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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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Glucose Mediates Niche-Specific Repression of Staphylococcus aureus Toxic Shock Syndrome Toxin-1 through the Activity of CcpA in the Vaginal Environment. J Bacteriol 2022; 204:e0026922. [PMID: 36106854 PMCID: PMC9578429 DOI: 10.1128/jb.00269-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus chronically colonizes up to 30% of the human population on the skin or mucous membranes, including the nasal tract or vaginal canal. While colonization is often benign, this bacterium also has the capability to cause serious infections. Menstrual toxic shock syndrome (mTSS) is a serious toxinosis associated with improper use of tampons, which can induce an environment that is favorable to the production of the superantigen known as toxic shock syndrome toxin-1 (TSST-1). To better understand environmental signaling that influences TSST-1 production, we analyzed expression in the prototype mTSS strain S. aureus MN8. Using transcriptional and protein-based analysis in two niche-related media, we observed that TSST-1 expression was significantly higher in synthetic nasal medium (SNM) than in vaginally defined medium (VDM). One major divergence in medium composition was high glucose concentration in VDM. The glucose-dependent virulence regulator gene ccpA was deleted in MN8, and, compared with wild-type MN8, we observed increased TSST-1 expression in the ΔccpA mutant when grown in VDM, suggesting that TSST-1 is repressed by catabolite control protein A (CcpA) in the vaginal environment. We were able to relieve CcpA-mediated repression by modifying the glucose level in vaginal conditions, confirming that changes in nutritional conditions contribute to the overexpression of TSST-1 that can lead to mTSS. We also compared CcpA-mediated repression to other key regulators of tst, finding that CcpA regulation is dominant compared to other characterized regulatory mechanisms. This study underlines the importance of environmental signaling for S. aureus pathogenesis in the context of mTSS. IMPORTANCE Menstrual toxic shock syndrome (mTSS) is caused by strains of Staphylococcus aureus that overproduce a toxin known as toxic shock syndrome toxin-1 (TSST-1). This work studied how glucose levels in a model vaginal environment could influence the amount of TSST-1 that is produced by S. aureus. We found that high levels of glucose repress TSST-1 production, and this is done by a regulatory protein called catabolite control protein A (CcpA). The research also demonstrated that, compared with other regulatory proteins, the CcpA regulator appears to be the most important for maintaining low levels of TSST-1 in the vaginal environment, and this information helps to understand how changes in the vaginal environmental can lead to mTSS.
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Al-Khalaifah HS. Major Molecular Factors Related to Leishmania Pathogenicity. Front Immunol 2022; 13:847797. [PMID: 35769465 PMCID: PMC9236557 DOI: 10.3389/fimmu.2022.847797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Leishmaniasis is a major health problem with 600k - 1M new cases worldwide and 1 billion at risk. It involves a wide range of clinical forms ranging from self-healing cutaneous lesions to systemic diseases that are fatal if not treated, depending on the species of Leishmania. Leishmania sp. are digenetic parasites that have two different morphological stages. Leishmania parasites possess a number of invasive/evasive and pathoantigenic determinants that seem to have critical roles in Leishmania infection of macrophages which leads to successful intracellular parasitism in the parasitophorous vacuoles. These determinants are traditionally known as “virulence factors”, and are considered to be good targets for developing specific inhibitors to attenuate virulence of Leishmania by gene deletions or modifications, thus causing infective, but non-pathogenic mutants for vaccination. Pathway of biosynthesis is critical for keeping the parasite viable and is important for drug designing against these parasites. These drugs are aimed to target enzymes that control these pathways. Accordingly, maintaining low level of parasitic infection and in some cases as a weapon to eradicate infection completely. The current paper focuses on several virulence factors as determinants of Leishmania pathogenicity, as well as the metabolites produced by Leishmania to secure its survival in the host.
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Essien UC, Boswihi SS, Agbakoba NR, Udo EE. Description of Methicillin-Susceptible Staphylococcus aureus Clonal Complex 30 Related to the Pandemic Phage Type 80/81 Isolated from Patients in Three Tertiary Hospitals in Jos, North Central Nigeria. Med Princ Pract 2022; 31:269-275. [PMID: 35580557 PMCID: PMC9275013 DOI: 10.1159/000524755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 04/26/2022] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The prevalence of phage 80/81 Staphylococcus aureus strains, the pandemic strains that were dominant in the 1950s, had declined in the 1960s and 1970s. However, these strains have reemerged in some countries in recent years. This study investigated the antibacterial resistance, virulence, and the genetic backgrounds of CC30-MSSA isolates obtained from patients in three tertiary hospitals. MATERIALS AND METHODS Twenty-two CC30-MSSA isolates cultured from different clinical samples were investigated using antibiotic sensitivity testing, spa typing, multilocus sequence typing, and DNA microarray analysis. RESULTS All 22 isolates were susceptible to vancomycin (MIC ≤2 μg/mL), teicoplanin (MIC ≤2 μg/mL), and cefoxitin but were resistant to penicillin G (n = 22; 100.0%), tetracycline (n = 12; 54.5%), ciprofloxacin (n = 15; 68.2%), cadmium acetate (n = 22; 100%), mercuric chloride (n = 13; 59.1%), and ethidium bromide (n = 3; 13.6%). The isolates belonged to sequence type, ST30, and five spa types: t012 (n = 12; 54.5%), t019 (n = 5; 22.7%), t017 (n = 2; 9.1%), t037 (n = 2; 9.1%), and t318 (n = 1; 4.5%). All 22 isolates were positive for agrIII, cap8, clfA, clfB, icaA, icaC, icaD, cna, and staphylococcal enterotoxin gene clusters (seg, sei, sem, sen, seo, seu). Eight isolates carried lukS-PV and lukF-PV that code for Panton-Valentine leukocidin. CONCLUSION The current CC30-MSSA isolates share phenotypic and genotypic characteristics with the pandemic phage 80/81 isolates that were common in the 1950s and 1960s. Continued surveillance is recommended to keep abreast of the changing epidemiology of S. aureus causing healthcare and community-associated infections.
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Affiliation(s)
- Unyime C. Essien
- Faculty of Health Sciences and Technology, University of Jos, Jos, Nigeria
- Department of Medical Laboratory Science, Nnewi Campus, Nnamdi Azikiwe University, Awka, Nigeria
| | - Samar S. Boswihi
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Nneka R. Agbakoba
- Department of Medical Laboratory Science, Nnewi Campus, Nnamdi Azikiwe University, Awka, Nigeria
| | - Edet E. Udo
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
- *Edet E. Udo,
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Hwang J, Thompson A, Jaros J, Blackcloud P, Hsiao J, Shi VY. Updated understanding of Staphylococcus aureus in atopic dermatitis: From virulence factors to commensals and clonal complexes. Exp Dermatol 2021; 30:1532-1545. [PMID: 34293242 DOI: 10.1111/exd.14435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/18/2021] [Accepted: 07/20/2021] [Indexed: 12/22/2022]
Abstract
Atopic dermatitis (AD) is a common inflammatory dermatosis that has multiple contributing factors including genetic, immunologic and environmental. Staphylococcus aureus (SA) has long been associated with exacerbation of AD. SA produces many virulence factors that interact with the human skin and immune system. These superantigens and toxins have been shown to contribute to adhesion, inflammation and skin barrier destruction. Recent advances in genome sequencing techniques have led to a broadened understanding of the multiple ways SA interacts with the cutaneous environment in AD hosts. For example, temporal shifts in the microbiome, specifically in clonal complexes of SA, have been identified during AD flares and remission. Herein, we review mechanisms of interaction between the cutaneous microbiome and SA and highlight known differences in SA clonal complexes that contribute to AD pathogenesis. Detailed knowledge of the genetic strains of SA and cutaneous dysbiosis is becoming increasingly relevant in paving the way for microbiome-modulating and precision therapies for AD.
