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Gu J, Xiong M, Zhang J, Li Y. Prevalence and characterization of community-associated Staphylococcus aureus isolates from human mastitis in Beijing, China. Int J Med Microbiol 2024; 315:151623. [PMID: 38781847 DOI: 10.1016/j.ijmm.2024.151623] [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: 01/09/2024] [Revised: 04/14/2024] [Accepted: 05/20/2024] [Indexed: 05/25/2024] Open
Abstract
OBJECTIVES Staphylococcus aureus (S. aureus) spreads worldwide and occurrence of mastitis caused by it holds significant implications for public health. We aim to reveal the molecular typing, antibiotic resistance and virulence gene profile of S. aureus causing mastitis through investigation. METHODS A total of 200 isolates of S. aureus were collected from outpatients infected with mastitis in a hospital in Beijing from 2020.7 to 2021.7. The molecular characteristics were analyzed by MLST and spa typing, virulence genes were screened by PCR, antibiotic susceptible test was performed by VITEK® 2 Compact system and phylogenetic analysis was performed by MEGA11 and iTOL. RESULTS Nineteen sequence types (STs) belonging to 9 clone complexes (CCs) were identified. ST22 was the most dominant clone (77.0%, 154/200). MRSA accounted for 19.0% (38/200) and 89.5% (34/38) of MRSA isolates belonged to CC22 and CC59. The isolates had relatively low levels of antibiotic resistance, with the exception of β-lactams and macrolides with resistance rates above 50.0%. The carrying rate of pvl in the ST22-MRSA strains were 84.2% and the detection rates of seb and pvl in the MRSA isolates were significantly higher than those in the MSSA isolates, while the hlg, fnbA and sdrD showed opposite results. Whole genome sequenced specimens of MRSA strains X4 and B5 show the same evolutionary origin as ST22 EMRSA-15 (HE681097), which is popular in Europe. CONCLUSIONS The method based on molecular epidemiology is an important tool for tracking the spread of S. aureus infections. We need to be alert to the major MRSA clones CC22 and CC59 in the region and be vigilant to the possible pandemic and spread of ST22 EMRSA-15.
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Affiliation(s)
- Jihong Gu
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Mengyuan Xiong
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jing Zhang
- Department of Laboratory Medicine, Beijing Haidian Maternal and Child Health Hospital, Beijing, China.
| | - Yirong Li
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.
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2
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Balogh H, Anthony A, Stempel R, Vossen L, Federico VA, Valenzano GZ, Blackledge MS, Miller HB. Novel Anti-virulence Compounds Disrupt Exotoxin Expression in MRSA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594412. [PMID: 38798408 PMCID: PMC11118326 DOI: 10.1101/2024.05.15.594412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Hemolysins are lytic exotoxins expressed in most strains of S. aureus , but hemolytic activity varies between strains. We have previously reported several novel anti-virulence compounds that disrupt the S. aureus transcriptome, including hemolysin gene expression. This report delves further into our two lead compounds, loratadine and a structurally related brominated carbazole, and their effects on hemolysin production in MRSA. To gain understanding into how these compounds affect hemolysis, we analyzed these exotoxins at the DNA, RNA, and protein level after in vitro treatment. While lysis of red blood cells varied between strains, DNA sequence variation did not account for it. We hypothesized that our compounds would modulate gene expression of multiple hemolysins in a laboratory strain and a clinically relevant hospital-acquired strain of MRSA, both with SCC mec type II. RNA-seq analysis of differential gene expression in untreated and compound-treated cultures revealed hundreds of differentially expressed genes, with a significant enrichment in genes involved in hemolysis. The brominated carbazole and loratadine both displayed the ability to reduce hemolysis in the laboratory strain, but displayed differential activity in a hospital-acquired strain. These results corroborate gene expression studies as well as western blots of alpha hemolysin. Together, this work suggests that small molecules may alter exotoxin production in MRSA, but that the directionality and/or magnitude of the difference is likely strain-dependent.
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Nagarajan A, Scoggin K, Gupta J, Aminian M, Adams LG, Kirby M, Threadgill D, Andrews-Polymenis H. Collaborative Cross mice have diverse phenotypic responses to infection with Methicillin-resistant Staphylococcus aureus USA300. PLoS Genet 2024; 20:e1011229. [PMID: 38696518 PMCID: PMC11108197 DOI: 10.1371/journal.pgen.1011229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 05/21/2024] [Accepted: 03/18/2024] [Indexed: 05/04/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is an opportunistic pathogen causing diseases ranging from mild skin infections to life threatening conditions, including endocarditis, pneumonia, and sepsis. To identify host genes modulating this host-pathogen interaction, we infected 25 Collaborative Cross (CC) mouse strains with methicillin-resistant S. aureus (MRSA) and monitored disease progression for seven days using a surgically implanted telemetry system. CC strains varied widely in their response to intravenous MRSA infection. We identified eight 'susceptible' CC strains with high bacterial load, tissue damage, and reduced survival. Among the surviving strains, six with minimal colonization were classified as 'resistant', while the remaining six tolerated higher organ colonization ('tolerant'). The kidney was the most heavily colonized organ, but liver, spleen and lung colonization were better correlated with reduced survival. Resistant strains had higher pre-infection circulating neutrophils and lower post-infection tissue damage compared to susceptible and tolerant strains. We identified four CC strains with sexual dimorphism: all females survived the study period while all males met our euthanasia criteria earlier. In these CC strains, males had more baseline circulating monocytes and red blood cells. We identified several CC strains that may be useful as new models for endocarditis, myocarditis, pneumonia, and resistance to MRSA infection. Quantitative Trait Locus (QTL) analysis identified two significant loci, on Chromosomes 18 and 3, involved in early susceptibility and late survival after infection. We prioritized Npc1 and Ifi44l genes as the strongest candidates influencing survival using variant analysis and mRNA expression data from kidneys within these intervals.
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Affiliation(s)
- Aravindh Nagarajan
- Interdisciplinary Program in Genetics and Genomics, Texas A&M University, College Station, Texas, United States of America
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, Texas, United States of America
| | - Kristin Scoggin
- Interdisciplinary Program in Genetics and Genomics, Texas A&M University, College Station, Texas, United States of America
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Jyotsana Gupta
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, Texas, United States of America
| | - Manuchehr Aminian
- Department of Mathematics, Colorado State University, Fort Collins, Colorado, United States of America
- Department of Mathematics and Statistics, California State Polytechnic University, Pomona, California, United States of America
| | - L. Garry Adams
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Michael Kirby
- Department of Mathematics, Colorado State University, Fort Collins, Colorado, United States of America
| | - David Threadgill
- Interdisciplinary Program in Genetics and Genomics, Texas A&M University, College Station, Texas, United States of America
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas, United States of America
- Texas A&M Institute for Genome Sciences and Society, Texas A&M University, College Station, Texas, United States of America
- Department of Biochemistry & Biophysics and Department of Nutrition, Texas A&M University, College Station, Texas, United States of America
| | - Helene Andrews-Polymenis
- Interdisciplinary Program in Genetics and Genomics, Texas A&M University, College Station, Texas, United States of America
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, Texas, United States of America
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4
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Ulrich RJ, Podkowik M, Tierce R, Irnov I, Putzel G, Samhadaneh N, Lacey KA, Boff D, Morales SM, Makita S, Karagounis TK, Zwack EE, Zhou C, Kim R, Drlica K, Pironti A, van Bakel H, Torres VJ, Shopsin B. Prophage-encoded methyltransferase drives adaptation of community-acquired methicillin-resistant Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.17.589803. [PMID: 38659881 PMCID: PMC11042277 DOI: 10.1101/2024.04.17.589803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
We recently described the evolution of a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 variant responsible for an outbreak of skin and soft tissue infections. Acquisition of a mosaic version of the Φ11 prophage (mΦ11) that increases skin abscess size was an early step in CA-MRSA adaptation that primed the successful spread of the clone. The present report shows how prophage mΦ11 exerts its effect on virulence for skin infection without encoding a known toxin or fitness genes. Abscess size and skin inflammation were associated with DNA methylase activity of an mΦ11-encoded adenine methyltransferase (designated pamA). pamA increased expression of fibronectin-binding protein A (fnbA; FnBPA), and inactivation of fnbA eliminated the effect of pamA on abscess virulence without affecting strains lacking pamA. Thus, fnbA is a pamA-specific virulence factor. Mechanistically, pamA was shown to promote biofilm formation in vivo in skin abscesses, a phenotype linked to FnBPA's role in biofilm formation. Collectively, these data reveal a novel mechanism-epigenetic regulation of staphylococcal gene expression-by which phage can regulate virulence to drive adaptive leaps by S. aureus.
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Affiliation(s)
- Robert J. Ulrich
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Magdalena Podkowik
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
| | - Rebecca Tierce
- Division of Comparative Medicine, NYU Langone Health, New York, NY, USA
| | - Irnov Irnov
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Gregory Putzel
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Nora Samhadaneh
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Keenan A. Lacey
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Daiane Boff
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Sabrina M. Morales
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Sohei Makita
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, USA
| | - Theodora K. Karagounis
- Ronald O. Perelman Department of Dermatology, NYU Grossman School of Medicine, New York, NY, USA
| | - Erin E. Zwack
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Chunyi Zhou
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Randie Kim
- Ronald O. Perelman Department of Dermatology, NYU Grossman School of Medicine, New York, NY, USA
| | - Karl Drlica
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, USA
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, USA
| | - Alejandro Pironti
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Genomics Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Victor J. Torres
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
- Department of Host-Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Bo Shopsin
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
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5
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Yamazaki Y, Ito T, Tamai M, Nakagawa S, Nakamura Y. The role of Staphylococcus aureus quorum sensing in cutaneous and systemic infections. Inflamm Regen 2024; 44:9. [PMID: 38429810 PMCID: PMC10905890 DOI: 10.1186/s41232-024-00323-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND Staphylococcus aureus is a leading cause of human bacterial infections worldwide. It is the most common causative agent of skin and soft tissue infections, and can also cause various other infections, including pneumonia, osteomyelitis, as well as life-threatening infections, such as sepsis and infective endocarditis. The pathogen can also asymptomatically colonize human skin, nasal cavity, and the intestine. S. aureus colonizes approximately 20-30% of human nostrils, being an opportunistic pathogen for subsequent infection. Its strong ability to silently spread via human contact makes it difficult to eradicate S. aureus. A major concern with S. aureus is its capacity to develop antibiotic resistance and adapt to diverse environmental conditions. The variability in the accessory gene regulator (Agr) region of the genome contributes to a spectrum of phenotypes within the bacterial population, enhancing the likelihood of survival in different environments. Agr functions as a central quorum sensing (QS) system in S. aureus, allowing bacteria to adjust gene expression in response to population density. Depending on Agr expression, S. aureus secretes various toxins, contributing to virulence in infectious diseases. Paradoxically, expressing Agr may be disadvantageous in certain situations, such as in hospitals, causing S. aureus to generate Agr mutants responsible for infections in healthcare settings. MAIN BODY This review aims to demonstrate the molecular mechanisms governing the diverse phenotypes of S. aureus, ranging from a harmless colonizer to an organism capable of infecting various human organs. Emphasis will be placed on QS and its role in orchestrating S. aureus behavior across different contexts. SHORT CONCLUSION The pathophysiology of S. aureus infection is substantially influenced by phenotypic changes resulting from factors beyond Agr. Future studies are expected to give the comprehensive understanding of S. aureus overall profile in various settings.
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Affiliation(s)
- Yuriko Yamazaki
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Tomoka Ito
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Masakazu Tamai
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Seitaro Nakagawa
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Yuumi Nakamura
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan.
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan.
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6
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Konaklieva MI, Plotkin BJ. Targeting host-specific metabolic pathways-opportunities and challenges for anti-infective therapy. Front Mol Biosci 2024; 11:1338567. [PMID: 38455763 PMCID: PMC10918472 DOI: 10.3389/fmolb.2024.1338567] [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: 11/14/2023] [Accepted: 01/24/2024] [Indexed: 03/09/2024] Open
Abstract
Microorganisms can takeover critical metabolic pathways in host cells to fuel their replication. This interaction provides an opportunity to target host metabolic pathways, in addition to the pathogen-specific ones, in the development of antimicrobials. Host-directed therapy (HDT) is an emerging strategy of anti-infective therapy, which targets host cell metabolism utilized by facultative and obligate intracellular pathogens for entry, replication, egress or persistence of infected host cells. This review provides an overview of the host lipid metabolism and links it to the challenges in the development of HDTs for viral and bacterial infections, where pathogens are using important for the host lipid enzymes, or producing their own analogous of lecithin-cholesterol acyltransferase (LCAT) and lipoprotein lipase (LPL) thus interfering with the human host's lipid metabolism.
