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McDermott G, Walsh A, Crispie F, Frost S, Greally P, Cotter PD, O’Sullivan O, Renwick J. Insights into the Adolescent Cystic Fibrosis Airway Microbiome Using Shotgun Metagenomics. Int J Mol Sci 2024; 25:3893. [PMID: 38612702 PMCID: PMC11011389 DOI: 10.3390/ijms25073893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024] Open
Abstract
Cystic fibrosis (CF) is an inherited genetic disorder which manifests primarily in airway disease. Recent advances in molecular technologies have unearthed the diverse polymicrobial nature of the CF airway. Numerous studies have characterised the genus-level composition of this airway community using targeted 16S rDNA sequencing. Here, we employed whole-genome shotgun metagenomics to provide a more comprehensive understanding of the early CF airway microbiome. We collected 48 sputum samples from 11 adolescents and children with CF over a 12-month period and performed shotgun metagenomics on the Illumina NextSeq platform. We carried out functional and taxonomic analysis of the lung microbiome at the species and strain levels. Correlations between microbial diversity measures and independent demographic and clinical variables were performed. Shotgun metagenomics detected a greater diversity of bacteria than culture-based methods. A large proportion of the top 25 most-dominant species were anaerobes. Samples dominated by Staphylococcus aureus and Prevotella melaninogenica had significantly higher microbiome diversity, while no CF pathogen was associated with reduced microbial diversity. There was a diverse resistome present in all samples in this study, with 57.8% agreement between shotgun metagenomics and culture-based methods for detection of resistance. Pathogenic sequence types (STs) of S. aureus, Pseudomonas aeruginosa, Haemophilus influenzae and Stenotrophomonas maltophilia were observed to persist in young CF patients, while STs of S. aureus were both persistent and shared between patients. This study provides new insight into the temporal changes in strain level composition of the microbiome and the landscape of the resistome in young people with CF. Shotgun metagenomics could provide a very useful one-stop assay for detecting pathogens, emergence of resistance and conversion to persistent colonisation in early CF disease.
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Affiliation(s)
- Gillian McDermott
- Trinity Centre for Health Science, Clinical Microbiology Department, School of Medicine, Faculty of Health Science, Trinity College Dublin, Tallaght University Hospital, D24 NR0A Dublin, Ireland;
| | - Aaron Walsh
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 Co Cork, Ireland; (A.W.); (F.C.); (P.D.C.); (O.O.)
- APC Microbiome Ireland, University College Cork, T12 R229 Co Cork, Ireland
| | - Fiona Crispie
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 Co Cork, Ireland; (A.W.); (F.C.); (P.D.C.); (O.O.)
- APC Microbiome Ireland, University College Cork, T12 R229 Co Cork, Ireland
| | - Susanna Frost
- Tallaght University Hospital, Tallaght, D24 NR0 Dublin, Ireland (P.G.)
| | - Peter Greally
- Tallaght University Hospital, Tallaght, D24 NR0 Dublin, Ireland (P.G.)
- Hermitage Medical Clinic, Lucan, D20 W722 Dublin, Ireland
| | - Paul D. Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 Co Cork, Ireland; (A.W.); (F.C.); (P.D.C.); (O.O.)
- APC Microbiome Ireland, University College Cork, T12 R229 Co Cork, Ireland
| | - Orla O’Sullivan
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 Co Cork, Ireland; (A.W.); (F.C.); (P.D.C.); (O.O.)
- APC Microbiome Ireland, University College Cork, T12 R229 Co Cork, Ireland
| | - Julie Renwick
- Trinity Centre for Health Science, Clinical Microbiology Department, School of Medicine, Faculty of Health Science, Trinity College Dublin, Tallaght University Hospital, D24 NR0A Dublin, Ireland;
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2
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Svishchuk J, Ebbert K, Waddell B, Izydorczyk C, Acosta N, Somayaji R, Rabin HR, Bjornson CL, Lisboa L, Gregson DB, Conly JM, Surette MG, Parkins MD. Epidemiology and impact of methicillin-sensitive Staphylococcus aureus with β-lactam antibiotic inoculum effects in adults with cystic fibrosis. Antimicrob Agents Chemother 2023; 67:e0013623. [PMID: 37966229 PMCID: PMC10720481 DOI: 10.1128/aac.00136-23] [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: 01/31/2023] [Accepted: 08/22/2023] [Indexed: 11/16/2023] Open
Abstract
Staphylococcus aureus is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and small-colony-variants. The inoculum effect (IE) is characterized by reduced β-lactam susceptibility when assessed at high inoculum. The IE associates with worse outcomes in bacteremia and other high-density infections, and may therefore be relevant to CF. The prevalence of IE amongst a CF cohort (age ≥18 years), followed from 2013 to 2016, was investigated. Yearly methicillin-sensitive S. aureus (MSSA) isolates were screened at standard (5 × 105 CFU/mL) and high (5 × 107 CFU/mL) inoculum against narrow-spectrum anti-Staphylococcal β-lactams and those with anti-pseudomonal activity common to CF. A ≥ 4-fold increase in minimum inhibitory concentration between standard and high inoculum defined IE. Isolates underwent blaZ sequencing and genotyping and were compared against published genomes. Fifty-six percent (99/177) of individuals had MSSA infection. MSSA was observed at ≥105 CFU/mL in 44.8% of entry sputum samples. The prevalence of the IE was 25.0%-cefazolin; 13.5%-cloxacillin; 0%-meropenem; 1.0%-cefepime; 5.2%-ceftazidime; and 34.4%-piperacillin-tazobactam amongst baseline MSSA isolates assessed. blaZ A associated with cefazolin IE (P = 0.0011), whereas blaZ C associated with piperacillin-tazobactam IE (P < 0.0001). Baseline demographics did not reveal specific risk factors for IE-associated infections, nor were long-term outcomes different. Herein, we observed the IE in CF-derived MSSA disproportionally for cefazolin and piperacillin-tazobactam and this phenotype strongly associated with underlying blaZ genotype. The confirmation of CF being a high density infection, and the identification of high prevalence of MSSA with IE in CF supports the need for prospective pulmonary exacerbation treatment studies to understand the impact of this phenotype.