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Affiliation(s)
- Jonwei Hwang
- University of Illinois College of Medicine, Chicago, Illinois, USA
| | - Alyssa Thompson
- College of Medicine, University of Arizona, Tucson, Arizona, USA
| | - Joanna Jaros
- John H. Stroger Hospital Cook County Health Dermatology, Chicago, Illinois, USA
| | - Paul Blackcloud
- Division of Dermatology, University of California, Los Angeles, Los Angeles, California, USA
| | - Jennifer Hsiao
- Division of Dermatology, University of California, Los Angeles, Los Angeles, California, USA
| | - Vivian Y Shi
- Department of Dermatology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Di Gregorio S, Haim MS, Vielma Vallenilla J, Cohen V, Rago L, Gulone L, Aanensen DM, Argimón S, Mollerach M. Genomic Epidemiology of CC30 Methicillin-Resistant Staphylococcus aureus Strains from Argentina Reveals Four Major Clades with Distinctive Genetic Features. mSphere 2021; 6:e01297-20. [PMID: 33692199 PMCID: PMC8546718 DOI: 10.1128/msphere.01297-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/10/2021] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus clonal complex 30 (CC30) has given rise to epidemics worldwide and is one of the most prevalent lineages in Argentina, represented by sequence type 30 methicillin-resistant S. aureus SCCmec type IV (ST30-MRSA-IV). ST30-MRSA-IV has displaced previous prevalent clones in the country and demonstrated increased virulence. Despite the burden of infections caused by ST30-MRSA-IV both in hospitals and in communities in Argentina, no detailed genome-based characterization of this clone is available to date. In this study, we used whole-genome sequencing (WGS) to evaluate the genetic diversity, population structure, and genomic characteristics of 190 CC30-MRSA strains circulating in Argentina between 2004 and 2015. Phylogenetic analysis revealed the existence of 4 major clades: ARG-1 (CC30-MRSA-IVc-spa t012), ARG-2 (ST30-MRSA-IVc-spa t021 related), ARG-3 (ST30-MRSA-IVh/j-spa t021 and related), and ARG-4 (CC30-MRSA-IVc-spa t019 and related). The clades were characterized by different distributions of antimicrobial resistance determinants, virulence genes, and mobile genetic elements (MGEs). While ARG-1 and ARG-4 were related to global epidemic MRSA-16 (EMRSA-16) and South West Pacific (SWP) clones, respectively, ARG-3 was phylogenetically distinct from previously defined CC30 epidemic clones. ARG-4, the most prevalent and geographically disseminated in the collection (N = 164), was characterized by specific MGEs and chromosomal mutations that might have contributed to its virulence and success. To our knowledge, this is the first genomic epidemiology study of CC30-MRSA in Argentina, which will serve as baseline genomic data going forward to inform public health measures for infection prevention and control.IMPORTANCE The rise in prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is of public health concern. In Argentina, several studies documented a shift in the epidemiology of CA-MRSA since 2009, with clonal complex 30 (CC30) and, in particular, sequence type 30 MRSA SCCmec type IV (ST30-MRSA-IV) replacing other clones both in communities and in hospitals and possibly displaying increased virulence. By sequencing the whole genomes of 190 CC30 MRSA isolates recovered from Argentina between 2005 and 2015, we showed that they represented a diverse population composed of 4 major clades. The predominant clade evolved from the South West Pacific clone but has acquired a distinct repertoire of mobile genetic elements, virulence genes, and chromosomal mutations that might play a role in its success. Our work is the first extensive genomic study of CC30 S. aureus in Argentina and will contribute not only to the development of genomic surveillance in the region but also to our understanding of the global epidemiology of this pathogen.
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Affiliation(s)
- Sabrina Di Gregorio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
| | - María Sol Haim
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Jesús Vielma Vallenilla
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
| | - Victoria Cohen
- The Centre for Genomic Pathogen Surveillance (CGPS), Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Lucía Rago
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
| | - Lucía Gulone
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - David M Aanensen
- The Centre for Genomic Pathogen Surveillance (CGPS), Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Silvia Argimón
- The Centre for Genomic Pathogen Surveillance (CGPS), Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Marta Mollerach
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones en Bacteriología y Virología Molecular (IBaViM), Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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Zuo H, Uehara Y, Lu Y, Sasaki T, Hiramatsu K. Genetic and phenotypic diversity of methicillin-resistant Staphylococcus aureus among Japanese inpatients in the early 1980s. Sci Rep 2021; 11:5447. [PMID: 33686133 PMCID: PMC7940613 DOI: 10.1038/s41598-021-84481-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 02/16/2021] [Indexed: 01/02/2023] Open
Abstract
To trace the linkage between Japanese healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) strains in the early 1980s and the 2000s onward, we performed molecular characterizations using mainly whole-genome sequencing. Among the 194 S. aureus strains isolated, 20 mecA-positive MRSA (10.3%), 8 mecA-negative MRSA (4.1%) and 3 mecA-positive methicillin-susceptible S. aureus (MSSA) (1.5%) strains were identified. The most frequent sequence type (ST) was ST30 (n = 11), followed by ST5 (n = 8), ST81 (n = 4), and ST247 (n = 3). Rates of staphylococcal cassette chromosome mec (SCCmec) types I, II, and IV composed 65.2%, 13.0%, and 17.4% of isolates, respectively. Notably, 73.3% of SCCmec type I strains were susceptible to imipenem unlike SCCmec type II strains (0%). ST30-SCCmec I (n = 7) and ST5-SCCmec I (n = 5) predominated, whereas only two strains exhibited imipenem-resistance and were tst-positive ST5-SCCmec II, which is the current Japanese HA-MRSA genotype. All ST30 strains shared the common ancestor strain 55/2053, which caused the global pandemic of Panton-Valentine leukocidin-positive MSSA in Europe and the United States in the 1950s. Conspicuously more heterogeneous, the population of HA-MRSA clones observed in the 1980s, including the ST30-SCCmec I clone, has shifted to the current homogeneous population of imipenem-resistant ST5-SCCmec II clones, probably due to the introduction of new antimicrobials.
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Affiliation(s)
- Hui Zuo
- Department of Microbiology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Yuki Uehara
- Department of Microbiology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
- Department of Clinical Laboratory, St Luke's International Hospital, Tokyo, Japan.
- Department of Infectious Diseases, St Luke's International Hospital, Tokyo, Japan.
- Center for Infection Control Science Research, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Yujie Lu
- Center for Infection Control Science Research, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takashi Sasaki
- Center for Infection Control Science Research, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Animal Research Center, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Keiichi Hiramatsu
- Department of Microbiology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
- Center for Infection Control Science Research, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Aung MS, Urushibara N, Kawaguchiya M, Hirose M, Ike M, Ito M, Kobayashi N. Distribution of Virulence Factors and Resistance Determinants in Three Genotypes of Staphylococcus argenteus Clinical Isolates in Japan. Pathogens 2021; 10:pathogens10020163. [PMID: 33546443 PMCID: PMC7913748 DOI: 10.3390/pathogens10020163] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus argenteus, a novel staphylococcal species independent of S. aureus, causes a wide spectrum of infectious diseases. As detection of this species from humans and animals has been increasingly reported worldwide, its growing virulence and drug resistance via external genetic determinants has become concerning. In this study, the prevalence and genetic characteristics of virulence factors and drug resistance determinants were investigated for 82 S. argenteus clinical isolates in Hokkaido, Japan, for a one-year period starting in August 2019. These S. argenteus isolates corresponded to 0.66% of the total number of S. aureus isolates collected in the same period. The most prevalent genotype was sequence type (ST) 2250 and staphylocoagulase (coa) genotype XId (45.1%, n = 37), followed by ST1223-coa XV (30.5%, n = 25) and ST2198-coa XIV (24.4%, n = 20). Panton-Valentine leukocidin genes (lukS-PV-lukF-PV) were identified in a single ST2250 isolate. Only ST1223 isolates had the enterotoxin gene cluster (egc-2), seb, and selw (detection rate; 100%, 60%, and 84%, respectively), while sec, sey, sel26-sel27, tst-1 were only detected in ST2250 isolates (detection rate; 10.8%, 100%, 67.6%, and 10.8%, respectively). ST2198 isolates harbored selx at a significantly higher rate (60%) than isolates of other STs. Although most of S. argenteus isolates were susceptible to antimicrobials examined, ST2198 showed higher resistance rates to penicillin, macrolides, and aminoglycosides than other STs, and it harbored various resistance genes such as blaZ, erm(C), msr(A), lnuA, and aac(6′)-Ie-aph(2″)-Ia. Only one ST2250 isolate possessed SCCmec-IVc, showing resistance to oxacillin. blaZ was the most prevalent determinant of resistance in the three STs and belonged to two plasmid groups and a chromosomal group, suggesting its diverse origin. lnu(A) in ST2198 isolates was assigned to a major cluster with various staphylococcal species. The present study indicates that the prevalence of virulence factors and drug resistance profile/determinants differ depending on the lineage (ST) of S. argenteus.
