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Fan Y, Zhang K, Chen M, Li N, Liu X, Yang M, Liang X, Wu J, Guo B, Zheng H, Zhu Y, Zhang F, Hang J, Zhang H, Wang R, Yuan Q, Song X, Wu S, Shen B, Zhang J. Comparative efficacy of vancomycin in treating ST5 and ST764 methicillin-resistant Staphylococcus aureus infections in adult patients. mSphere 2023; 8:e0045723. [PMID: 37905831 PMCID: PMC10732099 DOI: 10.1128/msphere.00457-23] [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: 08/20/2023] [Accepted: 09/24/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that is resistant to multiple drugs and can cause serious infections. In recent years, one of the most widespread strains of MRSA worldwide has been the clonal complex 5 (CC5) type. Sequence type 5 (ST5) and ST764 are two prevalent CC5 strains. Although ST5 and ST764 are genotypically identical, ST764 is classified as a hybrid variant of ST5 with characteristics of community-associated MRSA (CA-MRSA). In contrast to ST5, ST764 lacks the tst and sec genes but carries the staphylococcal enterotoxin B (seb) gene. Vancomycin is commonly used as the first-line treatment for MRSA infections. However, it is currently unclear whether the genetic differences between the ST5 and ST764 strains have any impact on the efficacy of vancomycin in treating MRSA infections. We conducted a prospective observational study comparing the efficacy of vancomycin against ST5-MRSA and ST764-MRSA in five hospitals in China. There were significant differences in bacteriological efficacy between the two groups, with virulence genes, such as the tst gene, being a risk factor for bacterial persistence (adjusted odds ratio, 4.509; 95% confidence interval, 1.216 to 16.724; P = 0.024). In the future, it may be necessary to consider personalized vancomycin treatment strategies based on the genetic characteristics of MRSA isolates.
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Affiliation(s)
- Yaxin Fan
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Kaiting Zhang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Mengting Chen
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Nanyang Li
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaofen Liu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Minjie Yang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaoyu Liang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jufang Wu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Beining Guo
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Huajun Zheng
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai and Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, China
| | - Yongqiang Zhu
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai and Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, China
| | - Fengying Zhang
- Department of Pulmonary Medicine, Shanghai Putuo District People’s Hospital, Shanghai, China
| | - Jingqing Hang
- Department of Pulmonary Medicine, Shanghai Putuo District People’s Hospital, Shanghai, China
| | - Huifang Zhang
- Emergency and Critical Care Department, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ruilan Wang
- Emergency and Critical Care Department, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qing Yuan
- Department of Respiratory and Critical Care Medicine, Tenth People’s Hospital of Tongji University, Shanghai, China
| | - Xiaolian Song
- Department of Respiratory and Critical Care Medicine, Tenth People’s Hospital of Tongji University, Shanghai, China
| | - Shengbin Wu
- Department of Nephrology, Shanghai Ninth People’s Hospital, Shanghai, China
| | - Bo Shen
- Department of Nephrology, Shanghai Ninth People’s Hospital, Shanghai, China
| | - Jing Zhang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Population and Family Planning Commission, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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Targeted Proteomics Analysis of Staphylococcal Superantigenic Toxins in Menstrual Fluid from Women with Menstrual Toxic Shock Syndrome (mTSS). Toxins (Basel) 2022; 14:toxins14120886. [PMID: 36548783 PMCID: PMC9788610 DOI: 10.3390/toxins14120886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/23/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Menstrual toxic shock syndrome (mTSS) is a rare life-threatening febrile illness that occurs in women using intravaginal menstrual protection. It is caused by toxic shock syndrome toxin 1 (TSST-1) produced by Staphylococcus aureus, triggering a sudden onset of rash and hypotension, subsequently leading to multiple organ failure. Detecting TSST-1 and S. aureus virulence factors in menstrual fluid could accelerate the diagnosis and improve therapeutic management of mTSS. However, menstrual fluid is a highly complex matrix, making detection of bacterial toxins challenging. Here, we present a mass-spectrometry-based proteomics workflow for the targeted, quantitative analysis of four S. aureus superantigenic toxins in menstrual fluids (TSST-1, SEA, SEC, and SED). This method was applied to characterize toxin levels in menstrual fluids collected from patients with mTSS and healthy women. Toxins were detectable in samples from patients with mTSS and one healthy donor at concentrations ranging from 0 to 0.46 µg/mL for TSST-1, and 0 to 1.07 µg/mL for SEC. SEA and SED were never detected in clinical specimens, even though many S. aureus strains were positive for the corresponding genes. The method presented here could be used to explore toxin production in vivo in users of intravaginal devices to improve the diagnosis, understanding, and prevention of mTSS.
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Wong JJ, Ho FK, Choo PY, Chong KKL, Ho CMB, Neelakandan R, Keogh D, Barkham T, Chen J, Liu CF, Kline KA. Escherichia coli BarA-UvrY regulates the pks island and kills Staphylococci via the genotoxin colibactin during interspecies competition. PLoS Pathog 2022; 18:e1010766. [PMID: 36067266 PMCID: PMC9481169 DOI: 10.1371/journal.ppat.1010766] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 09/16/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022] Open
Abstract
Wound infections are often polymicrobial in nature, biofilm associated and therefore tolerant to antibiotic therapy, and associated with delayed healing. Escherichia coli and Staphylococcus aureus are among the most frequently cultured pathogens from wound infections. However, little is known about the frequency or consequence of E. coli and S. aureus polymicrobial interactions during wound infections. Here we show that E. coli kills Staphylococci, including S. aureus, both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. Colibactin biosynthesis is encoded by the pks locus, which we identified in nearly 30% of human E. coli wound infection isolates. While it is not clear how colibactin is released from E. coli or how it penetrates target cells, we found that the colibactin intermediate N-myristoyl-D-Asn (NMDA) disrupts the S. aureus membrane. We also show that the BarA-UvrY two component system (TCS) senses the environment created during E. coli and S. aureus mixed species interaction, leading to upregulation of pks island genes. Further, we show that BarA-UvrY acts via the carbon storage global regulatory (Csr) system to control pks expression. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition. Wound infections are often polymicrobial in nature and are associated with poor disease prognoses. Escherichia coli and Staphylococcus aureus are among the top five most cultured pathogens from wound infections. However, little is known about the polymicrobial interactions between E. coli and S. aureus during wound infections. In this study, we show that E. coli kills S. aureus both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. We also show that the BarA-UvrY two component system (TCS) regulates the pks island during this mixed species interaction, acting through the carbon storage global regulatory (Csr) system to control colibactin production. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition.
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Affiliation(s)
- Jun Jie Wong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Programme, Nanyang Technological University, Singapore, Singapore
| | - Foo Kiong Ho
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kelvin K. L. Chong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Nanyang Technological University Institute for Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
| | - Chee Meng Benjamin Ho
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
| | - Ramesh Neelakandan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Damien Keogh
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Timothy Barkham
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - John Chen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Chuan Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
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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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Roberts MC, Joshi PR, Monecke S, Ehricht R, Müller E, Gawlik D, Paudel S, Acharya M, Bhattarai S, Pokharel S, Tuladhar R, Chalise MK, Kyes RC. MRSA Strains in Nepalese Rhesus Macaques ( Macaca mulatta) and Their Environment. Front Microbiol 2019; 10:2505. [PMID: 31827462 PMCID: PMC6849405 DOI: 10.3389/fmicb.2019.02505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/17/2019] [Indexed: 12/19/2022] Open
Abstract
This study looked at 227 saliva samples from Rhesus macaques (Macaca mulatta) and 218 samples from the surrounding environments. From these samples, MRSA isolates were collected from Rhesus saliva samples (n = 13) and environmental samples (n = 19) near temple areas in Kathmandu, Nepal. For comparison, selected MRSA isolates (n = 5) were obtained from patients with wound infections from a Kathmandu hospital. All isolates were characterized using Abbott StaphyType® DNA microarrays. Eighteen isolates (62%) from monkeys (n = 4; 31%) and environmental samples (n = 14; 74%), were CC22-MRSA-IV. Most (n = 16) of them carried both, the PVL locus and toxic shock toxin gene (tst1), an unusual combination which is the same as in previously characterized strain from Nepalese macaques and pigs. The five human isolates also belonged to that strain type. Eight monkey MRSA isolates were CC361-MRSA-IV. One MRSA from a monkey and one from an environmental sample, were CC88-MRSA-V. Other environmental MRSA included one each, CC121-MRSA-VT, and CC772 -MRSA-V. Two were CC779-MRSA-VT, potentially a novel clone. All MRSA carried the blaZ gene. The aacA-aphD, dfrA, and erm (C) genes were very common in isolates from all sources. One macaque MRSA carried the resistance genes aphA3 and sat, neither previously identified in primate MRSA isolates. This current study suggests that humans could be a potential source of the MRSA in the macaques/environment and transmission may be linked to humans feeding the primates and/or living in close proximity to each other.