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Affiliation(s)
- J. Svishchuk
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - K. Ebbert
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - B. Waddell
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - C. Izydorczyk
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - N. Acosta
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - R. Somayaji
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - H. R. Rabin
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - C. L. Bjornson
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - L. Lisboa
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - D. B. Gregson
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - J. M. Conly
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - M. G. Surette
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - M. D. Parkins
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
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3
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Boutet-Dubois A, Magnan C, Lienard A, Pouget C, Bouchet F, Marchandin H, Larcher R, Lavigne JP, Pantel A. In Vivo-Acquired Resistance to Daptomycin during Methicillin-Resistant Staphylococcus aureus Bacteremia. Antibiotics (Basel) 2023; 12:1647. [PMID: 38136681 PMCID: PMC10740961 DOI: 10.3390/antibiotics12121647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 12/24/2023] Open
Abstract
Daptomycin (DAP) represents an interesting alternative to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. Different mechanisms of DAP resistance have been described; however, in vivo-acquired resistance is uncharacterized. This study described the phenotypic and genotypic evolution of MRSA strains that became resistant to DAP in two unrelated patients with bacteremia under DAP treatment, in two hospitals in the South of France. DAP MICs were determined using broth microdilution method on the pairs of isogenic (DAP-S/DAP-R) S. aureus isolated from bloodstream cultures. Whole genome sequencing was carried out using Illumina MiSeq Sequencing system. The two cases revealed DAP-R acquisition by MRSA strains within three weeks in patients treated by DAP. The isolates belonged to the widespread ST5 (patient A) and ST8 (patient B) lineages and were of spa-type t777 and t622, respectively. SNP analysis comparing each DAP-S/DAP-R pair confirmed that the isolates were isogenic. The causative mutations were identified in MprF (Multiple peptide resistance Factor) protein: L826F (Patient A) and S295L (Patient B), and in Cls protein: R228H (Patient B). These proteins encoded both proteins of the lipid biosynthetic enzymes. The resistance to DAP is particularly poorly described whereas DAP is highly prescribed to treat MRSA. Our study highlights the non-systematic cross-resistance between DAP and glycopeptides and the importance of monitoring DAP MIC in persistent MRSA bacteremia.
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Affiliation(s)
- Adeline Boutet-Dubois
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30029 Nîmes, France; (A.B.-D.); (C.M.); (C.P.); (A.P.)
| | - Chloé Magnan
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30029 Nîmes, France; (A.B.-D.); (C.M.); (C.P.); (A.P.)
| | - Alexi Lienard
- Laboratory of Medical Biology, CH Bassin de Thau, 34207 Sète, France;
| | - Cassandra Pouget
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30029 Nîmes, France; (A.B.-D.); (C.M.); (C.P.); (A.P.)
| | - Flavien Bouchet
- Department of Internal Medicine-Infectiology, CH Bassin de Thau, 34207 Sète, France;
| | - Hélène Marchandin
- HydroSciences Montpellier, Department of Microbiology and Hospital Hygiene, University of Montpellier, CNRS, IRD, CHU Nîmes, 30029 Nîmes, France;
| | - Romaric Larcher
- Department of Infectious Diseases, CHU Nîmes, 30029 Nîmes, France;
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30029 Nîmes, France; (A.B.-D.); (C.M.); (C.P.); (A.P.)
| | - Alix Pantel
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30029 Nîmes, France; (A.B.-D.); (C.M.); (C.P.); (A.P.)
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4
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Hall BG, Nisbet J. Building Phylogenetic Trees From Genome Sequences With kSNP4. Mol Biol Evol 2023; 40:msad235. [PMID: 37948764 PMCID: PMC10640685 DOI: 10.1093/molbev/msad235] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/15/2023] [Accepted: 10/18/2023] [Indexed: 11/12/2023] Open
Abstract
Performing phylogenetic analysis with genome sequences maximizes the information used to estimate phylogenies and the resolution of closely related taxa. The use of single-nucleotide polymorphisms (SNPs) permits estimating trees without genome alignments and permits the use of data sets of hundreds of microbial genomes. kSNP4 is a program that identifies SNPs without using a reference genome, estimates parsimony, maximum likelihood, and neighbor-joining trees, and is able to annotate the discovered SNPs. kSNP4 is a command-line program that does not require any additional programs or dependencies to install or use. kSNP4 does not require any programming experience or bioinformatics experience to install and use. It is suitable for use by students through senior investigators. It includes a detailed user guide that explains all of the many features of kSNP4. In this study, we provide a detailed step-by-step protocol for downloading, installing, and using kSNP4 to build phylogenetic trees from genome sequences.
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Affiliation(s)
- Barry G Hall
- Bellingham Research Institute, Portland, OR, USA
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5
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Worley JN, Crothers JW, Wolfgang WJ, Venkata SLG, Hoffmann M, Jayeola V, Klompas M, Allard M, Bry L. Prospective Genomic Surveillance Reveals Cryptic MRSA Outbreaks with Local to International Origins among NICU Patients. J Clin Microbiol 2023; 61:e0001423. [PMID: 37022157 PMCID: PMC10204624 DOI: 10.1128/jcm.00014-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/19/2023] [Indexed: 04/07/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections cause substantive morbidity and mortality in neonates. Using publicly available resources from the National Center of Biotechnology Information (NCBI) and Food and Drug Administration's (FDA) GalaxyTrakr pipeline, we illustrate the dynamics of MRSA colonization and infection in neonates. Over 217 days of prospective surveillance, analyses revealed concurrent MRSA transmission chains affecting 11 of 17 MRSA-colonized patients (65%), with two clusters that demonstrated intervals of more than a month among the appearance of isolates. All MRSA infected neonates (n = 3) showed previous colonization with the infecting strain. GalaxyTrakr clustering of the NICU strains, in the context of 21,521 international isolates deposited in NCBI's Pathogen Detection Resource, revealed NICU isolates to be distinct from adult MRSA strains seen locally and internationally. Clustering of the NICU strains within an international context enhanced the resolution of strain clusters and supported the rule-out of suspected, local transmission events within the NICU. Analyses also identified sequence type 1535 isolates, emergent in the Middle East, carrying a unique SCCmec with fusC and aac(6')-Ie/aph(2'')-1a that provided a multidrug-resistant phenotype. NICU genomic pathogen surveillance, leveraging public repositories and outbreak detection tools, supports rapid identification of cryptic MRSA clusters, and can inform infection prevention interventions for this vulnerable patient population. Results demonstrate that sporadic infections in the NICU may be indicative of hidden chains of asymptomatic transmission best identified with sequenced-based approaches.