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Affiliation(s)
- Meiji Soe Aung
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
- Correspondence: ; Tel.: +81-11-611-2111
| | - Noriko Urushibara
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Mitsuyo Kawaguchiya
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Mina Hirose
- Division of Pediatric Dentistry, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu 061-0293, Japan;
| | - Miyo Ike
- Sapporo Clinical Laboratory, Incorporated, Hokkaido, Sapporo 060-0005, Japan; (M.I.); (M.I.)
| | - Masahiko Ito
- Sapporo Clinical Laboratory, Incorporated, Hokkaido, Sapporo 060-0005, Japan; (M.I.); (M.I.)
| | - Nobumichi Kobayashi
- Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
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Crandall H, Kapusta A, Killpack J, Heyrend C, Nilsson K, Dickey M, Daly JA, Ampofo K, Pavia AT, Mulvey MA, Yandell M, Hulten KG, Blaschke AJ. Clinical and molecular epidemiology of invasive Staphylococcus aureus infection in Utah children; continued dominance of MSSA over MRSA. PLoS One 2020; 15:e0238991. [PMID: 32946486 PMCID: PMC7500648 DOI: 10.1371/journal.pone.0238991] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/27/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Invasive Staphylococcus aureus infections are a common cause of morbidity and mortality in children. In the early 2000's the proportion of infections due the methicillin-resistant S. aureus (MRSA) increased rapidly. We described the clinical and molecular epidemiology of invasive S. aureus disease in a pediatric population. METHODS We prospectively identified children in Utah with invasive S. aureus infections. Medical records were reviewed to determine diagnosis and clinical characteristics. Isolates were genotyped using multi-locus sequence typing. The presence of genes encoding the Panton-Valentine leukocidin (PVL) was determined using polymerase chain reaction. RESULTS Over a 4-year period between January 2009 and December 2012, we identified 357 children, hospitalized at Primary Children's Hospital, with invasive S. aureus infections and isolates available for the study. Methicillin-susceptible S. aureus (MSSA) caused 79% of disease, while MRSA caused only 21% of disease. Mortality associated with invasive S. aureus infection was 3.6%. The most common diagnoses were osteoarticular infections (38%) followed by central line associated blood stream infections (19%) and pneumonia (12%). We identified 41 multi-locus sequence types. The majority of isolates belonged to 6 predominant clonal complexes (CC5, CC8, CC15, CC30, CC45, CC59). PVL was present in a minority (16%) of isolates, of which most were ST8 MRSA. CONCLUSIONS MSSA was the primary cause of invasive S. aureus infections at our institution throughout the study period. A limited number of predominant strains accounted for the majority of invasive disease. The classic virulence factor PVL was uncommon in MSSA isolates. Further study is needed to improve our understanding of S. aureus virulence and disease pathogenesis.
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Affiliation(s)
- Hillary Crandall
- Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
| | - Aurélie Kapusta
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Jarrett Killpack
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Carly Heyrend
- Primary Children’s Hospital, Salt Lake City, Utah, United States of America
| | - Kody Nilsson
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Mandy Dickey
- Primary Children’s Hospital, Salt Lake City, Utah, United States of America
| | - Judy A. Daly
- Primary Children’s Hospital, Salt Lake City, Utah, United States of America
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Krow Ampofo
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Andrew T. Pavia
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Matthew A. Mulvey
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Mark Yandell
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
- Department of Human Genetics, USTAR Center for Genetic Discovery, University of Utah, Salt Lake City, Utah, United States of America
| | - Kristina G. Hulten
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Anne J. Blaschke
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
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Silence as a way of niche adaptation: mecC-MRSA with variations in the accessory gene regulator (agr) functionality express kaleidoscopic phenotypes. Sci Rep 2020; 10:14787. [PMID: 32901059 PMCID: PMC7479134 DOI: 10.1038/s41598-020-71640-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 08/19/2020] [Indexed: 11/09/2022] Open
Abstract
Functionality of the accessory gene regulator (agr) quorum sensing system is an important factor promoting either acute or chronic infections by the notorious opportunistic human and veterinary pathogen Staphylococcus aureus. Spontaneous alterations of the agr system are known to frequently occur in human healthcare-associated S. aureus lineages. However, data on agr integrity and function are sparse regarding other major clonal lineages. Here we report on the agr system functionality and activity level in mecC-carrying methicillin resistant S. aureus (MRSA) of various animal origins (n = 33) obtained in Europe as well as in closely related human isolates (n = 12). Whole genome analysis assigned all isolates to four clonal complexes (CC) with distinct agr types (CC599 agr I, CC49 agr II, CC130 agr III and CC1943 agr IV). Agr functionality was assessed by a combination of phenotypic assays and proteome analysis. In each CC, isolates with varying agr activity levels were detected, including the presence of completely non-functional variants. Genomic comparison of the agr I-IV encoding regions associated these phenotypic differences with variations in the agrA and agrC genes. The genomic changes were detected independently in divergent lineages, suggesting that agr variation might foster viability and adaptation of emerging MRSA lineages to distinct ecological niches.
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11
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Vaginal Tampon Colonization by Staphylococcus aureus in Healthy Women. Appl Environ Microbiol 2020; 86:AEM.01249-20. [PMID: 32680868 DOI: 10.1128/aem.01249-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/08/2020] [Indexed: 11/20/2022] Open
Abstract
Tampons recovered from a cohort of 737 healthy women (median age, 32 years) were analyzed for the presence of Staphylococcus aureus A total of 198 tampons (27%) were colonized by S. aureus, 28 (4%) by a strain producing toxic shock syndrome toxin 1 (TSST-1). S. aureus was detected more frequently in tampons that did not require an applicator for their insertion (74/233 [32%] versus 90/381 [24%]; odds ratio [OR] = 1.51 [95% confidence interval, 1.04 to 2.17]) and in women who used an intrauterine device for contraception (53/155 [34%] versus 145/572 [27%]; OR = 1.53 [95% confidence interval, 1.05 to 2.24]). The S. aureus strains isolated from tampons belonged to 22 different clonal complexes (CCs). The most prevalent CC was CC398 agr1 (n = 57 [27%]), a clone that does not produce superantigenic toxins, followed by CC30 agr3 (n = 27, 13%), producing TSST-1 (24/27 [89%]), the principal clone of S. aureus involved in menstrual toxic shock syndrome (MTSS).IMPORTANCE Menstrual toxic shock syndrome (MTSS) is an uncommon severe acute disease that occurs in healthy menstruating women colonized by TSST-1-producing S. aureus who use intravaginal protection, such as tampons and menstrual cups. The catamenial product collected by the protection serves as a growth medium for S. aureus and allows TSST-1 production. Previous studies evaluated the prevalence of genital colonization by S. aureus by vaginal swabbing, but they did not examine tampon colonization. This study demonstrated a high prevalence of tampon colonization by S. aureus and the presence of the CC30 TSST-1 S. aureus clone responsible for MTSS in tampons from healthy women. The results support the vaginal carriage of this lineage in healthy women. In addition, the higher prevalence of S. aureus within tampons that do not require an applicator indicates a crucial role for handwashing before tampon handling to decrease the risk of tampon contamination.