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Affiliation(s)
| | - Balbina J. Plotkin
- Department of Microbiology and Immunology, Midwestern University, Downers Grove, IL, United States
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7
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Herrera AL, Chaussee MS, Pietri JE. Experimental Acquisition, Maintenance, and Transmission of Methicillin-Resistant Staphylococcus aureus by the Common Bed Bug, Cimex lectularius. J Infect Dis 2024; 229:245-251. [PMID: 37523766 DOI: 10.1093/infdis/jiad302] [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: 06/09/2023] [Revised: 07/18/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
Here, we fed bed bugs through a membrane contaminated with methicillin-resistant Staphylococcus aureus (MRSA) at a concentration naturally present on human skin. We then determined the amount of viable MRSA present on their surface and internally over a period of 7 days. We also determined whether bed bugs that fed through the contaminated membrane could transmit MRSA to an uncontaminated membrane when taking a second blood meal 7 days later. Bed bugs acquired MRSA both externally on the cuticle surface as well as internally when feeding. MRSA was found to persist for 7 days both externally and internally in some bed bugs. Furthermore, MRSA replicated internally but not externally. Most importantly, bed bugs were able to transmit MRSA to an uncontaminated membrane feeder in 2 of 3 trials. These findings provide the first experimental support for the hypothesis that bed bugs may contribute to the transmission of MRSA in some settings.
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Affiliation(s)
- Andrea L Herrera
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
| | - Michael S Chaussee
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
| | - Jose E Pietri
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
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8
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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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9
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Jackson JK, Kennedy SJ, Felton EA, Cella E, Lima A, Becker D, Silbert S, Kim K, Azarian T, Shaw LN. Draft genome sequence of a highly proteolytic Staphylococcus aureus USA300 isolate from human urine. Microbiol Resour Announc 2023; 12:e0067923. [PMID: 37933968 PMCID: PMC10720404 DOI: 10.1128/mra.00679-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
The secreted proteases of Staphylococcus aureus have been shown to be critical during infection. Here, we present the draft genome sequence of S. aureus TGH337, a hyper-proteolytic USA300 strain isolated from human urine.
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Affiliation(s)
- Jessica K. Jackson
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Sarah J. Kennedy
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Emily A. Felton
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Eleonora Cella
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, USA
| | - Amorce Lima
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Deanna Becker
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Suzane Silbert
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Kami Kim
- Division of Infectious Disease and Internal Medicine, University of South Florida, Tampa, Florida, USA
- Center for Global Health Infectious Diseases Research, University of South Florida, Tampa, Florida, USA
- Global Emerging Diseases Institute, Tampa General Hospital, Tampa, Florida, USA
| | - Taj Azarian
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, USA
| | - Lindsey N. Shaw
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
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10
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Wang X, Uppu DSSM, Dickey SW, Burgin DJ, Otto M, Lee JC. Staphylococcus aureus delta toxin modulates both extracellular membrane vesicle biogenesis and amyloid formation. mBio 2023; 14:e0174823. [PMID: 37795985 PMCID: PMC10653798 DOI: 10.1128/mbio.01748-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/15/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Extracellular membrane vesicles (MVs) produced by Staphylococcus aureus in planktonic cultures encapsulate a diverse cargo of bacterial proteins, nucleic acids, and glycopolymers that are protected from destruction by external factors. δ-toxin, a member of the phenol soluble modulin family, was shown to be critical for MV biogenesis. Amyloid fibrils co-purified with MVs generated by virulent, community-acquired S. aureus strains, and fibril formation was dependent on expression of the S. aureus δ-toxin gene (hld). Mass spectrometry data confirmed that the amyloid fibrils were comprised of δ-toxin. Although S. aureus MVs were produced in vivo in a localized murine infection model, amyloid fibrils were not observed in the in vivo setting. Our findings provide critical insights into staphylococcal factors involved in MV biogenesis and amyloid formation.
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Affiliation(s)
- Xiaogang Wang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Divakara SSM Uppu
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Seth W. Dickey
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine,University of Maryland, Bethesda, Maryland, USA
| | - Dylan J. Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Jean C. Lee
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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11
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Chen Y, Yang J, Wang Y, You J, Zhu W, Liu C, Luan Y, Li L, Li H. Community-associated methicillin-resistant Staphylococcus aureus infection of diabetic foot ulcers in an eastern diabetic foot center in a tertiary hospital in China: a retrospective study. BMC Infect Dis 2023; 23:652. [PMID: 37789270 PMCID: PMC10548623 DOI: 10.1186/s12879-023-08631-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/20/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Diabetic foot concerns are a major public health problem. Methicillin-resistant Staphylococcus aureus (MRSA) plays a significant role in diabetic foot ulcers. Community-associated MRSA has become notorious for skin and skin soft tissue infections over the last two decades. This study investigated MRSA infection in diabetic foot patients at a tertiary hospital, focusing on the epidemiology and characteristics of community-associated MRSA. METHODS A total of 149 patients with diabetic foot infection whose culture results indicated Staphylococcus aureus as the source were selected. Epidemiological investigations, clinical characteristics, laboratory index records, antibiotic susceptibility analysis, and clinical outcome tracking were performed in all cases. Based on oxacillin resistance using the Vitek Compact 2 system, cases were divided into methicillin-sensitive Staphylococcus aureus and MRSA groups. Subgroup analysis of the MRSA group was performed in accordance with the Centers for Disease Control definition: community-associated MRSA and hospital-associated MRSA. RESULTS The MRSA group (n = 41, 27.5%) had a longer duration of ulcers and hospital stay and higher hospitalization costs than the methicillin-sensitive Staphylococcus aureus group (n = 108, 72.5%). According to the classification criteria of Infectious Diseases Society of America, the severity of infection in the community-associated MRSA group was higher than that in the hospital-associated MRSA group. The analysis of antimicrobial susceptibility of 41 MRSA isolates showed that the resistance rates to erythromycin, clindamycin, quinolone, gentamicin, tetracycline, and rifampicin were 78.0%, 68.3%, 31.7%, 17.1%, 9.8%, and 2.4%, respectively. All the MRSA strains were sensitive to linezolid, tigecycline, and vancomycin. The resistance rates to quinolones and gentamycin in the community-associated MRSA group (both 0%) were lower than those in the hospital-associated MRSA group. CONCLUSION Emergence of MRSA in diabetic foot ulcer was associated with a prolonged wound duration and increased consumption of medical resources. Community-associated MRSA strains predominated among MRSA isolates from diabetic foot wounds and caused more severe infections.
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Affiliation(s)
- Yixin Chen
- Department of Endocrinology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Jie Yang
- Department of Orthopedics, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Ying Wang
- Wound and Ostomy Care Clinic, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Jiaxing You
- Department of Orthopedics, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Weifen Zhu
- Department of Endocrinology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Chao Liu
- Department of Orthopedics, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Yi Luan
- Department of Cardiology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Lin Li
- Department of Endocrinology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
| | - Hong Li
- Department of Endocrinology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, 3 East Qing Chun Road, Hangzhou, 310016 China
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Alsolami A, ALGhasab NS, Alharbi MSM, Bashir AI, Saleem M, Syed Khaja AS, Aldakheel DF, Rakha E, Alshammari JA, Taha TE, Melibari Z, Alharbi YH, Almutlag AA, Said KB. Community-Acquired Methicillin-Resistant Staphylococcus aureus in Hospitals: Age-Specificity and Potential Zoonotic-Zooanthroponotic Transmission Dynamics. Diagnostics (Basel) 2023; 13:2089. [PMID: 37370983 DOI: 10.3390/diagnostics13122089] [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: 05/08/2023] [Revised: 05/29/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) lineages are a devastating clinical and public health issue. Data on local lineage profiles are limited. We report on the frequency of community-acquired and hospital-acquired cases (CA-MRSA, HA-MRSA). We studied 147 isolates from King Khalid tertiary care hospitals (KKH), each from a case in a patient and including 33 patients at the Maternity and Children's Hospital (MCH). Of the 147 isolates, 87 males (59%) and 60 females (41%) were in KKH. The overwhelming majority (80%; n = 119/147) were CA-MRSA in KKH. Intriguingly, despite significant differences between males (70%) and females (53%), lineage-acquisition remained age-specific around 58-60 years in both genders. However, while CA-MRSA dominated early in life (0-20, 70% MCH), it increased with age in KKH adults; 21-50 (28%), >50 (59%) until the overall 80% (n = 144/180). Major specimens included skin-wounds, surgeries (70.3%), blood (13.5%), sputum (8.8%), very rarely urine (4.1%), and nasal (3.4%), albeit most patients showed severe enteritis and necrotizing pneumonia. Antibiograms showed high beta lactam resistances, including amoxicillin-clavulanate (83%), oxacillin (84%), cefoxitin FOX (100%), penicillin and ampicillin (~100%), as well as high resistance (82%) to carbapenem. Fortunately, high susceptibility was seen to non-beta lactams and, to a lesser extent, gentamicin, erythromycin, and fusidic acid; 33%, 34%, and 38%, respectively, in KKH. A similar pattern was seen in MCH except for a low resistance pattern to gentamicin CN, clindamycin CD, erythromycin E, and tobramycin TOB; 34%, 31%, 39%, and 41%, respectively, except for fusidic acid. These findings have significant clinical implications for MRSA patient management strategies. Clinical- and lineage-profiles imply host-selection and zoonotic-zooanthroponotic transmission dynamics. Future molecular typing, sequencing, and characterization of dominant clone(s) is imperative.
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Affiliation(s)
- Ahmed Alsolami
- Department of Internal Medicine, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Naif Saad ALGhasab
- Department of Cardiology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Mohammed S M Alharbi
- Department of Internal Medicine, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Abdelhafiz I Bashir
- Department of Physiology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Mohd Saleem
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | | | - Dakheel F Aldakheel
- Medical Coordination Unit, Ha'il General Hospital, Ha'il 55428, Saudi Arabia
| | - Ehab Rakha
- Departments of Microbiology, King Khalid Hospital, Ha'il 55421, Saudi Arabia
- Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Jabar Aziz Alshammari
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Taha E Taha
- Department of Epidemiology, John Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Ziyad Melibari
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Yaseer H Alharbi
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Ali A Almutlag
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
| | - Kamaleldin B Said
- Department of Pathology, College of Medicine, University of Ha'il, Ha'il 55476, Saudi Arabia
- Genomics, Bioinformatics and Systems Biology, Carleton University, 1125 Colonel-By Drive, Ottawa, ON K1S 5B6, Canada
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13
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Dubyak GR, Miller BA, Pearlman E. Pyroptosis in neutrophils: Multimodal integration of inflammasome and regulated cell death signaling pathways. Immunol Rev 2023; 314:229-249. [PMID: 36656082 PMCID: PMC10407921 DOI: 10.1111/imr.13186] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Pyroptosis is a proinflammatory mode of lytic cell death mediated by accumulation of plasma membrane (PM) macropores composed of gasdermin-family (GSDM) proteins. It facilitates two major functions in innate immunity: (i) elimination of intracellular replicative niches for pathogenic bacteria; and (ii) non-classical secretion of IL-1 family cytokines that amplify host-beneficial inflammatory responses to microbial infection or tissue damage. Physiological roles for gasdermin D (GSDMD) in pyroptosis and IL-1β release during inflammasome signaling have been extensively characterized in macrophages. This involves cleavage of GSDMD by caspase-1 to generate GSDMD macropores that mediate IL-1β efflux and progression to pyroptotic lysis. Neutrophils, which rapidly accumulate in large numbers at sites of tissue infection or damage, become the predominant local source of IL-1β in coordination with their potent microbiocidal capacity. Similar to macrophages, neutrophils express GSDMD and utilize the same spectrum of diverse inflammasome platforms for caspase-1-mediated cleavage of GSDMD. Distinct from macrophages, neutrophils possess a remarkable capacity to resist progression to GSDMD-dependent pyroptotic lysis to preserve their viability for efficient microbial killing while maintaining GSDMD-dependent mechanisms for export of bioactive IL-1β. Rather, neutrophils employ cell-specific mechanisms to conditionally engage GSDMD-mediated pyroptosis in response to bacterial pathogens that use neutrophils as replicative niches. GSDMD and pyroptosis have also been mechanistically linked to induction of NETosis, a signature neutrophil pathway that expels decondensed nuclear DNA into extracellular compartments for immobilization and killing of microbial pathogens. This review summarizes a rapidly growing number of recent studies that have produced new insights, unexpected mechanistic nuances, and some controversies regarding the regulation of, and roles for, neutrophil inflammasomes, pyroptosis, and GSDMs in diverse innate immune responses.