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Affiliation(s)
- Jay N. Worley
- Massachusetts Host-Microbiome Center, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Jessica W. Crothers
- Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, Vermont, USA
- Translational Global Infectious Disease Research Center, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - William J. Wolfgang
- Wadsworth Center, Division of Infectious Diseases, New York State Department of Health, Albany, New York, USA
| | - Sai Laxmi Gubbala Venkata
- Wadsworth Center, Division of Infectious Diseases, New York State Department of Health, Albany, New York, USA
| | - Maria Hoffmann
- Center for Food Safety and Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Victor Jayeola
- Center for Food Safety and Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Michael Klompas
- Department of Population Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marc Allard
- Center for Food Safety and Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Lynn Bry
- Massachusetts Host-Microbiome Center, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Clinical Microbiology Laboratory, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
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6
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Bonn CM, Rafiqullah IM, Crawford JA, Qian YM, Guthrie JL, Matuszewska M, Robinson DA, McGavin MJ. Repeated Emergence of Variant TetR Family Regulator, FarR, and Increased Resistance to Antimicrobial Unsaturated Fatty Acid among Clonal Complex 5 Methicillin-Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2023; 67:e0074922. [PMID: 36744906 PMCID: PMC10019231 DOI: 10.1128/aac.00749-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Resistance-nodulation-division (RND) superfamily efflux pumps promote antibiotic resistance in Gram-negative pathogens, but their role in Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) is undocumented. However, recent in vitro selections for resistance of S. aureus to an antimicrobial fatty acid, linoleic acid, and an antibiotic, rhodomyrtone, identified H121Y and C116R substitution variants, respectively, in a TetR family regulator, FarR, promoting increased expression of the RND pump FarE. Hypothesizing that in vivo selection pressures have also promoted the emergence of FarR variants, we searched available genome data and found that strains with FarRH121Y from human and bovine hosts have emerged sporadically in clonal complexes (CCs) CC1, CC30, CC8, CC22, and CC97, whereas multiple FarR variants have occurred within CC5 hospital-associated (HA)-MRSA. Of these, FarRE160G and FarRE93EE were exclusive to CC5, while FarRC116Y, FarRP165L, and FarRG166D also occurred in nonrelated CCs, primarily from bovine hosts. Within CC5, FarRC116Y and FarRG166D strains were polyphyletic, each exhibiting two emergence events. FarRC116Y and FarRE160G were individually sufficient to confer increased expression of FarE and enhanced resistance to linoleic acid (LA). Isolates with FarRE93EE were most closely related to S. aureus N315 MRSA and exhibited increased resistance independently of FarRE93EE. Accumulation of pseudogenes and additional polymorphisms in FarRE93EE strains contributed to a multiresistance phenotype which included fosfomycin and fusidic acid resistance in addition to increased linoleic acid resistance. These findings underscore the remarkable adaptive capacity of CC5 MRSA, which includes the polyphyletic USA100 lineage of HA-MRSA that is endemic in the Western hemisphere and known for the acquisition of multiple resistance phenotypes.
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Affiliation(s)
- Camryn M. Bonn
- Department of Microbiology, University of Western Ontario, London, Ontario, Canada
| | - Iftekhar M. Rafiqullah
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - John A. Crawford
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Yi Meng Qian
- Department of Microbiology, University of Western Ontario, London, Ontario, Canada
| | - Jennifer L. Guthrie
- Department of Microbiology, University of Western Ontario, London, Ontario, Canada
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Marta Matuszewska
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - D. Ashley Robinson
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Martin J. McGavin
- Department of Microbiology, University of Western Ontario, London, Ontario, Canada
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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7
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Pouget C, Chatre C, Lavigne JP, Pantel A, Reynes J, Dunyach-Remy C. Effect of Antibiotic Exposure on Staphylococcus epidermidis Responsible for Catheter-Related Bacteremia. Int J Mol Sci 2023; 24:ijms24021547. [PMID: 36675063 PMCID: PMC9863639 DOI: 10.3390/ijms24021547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/16/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Coagulase-negative staphylococci (CoNS) and especially Staphylococcus epidermidis are responsible for health care infections, notably in the presence of foreign material (e.g., venous or central-line catheters). Catheter-related bacteremia (CRB) increases health care costs and mortality. The aim of our study was to evaluate the impact of 15 days of antibiotic exposure (ceftobiprole, daptomycin, linezolid and vancomycin) at sub-inhibitory concentration on the resistance, fitness and genome evolution of 36 clinical strains of S. epidermidis responsible for CRB. Resistance was evaluated by antibiogram, the ability to adapt metabolism by the Biofilm Ring test® and the in vivo nematode virulence model. The impact of antibiotic exposure was determined by whole-genome sequencing (WGS) and biofilm formation experiments. We observed that S. epidermidis strains presented a wide variety of virulence potential and biofilm formation. After antibiotic exposure, S. epidermidis strains adapted their fitness with an increase in biofilm formation. Antibiotic exposure also affected genes involved in resistance and was responsible for cross-resistance between vancomycin, daptomycin and ceftobiprole. Our data confirmed that antibiotic exposure modified bacterial pathogenicity and the emergence of resistant bacteria.