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12
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Rasigade JP, Leclère A, Alla F, Tessier A, Bes M, Lechiche C, Vernet-Garnier V, Laouénan C, Vandenesch F, Leport C. Staphylococcus aureus CC30 Lineage and Absence of sed, j, r-Harboring Plasmid Predict Embolism in Infective Endocarditis. Front Cell Infect Microbiol 2018; 8:187. [PMID: 29938201 PMCID: PMC6003251 DOI: 10.3389/fcimb.2018.00187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/14/2018] [Indexed: 12/28/2022] Open
Abstract
Staphylococcus aureus induces severe infective endocarditis (IE) where embolic complications are a major cause of death. Risk factors for embolism have been reported such as a younger age or larger IE vegetations, while methicillin resistance conferred by the mecA gene appeared as a protective factor. It is unclear, however, whether embolism is influenced by other S. aureus characteristics such as clonal complex (CC) or virulence pattern. We examined clinical and microbiological predictors of embolism in a prospective multicentric cohort of 98 French patients with monomicrobial S. aureus IE. The genomic contents of causative isolates were characterized using DNA array. To preserve statistical power, genotypic predictors were restricted to CC, secreted virulence factors and virulence regulators. Multivariate regularized logistic regression identified three independent predictors of embolism. Patients at higher risk were younger than the cohort median age of 62.5 y (adjusted odds ratio [OR] 0.14; 95% confidence interval [CI] 0.05-0.36). S. aureus characteristics predicting embolism were a CC30 genetic background (adjusted OR 9.734; 95% CI 1.53-192.8) and the absence of pIB485-like plasmid-borne enterotoxin-encoding genes sed, sej, and ser (sedjr; adjusted OR 0.07; 95% CI 0.004-0.457). CC30 S. aureus has been repeatedly reported to exhibit enhanced fitness in bloodstream infections, which might impact its ability to cause embolism. sedjr-encoded enterotoxins, whose superantigenic activity is unlikely to protect against embolism, possibly acted as a proxy to others genes of the pIB485-like plasmid found in genetically unrelated isolates from mostly embolism-free patients. mecA did not independently predict embolism but was strongly associated with sedjr. This mecA-sedjr association might have driven previous reports of a negative association of mecA and embolism. Collectively, our results suggest that the influence of S. aureus genotypic features on the risk of embolism may be stronger than previously suspected and independent of clinical risk factors.
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Affiliation(s)
- Jean-Philippe Rasigade
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Amélie Leclère
- UMR-1137, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Institut National de la Santé et de la Recherche Médicale, UMR-1137, Paris, France
| | - François Alla
- CIC-1433 Epidémiologie Clinique, Institut National de la Santé et de la Recherche Médicale, Centre Hospitalier Universitaire de Nancy, Nancy, France.,EA4360, Apemac, Université de Lorraine, Nancy, France
| | - Adrien Tessier
- UMR-1137, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Institut National de la Santé et de la Recherche Médicale, UMR-1137, Paris, France
| | - Michèle Bes
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Catherine Lechiche
- Service de Maladies Infectieuses et Tropicales Centre Hospitalier Universitaire de Nîmes Caremeau, Nîmes, France
| | - Véronique Vernet-Garnier
- Faculté de Médecine EA 4687 Université de Reims Champagne Ardenne, Reims, France.,Laboratoire de Bactériologie, Centre Hospitalier Universitaire de Reims Robert Debré, Reims, France
| | - Cédric Laouénan
- UMR-1137, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Institut National de la Santé et de la Recherche Médicale, UMR-1137, Paris, France.,Service de Biostatistiques, Hôpital Bichat, AP-HP, Paris, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France.,Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Catherine Leport
- UMR-1137, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Institut National de la Santé et de la Recherche Médicale, UMR-1137, Paris, France.,Unité de Coordination du Risque Épidémique et Biologique, AP-HP, Paris, France
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13
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Zhang L, Gao J, Barkema HW, Ali T, Liu G, Deng Y, Naushad S, Kastelic JP, Han B. Virulence gene profiles: alpha-hemolysin and clonal diversity in Staphylococcus aureus isolates from bovine clinical mastitis in China. BMC Vet Res 2018; 14:63. [PMID: 29499697 PMCID: PMC5834907 DOI: 10.1186/s12917-018-1374-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 02/14/2018] [Indexed: 12/20/2022] Open
Abstract
Background Staphylococcus aureus, a common cause of bovine mastitis, is known for its ability to acquire to antimicrobial resistance and to secrete numerous virulence factors that can exacerbate inflammation. In addition, alpha-hemolysin has an important role in S. aureus infections, diversity of the hla gene (that produces alpha-hmolysin) in S. aureus isolated from bovine mastitis has not been well characterized. The objective was, therefore, to determine diversity of virulence genes, hla gene sequences, and clonal profiles of S. aureus from bovine mastitis in Chinese dairy herds, and to evaluate inter-relationships. Results The antimicrobials resistance varies from as low as 1.9% (2/103) for CTX to as high as 76.7% (79/103) for penicilin in the 103 isolates and 46 (44.7%) S. aureus were determined as multi-resistant isolates with diverse resistance patterns. Thirty-eight virulence gene patterns (with variable frequencies) were identified in the 103 isolates and correlated with MLST types, indicating a great diversity. Although the hla gene also had great diversity (14 genotypes), Hla peptides were relatively more conserved. With 7 clonal complexes identified from 24 spa types and 7 MLST types. Regarding the letter, ST 97 was the dominant type in S. aureus from bovine mastitis in China. Furthermore, based on phylogenetic analysis, there was a distinct evolutionary relationship between the hla gene and MLST. Conclusion Multi-resistant S. aureus occurred in bovine mastitis with diverse resistance patterns. The diversity of virulence gene profiles, especially the hla gene and, their relationship with molecular types were reported for the first time in S. aureus from bovine mastitis, which will be useful for future studies on immunogenicity and vaccine development. In addition, based on the distinct evolutionary relationship between the hla gene and MLST types, we inferred that the hla gene has potential role for molecular typing of S. aureus. Electronic supplementary material The online version of this article (10.1186/s12917-018-1374-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Limei Zhang
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Jian Gao
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Herman W Barkema
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Tariq Ali
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Gang Liu
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Youtian Deng
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Sohail Naushad
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - John P Kastelic
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Bo Han
- College of Veterinary Medicine, China Agricultural University, Yuan Ming Yuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China.
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14
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Suligoy CM, Lattar SM, Noto Llana M, González CD, Alvarez LP, Robinson DA, Gómez MI, Buzzola FR, Sordelli DO. Mutation of Agr Is Associated with the Adaptation of Staphylococcus aureus to the Host during Chronic Osteomyelitis. Front Cell Infect Microbiol 2018; 8:18. [PMID: 29456969 PMCID: PMC5801681 DOI: 10.3389/fcimb.2018.00018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 01/12/2018] [Indexed: 11/13/2022] Open
Abstract
Selection pressures exerted on Staphylococcus aureus by host factors may lead to the emergence of mutants better adapted to the evolving conditions at the infection site. This study was aimed at identifying the changes that occur in S. aureus exposed to the host defense mechanisms during chronic osteomyelitis and evaluating whether these changes affect the virulence of the organism. Genome assessment of two S. aureus isolates collected 13 months apart (HU-85a and HU-85c) from a host with chronic osteomyelitis was made by whole genome sequencing. Agr functionality was assessed by qRT-PCR. Isolates were tested in a rat model of osteomyelitis and the bacterial load (CFU/tibia) and the morphometric osteomyelitic index (OI) were determined. The ability of the isolates to trigger the release of proinflammatory cytokines was determined on macrophages in culture. Persistence of S. aureus within the host resulted in an agrC frameshift mutation that likely led to the observed phenotype. The capacity to cause bone tissue damage and trigger proinflammatory cytokines by macrophages of the agr-deficient, unencapsulated derivative (HU-85c) was decreased when compared with those of the isogenic CP8-capsulated parental strain (HU-85a). By comparison, no significant differences were found in the bacterial load or the OI from rats challenged with isogenic Reynolds strains [CP5, CP8, and non-typeable (NT)], indicating that lack of CP expression alone was not likely responsible for the reduced capacity to cause tissue damage in HU-85c compared with HU-85a. The production of biofilm was significantly increased in the isogenic derivative HU-85c. Lack of agr-dependent factors makes S. aureus less virulent during chronic osteomyelitis and alteration of the agr functionality seems to permit better adaptation of S. aureus to the chronically infected host.