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Affiliation(s)
- Marilyn C. Roberts
- Department of Environmental and Occupational Health, School of Public Health, University of Washington, Seattle, WA, United States
| | | | - Stefan Monecke
- Leibniz Institute of Photonic Technology, Jena, Germany
- InfectoGnostics – Research Campus Jena, Jena, Germany
- Institute for Medical Microbiology and Hygiene, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Dresden, Germany
| | - Ralf Ehricht
- Leibniz Institute of Photonic Technology, Jena, Germany
- InfectoGnostics – Research Campus Jena, Jena, Germany
| | - Elke Müller
- Leibniz Institute of Photonic Technology, Jena, Germany
- InfectoGnostics – Research Campus Jena, Jena, Germany
| | | | | | | | | | - Sujana Pokharel
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal
| | - Reshma Tuladhar
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal
| | - Mukesh K. Chalise
- Nepal Biodiversity Research Society, Central Department of Zoology, Tribhuvan University, Kirtipur, Nepal
| | - Randall C. Kyes
- Department of Environmental and Occupational Health, School of Public Health, University of Washington, Seattle, WA, United States
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Monecke S, Syed MA, Khan MA, Ahmed S, Tabassum S, Gawlik D, Müller E, Reissig A, Braun SD, Ehricht R. Genotyping of methicillin-resistant Staphylococcus aureus from sepsis patients in Pakistan and detection of antibodies against staphylococcal virulence factors. Eur J Clin Microbiol Infect Dis 2019; 39:85-92. [PMID: 31482419 DOI: 10.1007/s10096-019-03695-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 08/28/2019] [Indexed: 05/15/2023]
Abstract
In order to obtain more information on the MRSA population structure in the border region of Afghanistan and Pakistan, we collected and genotyped MRSA causing bloodstream infections from a tertiary care hospital in Peshawar, Pakistan, that serves the local population as well as Afghan immigrants and refugees. Thirty-one MRSA isolates from 30 patients were included and characterized by microarray hybridisation. For 25 patients, serum samples were tested using protein microarrays in order to detect antibodies against staphylococcal virulence factors. The most conspicuous result was the high rate of PVL-positive MRSA. Twenty-two isolates (71%) harboured lukF/S-PV genes. The most common lineage was CC772-MRSA-V/VT (PVL+) to which eleven isolates were assigned. The second most common strain was, surprisingly, CC8-MRSA-[IV+ACME] (PVL+), "USA300" (9 isolates). Two isolates were tst1 positive CC22-MRSA-IV, matching the Middle Eastern "Gaza Epidemic Strain". Another two were PVL-positive CC30-MRSA-IV. The remaining isolates belonged to, possibly locally emerging, CC1, CC5, and CC8 strains with SCC mec IV elements. Twenty-three patient sera were positive for anti-PVL-IgG antibodies. Several questions arise from the present study. It can be assumed that MRSA and high rates of PVL-positive S. aureus/MRSA are a public health issue in the Afghanistan/Pakistan border region. A possible emergence of the "USA300" clone as well as of the CC772 lineage warrants further investigation.
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Affiliation(s)
- Stefan Monecke
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany. .,InfectoGnostics Research Campus Jena, Jena, Germany. .,Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, Dresden, Germany.
| | - Muhammad Ali Syed
- Department of Microbiology, The University of Haripur, Haripur, Pakistan
| | - Mushtaq Ahmad Khan
- Department of Microbiology, Hazara University Mansehra, Mansehra, Pakistan
| | - Shehzad Ahmed
- Department of Microbiology, Hazara University Mansehra, Mansehra, Pakistan
| | - Sadia Tabassum
- Department of Zoology, Hazara University Mansehra, Mansehra, Pakistan
| | | | - Elke Müller
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany.,InfectoGnostics Research Campus Jena, Jena, Germany
| | - Annett Reissig
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany.,InfectoGnostics Research Campus Jena, Jena, Germany
| | - Sascha D Braun
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany.,InfectoGnostics Research Campus Jena, Jena, Germany
| | - Ralf Ehricht
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany.,InfectoGnostics Research Campus Jena, Jena, Germany
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Rodrigues VCDC, de Oliveira IP, Bezerra RMN, Antunes AEC. Riscos microbiológicos de fórmulas para lactentes. BRAZILIAN JOURNAL OF FOOD TECHNOLOGY 2019. [DOI: 10.1590/1981-6723.05618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Resumo O objetivo desse trabalho foi discorrer sobre os principais perigos biológicos encontrados em fórmulas infantis a partir dos relatos da literatura, especialmente de registros de surtos. Este estudo é de cunho exploratório por meio de revisão bibliográfica, sendo utilizados como fontes de dados sites de busca científica. Dentre os principais micro-organismos causadores de doenças ligadas à ingestão de fórmulas infantis estão o Cronobacter sakazakii e a Salmonella enterica, porém outras bactérias, como Clostridium botulinum, Klebsiella pneumoniae, Staphylococcus aureus e Bacillus cereus, podem ser responsáveis por contaminações destas fórmulas. Visto que lactentes apresentam os sistemas imunológico e metabólico ainda em desenvolvimento, estes representam um público mais vulnerável a contaminantes, fazendo-se fundamental o oferecimento de alimentos seguros desde o processamento na indústria até a administração nas residências e unidades hospitalares.
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Johnson TR, Gómez BI, McIntyre MK, Dubick MA, Christy RJ, Nicholson SE, Burmeister DM. The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing. Int J Mol Sci 2018; 19:ijms19092699. [PMID: 30208569 PMCID: PMC6164292 DOI: 10.3390/ijms19092699] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/16/2022] Open
Abstract
The ecological community of microorganisms in/on humans, termed the microbiome, is vital for sustaining homeostasis. While culture-independent techniques have revealed the role of the gut microbiome in human health and disease, the role of the cutaneous microbiome in wound healing is less defined. Skin commensals are essential in the maintenance of the epithelial barrier function, regulation of the host immune system, and protection from invading pathogenic microorganisms. In this review, we summarize the literature derived from pre-clinical and clinical studies on how changes in the microbiome of various acute and chronic skin wounds impact wound healing tissue regeneration. Furthermore, we review the mechanistic insights garnered from model wound healing systems. Finally, in the face of growing concern about antibiotic-resistance, we will discuss alternative strategies for the treatment of infected wounds to improve wound healing and outcomes. Taken together, it has become apparent that commensals, symbionts, and pathogens on human skin have an intimate role in the inflammatory response that highlights several potential strategies to treat infected, non-healing wounds. Despite these promising results, there are some contradictory and controversial findings from existing studies and more research is needed to define the role of the human skin microbiome in acute and chronic wound healing.
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Affiliation(s)
- Taylor R Johnson
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - Belinda I Gómez
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Matthew K McIntyre
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
- School of Medicine, New York Medical College, Valhalla, New York, NY 10595, USA.
| | - Michael A Dubick
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Robert J Christy
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
| | - Susannah E Nicholson
- Department of Surgery, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229, USA.
| | - David M Burmeister
- United States Army Institute of Surgical Research, 3650 Chambers Pass, JBSA Fort Sam Houston, TX 78234, USA.
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Eriodictyol protects against Staphylococcus aureus-induced lung cell injury by inhibiting alpha-hemolysin expression. World J Microbiol Biotechnol 2018; 34:64. [PMID: 29671126 DOI: 10.1007/s11274-018-2446-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/14/2018] [Indexed: 10/17/2022]
Abstract
Staphylococcus aureus (S. aureus) is a common pathogenic bacterium that causes various diseases in both humans and animals. With the increased prevalence of methicillin-resistant S. aureus, the therapeutic effects of commonly used antibiotics are limited against S. aureus infection. Novel treatment strategies and new antibiotics are needed urgently to address this concern. Many studies have shown that virulence factors secreted from S. aureus play vital roles in their pathogenic processes. Alpha-hemolysin (Hla), an important exotoxin in S. aureus, is one such virulence factor that increases sensitivity of multiple host cells to S. aureus resulting in various diseases. Eriodictyol is a flavonoid compound that exists in many fruits and vegetables. In this study, eriodictyol was demonstrated to inhibit the expression of Hla by hemolysis assays, western blotting, and RT-qPCR at the sub-minimal inhibitory concentration. In live/dead and cytotoxicity assays, the results showed that eriodictyol protected A549 cells against Hla-induced injury in a dose-dependent manner. The minimal inhibitory concentration of eriodictyol against S. aureus was 512 µg/mL. Eriodictyol can downregulate S. aureus Hla at both the expressional and transcriptional levels without affecting S. aureus growth. In addition, cell assays had proved that eriodictyol could protect A549 cells against Hla damage. Eriodictyol could therefore have the potential to treat S. aureus infection targeting Hla.