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Affiliation(s)
- Cassandra Pouget
- Department of Microbiology and Hospital Hygiene, Bacterial Virulence and Chronic Infections, INSERM U1047, CHU Nîmes Univiversity Montpellier, CEDEX 09, 30029 Nîmes, France
| | - Clotilde Chatre
- Department of Infectious and Tropical Diseases, CH Perpignan, 66000 Perpignan, France
| | - Jean-Philippe Lavigne
- Department of Microbiology and Hospital Hygiene, Bacterial Virulence and Chronic Infections, INSERM U1047, CHU Nîmes Univiversity Montpellier, CEDEX 09, 30029 Nîmes, France
| | - Alix Pantel
- Department of Microbiology and Hospital Hygiene, Bacterial Virulence and Chronic Infections, INSERM U1047, CHU Nîmes Univiversity Montpellier, CEDEX 09, 30029 Nîmes, France
| | - Jacques Reynes
- Department of Infectious and Tropical Diseases, IRD UMI 233, INSERM U1175, CHU Montpellier, University Montpellier, CEDEX 5, 34295 Montpellier, France
| | - Catherine Dunyach-Remy
- Department of Microbiology and Hospital Hygiene, Bacterial Virulence and Chronic Infections, INSERM U1047, CHU Nîmes Univiversity Montpellier, CEDEX 09, 30029 Nîmes, France
- Correspondence: ; Tel.: +33-4-6668-3202
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8
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Silvola J, Gröndahl-Yli-Hannuksela K, Hirvioja T, Rantakokko-Jalava K, Rintala E, Auranen K, Junnila J, Marttila H, Lindholm L, Vuopio J. Whole genome sequencing reveals new links between spa t172/CC59 methicillin-resistant Staphylococcus aureus cases in low-endemicity region of Southwest Finland, 2007‒2016. Sci Rep 2022; 12:21326. [PMID: 36494398 PMCID: PMC9734107 DOI: 10.1038/s41598-022-25556-w] [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: 04/05/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) rates have remained relatively low in Finland. In Southwest Finland, however, annual MRSA incidence increased from 12 to 25/100,000 between 2007 and 2016 with spa t172 strain causing one fourth (237/983) of all cases. This provoked us to study the molecular epidemiology of t172-MRSA, aiming to better understand the transmission of this strain type. We combined epidemiological data and whole genome sequencing (WGS) of a set of 64 (27%, 64/237) t172-MRSA isolates covering 10 years. Isolates represented sporadic and index cases of all identified healthcare-associated outbreaks (HAOs) and family clusters (FCs). Among the included 62 isolates, core-genome MLST analysis revealed eight genomic clusters comprising 24 (38.7%) isolates and 38 (61.3%) non-clustered isolates. Cluster 1 comprised ten and the remaining seven clusters two isolates each, respectively. Two epidemiologically distinct HAOs were linked in cluster 1. FCs were involved in all clusters. All strains were associated with epidemic clonal complex CC59. We were able to confirm the spread of several successful t172-MRSA subclones in regional healthcare and the community. WGS complemented routine surveillance by revealing undetected links between t172-MRSA cases. Targeted, WGS-based typing could enhance MRSA surveillance without the need for routine WGS diagnostics.
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Affiliation(s)
- Jaakko Silvola
- grid.1374.10000 0001 2097 1371Institute of Biomedicine, University of Turku, Turku, Finland
| | | | - Tiina Hirvioja
- grid.410552.70000 0004 0628 215XDepartment of Hospital Hygiene & Infection Control, Turku University Hospital, Turku, Finland
| | - Kaisu Rantakokko-Jalava
- grid.410552.70000 0004 0628 215XClinical Microbiology Laboratory, Turku University Hospital, Turku, Finland
| | - Esa Rintala
- grid.410552.70000 0004 0628 215XDepartment of Hospital Hygiene & Infection Control, Turku University Hospital, Turku, Finland
| | - Kari Auranen
- grid.1374.10000 0001 2097 1371Department of Mathematics and Statistics and Department of Clinical Medicine, University of Turku, Turku, Finland
| | - Jenna Junnila
- grid.1374.10000 0001 2097 1371Institute of Biomedicine, University of Turku, Turku, Finland
| | - Harri Marttila
- grid.410552.70000 0004 0628 215XDepartment of Hospital Hygiene & Infection Control, Turku University Hospital, Turku, Finland
| | - Laura Lindholm
- grid.14758.3f0000 0001 1013 0499Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Jaana Vuopio
- grid.1374.10000 0001 2097 1371Institute of Biomedicine, University of Turku, Turku, Finland ,grid.410552.70000 0004 0628 215XClinical Microbiology Laboratory, Turku University Hospital, Turku, Finland ,grid.14758.3f0000 0001 1013 0499Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
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9
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Biggs SL, Jennison AV, Bergh H, Graham R, Nimmo G, Whiley D. Limited evidence of patient-to-patient transmission of Staphylococcus aureus strains between children with cystic fibrosis, Queensland, Australia. PLoS One 2022; 17:e0275256. [PMID: 36206247 PMCID: PMC9543978 DOI: 10.1371/journal.pone.0275256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 09/13/2022] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES Here we used whole genome sequencing (WGS) to understand strain diversity and potential for patient-to-patient transmission of Staphylococcus aureus among children with cystic fibrosis (CF) in Queensland, Australia. METHODS S. aureus isolates (n = 401) collected between January 2018 and April 2019 from 184 patients with CF (n = 318 isolates) and 76 patients without CF (n = 83 isolates) were subjected to WGS and subsequent multilocus sequence typing (MLST), and a phylogeny was constructed from core genome single nucleotide polymorphism (SNP) analysis. The subsequent data was compared with available patient information. RESULTS WGS revealed that patients with CF were essentially colonised by the same genotypes as those seen in patients without CF. Sequence types (ST) for our patients with CF were predominantly ST5 (20.1%), ST30 (7.3%), ST15 (6.3%) and ST8 (5.3%). Two Australian clones, ST93 and ST239, typically seen in skin infections and health-care settings, respectively, were notably absent from our patients with CF. Based on a SNP distance threshold of 14 SNPs, 20 cluster types involving 50/260 patients were evident; of these, 6 clusters contained only patients found to be siblings or otherwise living in the same household. Epidemiological relationships could not be determined for a remaining 14 cluster types involving 38 patients, comprising 2-7 (median 2) patients each. Multiple S. aureus genotypes were observed in 19/73 CF patients who provided more than one sample. CONCLUSION These results show that WGS is a useful tool for surveillance of S. aureus strains in children with CF and that the strains in our CF cohort were largely consistent with those circulating in patients without CF. Overall, this confirms previous findings and indicates that S. aureus acquisition in children with CF is similar to that of other patient groups, with limited evidence of potential patient-to-patient transmission within this patient group.
