expression of surface-anchored and released protein A, facilitating its dissemination within the circulatory system to other organs. Protein A also plays another key role in subverting the host immune response through its ability to induce early shedding of TNF-α receptor 1 (TNFR1) from phagocytic cells. The increased levels of soluble TNFR1 present during experimental S. aureus ST239 infection may neutralize circulating TNF-α and impair the host inflammatory response. Protein A is also a virulence factor, as tested in our bacteremia model in mice, contributing to the durative tissue damage of abscess formation sites in ST239 infection. These functions of protein A eventually benefit to widespread infections of S. aureus ST239. We draw the conclusion that Staphylococcal Protein A may be a crucial determinant in the colonization and immune evasion of ST239 infections, contributing to persistent spread in the hospital settings. These results suggest that antibodies against protein A may provide insights into the development of novel treatments against S. aureus, especially HA-MRSA.
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Affiliation(s)
- Xufen Hong
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University Shanghai, China
| | - Juanxiu Qin
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Tianming Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Yingxin Dai
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Yanan Wang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Qian Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Lei He
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Huiying Lu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Qianqian Gao
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Yong Lin
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University Shanghai, China
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
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48
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Modulation of Staphylococcus aureus spreading by water. Sci Rep 2016; 6:25233. [PMID: 27125382 PMCID: PMC4850448 DOI: 10.1038/srep25233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 04/12/2016] [Indexed: 11/08/2022] Open
Abstract
Staphylococcus aureus is known to spread rapidly and form giant colonies on the surface of soft agar and animal tissues by a process called colony spreading. So far, the mechanisms underlying spreading remain poorly understood. This study investigated the spreading phenomenon by culturing S. aureus and its mutant derivatives on Tryptic Soy Agarose (TSA) medium. We found that S. aureus extracts water from the medium and floats on water at 2.5 h after inoculation, which could be observed using phase contrast microscopy. The floating of the bacteria on water could be verified by confocal microscopy using an S. aureus strain that constitutively expresses green fluorescence protein. This study also found that as the density of bacterial colony increases, a quorum sensing response is triggered, resulting in the synthesis of the biosurfactants, phenolic-soluble modulins (PSMs), which weakens water surface tension, causing water to flood the medium surface to allow the bacteria to spread rapidly. This study reveals a mechanism that explains how an organism lacking a flagellar motor is capable of spreading rapidly on a medium surface, which is important to the understanding of how S. aureus spreads in human tissues to cause infections.
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Wilde AD, Snyder DJ, Putnam NE, Valentino MD, Hammer ND, Lonergan ZR, Hinger SA, Aysanoa EE, Blanchard C, Dunman PM, Wasserman GA, Chen J, Shopsin B, Gilmore MS, Skaar EP, Cassat JE. Bacterial Hypoxic Responses Revealed as Critical Determinants of the Host-Pathogen Outcome by TnSeq Analysis of Staphylococcus aureus Invasive Infection. PLoS Pathog 2015; 11:e1005341. [PMID: 26684646 PMCID: PMC4684308 DOI: 10.1371/journal.ppat.1005341] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/23/2015] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus is capable of infecting nearly every organ in the human body. In order to infiltrate and thrive in such diverse host tissues, staphylococci must possess remarkable flexibility in both metabolic and virulence programs. To investigate the genetic requirements for bacterial survival during invasive infection, we performed a transposon sequencing (TnSeq) analysis of S. aureus during experimental osteomyelitis. TnSeq identified 65 genes essential for staphylococcal survival in infected bone and an additional 148 mutants with compromised fitness in vivo. Among the loci essential for in vivo survival was SrrAB, a staphylococcal two-component system previously reported to coordinate hypoxic and nitrosative stress responses in vitro. Healthy bone is intrinsically hypoxic, and intravital oxygen monitoring revealed further decreases in skeletal oxygen concentrations upon S. aureus infection. The fitness of an srrAB mutant during osteomyelitis was significantly increased by depletion of neutrophils, suggesting that neutrophils impose hypoxic and/or nitrosative stresses on invading bacteria. To more globally evaluate staphylococcal responses to changing oxygenation, we examined quorum sensing and virulence factor production in staphylococci grown under aerobic or hypoxic conditions. Hypoxic growth resulted in a profound increase in quorum sensing-dependent toxin production, and a concomitant increase in cytotoxicity toward mammalian cells. Moreover, aerobic growth limited quorum sensing and cytotoxicity in an SrrAB-dependent manner, suggesting a mechanism by which S. aureus modulates quorum sensing and toxin production in response to environmental oxygenation. Collectively, our results demonstrate that bacterial hypoxic responses are key determinants of the staphylococcal-host interaction.