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10
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Casabona MG, Kneuper H, Alferes de Lima D, Harkins CP, Zoltner M, Hjerde E, Holden MTG, Palmer T. Haem-iron plays a key role in the regulation of the Ess/type VII secretion system of Staphylococcus aureus RN6390. MICROBIOLOGY-SGM 2017; 163:1839-1850. [PMID: 29171824 PMCID: PMC5845736 DOI: 10.1099/mic.0.000579] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The Staphylococcus aureus type VII protein secretion system (T7SS) plays important roles in virulence and intra-species competition. Here we show that the T7SS in strain RN6390 is activated by supplementing the growth medium with haemoglobin, and its cofactor haemin (haem B). Transcript analysis and secretion assays suggest that activation by haemin occurs at a transcriptional and a post-translational level. Loss of T7 secretion activity by deletion of essC results in upregulation of genes required for iron acquisition. Taken together these findings suggest that the T7SS plays a role in iron homeostasis in at least some S. aureus strains.
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Affiliation(s)
- M Guillermina Casabona
- Division of Molecular Microbiology School of Life Sciences, University of Dundee, Dundee, UK
| | - Holger Kneuper
- Division of Molecular Microbiology School of Life Sciences, University of Dundee, Dundee, UK
| | - Daniela Alferes de Lima
- Division of Molecular Microbiology School of Life Sciences, University of Dundee, Dundee, UK
| | | | - Martin Zoltner
- Division of Molecular Microbiology School of Life Sciences, University of Dundee, Dundee, UK
| | - Erik Hjerde
- Department of Chemistry, Arctic University of Norway, Tromsø, Norway
| | | | - Tracy Palmer
- Division of Molecular Microbiology School of Life Sciences, University of Dundee, Dundee, UK
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Komuro H, Kato T, Okada S, Nakatani K, Matsumoto R, Nishida K, Iida H, Iida M, Tsujimoto S, Suganuma T. Toxic shock syndrome caused by suture abscess with methicillin-resistant Staphylococcus aureus (MRSA) with late onset after Caesarean section. IDCases 2017; 10:12-14. [PMID: 28791216 PMCID: PMC5536821 DOI: 10.1016/j.idcr.2017.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 11/28/2022] Open
Abstract
Toxic shock syndrome (TSS) is a rare but life-threatening multisystem disease known to develop in the early postoperative period after various surgery. We report a rare case in which a patient who underwent Caesarean section developed TSS caused by methicillin-resistant Staphylococcus aureus (MRSA) on the 39th postoperative day. She was treated with debridement because of the possible diagnosis of necrotizing soft tissue infections. Culture test from the resected specimen was positive for MRSA. She was diagnosed with TSS caused by suture abscess and was treated with intensive care including antimicrobials. After a good postoperative course, she was discharged on the 30th postoperative day. TSS occurring 4 weeks after operation is extremely rare, but late-onset of suture abscess is known to occur. We should becognizant of development with TSS beyond early postoperative period.
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Affiliation(s)
- Hiroyasu Komuro
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
| | - Takaharu Kato
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
- Department of Surgery, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama 330-8503, Japan
- Corresponding author at: Department of Surgery, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma-cho, Omiya-ku, Saitama, Saitama 330-8503, Japan.Department of SurgeryYokosuka General Hospital Uwamachi2-36 UwamachiYokosuka CityKanagawa238-8567Japan
| | - Shinichiro Okada
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
| | - Kensuke Nakatani
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
| | - Risa Matsumoto
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
| | - Kazuhiro Nishida
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
| | - Hiroyuki Iida
- Department of Internal Medicine, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka, Kanagawa 238-8567, Japan
| | - Maki Iida
- Department of Pathology, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka, Kanagawa 238-8567, Japan
| | - Shiro Tsujimoto
- Department of Pathology, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka, Kanagawa 238-8567, Japan
| | - Toshiyuki Suganuma
- Department of Surgery, Yokosuka General Hospital Uwamachi, 2-36 Uwamachi, Yokosuka City, Kanagawa 238-8567, Japan
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12
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Abstract
The virulence of many bacterial pathogens, including the important human pathogen Staphylococcus aureus, depends on the secretion of frequently large amounts of toxins. Toxin production involves the need for the bacteria to make physiological adjustments for energy conservation. While toxins are primarily targets of gene regulation, such changes may be accomplished by regulatory functions of the toxins themselves. However, mechanisms by which toxins regulate gene expression have remained poorly understood. We show here that the staphylococcal phenol-soluble modulin (PSM) toxins have gene regulatory functions that, in particular, include inducing expression of their own transport system by direct interference with a GntR-type repressor protein. This capacity was most pronounced in PSMs with low cytolytic capacity, demonstrating functional specification among closely related members of that toxin family during evolution. Our study presents a molecular mechanism of gene regulation by a bacterial toxin that adapts bacterial physiology to enhanced toxin production. Toxins play a major role in many bacterial diseases. When toxins are produced during infection, the bacteria need to balance this energy-consuming task with other physiological processes. However, it has remained poorly understood how toxins can impact gene expression to trigger such adaptations. We found that specific members of a toxin family in the major human pathogen Staphylococcus aureus have evolved for gene regulatory purposes. These specific toxins interact with a DNA-binding regulator protein to enable production of the toxin export machinery and ascertain that the machinery is not expressed when toxins are not made and it is not needed. Our study gives mechanistic insight into how toxins may directly adjust bacterial physiology to times of toxin production during infection.
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Kong C, Neoh HM, Nathan S. Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy. Toxins (Basel) 2016; 8:toxins8030072. [PMID: 26999200 PMCID: PMC4810217 DOI: 10.3390/toxins8030072] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/03/2016] [Accepted: 03/10/2016] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.
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Affiliation(s)
- Cin Kong
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
| | - Hui-min Neoh
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, 56000 Cheras, Kuala Lumpur, Malaysia.
| | - Sheila Nathan
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia.
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Javid Khojasteh V, Alfakhri S, Foster HA. Effects of Silver Sulphadiazine on Production of Extracellular Proteins by Strains of Staphylococcus Aureus Isolated from Burns Wound. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2016; 15:653-60. [PMID: 27642339 PMCID: PMC5018296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies had shown that sub-inhibitory concentrations of silver sulphadiazine (AgSD) stimulated the production of Toxic Shock Syndrome Toxin-1 in certain strains (responder strains) of Staphylococcus aureus and that protease production was also affected. No changes were detected in other strains (non-responders). Extracellular proteins from eleven responder and non-responder strains grown with and without AgSD were separated by SDS PAGE. There were three classes of response, responder strains that showed enhancement of synthesis of certain proteins, non-responder strains that showed no change and responder strains that showed a general decrease in exoprotein production in the early stages of growth. The results showed that the effects of AgSD were complex and that S. aureus strains were heterogenous with respect to their response to sub-inhibitory concentrations of AgSD.
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Affiliation(s)
- Vahideh Javid Khojasteh
- Department of Microbiology,Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran .,E-mail:
| | - Souad Alfakhri
- Biomedical Sciences Research Institute, School of Environment and Life Sciences, University of Salford, The Crescent, Salford M5 4WT, UK .
| | - Howard Anthony Foster
- Biomedical Sciences Research Institute, School of Environment and Life Sciences, University of Salford, The Crescent, Salford M5 4WT, UK.
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Superantigen-Producing Staphylococcus aureus Elicits Systemic Immune Activation in a Murine Wound Colonization Model. Toxins (Basel) 2015; 7:5308-19. [PMID: 26670252 PMCID: PMC4690136 DOI: 10.3390/toxins7124886] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/16/2015] [Accepted: 12/01/2015] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus, the most common cause of wound infection, produces several exotoxins, including superantigens (SAgs). SAgs are the potent activators of the immune system. Given this unique property, we hypothesized that SAgs produced by S. aureus in wounds would have local, as well as systemic immunologic effects. We tested our hypothesis using a novel staphylococcal skin wound infection model in transgenic mice expressing HLA-DR3. Skin wounds were left uninfected or colonized with S. aureus strains producing SAgs or an isogenic strain not producing any SAg. Animals with wounds challenged with SAg-producing S. aureus had increased morbidity and lower serum IL-17 levels compared to those challenged with the SAg non-producing S. aureus (p = 0.027 and p = 0.032, respectively). At Day 8 following microbial challenge, compared to mice with uninfected wounds, the proportion of Vβ8⁺CD4⁺ T cells was increased, while the proportion of Vβ8⁺CD8⁺ T cells was decreased only in the spleens of mice challenged with SAg-producing S. aureus (p < 0.001). No such changes were measured in mice challenged with SAg non-producing S. aureus. Lungs, livers and kidneys from mice challenged with SAg-producing, but not SAg non-producing, S. aureus showed inflammatory changes. Overall, SAg-mediated systemic immune activation in wounds harboring S. aureus may have clinical implications.
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Emergence of Panton-Valentine leukocidin-positive ST59 methicillin-susceptible Staphylococcus aureus with high cytolytic peptide expression in association with community-acquired pediatric osteomyelitis complicated by pulmonary embolism. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2015; 48:565-73. [DOI: 10.1016/j.jmii.2014.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/19/2014] [Accepted: 04/23/2014] [Indexed: 11/20/2022]
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Andrey DO, Jousselin A, Villanueva M, Renzoni A, Monod A, Barras C, Rodriguez N, Kelley WL. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus. PLoS One 2015; 10:e0135579. [PMID: 26275216 PMCID: PMC4537247 DOI: 10.1371/journal.pone.0135579] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 07/24/2015] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1), encoded by tst(H), and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1), RNAIII, rot, and the alternative stress sigma factor sigB (σB). By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression.