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Affiliation(s)
- George R. Dubyak
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Brandon A. Miller
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Eric Pearlman
- Department of Ophthalmology, University of California, Irvine, California, USA
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
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14
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Lyon LM, Doran KS, Horswill AR. Staphylococcus aureus Fibronectin-Binding Proteins Contribute to Colonization of the Female Reproductive Tract. Infect Immun 2023; 91:e0046022. [PMID: 36511703 PMCID: PMC9872658 DOI: 10.1128/iai.00460-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic pathogen and frequent colonizer of human skin and mucosal membranes, including the vagina, with vaginal colonization reaching nearly 25% in some pregnant populations. MRSA vaginal colonization can lead to aerobic vaginitis (AV), and during pregnancy, bacterial ascension into the upper reproductive tract can lead to adverse birth outcomes. USA300, the most prominent MRSA lineage to colonize pregnant individuals, is a robust biofilm former and causative agent of invasive infections; however, little is known about how it colonizes and ascends in the female reproductive tract (FRT). Our previous studies showed that a MRSA mutant of seven fibrinogen-binding adhesins was deficient in FRT epithelial attachment and colonization. Using both monolayer and multilayer air-liquid interface cell culture models, we determine that one class of these adhesins, the fibronectin binding proteins (FnBPA and FnBPB), are critical for association with human vaginal epithelial cells (hVECs) and hVEC invasion through interactions with α5β1 integrin. We observe that both FnBPs are important for biofilm formation as single and double fnbAB mutants exhibit reduced biofilm formation on hVECs. Using heterologous expression of fnbA and fnbB in Staphylococcus carnosus, FnBPs are also found to be sufficient for hVEC cellular association, invasion, and biofilm formation. In addition, we found that an ΔfnbAB mutant displays attenuated ascension in our murine vaginal colonization model. Better understanding of MRSA FRT colonization and ascension can ultimately inform treatment strategies to limit MRSA vaginal burden or prevent ascension, especially during pregnancy and in those prone to AV.
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Affiliation(s)
- Laurie M. Lyon
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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Cao J, Zhang H, He Z, Piao Z, Zong X, Sun B. Genotypic and Phenotypic Characterization of Some psms Hypervirulent Clinical Isolates of Staphylococcus aureus in a Tertiary Hospital in Hefei, Anhui. Infect Drug Resist 2023; 16:1471-1484. [PMID: 36949844 PMCID: PMC10025015 DOI: 10.2147/idr.s399688] [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: 11/30/2022] [Accepted: 02/17/2023] [Indexed: 03/15/2023] Open
Abstract
Background Staphylococcus aureus is a highly successful pathogen that can cause various infectious diseases, from relatively mild skin infections to life-threatening severe systemic diseases. The widespread pathogenicity of S. aureus is mainly due to its ability to produce many virulence factors that help destroy various host cells, causing disease. Our primary goal in this study was to explore the genes of highly virulent strains, to identify genes closely associated with high virulence, and to provide ideas for the treatment of infection by highly virulent clinical strains. Results This study collected 221 clinical strains from The First Affiliated Hospital Of The University of Science and Technology of China (USTC); their hemolytic abilities were tested. Eight isolates were selected based on their highly hemolytic ability and tested their hemolytic activity again; their phenotypes and gene sequences were also explored. Whole-genome sequencing (WGS) showed six plasmids (pN315, pNE131, pSJH901, pSJH101, SAP106B, and MSSA476), eight antibiotic resistance genes [blaR1, blaI, blaZ, mecA, erm(C), erm(T), tet(38), and fosB-Saur] and seventy-two virulence related genes. Three highly virulent strains, namely X21111206, 21092239, and 21112607, were found according the Galleria mellonella infection model. Therefore, we selected 10 representative virulence genes for qRT-PCR: psmα, psmβ, hlgA, hlgB, hlgC, hla, clfA, clfB, spa, and sak. Among them, the expression levels of psmα and psmβ, the three isolates, were significantly higher than the positive control NCTC8325. Conclusion Significant differences appear in the expression of virulence genes in the highly virulent strains, particularly the psmα and psmβ, It may be that the high expression of psm gene is the cause of the high virulence of Staphylococcus aureus. We can reduce the pathogenicity of Staphylococcus aureus by inhibiting the expression of psm gene, which may provide a strong basis for psm as a new target for clinical treatment of S. aureus infection.
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Affiliation(s)
- Jiaxin Cao
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Huimin Zhang
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Zhien He
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Zhongwan Piao
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- Correspondence: Baolin Sun; Zhongwan Piao, Email ;
| | - Xianchun Zong
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
| | - Baolin Sun
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
- Correspondence: Baolin Sun; Zhongwan Piao, Email ;
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16
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Sabat AJ, Wouthuyzen-Bakker M, Rondags A, Hughes L, Akkerboom V, Koutsopetra O, Friedrich AW, Bathoorn E. Case Report: Necrotizing fasciitis caused by Staphylococcus aureus positive for a new sequence variant of exfoliative toxin E. Front Genet 2022; 13:964358. [PMID: 36186447 PMCID: PMC9520408 DOI: 10.3389/fgene.2022.964358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/12/2022] [Indexed: 11/29/2022] Open
Abstract
Objectives: Necrotizing fasciitis (NF) caused by S. aureus is a rare, aggressive and rapidly progressing superficial fascia infection with a high mortality rate. The aim of this study was to identify virulence-related genes from a complete genome sequence of a methicillin-susceptible S. aureus (MSSA) isolate recovered from a monomicrobial case of NF. Materials and methods: The MSSA isolate UMCG579 was cultured from a pus collection from the subcutis of a patient with NF. The genome of isolate UMCG579 was sequenced using MinION (Oxford Nanopore) and MiSeq (illumina) platforms. Results: The genome of the UMCG579 isolate was composed of a 2,741,379 bp chromosome and did not harbor any plasmids. Virulence factor profiling identified multiple pore-forming toxin genes in the UMCG579 chromosome, including the Panton-Valentine leukocidin (PVL) genes, and none of the superantigen genes. The UMCG579 isolate harbored a new sequence variant of the recently described ete gene encoding exfoliative toxin (type E). A search in the GenBank database revealed that the new sequence variant (ete2) was exclusively found among isolates (n = 115) belonging to MLST CC152. While the majority of S. aureus ete-positive isolates were recovered from animal sources, S. aureus ete2-positive isolates originated from human carriers and human infections. Comparative genome analysis revealed that the ete2 gene was located on a 8777 bp genomic island. Conclusion: The combination of two heterogeneously distributed potent toxins, ETE2 and PVL, is likely to enhance the pathogenic ability of S. aureus isolates. Since anti-virulence therapies for the treatment of S. aureus infections continue to be explored, the understanding of specific pathogenetic mechanisms may have an important prophylactic and therapeutic value. Nevertheless, the exact contribution of ETE sequence variants to S. aureus virulence in NF infections must be determined.
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Affiliation(s)
- Artur J. Sabat
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- *Correspondence: Artur J. Sabat,
| | - Marjan Wouthuyzen-Bakker
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Angelique Rondags
- Department of Dermatology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Laura Hughes
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Viktoria Akkerboom
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Olga Koutsopetra
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alexander W. Friedrich
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Erik Bathoorn
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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Anti-Restriction Gene Homologs Are Highly Represented in Methicillin-Resistant and Multidrug-Resistant Staphylococcus aureus ST239 and ST398: Implications for Resistance Gene Acquisitions. Antibiotics (Basel) 2022; 11:antibiotics11091217. [PMID: 36139996 PMCID: PMC9495042 DOI: 10.3390/antibiotics11091217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/01/2022] [Accepted: 09/04/2022] [Indexed: 11/17/2022] Open
Abstract
Multidrug resistance is commonly acquired by transferring DNA from one bacterium to another. However, the mechanisms that enhance the acquisitions of foreign genes are poorly understood, as well as the dynamics of their transmission between hosts in different environments. Here, genomic approaches were applied to evaluate the enrichment of the S. aureus chromosome with resistance traits in groups of genomes with or without anti-restriction genes and to analyze some evolutionary aspects of these acquisitions. Furthermore, the role played by an anti-restriction gene in improving multiresistance in MRSA was investigated by molecular cloning. A strong association was observed between the presence of anti-restriction gene homologs and patterns of multidrug resistance. Human isolates, mainly ST239-SCCmecIII, carry ardA-H1, and from animal sources, mainly CC398, carry ardA-H2. Increased DNA transfer was observed for clones that express the ardA-H1 allele, corroborating its role in promoting gene transfer. In addition, ardA-H1 was expressed in the dsDNA format in the BMB9393 strain. The evolution of successful multidrug-resistant MRSA lineages of the ST239 and ST398 was initiated not only by the entry of the mec cassette but also by the acquisition of anti-restriction gene homologs. Understanding the mechanisms that affect DNA transfer may provide new tools to control the spread of drug resistance.
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18
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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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Kinney KJ, Stach JM, Kulhankova K, Brown M, Salgado-Pabón W. Vegetation Formation in Staphylococcus Aureus Endocarditis Inversely Correlates With RNAIII and sarA Expression in Invasive Clonal Complex 5 Isolates. Front Cell Infect Microbiol 2022; 12:925914. [PMID: 35860377 PMCID: PMC9289551 DOI: 10.3389/fcimb.2022.925914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/14/2022] [Indexed: 01/29/2023] Open
Abstract
Infective endocarditis (IE) is one of the most feared and lethal diseases caused by Staphylococcus aureus. Once established, the infection is fast-progressing and tissue destructive. S. aureus of the clonal complex 5 (CC5) commonly cause IE yet are severely understudied. IE results from bacterial colonization and formation of tissue biofilms (known as vegetations) on injured or inflamed cardiac endothelium. S. aureus IE is promoted by adhesins, coagulases, and superantigens, with the exotoxins and exoenzymes likely contributing to tissue destruction and dissemination. Expression of the large repertoire of virulence factors required for IE and sequelae is controlled by complex regulatory networks. We investigated the temporal expression of the global regulators agr (RNAIII), rot, sarS, sarA, sigB, and mgrA in 8 invasive CC5 isolates and established intrinsic expression patterns associated with IE outcomes. We show that vegetation formation, as tested in the rabbit model of IE, inversely correlates with RNAIII and sarA expression during growth in Todd-Hewitt broth (TH). Large vegetations with severe sequelae arise from strains with high-level expression of colonization factors but slower transition towards expression of the exotoxins. Overall, strains proficient in vegetation formation, a hallmark of IE, exhibit lower expression of RNAIII and sarA. Simultaneous high expression of RNAIII, sarA, sigB, and mgrA is the one phenotype assessed in this study that fails to promote IE. Thus, RNAIII and sarA expression that provides for rheostat control of colonization and virulence genes, rather than an on and off switch, promote both vegetation formation and lethal sepsis.