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Affiliation(s)
- Sharon L. Biggs
- School of Medicine, The University of Queensland, UQ Centre for Clinical Research (UQCCR), Herston, Queensland, Australia
| | - Amy V. Jennison
- Public and Environmental Health, Forensic and Scientific Services, Coopers Plains, Queensland, Australia
| | - Haakon Bergh
- Pathology Queensland Central Laboratory, Herston, Queensland, Australia
| | - Rikki Graham
- Public and Environmental Health, Forensic and Scientific Services, Coopers Plains, Queensland, Australia
| | - Graeme Nimmo
- School of Medicine, Griffith University, Gold Coast, Queensland, Australia
| | - David Whiley
- School of Medicine, The University of Queensland, UQ Centre for Clinical Research (UQCCR), Herston, Queensland, Australia
- Pathology Queensland Central Laboratory, Herston, Queensland, Australia
- * E-mail:
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10
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The Persistence of Staphylococcus aureus in Pressure Ulcers: A Colonising Role. Genes (Basel) 2021; 12:genes12121883. [PMID: 34946833 PMCID: PMC8701790 DOI: 10.3390/genes12121883] [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: 10/24/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022] Open
Abstract
Decubitus pressure ulcers (PU) are a major complication of immobilised patients. Staphylococcus aureus is one of the most frequently detected microorganisms in PU samples; however, its persistence and role in the evolution of these wounds is unknown. In this study, we analysed S. aureus strains isolated from PU biopsies at inclusion and day 28. Eleven S. aureus (21.1%) were detected in 52 patients at inclusion. Only six PUs (11.5%) continued to harbour this bacterium at day 28. Using a whole genome sequencing approach (Miseq®, Illumina), we confirmed that these six S. aureus samples isolated at D28 were the same strain as that isolated at inclusion, with less than 83 bp difference. Phenotypical studies evaluating the growth profiles (Infinite M Mano, Tecan®) and biofilm formation (Biofilm Ring Test®) did not detect any significant difference in the fitness of the pairs of S. aureus. However, using the Caenorhabditis elegans killing assay, a clear decrease of virulence was observed between strains isolated at D28 compared with those isolated at inclusion, regardless of the clinical evolution of the PU. Moreover, all strains at inclusion were less virulent than a control S. aureus strain, i.e., NSA739. An analysis of polymicrobial communities of PU (by metabarcoding approach), in which S. aureus persisted, demonstrated no impact of Staphylococcus genus on PU evolution. Our study suggested that S. aureus presented a colonising profile on PU with no influence on wound evolution.
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11
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Boudet A, Sorlin P, Pouget C, Chiron R, Lavigne JP, Dunyach-Remy C, Marchandin H. Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics. Front Microbiol 2021; 12:750489. [PMID: 34721354 PMCID: PMC8554194 DOI: 10.3389/fmicb.2021.750489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.
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Affiliation(s)
- Agathe Boudet
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Pauline Sorlin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
| | | | - Raphaël Chiron
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Centre de Ressources et de Compétences de la Mucoviscidose, CHU de Montpellier, Montpellier, France
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Catherine Dunyach-Remy
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Hélène Marchandin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
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12
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First Report of CC5-MRSA-IV-SCC fus "Maltese Clone" in Bat Guano. Microorganisms 2021; 9:microorganisms9112264. [PMID: 34835390 PMCID: PMC8619057 DOI: 10.3390/microorganisms9112264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a widespread pathogen that could cause different illnesses in both human and animals. Presence of MRSA in animals raises concerns of their capacity to act as reservoirs, particularly in wild animals. This study aimed to characterize the resistance and virulence patterns of S. aureus strains isolated from bat guano in Algeria. From March to May 2016, 98 bat guano samples from Aokas’s cave (Bejaia, Algeria) were collected. Swabs were taken for microbiological studies. Isolates were identified by Vitek® MS system, and antibiotic susceptibility was determined by disk diffusion method. The clonal origin, virulence and antibiotic resistance profiles of S. aureus isolates were characterized by whole genome sequencing. Eleven S. aureus strains were obtained from the 98 guano samples. Seven isolates were sensitive to all antibiotics tested and four (36.3%) were resistant to penicillin G, cefoxitin and fusidic acid. The four MRSA isolates were assigned to the sequence type ST149 and related to spa type t010. These isolates harbored a SCCmecIV element and the fusidic acid resistance element Q6GD50 (fusC). They carried different virulence genes including several enterotoxins (sea, egc enterotoxin locus, sec, sel), and the toxic shock syndrome toxin (tst). Our results highlight that bat guano may constitute an important reservoir of MRSA strains.
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13
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Lavigne JP, Hosny M, Dunyach-Remy C, Boutet-Dubois A, Schuldiner S, Cellier N, Yahiaoui-Martinez A, Molle V, La Scola B, Marchandin H, Sotto A. Long-Term Intrahost Evolution of Staphylococcus aureus Among Diabetic Patients With Foot Infections. Front Microbiol 2021; 12:741406. [PMID: 34552578 PMCID: PMC8452158 DOI: 10.3389/fmicb.2021.741406] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/11/2021] [Indexed: 01/22/2023] Open
Abstract
Staphylococcus aureus is one of the main pathogens isolated from diabetic foot infections (DFI). The purpose of this study was to evaluate the importance of the persistence of S. aureus in this environment and the possible modifications of the bacterial genome content over time. Molecular typing of S. aureus isolates cultured from patients with the same DFI over a 7-year study revealed a 25% rate of persistence of this species in 48 patients, with a short median persistence time of 12weeks (range: 4-52weeks). Non-specific clonal complexes were linked to this persistence. During the follow-up, bla genes were acquired in three cases, whereas some virulence markers were lost in all cases after a long period of colonization (21.5weeks). Only one patient (2%) had a long-term persistence of 48weeks. The genome sequencing of a clonal pair of early/late strains isolated in this patient showed mutations in genes encoding bacterial defence and two-component signal transduction systems. Although, this study suggests that the long-term persistence of S. aureus in DFI is a rare event, genomic evolution is observed, highlighting the low adaptive ability of S. aureus to the specific environment and stressful conditions of diabetic foot ulcers. These results provide the basis for better understanding of S. aureus dynamics during persistent colonization in chronic wounds.