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Affiliation(s)
- Diego O. Andrey
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Ambre Jousselin
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Maite Villanueva
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Antoinette Monod
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Christine Barras
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Natalia Rodriguez
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - William L. Kelley
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
- * E-mail:
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18
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A fatal case of staphylococcal toxic shock syndrome. Med J Armed Forces India 2015; 71:S107-10. [PMID: 26265799 DOI: 10.1016/j.mjafi.2013.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 05/28/2013] [Indexed: 11/22/2022] Open
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Differences in Staphylococcus aureus nasal carriage and molecular characteristics among community residents and healthcare workers at Sun Yat-Sen University, Guangzhou, Southern China. BMC Infect Dis 2015. [PMID: 26223250 PMCID: PMC4520063 DOI: 10.1186/s12879-015-1032-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background The pathogenic potential and commensal nature of Staphylococcus aureus allows for easy transmission both within and outside of the hospital environment, and nasal carriage may be responsible for some serious infections. This study aimed to determine the molecular and epidemiological characteristics of nasal colonization by S. aureus in community residents (CR) and healthcare workers (HW) at Sun Yat-Sen University, Guangzhou, China. Methods A total of 589 volunteers, both CR (n = 297) and HW (n = 292), were recruited. Each subject completed a questionnaire, and specimens were obtained from the anterior nares for S. aureus screening. Genotypic analysis included pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, and virulence gene detection. Results A total of 138 S. aureus isolates were recovered from separate subjects (23.4 %, 138/589), with four isolates showing methicillin resistance (0.7 %, 4/589). The prevalence of S. aureus carriage was 25.3 % (75/297) in CR and 21.6 % (63/292) in HW. Methicillin-resistant S. aureus (MRSA) were isolated from one CR (0.3 %, 1/297) and three HW (1.0 %, 3/292). The most common risk factors for S. aureus carriage in CR were being male, age ≤ 30 years, and nasal cavity cleaning habits. Having a household member in the healthcare profession was associated with increased risk among HW. Sequence type (ST)188 and ST59 were the most prevalent among the 20 observed STs, accounting for 14.6 % and 12.2 % of all isolates, respectively. The four MRSA isolates presented four different STs, with one isolate carrying a type IVa SCCmec element and the other three isolates containing type III SCCmec. PFGE analysis grouped the 129 isolates into 23 pulsotypes, with profiles A, N, E, L, and O the most prevalent. The Panton-Valentine leucocidin gene (pvl) was identified in two of the 138 isolates, while 57.5 % of isolates carried both the Staphylococcus aureus enterotoxin A (sea) and enterotoxin B (seb) genes. Conclusions These data indicate a low prevalence of nasal MRSA carriage but evidence of molecular heterogeneity among S. aureus isolates from CR and HW at Sun Yat-Sen University, Guangzhou. Differences in epidemiological and molecular characteristics of S. aureus between CR and HW populations may be useful for the understanding and prevention of S. aureus infection. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1032-7) contains supplementary material, which is available to authorized users.
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Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) and Fatal Pneumonia with Pediatric Deaths in Krasnoyarsk, Siberian Russia: Unique MRSA's Multiple Virulence Factors, Genome, and Stepwise Evolution. PLoS One 2015; 10:e0128017. [PMID: 26047024 PMCID: PMC4457420 DOI: 10.1371/journal.pone.0128017] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 04/21/2015] [Indexed: 12/25/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a common multidrug-resistant (MDR) pathogen. We herein discussed MRSA and its infections in Krasnoyarsk, Siberian Russia between 2007 and 2011. The incidence of MRSA in 3,662 subjects was 22.0% and 2.9% for healthcare- and community-associated MRSA (HA- and CA-MRSA), respectively. The 15-day mortality rates for MRSA hospital- and community-acquired pneumonia (HAP and CAP) were 6.5% and 50%, respectively. MRSA CAP cases included pediatric deaths; of the MRSA pneumonia episodes available, ≥27.3% were associated with bacteremia. Most cases of HA-MRSA examined exhibited ST239/spa3(t037)/SCCmecIII.1.1.2 (designated as ST239Kras), while all CA-MRSA cases examined were ST8/spa1(t008)/SCCmecIV.3.1.1(IVc) (designated as ST8Kras). ST239Kras and ST8Kras strongly expressed cytolytic peptide (phenol-soluble modulin α, PSMα; and δ-hemolysin, Hld) genes, similar to CA-MRSA. ST239Kras pneumonia may have been attributed to a unique set of multiple virulence factors (MVFs): toxic shock syndrome toxin-1 (TSST-1), elevated PSMα/Hld expression, α-hemolysin, the staphylococcal enterotoxin SEK/SEQ, the immune evasion factor SCIN/SAK, and collagen adhesin. Regarding ST8Kras, SEA was included in MVFs, some of which were common to ST239Kras. The ST239Kras (strain OC3) genome contained: a completely unique phage, φSa7-like (W), with no att repetition; S. aureus pathogenicity island SaPI2R, the first TSST-1 gene-positive (tst+) SaPI in the ST239 lineage; and a super copy of IS256 (≥22 copies/genome). ST239Kras carried the Brazilian SCCmecIII.1.1.2 and United Kingdom-type tst. ST239Kras and ST8Kras were MDR, with the same levofloxacin resistance mutations; small, but transmissible chloramphenicol resistance plasmids spread widely enough to not be ignored. These results suggest that novel MDR and MVF+ HA- and CA-MRSA (ST239Kras and ST8Kras) emerged in Siberian Russia (Krasnoyarsk) associated with fatal pneumonia, and also with ST239Kras, a new (Siberian Russian) clade of the ST239 lineage, which was created through stepwise evolution during its potential transmission route of Brazil-Europe-Russia/Krasnoyarsk, thereby selective advantages from unique MVFs and the MDR.
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Chung JW, Greenwood-Quaintance KE, Karau MJ, Tilahun A, Khaleghi SR, Chowdhary VR, David CS, Patel R, Rajagopalan G. Superantigens produced by catheter-associated Staphylococcus aureus elicit systemic inflammatory disease in the absence of bacteremia. J Leukoc Biol 2015; 98:271-81. [PMID: 25979434 DOI: 10.1189/jlb.4a1214-577rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 04/17/2015] [Indexed: 11/24/2022] Open
Abstract
SAgs, produced by Staphylococcus aureus, play a major role in the pathogenesis of invasive staphylococcal diseases by inducing potent activation of the immune system. However, the role of SAgs, produced by S. aureus, associated with indwelling devices or tissues, are not known. Given the prevalence of device-associated infection with toxigenic S. aureus in clinical settings and the potency of SAgs, we hypothesized that continuous exposure to SAgs produced by catheter-associated S. aureus could have systemic consequences. To investigate these effects, we established a murine in vivo catheter colonization model. One centimeter long intravenous catheters were colonized with a clinical S. aureus isolate producing SAgs or isogenic S. aureus strains, capable or incapable of producing SAg. Catheters were subcutaneously implanted in age-matched HLA-DR3, B6, and AE(o) mice lacking MHC class II molecules and euthanized 7 d later. There was no evidence of systemic infection. However, in HLA-DR3 transgenic mice, which respond robustly to SSAgs, the SSAg-producing, but not the nonproducing strains, caused a transient increase in serum cytokine levels and a protracted expansion of splenic CD4(+) T cells expressing SSAg-reactive TCR Vβ8. Lungs, livers, and kidneys from these mice showed infiltration with CD4(+) and CD11b(+) cells. These findings were absent in B6 and AE(o) mice, which are known to respond poorly to SSAgs. Overall, our novel findings suggest that systemic immune activation elicited by SAgs, produced by S. aureus colonizing foreign bodies, could have clinical consequences in humans.
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Affiliation(s)
- Jin-Won Chung
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Kerryl E Greenwood-Quaintance
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Melissa J Karau
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Ashenafi Tilahun
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Shahryar Rostamkolaei Khaleghi
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Vaidehi R Chowdhary
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Chella S David
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Robin Patel
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Govindarajan Rajagopalan
- *Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Divisions of Infectious Diseases and Rheumatology, Department of Medicine, and Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA; and Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
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Superantigens in Staphylococcus aureus isolated from prosthetic joint infection. Diagn Microbiol Infect Dis 2014; 81:201-7. [PMID: 25619753 DOI: 10.1016/j.diagmicrobio.2014.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/03/2014] [Accepted: 11/14/2014] [Indexed: 10/24/2022]
Abstract
Staphylococcus aureus is a common cause of prosthetic joint infection (PJI). The prevalence of superantigens (SAgs) among PJI-associated S. aureus is unknown. Eighty-four S. aureus isolates associated with PJI isolated between 1999 and 2006 were studied. SAg genes, sea, seb, sec, sed, see, seg, seh, sei, and tst, were assayed by PCR. Seventy-eight (92.9%) isolates carried at least 1 SAg gene studied, with 61 (72.6%) harboring more than 1. seg was most commonly (70.2%), and seh was least frequently (4.8%) detected. tst-positive isolates were associated with early infection and increased erythrocyte sedimentation rate at diagnosis (P=0.006 and P=0.021, respectively). seg and sei were associated with methicillin resistance (P=0.008 and P=0.002, respectively). A majority of PJI-associated isolates studied produced biologically active SAgs in both planktonic and biofilm growth modes. SAg genes are prevalent in S. aureus causing PJI.