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Affiliation(s)
- Kyle J. Kinney
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jessica M. Stach
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Katarina Kulhankova
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Matthew Brown
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Wilmara Salgado-Pabón
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States,Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, United States,*Correspondence: Wilmara Salgado-Pabón,
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20
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Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of hospital-acquired pneumonia. To better manage patients with MRSA pneumonia, we require a greater understanding of the host-pathogen interactions during infection. MRSA research focuses on highly virulent and cytotoxic strains, which demonstrate robust phenotypes in animal models of infection. However, nosocomial infections are often caused by hospital-acquired MRSA (HA-MRSA) isolates that exhibit low cytotoxicity and few or no phenotypes in mice, thereby confounding mechanistic studies of pathogenesis. Consequently, virulence pathways utilized by HA-MRSA in nosocomial pneumonia are largely unknown. Here, we report that conditioning mice with broad-spectrum antibiotics lowers the barrier to pneumonia, thereby transforming otherwise avirulent HA-MRSA isolates into lethal pathogens. HA-MRSA isolates are avirulent in gnotobiotic mice, mimicking results in conventional animals. Thus, the observed enhanced susceptibility to infection in antibiotic-treated mice is not due to depletion of the microbiota. More generally, we found that antibiotic conditioning leads to increased susceptibility to infection by diverse antimicrobial-resistant (AMR) pathogens of low virulence. Treatment with antibiotics leads to dehydration and malnutrition, suggesting a potential role for these clinically relevant and reducible hospital complications in susceptibility to pathogens. In sum, the model described here mitigates the impact of low virulence in immunocompetent mice, providing a convenient model to gain fundamental insight into the pathogenesis of nosocomial pathogens.
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21
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Kailasan S, Kant R, Noonan-Shueh M, Kanipakala T, Liao G, Shulenin S, Leung DW, Alm RA, Adhikari RP, Amarasinghe GK, Gross ML, Aman MJ. Antigenic landscapes on Staphylococcus aureus pore-forming toxins reveal insights into specificity and cross-neutralization. MAbs 2022; 14:2083467. [PMID: 35730685 PMCID: PMC9225675 DOI: 10.1080/19420862.2022.2083467] [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] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus carries an exceptional repertoire of virulence factors that aid in immune evasion. Previous single-target approaches for S. aureus-specific vaccines and monoclonal antibodies (mAbs) have failed in clinical trials due to the multitude of virulence factors released during infection. Emergence of antibiotic-resistant strains demands a multi-target approach involving neutralization of different, non-overlapping pathogenic factors. Of the several pore-forming toxins that contribute to S. aureus pathogenesis, efforts have largely focused on mAbs that neutralize α-hemolysin (Hla) and target the receptor-binding site. Here, we isolated two anti-Hla and three anti-Panton-Valentine Leukocidin (LukSF-PV) mAbs, and used a combination of hydrogen deuterium exchange mass spectrometry (HDX-MS) and alanine scanning mutagenesis to delineate and validate the toxins’ epitope landscape. Our studies identified two novel, neutralizing epitopes targeted by 2B6 and CAN6 on Hla that provided protection from hemolytic activity in vitro and showed synergy in rodent pneumonia model against lethal challenge. Of the anti-LukF mAbs, SA02 and SA131 showed specific neutralization activity to LukSF-PV while SA185 showed cross-neutralization activity to LukSF-PV, γ-hemolysin HlgAB, and leukotoxin ED. We further compared these antigen-specific mAbs to two broadly neutralizing mAbs, H5 (targets Hla, LukSF-PV, HlgAB, HlgCB, and LukED) and SA185 (targeting LukSF-PV, HlgAB, and LukED), and identified molecular level markers for broad-spectrum reactivity among the pore-forming toxins by HDX-MS. To further underscore the need to target the cross-reactive epitopes on leukocidins for the development of broad-spectrum therapies, we annotated Hla sequences isolated from patients in multiple countries for genomic variations within the perspective of our defined epitopes.
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Affiliation(s)
| | - Ravi Kant
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
| | | | | | - Grant Liao
- Integrated BioTherapeutics, Rockville, USA
| | | | - Daisy W Leung
- Department of Medicine, Washington University in St. Louis, St. Louis, USA
| | - Richard A Alm
- Boston University School of Law, Boston University, Boston, USA
| | | | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
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Laabei M, Peacock SJ, Blane B, Baines SL, Howden BP, Stinear TP, Massey RC. Significant variability exists in the cytotoxicity of global methicillin-resistant Staphylococcus aureus lineages. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34928202 PMCID: PMC8744995 DOI: 10.1099/mic.0.001119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus is a major human pathogen where the emergence of antibiotic resistant lineages, such as methicillin-resistant S. aureus (MRSA), is a major health concern. While some MRSA lineages are restricted to the healthcare setting, the epidemiology of MRSA is changing globally, with the rise of specific lineages causing disease in healthy people in the community. In the past two decades, community-associated MRSA (CA-MRSA) has emerged as a clinically important and virulent pathogen associated with serious skin and soft-tissue infections (SSTI). These infections are primarily cytotoxin driven, leading to the suggestion that hypervirulent lineages/multi-locus sequence types (STs) exist. To examine this, we compared the cytotoxicity of 475 MRSA isolates representing five major MRSA STs (ST22, ST93, ST8, ST239 and ST36) by employing a monocyte-macrophage THP-1 cell line as a surrogate for measuring gross cytotoxicity. We demonstrate that while certain MRSA STs contain highly toxic isolates, there is such variability within lineages to suggest that this aspect of virulence should not be inferred from the genotype of any given isolate. Furthermore, by interrogating the accessory gene regulator (Agr) sequences in this collection we identified several Agr mutations that were associated with reduced cytotoxicity. Interestingly, the majority of isolates that were attenuated in cytotoxin production contained no mutations in the agr locus, indicating a role of other undefined genes in S. aureus toxin regulation.
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Affiliation(s)
- Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, UK
- *Correspondence: Maisem Laabei,
| | - Sharon J. Peacock
- Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Hills Road, Box 157, Cambridge, CB2 0QQ, UK
| | - Beth Blane
- Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Hills Road, Box 157, Cambridge, CB2 0QQ, UK
| | - Sarah L. Baines
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Benjamin P. Howden
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Microbiological Diagnostic Unit Public Health Laboratory, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Ruth C. Massey
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
- *Correspondence: Ruth C. Massey,
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23
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Koch N, Islam NF, Sonowal S, Prasad R, Sarma H. Environmental antibiotics and resistance genes as emerging contaminants: Methods of detection and bioremediation. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100027. [PMID: 34841318 PMCID: PMC8610363 DOI: 10.1016/j.crmicr.2021.100027] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/02/2021] [Accepted: 03/07/2021] [Indexed: 12/13/2022] Open
Abstract
In developing countries, the use of antibiotics has helped to reduce the mortality rate by minimizing the deaths caused by pathogenic infections, but the costs of antibiotic contamination remain a major concern. Antibiotics are released into the environment, creating a complicated environmental problem. Antibiotics are used in human, livestock and agriculture, contributing to its escalation in the environment. Environmental antibiotics pose a range of risks and have significant effects on human and animal health. Nevertheless, this is the result of the development of antibiotic-resistant and multi-drug-resistant bacteria. In the area of health care, animal husbandry and crop processing, the imprudent use of antibiotic drugs produces antibiotic-resistant bacteria. This threat is the deepest in the developing world, with an estimated 700,000 people suffering from antibiotic-resistant infections each year. The study explores how bacteria use a wide variety of antibiotic resistance mechanism and how these approaches have an impact on the environment and on our health. The paper focuses on the processes by which antibiotics degrade, the health effects of these emerging contaminants, and the tolerance of bacteria to antibiotics.
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Affiliation(s)
- Niharika Koch
- Department of Botany, Mahatma Gandhi Central University, Motihari 845401, Bihar, India
| | - Nazim F. Islam
- Department of Botany, Nanda Nath Saikia College, Titabar, Assam 785630, India
| | - Songita Sonowal
- Department of Botany, Mahatma Gandhi Central University, Motihari 845401, Bihar, India
| | - Ram Prasad
- Department of Botany, Mahatma Gandhi Central University, Motihari 845401, Bihar, India
| | - Hemen Sarma
- Department of Botany, Nanda Nath Saikia College, Titabar, Assam 785630, India
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24
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Liao G, Wu Z, Lv J, Ren Q, Chen W. Investigation of clonal diversity, virulence genes, and antibiotic resistance of Staphylococcus aureus recovered from raw cow milk in southern Xinjiang, China. Folia Microbiol (Praha) 2021; 67:245-252. [PMID: 34735675 DOI: 10.1007/s12223-021-00924-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/21/2021] [Indexed: 10/19/2022]
Abstract
Staphylococcus aureus is an important pathogen of humans and animals. The aim of this study was to characterize 71 of S. aureus isolates from raw cow milk in southern Xinjiang of China, including molecular typing, distribution of virulence genes, and antimicrobial susceptibility. The isolates belonged to 18 sequence types (STs) (including 11 novel STs) and 6 spa types which were divided into five different clonal complexes (CCs), including CC188, CC352, CC22, CC398, and CC5406. The majority of the strains was grouped into multilocus sequence typing (MLST) CC188 (n = 41), t189 (n = 40), and ST5796 (n = 17). Only 30.9, 12.7, 11.3, and 9.9% of the isolates were resistant to erythromycin, clindamycin/norfloxacin, tetracycline, and gentamicin, respectively. Nine of multidrug resistant (MDR) isolates were observed which was associated with CC398-t2876. The adhesion molecules clfa, clfb, and hlb were most frequently detected with the percentage rate of 98.6% (70/71), 98.6% (70/71), and 90.1% (64/71), respectively. The percentage rates of the staphylococcal enterotoxin genes sea, seb, sec, sed, seg, and sei in S. aureus isolates were 5.6, 19.8, 40.8, 1.4, 49.3, and 30.9%, respectively. The see, seh, and sej genes were not found. This study provides data about the occurrence of S. aureus in raw cow milk, revealing high carriage frequency, drug resistance, and population structure of S. aureus. Furthermore, this study suggests that effective hygienic measures be taken when handling dairy cows, in order to prevent spreading MDR strains to human through direct contact and/or consumption of contaminated food.
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Affiliation(s)
- Guanghua Liao
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Sciences, Tarim University, Alar, 86-843300, China
| | - Zihao Wu
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Sciences, Tarim University, Alar, 86-843300, China
| | - Junfan Lv
- College of Animal Sciences, Key Laboratory of Tarim Animal Husbandry and Science Technology of Xinjiang Production & Construction Corps, Tarim University, Alar, 86-843300, China
| | - Qiang Ren
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Sciences, Tarim University, Alar, 86-843300, China
| | - Wei Chen
- Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps, College of Life Sciences, Tarim University, Alar, 86-843300, China. .,College of Animal Sciences, Key Laboratory of Tarim Animal Husbandry and Science Technology of Xinjiang Production & Construction Corps, Tarim University, Alar, 86-843300, China.
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25
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Chen PY, Chuang YC, Wang JT, Sheng WH, Chen YC, Chang SC. Sequence type 8 as an emerging clone of methicillin-resistant Staphylococcus aureus causing bloodstream infections in Taiwan. Emerg Microbes Infect 2021; 10:1908-1918. [PMID: 34520335 PMCID: PMC8475108 DOI: 10.1080/22221751.2021.1981158] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sequence type (ST) 8 has not been a common methicillin-resistant Staphylococcus aureus (MRSA) clone in Asia until recently. We aimed to determine the clinical significance and microbiological characteristics of MRSA bacteraemia (MRSAB) caused by ST8 and other endemic clones. A total of 281 non-duplicated MRSAB were identified in a medical centre between 2016 and 2018. Sequencing of target genes was performed to determine ST and to confirm ST8 belonging to USA300. Antimicrobial susceptibility testing was performing by using Sensititre standard panel. In total, ST8 accounted for 18.5% of MRSAB ranking after ST239 (31.0%) and ST59 (23.5%). However, it increased to become the most prevalent clone finally. All ST8 isolates belonged to spa clonal complex008, and carried SCCmec IV/IVa, PVL and ACME genes, indicating USA300. ST8/USA300 isolates were highly susceptible to non-β-lactams antibiotics, except fluoroquinolone and erythromycin. ST8/USA300 MRSAB is commonly developed in community settings with either healthcare risks or not (71.2%). Compared to other STs MRSAB, ST8/USA300 MRSAB patients had more diabetes mellitus (50.0%), more admitted from long-term care facility residents (25.0%), had more skin ad soft tissue infection as primary focus (25.0%), and had fewer vascular devices (26.9%) at MRSAB onset. On multivariable analysis, isolates with vancomycin MIC were significantly associated with mortality in the dose-response relationship, rather than STs. This report depicts the clinical features of ST8/USA300 MRSAB and clonal shift from prior endemic clones to ST8/USA300. Our data strongly support long-term surveillance to ascertain whether ST8/USA300 will successfully disseminate and demonstrate its pathogenicity on clinical outcomes.