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Affiliation(s)
- Carlos M Suligoy
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Santiago M Lattar
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Mariángeles Noto Llana
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Cintia D González
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Lucía P Alvarez
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - D Ashley Robinson
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Marisa I Gómez
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Fernanda R Buzzola
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Daniel O Sordelli
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
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15
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Wang L, Si W, Xue H, Zhao X. Characterization of a functional insertion sequence IS Sau2 from Staphylococcus aureus. Mob DNA 2018; 9:3. [PMID: 29371891 PMCID: PMC5771124 DOI: 10.1186/s13100-018-0108-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/08/2018] [Indexed: 11/26/2022] Open
Abstract
Background ISSau2 has been suggested as a member of the IS150 f subgroup in the IS3 family. It encodes a fusion transposase OrfAB produced by programmed − 1 translational frameshifting with two overlapping reading frames orfA and orfB. To better characterize ISSau2, the binding and cleaving activities of the ISSau2 transposase and its transposition frequency were studied. Results The purified ISSau2 transposase OrfAB was a functional protein in vitro since it bound specifically to ISSau2 terminal inverted repeat sequences (IRs) and cleaved the transposon ends at the artificial mini-transposon pUC19-IRL-gfp-IRR. In addition, the transposition frequency of ISSau2 in vivo was approximately 1.76 ± 0.13 × 10− 3, based on a GFP hop-on assay. Furthermore, OrfB cleaved IRs with the similar catalytic activity of OrfAB, while OrfA had no catalytic activity. Finally, either OrfA or OrfB significantly reduced the transposition of ISSau2 induced by OrfAB. Conclusion We have confirmed that ISSau2 is a member of IS150/IS3 family. The ISSau2 transposase OrfAB could bind to and cleave the specific fragments containing the terminal inverted repeat sequences and induce the transposition, suggesting that ISSau2 is at least partially functional. Meanwhile, both OrfA and OrfB inhibited the transposition by ISSau2. Our results will help understand biological roles of ISSau2 in its host S. aureus.
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Affiliation(s)
- Liangliang Wang
- 1College of Animal Science and Technology, Northwest A&F University, No.3 Taicheng Road, Yangling, 712100 Shaanxi Province People's Republic of China.,2School of Pharmaceutical Sciences, Tsinghua University, Beijing, People's Republic of China.,3Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, People's Republic of China
| | - Wei Si
- 1College of Animal Science and Technology, Northwest A&F University, No.3 Taicheng Road, Yangling, 712100 Shaanxi Province People's Republic of China
| | - Huping Xue
- 1College of Animal Science and Technology, Northwest A&F University, No.3 Taicheng Road, Yangling, 712100 Shaanxi Province People's Republic of China
| | - Xin Zhao
- 1College of Animal Science and Technology, Northwest A&F University, No.3 Taicheng Road, Yangling, 712100 Shaanxi Province People's Republic of China.,4Department of Animal Science, McGill University, Quebec, Canada
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16
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Spread of Tst-Positive Staphylococcus aureus Strains Belonging to ST30 Clone among Patients and Healthcare Workers in Two Intensive Care Units. Toxins (Basel) 2017; 9:toxins9090270. [PMID: 28869541 PMCID: PMC5618203 DOI: 10.3390/toxins9090270] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is a major cause of infections. Toxic shock syndrome toxin (TSST-1) and Panton–Valentine leukocidin (PVL) are associated with severe clinical syndromes. S. aureus colonizing isolates recovered from healthcare workers and patients in the intensive care unit (ICU) of a university hospital comprising Group A were compared with those from adult non-ICU carriers (Group B). mecA, lukS/lukF-PV (Panton–Valentine leukocidin, PVL), and tst (toxic shock syndrome toxin) gene carriage was detected by PCR. Clones were identified in all methicillin-resistant S. aureus (MRSA) and toxin-positive methicillin-susceptible strains (MSSA) by pulsed-field gel electrophoresis (PFGE), agr groups, and multi locus sequencing typing (MLST). Group A included 90 S. aureus isolates, whereas Group B 53. PVL was more frequently found among MRSA vs. MSSA (p < 0.001) and in strains of Group B as compared to Group A (p < 0.001), consistent with the spread of ST80-IV. Higher incidence of tst gene carriage was identified among MSSA vs. MRSA (P 0.005) belonging mainly to ST30, and Group A vs. Group B (P 0.002). The wide dissemination of ST80-IV mainly in the community is responsible for a high percentage of PVL-positive MRSA, while silent spread of tst-positive S. aureus clones among ICU patients and personnel poses a threat of hospital transmission and possible severe infections.
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17
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Staphylococcus aureus Alpha-Toxin Is Conserved among Diverse Hospital Respiratory Isolates Collected from a Global Surveillance Study and Is Neutralized by Monoclonal Antibody MEDI4893. Antimicrob Agents Chemother 2016; 60:5312-21. [PMID: 27324766 PMCID: PMC4997823 DOI: 10.1128/aac.00357-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/14/2016] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus infections lead to an array of illnesses ranging from mild skin infections to serious diseases, such endocarditis, osteomyelitis, and pneumonia. Alpha-toxin (Hla) is a pore-forming toxin, encoded by the hla gene, that is thought to play a key role in S. aureus pathogenesis. A monoclonal antibody targeting Hla, MEDI4893, is in clinical development for the prevention of S. aureus ventilator-associated pneumonia (VAP). The presence of the hla gene and Hla protein in 994 respiratory isolates collected from patients in 34 countries in Asia, Europe, the United States, Latin America, the Middle East, Africa, and Australia was determined. Hla levels were correlated with the geographic location, age of the subject, and length of stay in the hospital. hla gene sequence analysis was performed, and mutations were mapped to the Hla crystal structure. S. aureus supernatants containing Hla variants were tested for susceptibility or resistance to MEDI4893. The hla gene was present and Hla was expressed in 99.0% and 83.2% of the isolates, respectively, regardless of geographic region, hospital locale, or age of the subject. More methicillin-susceptible than methicillin-resistant isolates expressed Hla (86.9% versus 78.8%; P = 0.0007), and S. aureus isolates from pediatric patients expressed the largest amounts of Hla. Fifty-seven different Hla subtypes were identified, and 91% of the isolates encoded an Hla subtype that was neutralized by MED4893. This study demonstrates that Hla is conserved in diverse S. aureus isolates from around the world and is an attractive target for prophylactic monoclonal antibody (MAb) or vaccine development.
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18
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Comparative genome-scale modelling of Staphylococcus aureus strains identifies strain-specific metabolic capabilities linked to pathogenicity. Proc Natl Acad Sci U S A 2016; 113:E3801-9. [PMID: 27286824 DOI: 10.1073/pnas.1523199113] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a preeminent bacterial pathogen capable of colonizing diverse ecological niches within its human host. We describe here the pangenome of S. aureus based on analysis of genome sequences from 64 strains of S. aureus spanning a range of ecological niches, host types, and antibiotic resistance profiles. Based on this set, S. aureus is expected to have an open pangenome composed of 7,411 genes and a core genome composed of 1,441 genes. Metabolism was highly conserved in this core genome; however, differences were identified in amino acid and nucleotide biosynthesis pathways between the strains. Genome-scale models (GEMs) of metabolism were constructed for the 64 strains of S. aureus These GEMs enabled a systems approach to characterizing the core metabolic and panmetabolic capabilities of the S. aureus species. All models were predicted to be auxotrophic for the vitamins niacin (vitamin B3) and thiamin (vitamin B1), whereas strain-specific auxotrophies were predicted for riboflavin (vitamin B2), guanosine, leucine, methionine, and cysteine, among others. GEMs were used to systematically analyze growth capabilities in more than 300 different growth-supporting environments. The results identified metabolic capabilities linked to pathogenic traits and virulence acquisitions. Such traits can be used to differentiate strains responsible for mild vs. severe infections and preference for hosts (e.g., animals vs. humans). Genome-scale analysis of multiple strains of a species can thus be used to identify metabolic determinants of virulence and increase our understanding of why certain strains of this deadly pathogen have spread rapidly throughout the world.