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Chung JW, Karau MJ, Greenwood-Quaintance KE, Ballard AD, Tilahun A, Khaleghi SR, David CS, Patel R, Rajagopalan G. Superantigen profiling of Staphylococcus aureus infective endocarditis isolates. Diagn Microbiol Infect Dis 2014; 79:119-24. [PMID: 24745820 DOI: 10.1016/j.diagmicrobio.2014.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/05/2014] [Accepted: 03/09/2014] [Indexed: 12/20/2022]
Abstract
The frequency of superantigen production among Staphylococcus aureus isolates associated with endocarditis is not well defined. We tested 154 S. aureus isolates from definite infective endocarditis cases for the presence of staphylococcal enterotoxins A-E, H, and TSST-1 by PCR, enzyme-linked immunosorbent assay, and using an HLA-DR3 transgenic mouse splenocyte proliferation assay. Sixty-three isolates (50.8%) tested positive for at least 1 superantigen gene, with 21 (16.9%) testing positive for more than 2. tst (28.6%) was most common, followed by seb (27%), sea (22.2%), sed (20.6%), see (17.5%), and sec (11.1%). Of 41 methicillin-resistant S. aureus, 21 had superantigen genes, with sed being more frequently detected in this group compared to methicillin-susceptible S. aureus (P < 0.05). Superantigen genes were not associated with mortality (P = 0.81). 75% of PCR-positive isolates induced robust splenocyte proliferation. Overall, more than half of S. aureus isolates causing endocarditis carry superantigen genes, of which most are functional.
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Affiliation(s)
- Jin-Won Chung
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA; Division of Infectious Diseases, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Melissa J Karau
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kerryl E Greenwood-Quaintance
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Alessandro D Ballard
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Ashenafi Tilahun
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - Chella S David
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Robin Patel
- Divisions of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA; Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Govindarajan Rajagopalan
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA; Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA.
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Aman MJ, Adhikari RP. Staphylococcal bicomponent pore-forming toxins: targets for prophylaxis and immunotherapy. Toxins (Basel) 2014; 6:950-72. [PMID: 24599233 PMCID: PMC3968370 DOI: 10.3390/toxins6030950] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/22/2014] [Accepted: 02/26/2014] [Indexed: 01/09/2023] Open
Abstract
Staphylococccus aureus represents one of the most challenging human pathogens as well as a common colonizer of human skin and mucosal surfaces. S. aureus causes a wide range of diseases from skin and soft tissue infection (SSTI) to debilitating and life-threatening conditions such as osteomyelitis, endocarditis, and necrotizing pneumonia. The range of diseases reflects the remarkable diversity of the virulence factors produced by this pathogen, including surface antigens involved in the establishment of infection and a large number of toxins that mediate a vast array of cellular responses. The staphylococcal toxins are generally believed to have evolved to disarm the innate immune system, the first line of defense against this pathogen. This review focuses on recent advances on elucidating the biological functions of S. aureus bicomponent pore-forming toxins (BCPFTs) and their utility as targets for preventive and therapeutic intervention. These toxins are cytolytic to a variety of immune cells, primarily neutrophils, as well as cells with a critical barrier function. The lytic activity of BCPFTs towards immune cells implies a critical role in immune evasion, and a number of epidemiological studies and animal experiments relate these toxins to clinical disease, particularly SSTI and necrotizing pneumonia. Antibody-mediated neutralization of this lytic activity may provide a strategy for development of toxoid-based vaccines or immunotherapeutics for prevention or mitigation of clinical diseases. However, certain BCPFTs have been proposed to act as danger signals that may alert the immune system through an inflammatory response. The utility of a neutralizing vaccination strategy must be weighed against such immune-activating potential.
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Affiliation(s)
- M Javad Aman
- Integrated BioTherapeutics Inc., 21 Firstfield Rd., Gaithersburg, MD 20878, USA.
| | - Rajan P Adhikari
- Integrated BioTherapeutics Inc., 21 Firstfield Rd., Gaithersburg, MD 20878, USA.
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Stieber B, Monecke S, Müller E, Baier V, Coombs GW, Ehricht R. Development and usage of protein microarrays for the quantitative measurement of Panton-Valentine leukocidin. Mol Cell Probes 2013; 28:123-32. [PMID: 24308917 DOI: 10.1016/j.mcp.2013.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/21/2013] [Accepted: 11/22/2013] [Indexed: 01/31/2023]
Abstract
Staphylococcus aureus is a human pathogen that can harbour several genes encoding exotoxins including leukocidins. A clinically most relevant factor is Panton-Valentine leukocidin (PVL) because of its association with chronic, recurrent or severe skin and soft tissue infections. In this study an antibody array was designed and used to obtain an overview about the in vitro PVL expression levels of 266 clinical isolates of MRSA as well as of MSSA belonging to a wide variety of clonal complexes. For that purpose, a novel precipitation based method was used. Unknown PVL concentrations were determined by mapping the signal intensities for spotted monoclonal antibodies to calibration curves that resulted from experiments with known concentrations of recombinant LukF-PV. In most cases, isolates belonging to one clonal complex (CC) showed similar PVL expressions. However, there were also CCs with widely varying PVL concentrations. First analyses, based on in vitro PVL measurements, showed low PVL concentrations in isolates from severe and fatal conditions that are not associated with PVL, such as sepsis, while isolates from skin and soft tissue infections yielded higher concentrations. Agr-group I and IV isolates generally produced more PVL than isolates from agr-groups II and III. The few isolates harbouring the gene encoding toxic shock syndrome toxin (tst1) were particularly low level PVL producers. However, these issues warrant further studies. The method described herein allows rapid quantification of expressed proteins such as PVL in collections of clinical isolates in order to correlate with clinical or genotypic data with a potential for further parallelisation.
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Affiliation(s)
- Bettina Stieber
- Alere Technologies GmbH, Jena, Germany; Institute for Medical Microbiology and Hygiene, Technical University of Dresden, Dresden, Germany.
| | - Stefan Monecke
- Alere Technologies GmbH, Jena, Germany; Institute for Medical Microbiology and Hygiene, Technical University of Dresden, Dresden, Germany
| | | | | | - Geoffrey W Coombs
- Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine - WA, Royal Perth Hospital, Perth, Western Australia, Australia; Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS), Typing and Research, School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
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Asensi GF, de Sales NFF, Dutra FF, Feijó DF, Bozza MT, Ulrich RG, Miyoshi A, de Morais K, Azevedo VADC, Silva JT, Le Loir Y, Paschoalin VMF. Oral immunization with Lactococcus lactis secreting attenuated recombinant staphylococcal enterotoxin B induces a protective immune response in a murine model. Microb Cell Fact 2013; 12:32. [PMID: 23561053 PMCID: PMC3623888 DOI: 10.1186/1475-2859-12-32] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/22/2013] [Indexed: 11/14/2022] Open
Abstract
Background Staphylococcus aureus is unrestrictedly found in humans and in animal species that maintain thermal homeostasis. Inadequate cleaning of processing equipment or inappropriate handling can contaminate processed food and cause severe food poisoning. Staphylococcal enterotoxin B (SEB), a potent superantigenic exotoxin, is produced by 50% of clinical isolates of S. aureus and is associated with massive food poisoning and with the induction of toxic shock syndrome. Results A gene sequence encoding a recombinant SEB (rSEB), devoid of superantigenic activity, was successfully cloned and expressed in a cytoplasmic or a secreted form in the food-grade lactic acid bacterium Lactococcus lactis. The recombinant protein detected in the cytoplasm or in the culture medium exhibited the expected molecular mass and was recognized by a SEB-polyclonal antibody. Oral immunization with the recombinant L. lactis strains induced a protective immune response in a murine model of S. aureus infection. Immunized mice survived intraperitoneal challenge with an S. aureus SEB-producer strain. Counts of S. aureus in the spleen of rSEB-immunized mice were significantly reduced. The rSEB-immunized mice showed significant titers of anti-SEB IgA and IgG in stools and serum, respectively. Both recombinant L. lactis strains were able to elicit cellular or systemic immune responses in mice, with no significant difference if rSEB was produced in its cytoplasmic or secreted form. However, recombinant L. lactis expressing the cytoplasmic rSEB increased the survival rate of the challenged mice by 43%. Conclusions These findings show the vaccine efficacy of L. lactis carrying an attenuated SEB, in a murine model, following lethal S. aureus challenge.