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Affiliation(s)
- Pao-Yu Chen
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yu-Chung Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Jann-Tay Wang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,National Institutes of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan
| | - Wang-Huei Sheng
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yee-Chun Chen
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,National Institutes of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan.,College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shan-Chwen Chang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,College of Medicine, National Taiwan University, Taipei, Taiwan
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26
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Chen CJ, Yang Lauderdale TL, Huang YC. Evolution and Population Structures of Prevalent Methicillin-Resistant Staphylococcus aureus in Taiwan. Front Microbiol 2021; 12:725340. [PMID: 34603254 PMCID: PMC8482045 DOI: 10.3389/fmicb.2021.725340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Global methicillin-resistant Staphylococcus aureus (MRSA) strains were dominated by few genetic lineages, suggesting their inherent advantage of competitive fitness. The information of genome evolution and population structures of prevalent MRSA strains can help gain a better understanding of the success of the pandemic clones. Whole-genome sequencing was performed in 340 MRSA isolates belonging to three prevalent lineages, including ST59 (129 isolates), ST239/241 (140 isolates), and ST5 (71 isolates), collected from 1996 to 2016 in Taiwan. The time-scaled phylogeny and evolutionary pathways were estimated by Bayesian analysis using Markov chain Monte Carlo. The toxome, resistome, and plasmids were characterized by screening the raw reads with a public database. ST59, ST239/241, and ST5 MRSA were estimated to emerge in 1974, 1979, and 1995, respectively, in Taiwan. ST59 evolved through two major pathways, generating two subclones in 1980 and 1984. Both ST59 subclones remained prevalent in the healthcare and community environments in late 2010s. ST239/241 diverged into three subclones, respectively, in 1989, 1993, and 1995. The 1995-emerging ST239 subclone predominated after 2000 by replacing two previous early subclones. ST5 could be subdivided into two clades within 3 years of introduction, but no substantial difference of genomic profiles was identified in the strains of distinct clades. Each of the three pandemic MRSA lineages harbored its own specific toxome, resistome, and plasmids. The frequently identified genetic diversities between the subclones of the same lineage were genes mediating immune evasion, leukocidins, enterotoxins, and resistance to aminoglycosides. In conclusion, MRSA ST59 and ST239/241 emerged in the 1970s and evolved drastically during 1980 and 1995, resulting in three successful subclones prevailing in Taiwan. ST5 was introduced late in 1995 without a significant genetic drift during 20 years of evolution.
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Affiliation(s)
- Chih-Jung Chen
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Molecular Infectious Diseases Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Tsai-Ling Yang Lauderdale
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan
| | - Yhu-Chering Huang
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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27
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Daptomycin versus Vancomycin for the Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infection with or without Endocarditis: A Systematic Review and Meta-Analysis. Antibiotics (Basel) 2021; 10:antibiotics10081014. [PMID: 34439067 PMCID: PMC8389004 DOI: 10.3390/antibiotics10081014] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/05/2021] [Accepted: 08/19/2021] [Indexed: 12/29/2022] Open
Abstract
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of invasive infections, mainly bloodstream infections (BSI) with or without endocarditis. The purpose of this meta-analysis was to compare vancomycin, the mainstay treatment, with daptomycin as therapeutic options in this context. Materials: PubMed, Embase and the Cochrane Database were searched from their inception to 15 February 2020. The primary outcome was all-cause mortality. Secondary outcomes included clinical failure, infection recurrence, persistence of infection, length-of-stay, antibiotic discontinuation due to adverse events (AEs) and 30-day re-admission. This study was registered with PROSPERO, CRD42020169413. Results: Eight studies (1226 patients, 554 vs. 672 in daptomycin vs. vancomycin, respectively) were included. No significant difference in terms of overall mortality was observed [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.40–1.33, I2 = 67%]. Daptomycin was associated with a significantly reduced risk of clinical failure (OR 0.58, 95% CI 0.38–0.89, I2 = 60%), as confirmed by pooling adjusted effect sizes (adjusted OR against the use of vancomycin 1.94, 95%CI 1.33–1.82, I2 = 41%), and was linked with fewer treatment-limiting AEs (OR 0.15, 95%CI 0.06–0.36, I2 = 19%). No difference emerged between the two treatments as secondary outcomes. Results were not robust to unmeasured confounding (E-value lower than 95% CI 1.00 for all-cause mortality). Conclusions: Against MRSA BSI, with or without endocarditis, daptomycin seems to be associated with a lower risk of clinical failure and treatment-limiting AEs compared with vancomycin. Further studies are needed to better characterize the differences between the two drugs.
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28
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Szultka-Młyńska M, Janiszewska D, Pomastowski P, Złoch M, Kupczyk W, Buszewski B. Identification of Bacteria Associated with Post-Operative Wounds of Patients with the Use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Approach. Molecules 2021; 26:5007. [PMID: 34443592 PMCID: PMC8402041 DOI: 10.3390/molecules26165007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 11/25/2022] Open
Abstract
The bacterial infection of post-operative wounds is a common health problem. Therefore, it is important to investigate fast and accurate methods of identifying bacteria in clinical samples. The aim of the study was to analyse the use of the MALDI-TOF MS technique to identify microorganism wounds that are difficult to heal. The most common bacteria are Escherichia coli, Staphylococcus spp., and Enterococcus spp. We also demonstrate the effect of culture conditions, such as the used growth medium (solid: Brain Heart Infusion Agar, Mueller Hilton Agar, Glucose Bromocresol Purple Agar, and Vancomycin Resistance Enterococci Agar Base and liquid: Tryptic Soy Broth and BACTEC Lytic/10 Anaerobic/F), the incubation time (4, 6, and 24h), and the method of the preparation of bacterial protein extracts (the standard method based on the Bruker guideline, the Sepsityper method) to identify factors and the quality of the obtained mass spectra. By comparing the protein profiles of bacteria from patients not treated with antibiotics to those treated with antibiotics based on the presence/absence of specific signals and using the UniProt platform, it was possible to predict the probable mechanism of the action of the antibiotic used and the mechanism of drug resistance.
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Affiliation(s)
- Małgorzata Szultka-Młyńska
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun, Poland; (D.J.); (B.B.)
| | - Daria Janiszewska
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun, Poland; (D.J.); (B.B.)
| | - Paweł Pomastowski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland; (P.P.); (M.Z.)
| | - Michał Złoch
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland; (P.P.); (M.Z.)
| | - Wojciech Kupczyk
- Department of General, Gastroenterological and Oncological Surgery, Collegium Medicum, Nicolaus Copernicus University, 87-100 Torun, Poland;
| | - Bogusław Buszewski
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun, Poland; (D.J.); (B.B.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wilenska 4, 87-100 Torun, Poland; (P.P.); (M.Z.)
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29
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Hommes JW, Kratofil RM, Wahlen S, de Haas CJC, Hildebrand RB, Hovingh GK, Otto M, van Eck M, Hoekstra M, Korporaal SJA, Surewaard BGJ. High density lipoproteins mediate in vivo protection against staphylococcal phenol-soluble modulins. Sci Rep 2021; 11:15357. [PMID: 34321507 PMCID: PMC8319287 DOI: 10.1038/s41598-021-94651-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus virulence has been associated with the production of phenol-soluble modulins (PSMs). These PSMs have distinct virulence functions and are known to activate, attract and lyse neutrophils. These PSM-associated biological functions are inhibited by lipoproteins in vitro. We set out to address whether lipoproteins neutralize staphylococcal PSM-associated virulence in experimental animal models. Serum from both LCAT an ABCA1 knockout mice strains which are characterised by near absence of high-density lipoprotein (HDL) levels, was shown to fail to protect against PSM-induced neutrophil activation and lysis in vitro. Importantly, PSM-induced peritonitis in LCAT-/- mice resulted in increased lysis of resident peritoneal macrophages and enhanced neutrophil recruitment into the peritoneal cavity. Notably, LCAT-/- mice were more likely to succumb to staphylococcal bloodstream infections in a PSM-dependent manner. Plasma from homozygous carriers of ABCA1 variants characterized by very low HDL-cholesterol levels, was found to be less protective against PSM-mediated biological functions compared to healthy humans. Therefore, we conclude that lipoproteins present in blood can protect against staphylococcal PSMs, the key virulence factor of community-associated methicillin resistant S. aureus.
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Affiliation(s)
- Josefien W Hommes
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Rachel M Kratofil
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Sigrid Wahlen
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Diagnostic Sciences, Laboratory of Experimental Immunology, Ghent University, Ghent, Belgium
| | - Carla J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Reeni B Hildebrand
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - G Kees Hovingh
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Micheal Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Miranda van Eck
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Menno Hoekstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Suzanne J A Korporaal
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands.,Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bas G J Surewaard
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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30
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Tomlinson BR, Malof ME, Shaw LN. A global transcriptomic analysis of Staphylococcus aureus biofilm formation across diverse clonal lineages. Microb Genom 2021; 7. [PMID: 34227933 PMCID: PMC8477394 DOI: 10.1099/mgen.0.000598] [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] [Indexed: 01/23/2023] Open
Abstract
A key characteristic of Staphylococcus aureus infections, and one that also varies phenotypically between clones, is that of biofilm formation, which aids in bacterial persistence through increased adherence and immune evasion. Though there is a general understanding of the process of biofilm formation - adhesion, proliferation, maturation and dispersal - the tightly orchestrated molecular events behind each stage, and what drives variation between S. aureus strains, has yet to be unravelled. Herein we measure biofilm progression and dispersal in real-time across the five major S. aureus CDC-types (USA100-USA500) revealing adherence patterns that differ markedly amongst strains. To gain insight into this, we performed transcriptomic profiling on these isolates at multiple timepoints, compared to planktonically growing counterparts. Our findings support a model in which eDNA release, followed by increased positive surface charge, perhaps drives initial abiotic attachment. This is seemingly followed by cooperative repression of autolysis and activation of poly-N-acetylglucosamine (PNAG) production, which may indicate a developmental shift in structuring the biofilm matrix. As biofilms mature, diminished translational capacity was apparent, with 53 % of all ribosomal proteins downregulated, followed by upregulation of anaerobic respiration enzymes. These findings are noteworthy because reduced cellular activity and an altered metabolic state have been previously shown to contribute to higher antibiotic tolerance and bacterial persistence. In sum, this work is, to our knowledge, the first study to investigate transcriptional regulation during the early, establishing phase of biofilm formation, and to compare global transcriptional regulation both temporally and across multiple clonal lineages.
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Affiliation(s)
- Brooke R Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Morgan E Malof
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
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31
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Tomlinson BR, Malof ME, Shaw LN. A global transcriptomic analysis of Staphylococcus aureus biofilm formation across diverse clonal lineages. Microb Genom 2021. [PMID: 34227933 DOI: 10.1099/mgen0000598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
A key characteristic of Staphylococcus aureus infections, and one that also varies phenotypically between clones, is that of biofilm formation, which aids in bacterial persistence through increased adherence and immune evasion. Though there is a general understanding of the process of biofilm formation - adhesion, proliferation, maturation and dispersal - the tightly orchestrated molecular events behind each stage, and what drives variation between S. aureus strains, has yet to be unravelled. Herein we measure biofilm progression and dispersal in real-time across the five major S. aureus CDC-types (USA100-USA500) revealing adherence patterns that differ markedly amongst strains. To gain insight into this, we performed transcriptomic profiling on these isolates at multiple timepoints, compared to planktonically growing counterparts. Our findings support a model in which eDNA release, followed by increased positive surface charge, perhaps drives initial abiotic attachment. This is seemingly followed by cooperative repression of autolysis and activation of poly-N-acetylglucosamine (PNAG) production, which may indicate a developmental shift in structuring the biofilm matrix. As biofilms mature, diminished translational capacity was apparent, with 53 % of all ribosomal proteins downregulated, followed by upregulation of anaerobic respiration enzymes. These findings are noteworthy because reduced cellular activity and an altered metabolic state have been previously shown to contribute to higher antibiotic tolerance and bacterial persistence. In sum, this work is, to our knowledge, the first study to investigate transcriptional regulation during the early, establishing phase of biofilm formation, and to compare global transcriptional regulation both temporally and across multiple clonal lineages.