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Ramundo MS, Beltrame CO, Botelho AMN, Coelho LR, Silva-Carvalho MC, Ferreira-Carvalho BT, Nicolás MF, Guedes IA, Dardenne LE, O'Gara J, Figueiredo AMS. A unique SaeS allele overrides cell-density dependent expression of saeR and lukSF-PV in the ST30-SCCmecIV lineage of CA-MRSA. Int J Med Microbiol 2016; 306:367-80. [PMID: 27265234 DOI: 10.1016/j.ijmm.2016.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 05/06/2016] [Accepted: 05/08/2016] [Indexed: 12/11/2022] Open
Abstract
ST30 (CC30)-SCCmec IV (USA1100) is one of the most common community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) lineages. ST30 isolates typically carry lukSF-PV genes encoding the Panton-Valentine leukocidin (PVL) and are responsible for outbreaks of invasive infections worldwide. In this study, twenty CC30 isolates were analyzed. All were very susceptible to non-β-lactam antimicrobials, 18/20 harbored the lukSF-PV genes, only 1/20 exhibited agr-rnaIII dysfunction, and the majority was not able to form biofilm on inert surfaces. Analysis of lukSF-PV temporal regulation revealed that opposite to other CA-MRSA isolates, these genes were more highly expressed in early log phase than in stationary phase. This inverted lukSF-PV temporal expression was associated with a similar pattern of saeRS expression in the ST30 isolates, namely high level expression in log phase and reduced expression in stationary phase. Reduced saeRS expression in stationary phase was associated with low expression levels of the sae regulators, agr and agr-upregulator sarA, which activate the stationary phase sae-P1 promoter and overexpression of agr-RNAIII restored the levels of saeR and lukSF-PV trancripts in stationary phase. Altered SaeRS activity in the ST30 isolates was attributed to amino acid substitutions (N227S, E268K and S351T) in the HTPase_c domain of SaeS (termed SaeS(SKT)). Complementation of a USA300 saeS mutant with the saeS(SKT) and saeS alleles under the direction of the log phase sae-P3 promoter revealed that saeR and lukSF-PV transcription levels were more significantly activated by saeS(SKT) than saeS. In summary our data identify a unique saeS allele (saeS(SKT)) which appears to override cell-density dependent SaeR and PVL expression in ST30 CA-MRSA isolates. Further studies to determine the contribution of saeS(SKT) allele to the pathogenesis of infections caused by ST30 isolates are merited.
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Affiliation(s)
- Mariana Severo Ramundo
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
| | - Cristiana Ossaille Beltrame
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
| | - Ana Maria Nunes Botelho
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
| | - Leonardo Rocchetto Coelho
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
| | - Maria Cicera Silva-Carvalho
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
| | | | | | | | | | - James O'Gara
- School of Natural Sciences, Microbiology Department, NUI Galway, Galway, Ireland.
| | - Agnes Marie Sá Figueiredo
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, RJ, Brazil.
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Montanaro L, Ravaioli S, Ruppitsch W, Campoccia D, Pietrocola G, Visai L, Speziale P, Allerberger F, Arciola CR. Molecular Characterization of a Prevalent Ribocluster of Methicillin-Sensitive Staphylococcus aureus from Orthopedic Implant Infections. Correspondence with MLST CC30. Front Cell Infect Microbiol 2016; 6:8. [PMID: 26909340 PMCID: PMC4754407 DOI: 10.3389/fcimb.2016.00008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 01/15/2016] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is the leading etiologic agent of orthopedic implant infections. Here a ribocluster of 27 S. aureus strains underwent further molecular characterization and subtyping by multilocus sequence typing (MLST) and spa-typing. This cluster had been detected by automated ribotyping (with the EcoRI restriction enzyme) of 200 S. aureus isolates from periprosthetic infections of patients who underwent revision at the Rizzoli Orthopaedic Institute. The ribocluster, consisting of agr type III strains, with a 74% co-occurrence of bone sialoprotein-binding (bbp) and collagen-binding (cna) genes, lacked mecA and IS256, and exhibited a high prevalence of the toxic shock syndrome toxin gene (tst, 85%). Strains' relatedness was analyzed by BURP and eBURST. Two predominant spa types, t012 (32%) and t021 (36%), and one predominant sequence type, ST30 (18/27, 67%) were identified: a S. aureus lineage spread worldwide belonging to MLST CC30. Two new sequence types (ST2954, ST2960) and one new spa type (t13129) were detected for the first time. Interestingly, the 27-strain cluster detected by ribotyping corresponded exactly to MLST CC30, the sole CC identified by eBURST.
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Affiliation(s)
- Lucio Montanaro
- Research Unit on Implant Infections, Rizzoli Orthopaedic InstituteBologna, Italy; Department of Experimental, Diagnostic, and Specialty Medicine, University of BolognaBologna, Italy
| | - Stefano Ravaioli
- Research Unit on Implant Infections, Rizzoli Orthopaedic InstituteBologna, Italy; Department of Experimental, Diagnostic, and Specialty Medicine, University of BolognaBologna, Italy
| | - Werner Ruppitsch
- Division of Human Medicine, Austrian Agency for Health and Food Safety Vienna, Austria
| | - Davide Campoccia
- Research Unit on Implant Infections, Rizzoli Orthopaedic Institute Bologna, Italy
| | - Giampiero Pietrocola
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia Pavia, Italy
| | - Livia Visai
- Molecular Medicine Department, Center for Health Technologies (CHT), UdR INSTM, University of PaviaPavia, Italy; Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri FoundationIRCCS, Pavia, Italy
| | - Pietro Speziale
- Unit of Biochemistry, Department of Molecular Medicine, University of Pavia Pavia, Italy
| | - Franz Allerberger
- Division of Human Medicine, Austrian Agency for Health and Food Safety Vienna, Austria
| | - Carla Renata Arciola
- Research Unit on Implant Infections, Rizzoli Orthopaedic InstituteBologna, Italy; Department of Experimental, Diagnostic, and Specialty Medicine, University of BolognaBologna, Italy
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Xiao M, Zhao R, Zhang Q, Fan X, O’Sullivan MVN, Li DF, Wang XY, Wu HL, Kong F, Xu YC. Genotypic Diversity of Staphylococcus aureus α-Hemolysin Gene (hla) and Its Association with Clonal Background: Implications for Vaccine Development. PLoS One 2016; 11:e0149112. [PMID: 26866483 PMCID: PMC4750931 DOI: 10.1371/journal.pone.0149112] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/27/2016] [Indexed: 11/30/2022] Open
Abstract
The α-hemolysin, encoded by the hla gene, is a major virulence factor in S. aureus infections. Changes in key amino acid residues of α-hemolysin can result in reduction, or even loss, of toxicity. The aim of this study was to investigate the diversity of the hla gene sequence and the relationship of hla variants to the clonal background of S. aureus isolates. A total of 47 clinical isolates from China were used in this study, supplemented with in silico analysis of 318 well-characterized whole genome sequences from globally distributed isolates. A total of 28 hla genotypes were found, including three unique to isolates from China, 20 found only in the global genomes and five found in both. The hla genotype generally correlated with the clonal background, particularly the multilocus sequence type, but was not related to geographic origin, host source or methicillin-resistance phenotype. In addition, the hla gene showed greater diversity than the seven loci utilized in the MLST scheme for S. aureus. Our investigation has provided genetic data which may be useful for future studies of toxicity, immunogenicity and vaccine development.