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Genetic nature and virulence of community-associated methicillin-resistant Staphylococcus aureus. Biomedicine (Taipei) 2013. [DOI: 10.1016/j.biomed.2012.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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A new local variant (ST764) of the globally disseminated ST5 lineage of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) carrying the virulence determinants of community-associated MRSA. Antimicrob Agents Chemother 2013; 57:1589-95. [PMID: 23318800 DOI: 10.1128/aac.01147-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The ST5 lineage of methicillin-resistant Staphylococcus aureus (MRSA) is one of the most globally disseminated hospital-associated MRSA (HA-MRSA) lineages. We isolated a new local variant (designated ST764) over at least 5 years that causes invasive infections, including necrotizing fasciitis, and is carried by medical students, as well as household members. Analysis of the genome sequence of one isolate compared to that of the reference ST5 strain revealed that ST764 had acquired virulence traits similar to those of community-associated MRSA (CA-MRSA) through the acquisition of two new mobile genetic elements, ACMEII and SaPInn54, which carried ACME arcA and the staphylococcal enterotoxin B gene (seb), respectively, and through enhanced expression of cytolytic peptide genes, although ST764 was negative for Panton-Valentine leukocidin. Other differences between ST764 and ST5 included the acquisition of an ACMEII-related cassette (cJR1), prophage φ2NN54, and streptococcal Tn5251 and decreased numbers of copies of Tn554. As for superantigen genes, although the two possessed seg, sei, sem, sen, and seo, ST764 lacked tst, sec, sel, and sep. The data suggest that ST764 MRSA is a novel hybrid variant of ST5 HA-MRSA with the characteristics of CA-MRSA and that the evolution of ST764 includes multiple steps, e.g., acquisition of novel or nonstaphylococcal mobile elements.
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Distribution, polymorphism and temporal expression of egc in Staphylococcus aureus isolates from various foods in China. Food Control 2013. [DOI: 10.1016/j.foodcont.2012.06.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Prophage Typing of Methicillin Resistant Staphylococcus aureus Isolated from a Tertiary Care Hospital in Tehran, Iran. Jundishapur J Microbiol 2012. [DOI: 10.5812/jjm.4616] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Linezolid is superior to vancomycin in experimental pneumonia caused by Superantigen-Producing staphylococcus aureus in HLA class II transgenic mice. Antimicrob Agents Chemother 2012; 56:5401-5. [PMID: 22850509 DOI: 10.1128/aac.01080-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Superantigens (SAg), the potent activators of the immune system, are important determinants of Staphylococcus aureus virulence and pathogenicity. Superior response to SAg in human leukocyte antigen (HLA)-DR3 transgenic mice rendered them more susceptible than C57BL/6 mice to pneumonia caused by SAg-producing strains of S. aureus. Linezolid, a bacterial protein synthesis inhibitor, was superior to vancomycin in inhibiting SAg production by S. aureus in vitro and conferred greater protection from pneumonia caused by SAg-producing staphylococci.
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In vitro studies of toxic shock toxin-1-secreting Staphylococcus aureus and implications for burn care in children. Pediatr Infect Dis J 2012; 31:e73-7. [PMID: 22301473 DOI: 10.1097/inf.0b013e3182493b21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The main etiologic agent of toxic shock syndrome is the toxic shock syndrome toxin-1 (TSST-1) protein secreted by Staphylococcus aureus. Diagnosis of toxic shock syndrome is difficult and is significantly underdiagnosed in young children with burns due to the nonspecific presentation coupled with a rapid deterioration in patient condition. METHODS The lytic and cytolytic activity of a number of clinical and laboratory TSST-1-positive strains of methicillin-susceptible S. aureus (101, 253, 279 and RN4282, respectively) and Pseudomonas aeruginosa PAO1 strain were tested in vitro using an assay designed to assess the relative exotoxin activity of bacteria using phospholipid vesicles and a T cell toxicity assay. In addition, the activity of lytic exotoxins such as δ -toxin and the secretion of nonlytic TSST-1 toxin from S. aureus was measured using the vesicle assay and Western blotting over the 20-hour growth of TSST-1-positive S. aureus culture. RESULTS Both the vesicle and T cell assays suggest a lytic exotoxin-mediated mechanism of vesicle rupture and T cell death, with high levels of vesicle lysis and T cell toxicity. It is important to note that the clinical TSST-1-positive methicillin-susceptible S. aureus strains exhibited lytic exotoxin production as well as TSST-1 expression as confirmed by Western blot. CONCLUSION We suggest that there is no correlation between the expression of TSST-1 and lack of exotoxin production. We also suggest that apurulence in an S. aureus-infected burn wound in a child should not be used to rule out toxic shock syndrome.
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Chocs toxiques dans les infections à cocci à Gram positif. MEDECINE INTENSIVE REANIMATION 2012. [DOI: 10.1007/s13546-012-0460-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Cheung GYC, Otto M. The potential use of toxin antibodies as a strategy for controlling acute Staphylococcus aureus infections. Expert Opin Ther Targets 2012; 16:601-12. [PMID: 22530584 DOI: 10.1517/14728222.2012.682573] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION The pandemic human pathogen, Staphylococcus aureus, displays high levels of antibiotic resistance and is a major cause of hospital- and community-associated infections. S. aureus disease manifestation is to a great extent due to the production of a large arsenal of virulence factors, which include a series of secreted toxins. Antibodies to S. aureus toxins are found in people who are infected or asymptomatically colonized with S. aureus. Immunotherapies consisting of neutralizing anti-toxin antibodies could provide immediate aid to patients with impaired immune systems or in advanced stages of disease. AREAS COVERED Important S. aureus toxins, their roles in pathogenesis, rationales for selecting S. aureus toxins for immunization efforts, and caveats associated with monoclonal antibody-based passive immunization are discussed. This review will focus on hyper-virulent community-associated methicillin-resistant S. aureus because of their recent surge and clinical importance. EXPERT OPINION Antibodies against genome-encoded toxins may be more broadly applicable than those directed against toxins found only in a sub-population of S. aureus isolates. Furthermore, there is substantial functional redundancy among S. aureus toxins. Thus, an optimal anti-S. aureus formulation may consist of multiple antibodies directed against a series of key S. aureus genome-encoded toxins.
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Affiliation(s)
- Gordon Y C Cheung
- Laboratory of Human Bacterial Pathogenesis, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
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Vandenesch F, Lina G, Henry T. Staphylococcus aureus hemolysins, bi-component leukocidins, and cytolytic peptides: a redundant arsenal of membrane-damaging virulence factors? Front Cell Infect Microbiol 2012; 2:12. [PMID: 22919604 PMCID: PMC3417661 DOI: 10.3389/fcimb.2012.00012] [Citation(s) in RCA: 233] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Accepted: 01/31/2012] [Indexed: 12/17/2022] Open
Abstract
One key aspect of the virulence of Staphylococcus aureus lies in its ability to target the host cell membrane with a large number of membrane-damaging toxins and peptides. In this review, we describe the hemolysins, the bi-component leukocidins (which include the Panton Valentine leukocidin, LukAB/GH, and LukED), and the cytolytic peptides (phenol soluble modulins). While at first glance, all of these factors might appear redundant, it is now clear that some of these factors play specific roles in certain S. aureus life stages and diseases or target specific cell types or species. In this review, we present an update of the literature on toxin receptors and their cell type and species specificities. Furthermore, we review epidemiological studies and animal models illustrating the role of these membrane-damaging factors in various diseases. Finally, we emphasize the interplay of these factors with the host immune system and highlight all their non-lytic functions.
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Affiliation(s)
- François Vandenesch
- Bacterial Pathogenesis and Innate Immunity Laboratory, INSERM U851 "Immunity, Infection and Vaccination," Lyon, France
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36
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Hennekinne JA, De Buyser ML, Dragacci S. Staphylococcus aureus and its food poisoning toxins: characterization and outbreak investigation. FEMS Microbiol Rev 2011; 36:815-36. [PMID: 22091892 DOI: 10.1111/j.1574-6976.2011.00311.x] [Citation(s) in RCA: 538] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 09/15/2011] [Accepted: 10/03/2011] [Indexed: 11/29/2022] Open
Abstract
Staphylococcal food poisoning (SFP) is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs) preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All of them have superantigenic activity whereas half of them have been proved to be emetic, representing a potential hazard for consumers. This review, divided into four parts, will focus on the following: (1) the worldwide story of SFP outbreaks, (2) the characteristics and behaviour of S. aureus in food environment, (3) the toxinogenic conditions and characteristics of SEs, and (4) SFP outbreaks including symptomatology, occurrence in the European Union and currently available methods used to characterize staphylococcal outbreaks.
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Affiliation(s)
- Jacques-Antoine Hennekinne
- French Agency for Food, Environmental and Occupational Health & Safety (Anses), Food Safety Laboratory of Maisons-Alfort, European Union Reference Laboratory for Coagulase Positive Staphylococci, Maisons-Alfort, France.