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Affiliation(s)
- Jean-Philippe Lavigne
- VBIC, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, Université de Montpellier, CHU Nîmes, Nîmes, France
| | - Michel Hosny
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
| | - Catherine Dunyach-Remy
- VBIC, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, Université de Montpellier, CHU Nîmes, Nîmes, France
| | - Adeline Boutet-Dubois
- VBIC, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, Université de Montpellier, CHU Nîmes, Nîmes, France
| | - Sophie Schuldiner
- VBIC, INSERM U1047, Service des Maladies Métaboliques et Endocriniennes, Université de Montpellier, CHU Nîmes, Nîmes, France
| | | | - Alex Yahiaoui-Martinez
- VBIC, INSERM U1047, Service de Microbiologie et Hygiène Hospitalière, Université de Montpellier, CHU Nîmes, Nîmes, France
| | - Virginie Molle
- Laboratory of Pathogen Host Interactions, UMR 5235, CNRS, Université de Montpellier, Montpellier, France
| | - Bernard La Scola
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
| | - Hélène Marchandin
- HydroSciences Montpellier, CNRS, IRD, Service de Microbiologie et Hygiène Hospitalière, Université de Montpellier, CHU Nîmes, Nîmes, France
| | - Albert Sotto
- VBIC, INSERM U1047, Service des Maladies Infectieuses et Tropicales, Université de Montpellier, CHU Nîmes, Nîmes, France
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14
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Rumpf C, Lange J, Schwartbeck B, Kahl BC. Staphylococcus aureus and Cystic Fibrosis-A Close Relationship. What Can We Learn from Sequencing Studies? Pathogens 2021; 10:pathogens10091177. [PMID: 34578208 PMCID: PMC8466686 DOI: 10.3390/pathogens10091177] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/13/2023] Open
Abstract
Staphylococcus aureus is next to Pseudomonas aeruginosa the most isolated pathogen from the airways of cystic fibrosis (CF) patients, who are often infected by a dominant S. aureus clone for extended periods. To be able to persist, the pathogen has to adapt to the hostile niche of the airways to counteract host defence, antibiotic therapy and the competition with coinfecting pathogens. S. aureus is equipped with many virulence factors including adhesins, toxins that are localized on the chromosome, on plasmids or are phage-related. S. aureus is especially versatile and adaptation and evolution of the pathogen occurs by the acquisition of new genes by horizontal gene transfer (HGT), changes in nucleotides (single nucleotide variations, SNVs) that can cause a selective advantage for the bacteria and become fixed in subpopulations. Methicillin-resistant S. aureus are a special threat to CF patients due to the more severe lung disease occurring in infected patients. Today, with decreasing costs for sequencing, more and more studies using S. aureus isolates cultured from CF patients are being published, which use whole genome sequencing (WGS), multilocus sequence typing (MLST) or spa-sequence typing (spa-typing) to follow the population dynamics of S. aureus, elucidate the underlying mechanisms of phenotypic variants, newly acquired resistance or adaptation to the host response in this particular niche. In the first part of this review, an introduction to the genetic make-up and the pathogenesis of S. aureus with respect to CF is provided. The second part presents an overview of recent studies and their findings using genotypic methods such as single or multilocus sequencing and whole genome sequencing, which identify factors contributing to the adaptation of S. aureus and its evolution in the airways of individuals with CF.
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15
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Porterfield HS, Maakestad LJ, LaMarche MM, Thurman AL, Kienenberger ZE, Pitcher NJ, Hansen AR, Zirbes CF, Boyken L, Muyskens BL, Pezzulo AA, Singh SB, Twait E, Ford B, Diekema DJ, Reeb V, Fischer AJ. MRSA strains with distinct accessory genes predominate at different ages in cystic fibrosis. Pediatr Pulmonol 2021; 56:2868-2878. [PMID: 34219414 PMCID: PMC8395597 DOI: 10.1002/ppul.25559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 01/30/2023]
Abstract
RATIONALE Methicillin resistant Staphylococcus aureus (MRSA) is prevalent and consequential in cystic fibrosis (CF). Whole genome sequencing (WGS) could reveal genomic differences in MRSA associated with poorer outcomes or detect MRSA transmission. OBJECTIVES To identify MRSA genes associated with low lung function and potential MRSA transmission in CF. METHODS We collected 97 MRSA isolates from 74 individuals with CF from 2017 and performed short-read WGS. We determined sequence type (ST) and the phylogenetic relationship between isolates. We aligned accessory genes from 25 reference genomes to genome assemblies, classified isolates by accessory gene content, and correlated the accessory genome to clinical outcomes. RESULTS The most prevalent ST were ST5 (N = 55), ST8 (N = 15), and ST105 (N = 14). Closely related MRSA strains were shared by family members with CF, but rarely between unrelated individuals. Three clusters of MRSA were identified by accessory genome content. Cluster A, including ST5 and ST105, was highly prevalent at all ages. Cluster B, including ST8, was more limited to younger patients. Cluster C included 6 distantly related strains. Patients 20 years old and younger infected with Cluster A had lower forced expiratory volume in the first second (FEV1 ) and higher sputum biomass compared to similar-aged patients with Cluster B. CONCLUSIONS In this CF cohort, we identified MRSA subtypes that predominate at different ages and differ by accessory gene content. The most prevalent cluster of MRSA, including ST5 and ST105, was associated with lower FEV1 . ST8 MRSA was more common in younger patients and thus has the potential to rise in prevalence as these patients age.