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Affiliation(s)
- Brooke R Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Morgan E Malof
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
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32
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In-Silico Pangenomics of SARS-CoV-2 Isolates Reveal Evidence for Subtle Adaptive Expression Strategies, Continued Clonal Evolution, and Sub-Clonal Emergences, Despite Genome Stability. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The devastating SARS-CoV2 pandemic is worsening with relapsing surges, emerging mutants, and increasing mortalities. Despite enormous efforts, it is not clear how SARS-CoV2 adapts and evolves in a clonal background. Laboratory research is hindered by high biosafety demands. However, the rapid sequence availability opened doors for bioinformatics. Using different bioinformatics programs, we investigated 6305 sequences for clonality, expressions strategies, and evolutionary dynamics. Results showed high nucleotide identity of 99.9% among SARS-CoV2 indicating clonal evolution and genome. High sequence identity and phylogenetic tree concordance were obtained with isolates from different regions. In any given tree topology, ~50% of isolates in a country formed country-specific sub-clusters. However, abundances of subtle overexpression strategies were found including transversions, signature-sequences and slippery-structures. Five different short tracks dominated with identical location patterns in all genomes where Slippery-4 AAGAA was the most abundant. Interestingly, transversion and transition substitutions mostly affected the same amino acid residues implying compensatory changes. To ensure these strategies were independent of sequence clonality, we simultaneously examined sequence homology indicators; tandem-repeats, restriction-site, and 3′UTR, 5′ UTR-caps and stem-loop locations in addition to stringent alignment parameters for 100% identity which all confirmed stability. Nevertheless, two rare events; a rearrangement in two SARS-CoV2 isolates against betacoronavirus ancestor and a polymorphism in S gene, were detected. Thus, we report on abundance of transversions, slippery sequences, and ON/OFF molecular structures, implying adaptive expressions had occurred, despite clonal evolution and genome stability. Furthermore, functional validation of the point mutations would provide insights into mechanisms of SARS-CoV2 virulence and adaptation.
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Rungelrath V, DeLeo FR. Staphylococcus aureus, Antibiotic Resistance, and the Interaction with Human Neutrophils. Antioxid Redox Signal 2021; 34:452-470. [PMID: 32460514 PMCID: PMC8020508 DOI: 10.1089/ars.2020.8127] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance:Staphylococcus aureus is among the leading causes of bacterial infections worldwide. The high burden of S. aureus among human and animal hosts, which includes asymptomatic carriage and infection, is coupled with a notorious ability of the microbe to become resistant to antibiotics. Notably, S. aureus has the ability to produce molecules that promote evasion of host defense, including the ability to avoid killing by neutrophils. Recent Advances: Significant progress has been made to better understand S. aureus-host interactions. These discoveries include elucidation of the role played by numerous S. aureus virulence molecules during infection. Based on putative functions, a number of these virulence molecules, including S. aureus alpha-hemolysin and protein A, have been identified as therapeutic targets. Although it has not been possible to develop a vaccine that can prevent S. aureus infections, monoclonal antibodies specific for S. aureus virulence molecules have the potential to moderate the severity of disease. Critical Issues: Therapeutic options for treatment of methicillin-resistant S. aureus (MRSA) are limited, and the microbe typically develops resistance to new antibiotics. New prophylactics and/or therapeutics are needed. Future Directions: Research that promotes an enhanced understanding of S. aureus-host interaction is an important step toward developing new therapeutic approaches directed to moderate disease severity and facilitate treatment of infection. This research effort includes studies that enhance our view of the interaction of S. aureus with human neutrophils. Antioxid. Redox Signal. 34, 452-470.
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Affiliation(s)
- Viktoria Rungelrath
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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Liu B, Sun B. Rsp promotes the transcription of virulence factors in an agr-independent manner in Staphylococcus aureus. Emerg Microbes Infect 2020; 9:796-812. [PMID: 32248753 PMCID: PMC7241556 DOI: 10.1080/22221751.2020.1752116] [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] [Indexed: 12/22/2022]
Abstract
Staphylococcus aureus is a major human pathogen that causes a great diversity of community- and hospital-acquired infections. Rsp, a member of AraC/XylS family of transcriptional regulators (AFTRs), has been reported to play an important role in the regulation of virulence determinants in S. aureus via an agr-dependent pathway. Here we demonstrated that Rsp could bind to the rsp promoter to positively regulate its own expression. We then constructed an isogenic rsp deletion strain and compared the haemolysis in the wild-type and rsp mutant strains. Our results indicated that the rsp mutant strain displayed decreased haemolytic activity, which was correlated with a dramatic decrease in the expression of hla and psm. Furthermore, we analysed the regulatory effects of Rsp in the agr mutant strain and found that they are agr-independent. Electrophoretic mobility shift assay indicated that Rsp can directly bind to the promoter regions of hla and psm. The mouse model of subcutaneous abscess showed that the rsp mutant strain displayed a significant defect in virulence compared to the wild-type strain. These findings reveal that Rsp positively regulates the virulence of S. aureus by promoting the expression of hla and psm through direct binding to their promoter regions.
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Affiliation(s)
- Banghui Liu
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, People's Republic of China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital, University of Science and Technology of China, Hefei, People's Republic of China
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Genardi S, Visvabharathy L, Cao L, Morgun E, Cui Y, Qi C, Chen YH, Gapin L, Berdyshev E, Wang CR. Type II Natural Killer T Cells Contribute to Protection Against Systemic Methicillin-Resistant Staphylococcus aureus Infection. Front Immunol 2020; 11:610010. [PMID: 33312179 PMCID: PMC7708336 DOI: 10.3389/fimmu.2020.610010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/22/2020] [Indexed: 12/31/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (SA) bacteremia is responsible for over 10,000 deaths in the hospital setting each year. Both conventional CD4+ T cells and γδ T cells play protective roles in SA infection through secretion of IFN-γ and IL-17. However, the role of other unconventional T cells in SA infection is largely unknown. Natural killer T (NKT) cells, a subset of innate-like T cells, are activated rapidly in response to a wide range of self and microbial lipid antigens presented by MHC I-like molecule CD1d. NKT cells are divided into two groups, invariant NKT (iNKT) and type II NKT cells, based on TCR usage. Using mice lacking either iNKT cells or both types of NKT cells, we show that both NKT cell subsets are activated after systemic SA infection and produce IFN-γ in response to SA antigen, however type II NKT cells are sufficient to control bacterial burden and inflammatory infiltrate in infected organs. This protective capacity was specific for NKT cells, as mice lacking mucosal associated invariant T (MAIT) cells, another innate-like T cell subset, had no increased susceptibility to SA systemic infection. We identify polar lipid species from SA that induce IFN-γ production from type II NKT cells, which requires both CD1d-TCR engagement and IL-12 production by antigen presenting cells. We also demonstrate that a population of T cells enriched for type II NKT cells are increased in PBMC of SA bacteremic patients compared to healthy controls. Therefore, type II NKT cells perform effector functions that enhance control of SA infection prior to conventional T cell activation and recognize SA-derived lipid antigens. As CD1d is highly conserved in humans, these CD1d-restricted SA lipid antigens could be used in the design of next generation SA vaccines targeting cell-mediated immunity.
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Affiliation(s)
- Samantha Genardi
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Lavanya Visvabharathy
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Liang Cao
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Eva Morgun
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Yongyong Cui
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Chao Qi
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Yi-Hua Chen
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Laurent Gapin
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Evgeny Berdyshev
- Department of Medicine, National Jewish Health, Denver, CO, United States
| | - Chyung-Ru Wang
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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Baker KS. Microbe hunting in the modern era: reflecting on a decade of microbial genomic epidemiology. Curr Biol 2020; 30:R1124-R1130. [PMID: 33022254 PMCID: PMC7534602 DOI: 10.1016/j.cub.2020.06.097] [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] [Indexed: 11/30/2022]
Abstract
Since the first recognition that infectious microbes serve as the causes of many human diseases, physicians and scientists have sought to understand and control their spread. For the past 150+ years, these ‘microbe hunters’ have learned to combine epidemiological information with knowledge of the infectious agent(s). In this essay, I reflect on the evolution of microbe hunting, beginning with the history of pre-germ theory epidemiological studies, through the microbiological and molecular eras. Now in the genomic age, modern-day microbe hunters are combining pathogen whole-genome sequencing with epidemiological data to enhance epidemiological investigations, advance our understanding of the natural history of pathogens and drivers of disease, and ultimately reshape our plans and priorities for global disease control and eradication. Indeed, as we have seen during the ongoing Covid-19 pandemic, the role of microbe hunters is now more important than ever. Despite the advances already made by microbial genomic epidemiology, the field is still maturing, with many more exciting developments on the horizon.
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Affiliation(s)
- Kate S Baker
- University of Liverpool, Institute for Infection, Ecology and Veterinary Sciences, Department of Clinical Infection, Microbiology, and Immunology, Liverpool L69 7ZB, UK.
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37
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Schulz A, Jiang L, de Vor L, Ehrström M, Wermeling F, Eidsmo L, Melican K. Neutrophil Recruitment to Noninvasive MRSA at the Stratum Corneum of Human Skin Mediates Transient Colonization. Cell Rep 2020; 29:1074-1081.e5. [PMID: 31665625 DOI: 10.1016/j.celrep.2019.09.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/16/2019] [Accepted: 09/18/2019] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is a leading cause of skin and soft issue infection, but paradoxically, it also transiently, and often harmlessly, colonizes human skin. An obstacle to understanding this contradiction has been a shortage of in vivo models reproducing the unique structure and immunology of human skin. In this work, we developed a humanized model to study how healthy adult human skin responds to colonizing methicillin-resistant S. aureus (MRSA). We demonstrate the importance of the outer stratum corneum as the major site of bacterial colonization and how noninvasive MRSA adhesion to corneocytes induces a local inflammatory response in underlying skin layers. This signaling recruits neutrophils to the skin, where they control bacterial numbers, mediating transiency in colonization. This work highlights the spatiotemporal aspects of human skin colonization and demonstrates a subclinical inflammatory response to noninvasive MRSA that allows human skin to regulate the bacterial population at its outer surface.
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Affiliation(s)
- Anette Schulz
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Long Jiang
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Lisanne de Vor
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Marcus Ehrström
- Department of Reconstructive Plastic Surgery, Karolinska University Hospital Solna, Stockholm 171 77, Sweden
| | - Fredrik Wermeling
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Liv Eidsmo
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Keira Melican
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden.
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38
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Bae JS, Da F, Liu R, He L, Lv H, Fisher EL, Rajagopalan G, Li M, Cheung GYC, Otto M. Contribution of Staphylococcal Enterotoxin B to Staphylococcus aureus Systemic Infection. J Infect Dis 2020; 223:1766-1775. [PMID: 32937658 DOI: 10.1093/infdis/jiaa584] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/14/2020] [Indexed: 11/15/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB), which is produced by the major human pathogen, Staphylococcus aureus, represents a powerful superantigenic toxin and is considered a bioweapon. However, the contribution of SEB to S. aureus pathogenesis has never been directly demonstrated with genetically defined mutants in clinically relevant strains. Many isolates of the predominant Asian community-associated methicillin-resistant S. aureus lineage sequence type (ST) 59 harbor seb, implying a significant role of SEB in the observed hypervirulence of this lineage. We created an isogenic seb mutant in a representative ST59 isolate and assessed its virulence potential in mouse infection models. We detected a significant contribution of seb to systemic ST59 infection that was associated with a cytokine storm. Our results directly demonstrate that seb contributes to S. aureus pathogenesis, suggesting the value of including SEB as a target in multipronged antistaphylococcal drug development strategies. Furthermore, they indicate that seb contributes to fatal exacerbation of community-associated methicillin-resistant S. aureus infection.