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Affiliation(s)
- Aimee D. Wilde
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Daniel J. Snyder
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Nicole E. Putnam
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Michael D. Valentino
- Departments of Ophthalmology and Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Neal D. Hammer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Zachery R. Lonergan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Scott A. Hinger
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Esar E. Aysanoa
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Catlyn Blanchard
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Paul M. Dunman
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Gregory A. Wasserman
- Departments of Medicine and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - John Chen
- Skirball Institute Program in Molecular Pathogenesis, Departments of Microbiology and Medicine, New York University Medical Center, New York, New York, United States of America
| | - Bo Shopsin
- Departments of Medicine and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Michael S. Gilmore
- Departments of Ophthalmology and Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Veterans Affairs Tennessee Valley Healthcare Services, Nashville, Tennessee, United States of America
| | - James E. Cassat
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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50
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Yeh CF, Liu TP, Cheng CW, Chang SC, Lee MH, Lu JJ. Molecular Characteristics of Disease-Causing and Commensal Staphylococcus lugdunensis Isolates from 2003 to 2013 at a Tertiary Hospital in Taiwan. PLoS One 2015; 10:e0134859. [PMID: 26248332 PMCID: PMC4527845 DOI: 10.1371/journal.pone.0134859] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/14/2015] [Indexed: 01/09/2023] Open
Abstract
Objectives Staphylococcus lugdunensis can cause community- and healthcare-associated infections. This study investigated the molecular characteristics of S. lugdunensis isolates collected at our hospital and compared the characteristics of the infectious and commensal isolates. Methods We collected the S. lugdunensis isolates between 2003 and 2013. The antimicrobial resistance test, SCCmec typing, accessory gene regulator (agr) typing, pulsed-field gel electrophoresis (PFGE), and δ-like hemolysin activity were performed. Results In total, 118 S. lugdunensis isolates were collected, of which 67 (56.8%) were classified into the infection group and 51 (43.2%) into the commensal group. The oxacillin resistance rate was 36.4%. The most common SCCmec types were SCCmec types V (51.4%) and II (32.6%). In total, 34 pulsotypes were identified. The PFGE typing revealed five clones (pulsotypes A, J, M, N, and P) at our hospital. Pulsotypes A and N caused the spread of high oxacillin resistance. In total, 10.2% (12 of 118) of the isolates lacked δ-like hemolysin activity. Compared with the infection group, the commensal group showed a higher percentage of multiple drug resistance and carried a higher percentage of SCCmec type II (11 of 22, 50% and 3 of 21, 14.3%) and a lower percentage of SCCmec type V (8 of 22, 36.4% and 14 of 21, 66.7%). The commensal group (27 PFGE types) showed higher genetic diversity than did the infection group (20 PFGE types). No difference was observed in the distribution of the five main pulsotypes, agr typing, and the presence of δ-like hemolysin activity between the two groups. Conclusions Five main clones were identified at our hospital. The commensal group showed higher genetic diversity, had a higher percentage of multidrug resistance, and carried a higher percentage of SCCmec type II and a lower percentage of SCCmec type V than did the infection group.
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Affiliation(s)
- Chun-Fu Yeh
- Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tsui-Ping Liu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chun-Wen Cheng
- Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Shih-Cheng Chang
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ming-Hsun Lee
- Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- * E-mail:
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