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Affiliation(s)
- Harry S Porterfield
- Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.,Department of Laboratory Medicine, National Institutes of Health Clinical Center, Bethesda, Maryland, USA
| | - Lucas J Maakestad
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Mason M LaMarche
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Andrew L Thurman
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Zoe E Kienenberger
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Nicholas J Pitcher
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Alexis R Hansen
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Christian F Zirbes
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Linda Boyken
- Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Bethany L Muyskens
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Alejandro A Pezzulo
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Sachinkumar B Singh
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Erik Twait
- State Hygienic Laboratory at the University of Iowa, Iowa City, Iowa, USA
| | - Bradley Ford
- Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Daniel J Diekema
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Valérie Reeb
- State Hygienic Laboratory at the University of Iowa, Iowa City, Iowa, USA
| | - Anthony J Fischer
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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16
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Long DR, Wolter DJ, Lee M, Precit M, McLean K, Holmes E, Penewit K, Waalkes A, Hoffman LR, Salipante SJ. Polyclonality, Shared Strains, and Convergent Evolution in Chronic Cystic Fibrosis Staphylococcus aureus Airway Infection. Am J Respir Crit Care Med 2021; 203:1127-1137. [PMID: 33296290 DOI: 10.1164/rccm.202003-0735oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Rationale: Staphylococcus aureus is the most common respiratory pathogen isolated from patients with cystic fibrosis (CF) in the United States. Although modes of acquisition and genetic adaptation have been described for Pseudomonas aeruginosa, resulting in improved diagnosis and treatment, these features remain more poorly defined for S. aureus.Objectives: To characterize the molecular epidemiology and genetic adaptation of S. aureus during chronic CF airway infection and in response to antibiotic therapy.Methods: We performed whole-genome sequencing of 1,382 S. aureus isolates collected longitudinally over a mean 2.2 years from 246 children with CF at five U.S. centers between 2008 and 2017. Results were integrated with clinical and demographic data to characterize bacterial population dynamics and identify common genetic targets of in vivo adaptation.Measurements and Main Results: Results showed that 45.5% of patients carried multiple, coexisting S. aureus lineages, often having different antibiotic susceptibility profiles. Adaptation during the course of infection commonly occurred in a set of genes related to persistence and antimicrobial resistance. Individual sequence types demonstrated wide geographic distribution, and we identified limited strain-sharing among children linked by common household or clinical exposures. Unlike P. aeruginosa, S. aureus genetic diversity was unconstrained, with an ongoing flow of new genetic elements into the population of isolates from children with CF.Conclusions: CF airways are frequently coinfected by multiple, genetically distinct S. aureus lineages, indicating that current clinical procedures for sampling isolates and selecting antibiotics are likely inadequate. Strains can be shared by patients in close domestic or clinical contact and can undergo convergent evolution in key persistence and antimicrobial-resistance genes, suggesting novel diagnostic and therapeutic approaches for future study.
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Affiliation(s)
- Dustin R Long
- Division of Critical Care Medicine, Department of Anesthesiology and Pain Medicine
| | - Daniel J Wolter
- Department of Pediatrics.,Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, Washington
| | | | | | - Kathryn McLean
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Washington, Seattle, Washington; and
| | - Elizabeth Holmes
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Washington, Seattle, Washington; and
| | - Kelsi Penewit
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Washington, Seattle, Washington; and
| | - Adam Waalkes
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Washington, Seattle, Washington; and
| | - Lucas R Hoffman
- Department of Pediatrics.,Department of Microbiology, and.,Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, Washington
| | - Stephen J Salipante
- Department of Laboratory Medicine and Pathology, School of Medicine, University of Washington, Seattle, Washington; and
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17
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Ward-specific clustering of methicillin-resistant Staphylococcus aureus spa-type t037 and t045 in two hospitals in South Africa: 2013 to 2017. PLoS One 2021; 16:e0253883. [PMID: 34185791 PMCID: PMC8241065 DOI: 10.1371/journal.pone.0253883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 06/14/2021] [Indexed: 12/02/2022] Open
Abstract
Introduction Methicillin-resistant Staphylococcus aureus (MRSA) is a highly clonal pathogen causing infections in various settings. The aim of this study was to determine if healthcare-associated (HA) MRSA isolates with the same spa-type originating from two geographically distinct hospitals in South Africa were genetically related based on PFGE. Furthermore, a small subset of MRSA isolates were characterised with WGS and then compared to PFGE to determine if PFGE is still a reliable method to define outbreaks and/or transmission chains. Methods Staphylococcus aureus isolated from blood cultures (BC) were submitted to the Centre for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses (CHARM) as part of a laboratory-based surveillance programme (GERMS-SA). The identified HA-MRSA isolates underwent molecular characterisation [Staphylococcal Chromosome Cassette (SCC) mec and spa-typing]. Pulsed-field gel electrophoresis (PFGE) was performed on selected isolates with the same spa-type. Twenty-one MRSA isolates were selected for whole-genome sequencing (WGS) based on spa-type, PFGE clustering, time and place of isolation. Results Eighteen percent (n = 95/529) and 33% (n = 234/710) of isolates collected, from two public tertiary academic hospitals in the Gauteng (GAU) and the Western Cape (WC) provinces, were identified as MRSA, respectively. The most dominant clone in the GAU hospital was t037-III-MRSA (43.2%; n = 41/95). The most dominant clones in the WC hospital was t037-III-MRSA (23.9%, n = 56/234) and t045-I-MRSA (23.5%, n = 55/234). The GAU-t037-III-MRSA cases and WC-t045-I-MRSA cases occurred in the paediatric patient population, whereas the WC-t037-III-MRSA cases occurred in the adult patient population. A novel spa-type (t19935) was detected in the GAU hospital. PFGE showed that the GAU- and WC-t037-III-MRSA isolates were genetically indistinguishable, as well as most of the WC-t045-I-MRSA isolates. The Vienna/Hungarian/Brazilian clone and British EMRSA-3 clone were in circulation and a low frequency of single nucleotide polymorphisms (SNP) (≤20) differences was observed among isolates with the same spa-type. Conclusion The low number of SNP differences is suggestive of uninterrupted strain transmission and the persistence of t037-III-MRSA and t045-I-MRSA from 2013 to 2017 in the two studied hospitals. Alternative infection prevention and control strategies should be considered to supplement control efforts.