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Affiliation(s)
- Justin S Bae
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Fei Da
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Ryan Liu
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Lei He
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Huiying Lv
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Emilie L Fisher
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Gordon Y C Cheung
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Otto
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Souli M, Ruffin F, Choi SH, Park LP, Gao S, Lent NC, Sharma-Kuinkel BK, Thaden JT, Maskarinec SA, Wanda L, Hill-Rorie J, Warren B, Hansen B, Fowler VG. Changing Characteristics of Staphylococcus aureus Bacteremia: Results From a 21-Year, Prospective, Longitudinal Study. Clin Infect Dis 2020; 69:1868-1877. [PMID: 31001618 DOI: 10.1093/cid/ciz112] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 02/21/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND We conducted a longitudinal study to evaluate changes in the clinical presentation and epidemiology of Staphylococcus aureus bacteremia (SAB) in an academic, US medical center. METHODS Consecutive patients with monomicrobial SAB were enrolled from January 1995 to December 2015. Each person's initial bloodstream S. aureus isolate was genotyped using spa typing. Clonal complexes (CCs) were assigned using Ridom StaphType software. Changes over time in both the patient and bacterial characteristics were estimated with linear regression. Associations between genotypes or clinical characteristics and complications were estimated using multivariable regression models. RESULTS Among the 2348 eligible participants, 54.2% had an implantable, foreign body of some type. This proportion increased significantly during the 21-year study period, by 0.96% annually (P = .002), as did comorbid conditions and acquisition outside of the hospital. Rates of any metastatic complication also significantly increased, by 0.94% annually (P = .019). Among the corresponding bloodstream S. aureus isolates, spa-CC012 (multi-locus sequence type [MLST] CC30), -CC004 (MLST CC45), -CC189 (MLST CC1), and -CC084 (MLST CC15) all significantly declined during the study period, while spa-CC008 (MLST CC8) significantly increased. Patients with SAB due to spa-CC008 were significantly more likely to develop metastatic complications in general, and abscesses, septic emboli, and persistent bacteremia in particular. After adjusting for demographic, racial, and clinical variables, the USA300 variant of spa-CC008 was independently associated with metastatic complications (odds ratio 1.42; 95% confidence interval 1.02-1.99). CONCLUSIONS Systematic approaches for monitoring complications of SAB and genotyping the corresponding bloodstream isolates will help identify the emergence of hypervirulent clones and likely improve clinical management of this syndrome.
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Affiliation(s)
- Maria Souli
- Department of Medicine, Duke University Medical Center, North Carolina.,Duke Clinical Research Institute, Durham, North Carolina.,Fourth Department of Internal Medicine, National and Kapodistrian University of Athens School of Medicine, Greece
| | - Felicia Ruffin
- Department of Medicine, Duke University Medical Center, North Carolina
| | - Seong-Ho Choi
- Department of Medicine, Duke University Medical Center, North Carolina.,Department of Internal Medicine, Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, South Korea
| | - Lawrence P Park
- Department of Medicine, Duke University Medical Center, North Carolina.,Duke Global Health Institute, Duke University, Durham, North Carolina
| | - Shengli Gao
- Department of Medicine, Duke University Medical Center, North Carolina.,The First People's Hospital of Wujiang District, Suzhou City, Jiangsu Province, China
| | | | | | - Joshua T Thaden
- Department of Medicine, Duke University Medical Center, North Carolina
| | | | - Lisa Wanda
- Department of Medicine, Duke University Medical Center, North Carolina.,School of Medicine, University of North Carolina, Chapel Hill
| | - Jonathan Hill-Rorie
- Department of Medicine, Duke University Medical Center, North Carolina.,Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Bobby Warren
- Department of Medicine, Duke University Medical Center, North Carolina
| | - Brenda Hansen
- Department of Medicine, Duke University Medical Center, North Carolina.,Pediatric Gastroenterology, University of North Carolina, Chapel Hill
| | - Vance G Fowler
- Department of Medicine, Duke University Medical Center, North Carolina.,Duke Clinical Research Institute, Durham, North Carolina
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Hamann HJ, Abutaleb NS, Pal R, Seleem MN, Ramachandran PV. β,γ-Diaryl α-methylene-γ-butyrolactones as potent antibacterials against methicillin-resistant Staphylococcus aureus. Bioorg Chem 2020; 104:104183. [PMID: 32971415 DOI: 10.1016/j.bioorg.2020.104183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/19/2020] [Accepted: 08/08/2020] [Indexed: 10/23/2022]
Abstract
A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) synthesized via allylboration or allylindation reactions were screened against methicillin-resistant Staphylococcus aureus (MRSA) USA300. Unlike natural AMGBLs, such as parthenolide, synthetic analogs bearing aryl moieties at the β- and γ-positions are potent against MRSA. The most potent molecules were comparable to vancomycin and linezolid, the drugs of the last resort for MRSA infections, in their effectiveness with minimum inhibitory concentrations (MICs) ranging from 3.0 to 5.2 μM. These lactones also exhibited potent antibacterial activity against other clinically important multidrug-resistant Gram-positive bacteria (except enterococci), while also showing high tolerability to mammalian cells. Several of these molecules surpassed vancomycin in their rapid killing of the high MRSA inoculum (2 h vs 12 h) in a standard time-kill kinetics assay, with compounds 1l and 1m significantly reducing the intracellular burden of MRSA by about 98-99%, at low concentrations. Additionally, the compounds surpassed vancomycin in inhibiting staphylococcal protease production, indicating that synthetic methylene lactones warrant further investigations as promising anti-MRSA candidates.
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Affiliation(s)
- Henry J Hamann
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, United States
| | - Nader S Abutaleb
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States
| | - Rusha Pal
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States; Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, IN 47907, United States.
| | - P Veeraraghavan Ramachandran
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, United States; Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, IN 47907, United States.
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41
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Oh JY, Chae JC, Han JI, Song WK, Lee CM, Park HM. Distribution and epidemiological relatedness of methicillin-resistant Staphylococcus aureus isolated from companion dogs, owners, and environments. J Vet Med Sci 2020; 82:1379-1386. [PMID: 32713876 PMCID: PMC7538317 DOI: 10.1292/jvms.19-0523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
This study aimed to investigate the distribution and epidemiological relatedness of
methicillin-resistant Staphylococcus aureus (MRSA) isolates from
companion dogs, owners, and residential environments of 72 households. Sampling was
performed twice from January to June 2018 and a total of 2,592 specimens were collected.
The specimens collected from each household were streaked on CHROM agar S.
aureus and the colonies grown on the medium were further identified using a
mass spectrometry microbial identification system. Antimicrobial susceptibility testing,
Panton-Valentine-Leukocidin (PVL) gene PCR, staphylococcal cassette
chromosome mec (SCCmec) typing, Staphylococcus
aureus Protein A (spa) typing, pulsed-field gel
electrophoresis (PFGE), and multi-locus sequence typing (MLST) were conducted to evaluate
the phenotypic and genotypic characteristics of the MRSA isolates. A total of 65
S. aureus strains (2.5%) were isolated and 49 (1.9%) of 65 strains were
MRSA displaying cefoxitin-resistance with mecA carriage. MRSA strains
were isolated from dogs (n=6, 9.2%), owners (n=27, 41.5%), and residential environments
(n=16, 24.6%), respectively. Overall prevalence of non-duplicated MRSA was 16.7% (12/72
households) at household level. ST72-SCCmec IVc MRSA clones predominantly
appeared in MRSA-positive families. Furthermore, PFGE analyses showed that
ST72-SCCmec IVc-t324 is shared between dog owners and dogs. To our
knowledge, this is the first study to report the sharing of ST72 MRSA between dogs and
their owners.
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Affiliation(s)
- Jae-Young Oh
- Department of Veterinary Internal Medicine, Konkuk University College of Veterinary Medicine, Seoul 05029, South Korea
| | - Jong-Chan Chae
- Division of Biotechnology, Chonbuk National University, Iksan 54596, South Korea
| | - Jae-Ik Han
- Laboratory of Wildlife Diseases, Chonbuk National University College of Veterinary Medicine, Iksan 54596, South Korea
| | - Won-Keun Song
- Department of Laboratory Medicine, Hallym University College of Medicine, Chuncheon 24252, South Korea
| | - Chang-Min Lee
- Department of Veterinary Internal Medicine, Chonnam National University College of Veterinary Medicine, Gwangju 61186, South Korea
| | - Hee-Myung Park
- Department of Veterinary Internal Medicine, Konkuk University College of Veterinary Medicine, Seoul 05029, South Korea
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Virulence factors and clonal diversity of Staphylococcus aureus in colonization and wound infection with emphasis on diabetic foot infection. Eur J Clin Microbiol Infect Dis 2020; 39:2235-2246. [PMID: 32683595 PMCID: PMC7669779 DOI: 10.1007/s10096-020-03984-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/03/2020] [Indexed: 12/12/2022]
Abstract
Foot ulcer is a common complication in diabetic subjects and infection of these wounds contributes to increased rates of morbidity and mortality. Diabetic foot infections are caused by a multitude of microbes and Staphylococcus aureus, a major nosocomial and community-associated pathogen, significantly contributes to wound infections as well. Staphylococcus aureus is also the primary pathogen commonly associated with diabetic foot osteomyelitis and can cause chronic and recurrent bone infections. The virulence capability of the pathogen and host immune factors can determine the occurrence and progression of S. aureus infection. Pathogen-related factors include complexity of bacterial structure and functional characteristics that provide metabolic and adhesive properties to overcome host immune response. Even though, virulence markers and toxins of S. aureus are broadly similar in different wound models, certain distinguishing features can be observed in diabetic foot infection. Specific clonal lineages and virulence factors such as TSST-1, leukocidins, enterotoxins, and exfoliatins play a significant role in determining wound outcomes. In this review, we describe the role of specific virulence determinants and clonal lineages of S. aureus that influence wound colonization and infection with special reference to diabetic foot infections.
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Marked increase in community-associated methicillin-resistant Staphylococcus aureus infections, Western Australia, 2004-2018. Epidemiol Infect 2020; 148:e153. [PMID: 32321605 PMCID: PMC7374805 DOI: 10.1017/s0950268820000849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
This study presents enhanced surveillance data from 2004 to 2018 for all community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) specimens collected in Western Australia (WA), and describes the changing epidemiology over this period. A total of 57 557 cases were reviewed. Annual incidence rates increased from 86.2 cases per 100 000 population to 245.6 per 100 000 population (IRR = 2.9, CI95 2.7-3.0). The proportion of isolates carrying Panton-Valentine leucocidin (PVL)-associated genes increased from 3.4% to 59.8% (χ2 test for trend 7021.9, P < 0.001). The emergence of PVL-positive, 'Queensland CA-MRSA' (ST93-IV) and 'WA 121' (ST5-IV) accounted for the majority of increases in CA-MRSA across the study period. It is unclear why some clones are more prolific in certain regions. In WA, CA-MRSA rates increase as indices of temperature and humidity increase after controlling for socioeconomic disadvantage. We suggest climatic conditions may contribute to transmission, along with other socio-behavioural factors. A better understanding of the ability for certain clones to form ecological niches and cause outbreaks is required.
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44
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Visvabharathy L, Genardi S, Cao L, He Y, Alonzo F, Berdyshev E, Wang CR. Group 1 CD1-restricted T cells contribute to control of systemic Staphylococcus aureus infection. PLoS Pathog 2020; 16:e1008443. [PMID: 32343740 PMCID: PMC7188215 DOI: 10.1371/journal.ppat.1008443] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/28/2020] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus (SA) is the causative agent of both skin/soft tissue infections as well as invasive bloodstream infections. Though vaccines have been developed to target both humoral and T cell-mediated immune responses against SA, they have largely failed due to lack of protective efficacy. Group 1 CD1-restricted T cells recognize lipid rather than peptide antigens. Previously found to recognize lipids derived from cell wall of Mycobacterium tuberculosis (Mtb), these cells were associated with protection against Mtb infection in humans. Using a transgenic mouse model expressing human group 1 CD1 molecules (hCD1Tg), we demonstrate that group 1 CD1-restricted T cells can recognize SA-derived lipids in both immunization and infection settings. Systemic infection of hCD1Tg mice showed that SA-specific group 1 CD1-restricted T cell response peaked at 10 days post-infection, and hCD1Tg mice displayed significantly decreased kidney pathology at this time point compared with WT control mice. Immunodominant SA lipid antigens recognized by group 1 CD1-restricted T cells were comprised mainly of cardiolipin and phosphatidyl glycerol, with little contribution from lysyl-phosphatidyl glycerol which is a unique bacterial lipid not present in mammals. Group 1 CD1-restricted T cell lines specific for SA lipids also conferred protection against SA infection in the kidney after adoptive transfer. They were further able to effectively control SA replication in vitro through direct antigen presentation by group 1 CD1-expressing BMDCs. Together, our data demonstrate a previously unknown role for group 1 CD1-restricted SA lipid-specific T cells in the control of systemic MRSA infection.