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Li Z, Stevens DL, Hamilton SM, Parimon T, Ma Y, Kearns AM, Ellis RW, Bryant AE. Fatal S. aureus hemorrhagic pneumonia: genetic analysis of a unique clinical isolate producing both PVL and TSST-1. PLoS One 2011; 6:e27246. [PMID: 22110621 PMCID: PMC3207839 DOI: 10.1371/journal.pone.0027246] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/12/2011] [Indexed: 02/02/2023] Open
Abstract
In 2008, an unusual strain of methicillin-sensitive Staphylococcus aureus (MSSA68111), producing both Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin-1 (TSST-1), was isolated from a fatal case of necrotizing pneumonia. Because PVL/TSST-1 co-production in S. aureus is rare, we characterized the molecular organization of these toxin genes in strain 68111. MSSA68111 carries the PVL genes within a novel temperate prophage we call ФPVLv68111 that is most similar, though not identical, to phage ФPVL--a phage type that is relatively rare worldwide. The TSST-1 gene (tst) in MSSA68111 is carried on a unique staphylococcal pathogenicity island (SaPI) we call SaPI68111. Features of SaPI68111 suggest it likely arose through multiple major recombination events with other known SaPIs. Both ФPVLv68111 and SaPI68111 are fully mobilizable and therefore transmissible to other strains. Taken together, these findings suggest that hypervirulent S. aureus have the potential to emerge worldwide.
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Affiliation(s)
- Zhi Li
- Veterans Affairs Medical Center, Boise, Idaho, United States of America.
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Lazarevic V, Beaume M, Corvaglia A, Hernandez D, Schrenzel J, François P. Epidemiology and virulence insights from MRSA and MSSA genome analysis. Future Microbiol 2011; 6:513-32. [DOI: 10.2217/fmb.11.38] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen responsible for a wide diversity of infections ranging from localized to life threatening diseases. From 1961 and the emergence of methicillin-resistant S. aureus (MRSA), this bacterium has shown a particular capacity to survive and adapt to drastic environmental changes and since the beginning of the 1990s it has spread worldwide. Until recently, S. aureus was considered as the prototype of a nosocomial pathogen but it has now been recognized as an agent responsible for outbreaks in the community. Several recent reports suggest that the epidemiology of MRSA is changing. Understanding of pathogenicity, virulence and emergence of epidemic clones within MRSA populations is not clearly defined, despite several attempts to identify common molecular features between strains that share similar epidemiological and/or virulence behavior. These studies included: pattern profiling of bacterial adhesins, analysis of clonal complex groups, molecular genotyping and enterotoxin content analysis. To date, all approaches failed to find a correlation between molecular determinants and clinical outcomes. We hypothesize that the capacity of the bacterium to become more invasive or virulent is determined by genetics. The utilization of massively parallel methods of analysis is therefore ideal to study the contribution of genetics. Therefore, this article focuses on the entire genome including coding sequences as well as noncoding sequences. This high resolution approach allows the monitoring micro- and macroevolution of MRSA and identification of specific genomic markers of evolution of invasive or highly virulent phenotypes.
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Affiliation(s)
- Vladimir Lazarevic
- Genomic Research Laboratory, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland
| | - Marie Beaume
- Genomic Research Laboratory, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland
| | - Anna Corvaglia
- Department of Microbiology & Molecular Medicine, University Medical Centre, University of Geneva, 1211 Geneva 4, Switzerland
| | - David Hernandez
- Genomic Research Laboratory, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland
| | - Jacques Schrenzel
- Genomic Research Laboratory, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland
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Control of the Staphylococcus aureus toxic shock tst promoter by the global regulator SarA. J Bacteriol 2010; 192:6077-85. [PMID: 20870770 DOI: 10.1128/jb.00146-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Staphylococcus aureus SarA global regulator controls the expression of numerous virulence genes, often in conjunction with the agr quorum-sensing system and its effector RNA, RNAIII. In the present study, we have examined the role of both SarA and RNAIII on the regulation of the promoter of tst, encoding staphylococcal superantigen toxic shock syndrome toxin 1 (TSST-1). In vitro DNA-protein interaction studies with purified SarA using gel shift and DNase I protection assays revealed one strong SarA binding site and evidence for a weaker site nearby within the minimal 400-bp promoter region upstream of tst. In vivo analysis of tst promoter activation using a p(tst)-luxAB reporter inserted in the chromosome revealed partial but not complete loss of tst expression in a Δhld-RNAIII strain. In contrast, disruption of sarA abrogated tst expression. No significant tst expression was found for the double Δhld-RNAIII-ΔsarA mutant. Introduction of a plasmid containing cloned hld-RNAIII driven by a non-agr-dependent promoter, p(HU), into isogenic parental wild-type or ΔsarA strains showed comparable levels of RNAIII detected by quantitative reverse transcription-PCR (qRT-PCR) but a two-log(10) reduction in p(tst)-luxAB reporter expression in the ΔsarA strain, arguing that RNAIII levels alone are not strictly determinant for tst expression. Collectively, our results indicate that SarA binds directly to the tst promoter and that SarA plays a significant and direct role in the expression of tst.
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Abstract
Superantigens (SAgs) are derived from diverse sources, including bacteria, viruses, and human hepatic tissue. SAgs initially cause lymphocyte activation but then result in clonal deletion and anergy, leading to immune tolerance. They can also act as superallergens by stimulating a broad spectrum of mast cells and basophils in patients with allergic conditions. The newly described staphylococcal SAg-like proteins subvert innate immune function by several mechanisms, which are distinct from SAgs' effects on lymphocytes and other acquired immune processes. There is mounting evidence to suggest that SAgs play a role in the pathophysiology of inflammatory airway disease. The pathophysiologic role of SAg-like proteins awaits clarification.
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Affiliation(s)
- Nicholas W Stow
- Department of Otorhinolaryngology-Head and Neck Surgery, North Shore Hospital, Private Bag 93-503 Takapuna, North Shore City 0740, Auckland, New Zealand.
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Abstract
The phage-related chromosomal islands (PRCIs) were first identified in Staphylococcus aureus as highly mobile, superantigen-encoding genetic elements known as the S. aureus pathogenicity islands (SaPIs). These elements are characterized by a specific set of phage-related functions that enable them to use the phage reproduction cycle for their own transduction and inhibit phage reproduction in the process. SaPIs produce many phage-like infectious particles; their streptococcal counterparts have a role in gene regulation but may not be infectious. These elements therefore represent phage satellites or parasites, not defective phages. In this Review, we discuss the shared genetic content of PRCIs, their life cycle and their ability to be transferred across large phylogenetic distances.
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Yamamoto T, Nishiyama A, Takano T, Yabe S, Higuchi W, Razvina O, Shi D. Community-acquired methicillin-resistant Staphylococcus aureus: community transmission, pathogenesis, and drug resistance. J Infect Chemother 2010; 16:225-54. [PMID: 20336341 PMCID: PMC7088255 DOI: 10.1007/s10156-010-0045-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Indexed: 11/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is able to persist not only in hospitals (with a high level of antimicrobial agent use) but also in the community (with a low level of antimicrobial agent use). The former is called hospital-acquired MRSA (HA-MRSA) and the latter community-acquired MRSA (CA-MRSA). It is believed MRSA clones are generated from S. aureus through insertion of the staphylococcal cassette chromosome mec (SCCmec), and outbreaks occur as they spread. Several worldwide and regional clones have been identified, and their epidemiological, clinical, and genetic characteristics have been described. CA-MRSA is likely able to survive in the community because of suitable SCCmec types (type IV or V), a clone-specific colonization/infection nature, toxin profiles (including Pantone-Valentine leucocidin, PVL), and narrow drug resistance patterns. CA-MRSA infections are generally seen in healthy children or young athletes, with unexpected cases of diseases, and also in elderly inpatients, occasionally surprising clinicians used to HA-MRSA infections. CA-MRSA spreads within families and close-contact groups or even through public transport, demonstrating transmission cores. Re-infection (including multifocal infection) frequently occurs, if the cores are not sought out and properly eradicated. Recently, attention has been given to CA-MRSA (USA300), which originated in the US, and is growing as HA-MRSA and also as a worldwide clone. CA-MRSA infection in influenza season has increasingly been noted as well. MRSA is also found in farm and companion animals, and has occasionally transferred to humans. As such, the epidemiological, clinical, and genetic behavior of CA-MRSA, a growing threat, is focused on in this study.