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Affiliation(s)
- Meng Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Rui Zhao
- Department of Laboratory, Beijing Electric Power Hospital, Beijing, China
| | - Qi Zhang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xin Fan
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Matthew V. N. O’Sullivan
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR – Pathology West, Westmead Hospital, University of Sydney, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Dong-Fang Li
- Binhai Genomics Institute, BGI-Tianjin, BGI-shenzhen, Tianjin, China
- Tianjin Translational Genomics Center, BGI-Tianjin, BGI-shenzhen, Tianjin, China
| | - Xin-Ying Wang
- Binhai Genomics Institute, BGI-Tianjin, BGI-shenzhen, Tianjin, China
- Tianjin Translational Genomics Center, BGI-Tianjin, BGI-shenzhen, Tianjin, China
| | - Hong-Long Wu
- Binhai Genomics Institute, BGI-Tianjin, BGI-shenzhen, Tianjin, China
- Tianjin Translational Genomics Center, BGI-Tianjin, BGI-shenzhen, Tianjin, China
| | - Fanrong Kong
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR – Pathology West, Westmead Hospital, University of Sydney, Westmead, New South Wales, Australia
| | - Ying-Chun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- * E-mail:
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22
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Zubair S, Fischer A, Liljander A, Meens J, Hegerman J, Gourlé H, Bishop RP, Roebbelen I, Younan M, Mustafa MI, Mushtaq M, Bongcam-Rudloff E, Jores J. Complete genome sequence of Staphylococcus aureus, strain ILRI_Eymole1/1, isolated from a Kenyan dromedary camel. Stand Genomic Sci 2015; 10:109. [PMID: 26594310 PMCID: PMC4654806 DOI: 10.1186/s40793-015-0098-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 11/10/2015] [Indexed: 11/29/2022] Open
Abstract
We report the genome of a Staphylococcus aureus strain (ILRI_Eymole1/1) isolated from a nasal swab of a dromedary camel (Camelus dromedarius) in North Kenya. The complete genome sequence of this strain consists of a circular chromosome of 2,874,302 bp with a GC-content of 32.88 %. In silico annotation predicted 2755 protein-encoding genes and 76 non-coding genes. This isolate belongs to MLST sequence type 30 (ST30). Phylogenetic analysis based on a subset of 283 core genes revealed that it falls within the human clonal complex 30 (CC30) S. aureus isolate cluster but is genetically distinct. About 79 % of the protein encoding genes are part of the CC30 core genome (genes common to all CC30 S. aureus isolates), ~18 % were within the variable genome (shared among multiple but not all isolates) and ~ 3 % were found only in the genome of the camel isolate. Among the 85 isolate-specific genes, 79 were located within putative phages and pathogenicity islands. Protein encoding genes associated with bacterial adhesion, and secretory proteins that are essential components of the type VII secretion system were also identified. The complete genome sequence of S. aureus strain ILRI_Eymole1/1 has been deposited in the European Nucleotide Archive under the accession no LN626917.1.
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Affiliation(s)
- Saima Zubair
- Department of Animal Breeding and Genetics, SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Anne Fischer
- International Livestock Research Institute, PO Box 30709, Nairobi, Kenya ; International Center for Insect Physiology and Ecology, PO Box 30722, Nairobi, Kenya
| | - Anne Liljander
- International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Jochen Meens
- Department of Infectious Diseases, Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Jan Hegerman
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany ; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany ; REBIRTH Cluster of Excellence, Hannover, Germany
| | - Hadrien Gourlé
- Department of Animal Breeding and Genetics, SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Richard P Bishop
- International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Ina Roebbelen
- International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
| | - Mario Younan
- Vétérinaires sans Frontières Germany, Nairobi, Kenya
| | - Mudassir Imran Mustafa
- Department of Public Health and Caring Science, Uppsala University, 751 22 Uppsala, Sweden
| | - Mamoona Mushtaq
- Department of Animal Breeding and Genetics, SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Erik Bongcam-Rudloff
- Department of Animal Breeding and Genetics, SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Joerg Jores
- International Livestock Research Institute, PO Box 30709, Nairobi, Kenya
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Sharma-Kuinkel BK, Mongodin EF, Myers JR, Vore KL, Canfield GS, Fraser CM, Rude TH, Fowler VG, Gill SR. Potential Influence of Staphylococcus aureus Clonal Complex 30 Genotype and Transcriptome on Hematogenous Infections. Open Forum Infect Dis 2015. [PMID: 26213692 PMCID: PMC4512144 DOI: 10.1093/ofid/ofv093] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background. The contemporary Staphylococcus aureus clonal complex (CC) 30 lineage is associated with complicated infections, including endocarditis and osteomyelitis. This lineage diverged from the phage-type 80/81 S aureus clone responsible for a major bacterial epidemic of the 20th century. The genome and transcriptome features that contribute to complicated infections of the CC30 lineage are unknown. Methods. Twenty-nine clinical methicillin-resistant S aureus (MRSA) strains (8 from CC30 and 21 from other major CCs were evaluated for virulence using murine and Galleria mellonella sepsis models. Genomic features of CC30 were identified by comparative genome sequencing and RNA-Seq transcriptome analysis of the 29 strains and 31 previously sequenced S aureus genomes. Results. The CC30 isolates displayed lower virulence in the sepsis models compared with other CCs [P < .0001]. Comparisons of orthologous proteins and transcriptome analysis identified genes (eg, nitric oxide reductase) and changes in metabolic pathways (eg, pyrimidine metabolism) that contribute to the distinct CC30 phenotype. Previously reported nonsynonymous single-nucleotide polymorphisms (SNPs) were found in accessory gene regulator C (agrC) and α-hemolysin (hla), molecules important for virulence. Additional nonsynonymous SNPs conserved across clinical CC30 isolates when compared with the first sequenced contemporary CC30 clone, MRSA-16, were identified in multiple genes, suggesting continuing evolutionary divergence in this lineage. Conclusions. Genomic and transcriptional analyses suggest that the CC30 lineage has acquired metabolic features that contribute to persistent and complicated infections. Absence of sepsis-induced mortality in animal models may be due in part to its unique genomic profile and suggests that specific genotypes of S aureus elicit distinct types of infection types.
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Affiliation(s)
| | - Emmanuel F Mongodin
- Institute for Genome Sciences , University of Maryland School of Medicine , Baltimore
| | - Jason R Myers
- Department of Microbiology and Immunology , University of Rochester , New York ; University of Rochester Genomics Research Center , University of Rochester , New York
| | - Kelly L Vore
- Department of Microbiology and Immunology , University of Rochester , New York
| | - Greg S Canfield
- Department of Microbiology and Immunology , University of Rochester , New York
| | - Claire M Fraser
- Institute for Genome Sciences , University of Maryland School of Medicine , Baltimore
| | - Thomas H Rude
- Department of Medicine , Duke University Medical Center , Durham, North Carolina
| | - Vance G Fowler
- Department of Medicine , Duke University Medical Center , Durham, North Carolina ; Duke Clinical Research Institute , Durham, North Carolina
| | - Steven R Gill
- Department of Microbiology and Immunology , University of Rochester , New York ; University of Rochester Genomics Research Center , University of Rochester , New York
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24
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Abstract
Staphylococcus aureus is a prominent global nosocomial and community-acquired bacterial pathogen. A strong restriction barrier presents a major hurdle for the introduction of recombinant DNA into clinical isolates of S. aureus. Here, we describe the construction and characterization of the IMXXB series of Escherichia coli strains that mimic the type I adenine methylation profiles of S. aureus clonal complexes 1, 8, 30, and ST93. The IMXXB strains enable direct, high-efficiency transformation and streamlined genetic manipulation of major S. aureus lineages. The genetic manipulation of clinical S. aureus isolates has been hampered due to the presence of restriction modification barriers that detect and subsequently degrade inappropriately methylated DNA. Current methods allow the introduction of plasmid DNA into a limited subset of S. aureus strains at high efficiency after passage of plasmid DNA through the restriction-negative, modification-proficient strain RN4220. Here, we have constructed and validated a suite of E. coli strains that mimic the adenine methylation profiles of different clonal complexes and show high-efficiency plasmid DNA transfer. The ability to bypass RN4220 will reduce the cost and time involved for plasmid transfer into S. aureus. The IMXXB series of E. coli strains should expedite the process of mutant construction in diverse genetic backgrounds and allow the application of new techniques to the genetic manipulation of S. aureus.