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Affiliation(s)
- Lavanya Visvabharathy
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, United States of America
| | - Samantha Genardi
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, United States of America
| | - Liang Cao
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, United States of America
| | - Ying He
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, United States of America
| | - Francis Alonzo
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University, Maywood, United States of America
| | - Evgeny Berdyshev
- Department of Medicine, National Jewish Health, Denver, United States of America
| | - Chyung-Ru Wang
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, United States of America
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Archana GJ, Sinha AY, Annamanedi M, Asrith KP, Kale SB, Kurkure NV, Doijad SP, Nagamani K, Hegde NR. Molecular characterisation of methicillin-resistant Staphylococcus aureus isolated from patients at a tertiary care hospital in Hyderabad, South India. Indian J Med Microbiol 2020; 38:183-191. [PMID: 32883932 DOI: 10.4103/ijmm.ijmm_20_151] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Context Infections with methicillin-resistant Staphylococcus aureus (MRSA) greatly influence clinical outcome. Molecular characterisation of MRSA can help to predict their spread and to institute treatment and hospital protocols. Aim The aim of this study is to understand the diversity of MRSA in a tertiary care hospital in Hyderabad, India. Settings and Design Samples collected at Gandhi Medical College, Hyderabad, and designed to assess hospital-or community-associated MRSA (HA-MRSA or CA-MRSA). Subjects and Methods MRSA were subjected to antibiotic susceptibility testing, pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and staphylococcal cassette chromosome-mec (SCCmec) typing. Statistical Analysis Used Discriminatory index and 95% confidence interval. Results Of the 30 MRSA, (a) 18 and 12 were HA-MRSA and CA-MRSA, respectively, and (b) 23.3% and 6.6% displayed induced clindamycin and intermediate vancomycin resistance, respectively. Genetic diversity was evident from the presence of (a) 20 pulsotypes, (b) eight spa types, with the predominance of t064 (n = 9) and (c) seven sequence types (ST), with the preponderance of ST22 and ST8 (9 each). ST22 and ST8 were the most prevalent among HA-MRSA and CA-MRSA, respectively. SCCmec type IV was the most frequent (n = 8). 44.4% of HA-MRSA belonged to SCCmec IV and V, whereas 33.3% of CA-MRSA belonged to SCCmec I and III; 33.3% (5/15) of the isolates harbouring the pvl gene belonged to SCCmec IVC/H. Conclusions ST8 was a dominant type along with other previously reported types ST22, ST239, and ST772 from India. The observations highlight the prevalence of genetically diverse clonal populations of MRSA, suggesting potential multiple origins.
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Affiliation(s)
- Ganapuram J Archana
- Department of Microbiology, Gandhi Medical College and Hospital, Secunderabad, Telangana, India
| | - Akhauri Yash Sinha
- Ella Foundation, Genome Valley, Turkapally, Shameerpet Mandal, Telangana, India
| | | | | | - Satyajit B Kale
- Department of Veterinary Pathology, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, Maharashtra, India
| | - Nitin V Kurkure
- Department of Veterinary Pathology, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, Maharashtra, India
| | - Swapnil P Doijad
- Division of Veterinary Public Health, ICAR Research Complex for Goa, Old Goa, Goa, India
| | - Kammili Nagamani
- Department of Microbiology, Gandhi Medical College and Hospital, Secunderabad, Telangana, India
| | - Nagendra R Hegde
- National Institute of Animal Biotechnology, Hyderabad, Telangana, India
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Diallo I, Provost P. RNA-Sequencing Analyses of Small Bacterial RNAs and their Emergence as Virulence Factors in Host-Pathogen Interactions. Int J Mol Sci 2020; 21:E1627. [PMID: 32120885 PMCID: PMC7084465 DOI: 10.3390/ijms21051627] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/22/2020] [Accepted: 02/25/2020] [Indexed: 12/14/2022] Open
Abstract
Proteins have long been considered to be the most prominent factors regulating so-called invasive genes involved in host-pathogen interactions. The possible role of small non-coding RNAs (sRNAs), either intracellular, secreted or packaged in outer membrane vesicles (OMVs), remained unclear until recently. The advent of high-throughput RNA-sequencing (RNA-seq) techniques has accelerated sRNA discovery. RNA-seq radically changed the paradigm on bacterial virulence and pathogenicity to the point that sRNAs are emerging as an important, distinct class of virulence factors in both gram-positive and gram-negative bacteria. The potential of OMVs, as protectors and carriers of these functional, gene regulatory sRNAs between cells, has also provided an additional layer of complexity to the dynamic host-pathogen relationship. Using a non-exhaustive approach and through examples, this review aims to discuss the involvement of sRNAs, either free or loaded in OMVs, in the mechanisms of virulence and pathogenicity during bacterial infection. We provide a brief overview of sRNA origin and importance, and describe the classical and more recent methods of identification that have enabled their discovery, with an emphasis on the theoretical lower limit of RNA sizes considered for RNA sequencing and bioinformatics analyses.
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Affiliation(s)
| | - Patrick Provost
- CHUQ Research Center/CHUL, Department of Microbiology-Infectious Disease and Immunity, Faculty of Medicine, Université Laval, Quebec, QC G1V 0A6, Canada;
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The 5' NAD Cap of RNAIII Modulates Toxin Production in Staphylococcus aureus Isolates. J Bacteriol 2020; 202:JB.00591-19. [PMID: 31871032 DOI: 10.1128/jb.00591-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/18/2019] [Indexed: 01/14/2023] Open
Abstract
Nicotinamide adenosine dinucleotide (NAD) has been found to be covalently attached to the 5' ends of specific RNAs in many different organisms, but the physiological consequences of this modification are largely unknown. Here, we report the occurrence of several NAD-RNAs in the opportunistic pathogen Staphylococcus aureus Most prominently, RNAIII, a central quorum-sensing regulator of this bacterium's physiology, was found to be 5' NAD capped in a range from 10 to 35%. NAD incorporation efficiency into RNAIII was found to depend in vivo on the -1 position of the P3 promoter. An increase in RNAIII's NAD content led to a decreased expression of alpha- and delta-toxins, resulting in reduced cytotoxicity of the modified strains. These effects seem to be caused neither by changes in RNAIII's secondary structure nor by a different translatability upon NAD attachment, as indicated by unaltered patterns in in vitro chemical probing and toeprinting experiments. Even though we did not observe any effect of this modification on RNAIII's secondary structure or translatability in vitro, additional unidentified factors might account for the modulation of exotoxins in vivo Ultimately, the study constitutes a step forward in the discovery of new roles of the NAD molecule in bacteria.IMPORTANCE Numerous organisms, including bacteria, are endowed with a 5' NAD cap in specific RNAs. While the presence of the 5' NAD cap modulates the stability of the modified RNA species, a significant biological function and phenotype have not been assigned so far. Here, we show the presence of a 5' NAD cap in RNAIII from S. aureus, a dual-function regulatory RNA involved in quorum-sensing processes and regulation of virulence factor expression. We also demonstrate that altering the natural NAD modification ratio of RNAIII leads to a decrease in exotoxin production, thereby modulating the bacterium's virulence. Our work unveils a new layer of regulation of RNAIII and the agr system that might be linked to the redox state of the NAD molecule in the cell.
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Wu K, Conly J, McClure JA, Kurwa HA, Zhang K. Arginine Catabolic Mobile Element in Evolution and Pathogenicity of the Community-Associated Methicillin-Resistant Staphylococcus aureus Strain USA300. Microorganisms 2020; 8:microorganisms8020275. [PMID: 32085445 PMCID: PMC7074830 DOI: 10.3390/microorganisms8020275] [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] [Received: 02/02/2020] [Accepted: 02/14/2020] [Indexed: 01/11/2023] Open
Abstract
USA300 is a predominant community-associated methicillin-resistant Staphylococcus aureus strain which carries an arginine catabolic mobile element (ACME). ACME contains potential virulence factors including an arginine deiminase (arc) pathway and an oligopeptide permease (opp-3) system, which are proposed to play a role in bacterial virulence and transmission. However, the role of ACME in evolution and pathogenicity of USA300 remains to be elucidated. ACME and arcA deletion mutants were created by allelic replacement from a USA300 clinical isolate. By comparing wild type and isogenic ACME deletion USA300 strains, ACME was shown not to contribute to bacterial survival on plastic surfaces, and mouse skin surfaces. ACME did not contribute to bacterial virulence in cell invasion and cytotoxicity assays, invertebrate killing assays and a mouse skin infection model. Wild-type ACME negative USA300 clinical isolates showed similar associations with invasive anatomic sites as ACME positive isolates. Our experiments also demonstrated that ACME can spontaneously excise from the bacterial chromosome to generate an ACME deletion strain at a low frequency. Our results do not support that the ACME element alone is a significant factor in the transmission and virulence of USA300 strain, and ACME may have been coincidently incorporated into the genome of USA300.
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Affiliation(s)
- Kaiyu Wu
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
| | - John Conly
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
- Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
- The Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Jo-Ann McClure
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Habib A. Kurwa
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Kunyan Zhang
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
- Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
- The Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
- Correspondence: ; Tel.: +1-403-210-8484
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A comparative genomic analysis between methicillin-resistant Staphylococcus aureus strains of hospital acquired and community infections in Yunnan province of China. BMC Infect Dis 2020; 20:137. [PMID: 32054452 PMCID: PMC7020539 DOI: 10.1186/s12879-020-4866-6] [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: 10/24/2019] [Accepted: 02/10/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Currently, Staphylococcus aureus is one of the most important pathogens worldwide, especially for methicillin-resistant S. aureus (MRSA) infection. However, few reports referred to patients' MRSA infections in Yunnan province, southwest China. METHODS In this study, we selected representative MRSA strains from patients' systemic surveillance in Yunnan province of China, performed the genomic sequencing and compared their features, together with some food derived strains. RESULTS Among sixty selective isolates, forty strains were isolated from patients, and twenty isolated from food. Among the patients' strains, sixteen were recognized as community-acquired (CA), compared with 24 for hospital-acquired (HA). ST6-t701, ST59-t437 and ST239-t030 were the three major genotype profiles. ST6-t701 was predominated in food strains, while ST59-t437 and ST239-t030 were the primary clones in patients. The clinical features between CA and HA-MRSA of patients were statistical different. Compared the antibiotic resistant results between patients and food indicated that higher antibiotic resistant rates were found in patients' strains. Totally, the average genome sizes of 60 isolates were 2.79 ± 0.05 Mbp, with GC content 33% and 84.50 ± 0.20% of coding rate. The core genomes of these isolates were 1593 genes. Phylogenetic analysis based on pan-genome and SNP of strains showed that five clustering groups were generated. Clustering ST239-t030 contained all the HA-MRSA cases in this study; clustering ST6-t701 referred to food and CA-MRSA infections in community; clustering ST59-t437 showed the heterogeneity for provoking different clinical diseases in both community and hospital. Phylogenetic tree, incorporating 24 isolates from different regions, indicated ST239-t030 strains in this study were more closely related to T0131 isolate from Tianjin, China, belonged to 'Turkish clade' from Eastern Europe; two groups of ST59-t437 clones of MRSA in Yunnan province were generated, belonged to the 'Asian-Pacific' clone (AP) and 'Taiwan' clone (TW) respectively. CONCLUSIONS ST239-t030, ST59-t437 and ST6-t701 were the three major MRSA clones in Yunnan province of China. ST239-t030 clonal Yunnan isolates demonstrated the local endemic of clone establishment for a number of years, whereas ST59-t437 strains revealed the multi-origins of this clone. In general, genomic study on epidemic clones of MRSA in southwest China provided the features and evolution of this pathogen.
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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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