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Affiliation(s)
- Tatsuo Yamamoto
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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François P, Scherl A, Hochstrasser D, Schrenzel J. Proteomic approaches to study Staphylococcus aureus pathogenesis. J Proteomics 2010; 73:701-8. [DOI: 10.1016/j.jprot.2009.10.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 10/07/2009] [Accepted: 10/22/2009] [Indexed: 12/25/2022]
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Ozaki K, Takano M, Higuchi W, Takano T, Yabe S, Nitahara Y, Nishiyama A, Yamamoto T. Genotypes, intrafamilial transmission, and virulence potential of nasal methicillin-resistant Staphylococcus aureus from children in the community. J Infect Chemother 2009; 15:84-91. [PMID: 19396517 DOI: 10.1007/s10156-009-0668-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 01/14/2009] [Indexed: 10/20/2022]
Abstract
Pediatric outpatients and healthy children in the community were examined for nasal methicillin-resistant Staphylococcus aureus (MRSA) in Japan. MRSA isolation frequencies were 0.7% (3/426) and 3.7% (5/136), respectively, in pediatric outpatients and healthy children in the community (overall frequency, 1.4%). The frequency of MRSA isolation was higher in children 5-9 years of age compared with the other age groups. All eight MRSA strains isolated were Panton-Valentine leukocidin-negative. Of these, three with the genotype multilocus sequence type (ST) 8/spa606/SCCmecIV (2 cases) and ST88/spa999/SCCmecIV/exfoliative toxin A gene (eta) were identical or similar to MRSA from bullous impetigo, determined by pulsed-field gel electrophoresis. One strain with ST764 (ST5 variant)/spa2/SCCmecII/staphylococcal enterotoxin B gene seb2 (seb variant) was similar to MRSA from bacteremia, and one with ST5/spa2/SCCmecII was the Pandemic New York/Japan clone. The remaining three strains, with ST22/spa998/SCCmecI, ST380/spa799/SCCmecIV, and ST857/spa416/SCCmecII, have not been identified. All MRSA strains were resistant to one or more non-beta-lactam antibiotics, and the ST5 and ST764 strains were multidrug-resistant. Family analysis demonstrated parent-to-child transmission (for ST8 and ST764), as well as acquisition from outside the family (for ST8 and ST380). The data suggest that young school-age children have a higher carriage rate of nasal MRSA than children of other ages, and that not only community-acquired MRSA strains but also MRSA strains with characteristics of hospital-acquired MRSA are spreading in the community.
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Affiliation(s)
- Kyoko Ozaki
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, 757 Ichibanchou, Asahimachidori, Niigata, 951-8510, Japan
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Abstract
The staphylococcal agr locus encodes a quorum sensing (QS) system that controls the expression of virulence and other accessory genes by a classical two-component signaling module. Like QS modalities in other Gram-positive bacteria, agr encodes an autoactivating peptide (AIP) that is the inducing ligand for AgrC, the agr signal receptor. Unlike other such systems, agr variants have arisen that show strong cross-inhibition in heterologous combinations, with important evolutionary implications. Also unlike other systems, the effector of global gene regulation in the agr system is a major regulatory RNA, RNAIII. In this review, we describe the functions of the agr system's elements, show how they interact to bring about the regulatory response, and discuss the role of QS in staphylococcal pathobiology. We conclude with the suggestion that agr autoactivation, unlike classical enzyme induction, can occur under suboptimal conditions and can distinguish self from non-self by inducing an exclusive and coordinated population wide response.
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Affiliation(s)
- Richard P Novick
- Kimmel Center for Biology and Medicine, New York University Medical Center, New York, New York 10016, USA.
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Queck SY, Jameson-Lee M, Villaruz AE, Bach THL, Khan BA, Sturdevant DE, Ricklefs SM, Li M, Otto M. RNAIII-independent target gene control by the agr quorum-sensing system: insight into the evolution of virulence regulation in Staphylococcus aureus. Mol Cell 2008; 32:150-8. [PMID: 18851841 DOI: 10.1016/j.molcel.2008.08.005] [Citation(s) in RCA: 425] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 06/11/2008] [Accepted: 08/01/2008] [Indexed: 12/16/2022]
Abstract
Cell-density-dependent gene regulation by quorum-sensing systems has a crucial function in bacterial physiology and pathogenesis. We demonstrate here that the Staphylococcus aureus agr quorum-sensing regulon is divided into (1) control of metabolism and PSM cytolysin genes, which occurs independently of the small regulatory RNA RNAIII, and (2) RNAIII-dependent control of additional virulence genes. Remarkably, PSM expression was regulated by direct binding of the AgrA response regulator. Our findings suggest that quorum-sensing regulation of PSMs was established before wide-ranging control of virulence was added to the agr regulon, which likely occurred by development of the RNAIII-encoding region around the gene encoding the PSM delta-toxin. Moreover, the agr regulon in the community-associated methicillin-resistant S. aureus MW2 considerably differed from that previously determined using laboratory strains. By establishing a two-level model of quorum-sensing target gene regulation in S. aureus, our study gives important insight into the evolution of virulence control in this leading human pathogen.
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Affiliation(s)
- Shu Y Queck
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
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Comparison of adhesion and virulence of two predominant hospital-acquired methicillin-resistant Staphylococcus aureus clones and clonal methicillin-susceptible S. aureus isolates. Infect Immun 2008; 76:5133-8. [PMID: 18779343 DOI: 10.1128/iai.01697-07] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virulence of SCCmec type IV hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates belonging to the major sequence type 8 (ST8 [Lyon clone]) and to a minor upcoming clone, ST5, was compared with that of methicillin-susceptible S. aureus (MSSA) isolates of matching sequence types. In vitro adhesion to human airway epithelial cells (HAECs) as an indicator of dissemination and mortality in a murine sepsis model as an indicator of virulence were evaluated. Ten MRSA isolates and 8 MSSA isolates of ST8 and 8 MRSA isolates and 8 MSSA isolates of ST5 were characterized with respect to multilocus sequence type; agr, spa, and capsule typing; in vitro doubling time; toxin and adhesin gene profiles; and adherence to HAECs. Adherence was significantly lower in the MRSA ST5 group than in the ST8 groups. Infections with MRSA and MSSA isolates ST8 and ST5 were compared. No change in virulence related to the presence of SCCmec was observed, since ST8 but not ST5 caused a significantly lower mortality in its presence. Despite their similar genetic backgrounds, individual clonal MRSA and MSSA isolates were heterogeneous in adherence and virulence. No one of these specific virulence factors determined in vitro was related to mouse mortality. In conclusion, in a bacteremic model, mortality was dependent on the ST and was differentially modulated by SCCmec; within an ST, clonality was not associated with a homogenous outcome.
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Abstract
Some clinical isolates of Staphylococcus aureus produce the superantigenic toxic shock syndrome toxin 1 (TSST-1), encoded by tst, located on pathogenicity islands. The expression of tst is complex and is influenced by environmental conditions such as pH, CO(2), and glucose. We identified a putative catabolite-responsive element (cre) in the promoter regions of all known tst genes, indicating that tst transcription may be regulated by the catabolite control protein CcpA. By introducing tst genes under the control of their native promoters or tst promoter-reporter gene fusions in wild-type strain Newman, we showed that glucose was able to repress tst transcription and TSST-1 production, whereas glucose repression was abolished in the corresponding Delta ccpA mutant. Stabilizing the pH ruled out a pH effect due to acid production during glucose catabolism. CcpA thus directly regulates tst transcription, linking carbohydrate utilization to virulence gene expression in S. aureus.
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Adhikari RP, Novick RP. Regulatory organization of the staphylococcal sae locus. MICROBIOLOGY-SGM 2008; 154:949-959. [PMID: 18310041 DOI: 10.1099/mic.0.2007/012245-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This paper describes an investigation of the complex internal regulatory circuitry of the staphylococcal sae locus and the impact of modifying this circuitry on the expression of external genes in the sae regulon. The sae locus contains four genes, the saeR and S two-component signalling module (TCS), and saeP and Q, two upstream genes of hitherto unknown function. It is expressed from two promoters, P(A)sae, which transcribes only the TCS, and P(C)sae, which transcribes the entire locus. A bursa aurealis (bursa) transposon insertion in saeP in a derivative of Staphylococcus aureus NCTC 8325 has a profound effect on sae function. It modifies the activity of the TCS, changing the expression of many genes in the sae regulon, even though transcription of the TCS (from P(A)sae) is not interrupted. Moreover, these effects are not due to disruption of saeP since an in-frame deletion in saeP has essentially no phenotype. The phenotype of S. aureus strain Newman is remarkably similar to that of the saeP : : bursa and this similarity is explained by an amino acid substitution in the Newman saeS gene that is predicted to modify profoundly the signalling function of the protein. This concurrence suggests that the saeP : : bursa insertion affects the signalling function of saeS, a suggestion that is supported by the ability of an saeQR clone, but not an saeR clone, to complement the effects of the saeP : : bursa insertion.
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Affiliation(s)
- Rajan P Adhikari
- The Kimmel Center for Biology and Medicine of the Skirball Institute, and Departments of Microbiology and Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Richard P Novick
- The Kimmel Center for Biology and Medicine of the Skirball Institute, and Departments of Microbiology and Medicine, New York University School of Medicine, New York, NY 10016, USA
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Identification of factors contributing to T-cell toxicity of Staphylococcus aureus clinical isolates. J Clin Microbiol 2008; 46:2112-4. [PMID: 18417658 DOI: 10.1128/jcm.00156-08] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We examined the ability of 206 clinical isolates of Staphylococcus aureus to lyse T cells and found differences between Agr groups. We found that the beta and delta hemolysins are involved and that methicillin-resistant S. aureus strains are less toxic than methicillin-susceptible S. aureus strains.
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