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25
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Characterization of Insertion Sequence ISSau2 in the Human and Livestock-Associated Staphylococcus aureus. PLoS One 2015; 10:e0127183. [PMID: 25978410 PMCID: PMC4433286 DOI: 10.1371/journal.pone.0127183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/12/2015] [Indexed: 01/13/2023] Open
Abstract
Mobile genetic elements play important roles in evolution and diversification of bacterial genomes. ISSau2 is 1660bp in length with terminal 5’-TG and CA-3’ dinucleotides and has two overlapping reading frames orfA and orfB. It has been found in a wide range of S. aureus, such as HA-MRSA252, LGA251, MRSA S0385 and ED133. To determine distribution of ISSau2, 164 S. aureus isolates from milk samples of mastitic cows from our laboratory and all the S. aureus strains from the National Center for Biotechnology Information (NCBI) database were screened for the presence of ISSau2. Next, in order to explore a potential relationship among S. aureus ISSau2-containing strains and isolates, a relationship among 10 ISSau2-positive S. aureus isolates and 27 ISSau2-positive S. aureus strains was investigated by a phylogenetic analysis. These ISSau2 isolates and strains could be classified into four groups (A, B, C and D). The strains or isolates in Group D were all isolated from mammary glands, suggesting tissue specificity. All strains in Group B had an identical ISSau2 derivative, termed ISSau21628, with 32bp deletion at the 3’ terminus. ISSau21628 in strain ST398 from Group B was closely related to ISSau2 in strain LGA251 from Group D.
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26
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Hanratty J, Changez H, Smith A, Wales C. Panton-Valentine Leukocidin Positive Staphylococcal aureus Infections of the Head and Neck: Case Series and Brief Review of Literature. J Oral Maxillofac Surg 2015; 73:666-70. [DOI: 10.1016/j.joms.2014.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/10/2014] [Accepted: 10/13/2014] [Indexed: 12/01/2022]
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27
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Aiyar A, Quayle AJ, Buckner LR, Sherchand SP, Chang TL, Zea AH, Martin DH, Belland RJ. Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections. Front Cell Infect Microbiol 2014; 4:72. [PMID: 24918090 PMCID: PMC4042155 DOI: 10.3389/fcimb.2014.00072] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/15/2014] [Indexed: 11/13/2022] Open
Abstract
The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium's capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C.trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxgenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.
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Affiliation(s)
- Ashok Aiyar
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Alison J Quayle
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Lyndsey R Buckner
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Shardulendra P Sherchand
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Theresa L Chang
- Department of Microbiology and Molecular Genetics, Public Health Research Institute Center, New Jersey Medical School-Rutgers, The State University of New Jersey Newark, NJ, USA
| | - Arnold H Zea
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - David H Martin
- Section of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Robert J Belland
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Sciences Center Memphis, TN, USA
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28
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Arsic B, Zhu Y, Heinrichs DE, McGavin MJ. Induction of the staphylococcal proteolytic cascade by antimicrobial fatty acids in community acquired methicillin resistant Staphylococcus aureus. PLoS One 2012; 7:e45952. [PMID: 23029337 PMCID: PMC3454333 DOI: 10.1371/journal.pone.0045952] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/23/2012] [Indexed: 01/31/2023] Open
Abstract
Community acquired methicillin resistant Staphylococcus aureus (CA-MRSA), and the USA300 strain of CA-MRSA in particular, are known for their rapid community transmission, and propensity to cause aggressive skin and soft tissue infections. To assess factors that contribute to these hallmark traits of CA-MRSA, we evaluated how growth of USA300 and production of secreted virulence factors was influenced on exposure to physiologic levels of unsaturated free fatty acids that would be encountered on the skin or anterior nares, which represent the first sites of contact with healthy human hosts. There was a sharp threshold between sub-inhibitory and inhibitory concentrations, such that 100 µM sapienic acid (C16∶1) and linoleic acid (C18∶1) were sufficient to prevent growth after 24 h incubation, while 25 µM allowed unrestricted growth, and 50 µM caused an approximate 10–12 h lag, followed by unimpeded exponential growth. Conversely, saturated palmitic or stearic acids did not affect growth at 100 µM. Although growth was not affected by 25 µM sapienic or linoleic acid, these and other unsaturated C16 and C18 fatty acids, but not their saturated counterparts, promoted robust production of secreted proteases comprising the Staphylococcal proteolytic cascade. This trait was also manifested to varying degrees in other CA-MRSA, and in genetically diverse methicillin susceptible S. aureus strains. Therefore, induction of the Staphylococcal proteolytic cascade by unsaturated fatty acids is another feature that should now be evaluated as a potential contributing factor in the aggressive nature of skin and soft tissue infections caused by USA300, and as a general virulence mechanism of S. aureus.
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Affiliation(s)
- Benjamin Arsic
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - Yue Zhu
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
| | - David E. Heinrichs
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Centre for Human Immunology, Western University, London, Ontario, Canada
| | - Martin J. McGavin
- Department of Microbiology and Immunology, Western University, London, Ontario, Canada
- Centre for Human Immunology, Western University, London, Ontario, Canada
- * E-mail:
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29
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McGavin MJ, Heinrichs DE. The staphylococci and staphylococcal pathogenesis. Front Cell Infect Microbiol 2012; 2:66. [PMID: 22919657 PMCID: PMC3417565 DOI: 10.3389/fcimb.2012.00066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 04/26/2012] [Indexed: 12/31/2022] Open
Affiliation(s)
- Martin J. McGavin
- Department of Microbiology and Immunology, Western UniversityLondon, ON, Canada
- *Correspondence: ;
| | - David E. Heinrichs
- Department of Microbiology and Immunology, Western UniversityLondon, ON, Canada
- *Correspondence: ;
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30
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Xu SX, McCormick JK. Staphylococcal superantigens in colonization and disease. Front Cell Infect Microbiol 2012; 2:52. [PMID: 22919643 PMCID: PMC3417409 DOI: 10.3389/fcimb.2012.00052] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/29/2012] [Indexed: 12/28/2022] Open
Abstract
Superantigens (SAgs) are a family of potent immunostimulatory exotoxins known to be produced by only a few bacterial pathogens, including Staphylococcus aureus. More than 20 distinct SAgs have been characterized from different S. aureus strains and at least 80% of clinical strains harbor at least one SAg gene, although most strains encode many. SAgs have been classically associated with food poisoning and toxic shock syndrome (TSS), for which these toxins are the causative agent. TSS is a potentially fatal disease whereby SAg-mediated activation of T cells results in overproduction of cytokines and results in systemic inflammation and shock. Numerous studies have also shown a possible role for SAgs in other diseases such as Kawasaki disease (KD), atopic dermatitis (AD), and chronic rhinosinusitis (CRS). There is also now a rich understanding of the mechanisms of action of SAgs, as well as their structures and function. However, we have yet to discover what purpose SAgs play in the life cycle of S. aureus, and why such a wide array of these toxins exists. This review will focus on recent developments within the SAg field in terms of the molecular biology of these toxins and their role in both colonization and disease.
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Affiliation(s)
- Stacey X Xu
- Department of Microbiology and Immunology, Centre for Human Immunology, Schulich School of Medicine and Dentistry, University of Western Ontario, London ON, Canada
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