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Gatt YE, Margalit H. Common Adaptive Strategies Underlie Within-Host Evolution of Bacterial Pathogens. Mol Biol Evol 2021; 38:1101-1121. [PMID: 33118035 PMCID: PMC7947768 DOI: 10.1093/molbev/msaa278] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Within-host adaptation is a hallmark of chronic bacterial infections, involving substantial genomic changes. Recent large-scale genomic data from prolonged infections allow the examination of adaptive strategies employed by different pathogens and open the door to investigate whether they converge toward similar strategies. Here, we compiled extensive data of whole-genome sequences of bacterial isolates belonging to miscellaneous species sampled at sequential time points during clinical infections. Analysis of these data revealed that different species share some common adaptive strategies, achieved by mutating various genes. Although the same genes were often mutated in several strains within a species, different genes related to the same pathway, structure, or function were changed in other species utilizing the same adaptive strategy (e.g., mutating flagellar genes). Strategies exploited by various bacterial species were often predicted to be driven by the host immune system, a powerful selective pressure that is not species specific. Remarkably, we find adaptive strategies identified previously within single species to be ubiquitous. Two striking examples are shifts from siderophore-based to heme-based iron scavenging (previously shown for Pseudomonas aeruginosa) and changes in glycerol-phosphate metabolism (previously shown to decrease sensitivity to antibiotics in Mycobacterium tuberculosis). Virulence factors were often adaptively affected in different species, indicating shifts from acute to chronic virulence and virulence attenuation during infection. Our study presents a global view on common within-host adaptive strategies employed by different bacterial species and provides a rich resource for further studying these processes.
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Affiliation(s)
- Yair E Gatt
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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Association of Diverse Staphylococcus aureus Populations with Pseudomonas aeruginosa Coinfection and Inflammation in Cystic Fibrosis Airway Infection. mSphere 2021; 6:e0035821. [PMID: 34160233 PMCID: PMC8265651 DOI: 10.1128/msphere.00358-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Staphylococcus aureus is one of the most common pathogens isolated from the airways of cystic fibrosis (CF) patients and often persists for extended periods. There is limited knowledge about the diversity of S. aureus in CF. We hypothesized that increased diversity of S. aureus would impact CF lung disease. Therefore, we conducted a 1-year observational prospective study with 14 patients with long-term S. aureus infection. From every sputum, 40 S. aureus isolates were chosen and characterized in terms of phenotypic appearance (size, hemolysis, mucoidy, and pigmentation), important virulence traits such as nuclease activity, biofilm formation, and molecular typing by spa sequence typing. Data about coinfection with Pseudomonas aeruginosa and clinical parameters such as lung function, exacerbation, and inflammatory markers in blood (C-reactive protein [CRP], interleukin 6 [IL-6], and S100A8/9 [calprotectin]) were collected. From 58 visits of 14 patients, 2,319 S. aureus isolates were distinguished into 32 phenotypes (PTs) and 50 spa types. The Simpson diversity index (SDI) was used to calculate the phenotypic and genotypic diversity, revealing a high diversity of PTs ranging from 0.19 to 0.87 among patients, while the diversity of spa types of isolates was less pronounced. The SDI of PTs was positively associated with P. aeruginosa coinfection and inflammatory parameters, with IL-6 being the most sensitive parameter. Also, coinfection with P. aeruginosa was associated with mucoid S. aureus and S. aureus with high nuclease activity. Our analyses showed that in CF patients with long-term S. aureus airway infection, a highly diverse and dynamic S. aureus population was present and associated with P. aeruginosa coinfection and inflammation. IMPORTANCE Staphylococcus aureus can persist for extended periods in the airways of people with cystic fibrosis (CF) in spite of antibiotic therapy and high numbers of neutrophils, which fail to eradicate this pathogen. Therefore, S. aureus needs to adapt to this hostile niche. There is only limited knowledge about the diversity of S. aureus in respiratory specimens. We conducted a 1-year prospective study with 14 patients with long-term S. aureus infection and investigated 40 S. aureus isolates from every sputum in terms of phenotypic appearance, nuclease activity, biofilm formation, and molecular typing. Data about coinfection with Pseudomonas aeruginosa and clinical parameters such as lung function, exacerbation, and inflammatory markers in blood were collected. Thirty-two phenotypes (PTs) and 50 spa types were distinguished. Our analyses revealed that in CF patients with long-term S. aureus airway infection, a highly diverse and dynamic S. aureus population was associated with P. aeruginosa coinfection and inflammation.
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Abstract
Advancements in comparative genomics have generated significant interest in defining applications for healthcare-associated pathogens. Clinical microbiology, however, relies on increasingly automated platforms to quickly identify pathogens, resistance mechanisms, and therapy options within CLIA- and FDA-approved frameworks. Additionally, and most notably, healthcare-associated pathogens, especially those that are resistant to antibiotics, represent a diverse spectrum of genera harboring complex genetic targets including antibiotic, biocide, and virulence determinants that can be highly transmissible and, at least for antibiotic resistance, serve as potential targets for containment efforts. U.S. public health investments have focused on rapidly detecting outbreaks and emerging resistance in healthcare-associated pathogens using reference, culture-based, and molecular methods that are distributed, for example, across national laboratory network infrastructures. Herein we describe the public health applications of genomic science that are built from the top-down for broad surveillance, as well as the bottom-up, starting with identification of infections and infectious clusters. For healthcare-associated, including antimicrobial-resistant, pathogens, we propose a combination of top-down and bottom-up genomic approaches leveraged across the public health spectrum, from local infection control, to regional and national containment efforts, to national surveillance for understanding emerging strain ecology and fitness of healthcare pathogens.
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In-Host Emergence of Linezolid Resistance in a Complex Pattern of Toxic Shock Syndrome Toxin-1-Positive Methicillin-Resistant Staphylococcus aureus Colonization in Siblings with Cystic Fibrosis. Toxins (Basel) 2021; 13:toxins13050317. [PMID: 33925199 PMCID: PMC8146457 DOI: 10.3390/toxins13050317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 01/01/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) can cause chronic lung infections in patients with Cystic Fibrosis (CF). One option for managing them is the use of linezolid. We hereby report the in-host emergence of linezolid resistance (LR) in MRSA in CF siblings via a population analysis. A collection of 171 MRSA strains from 68 samples were characterized by determining their linezolid Minimal Inhibitory Concentrations (MICs), analyzing the locus of staphylococcal protein A (spa) and whole genome sequencing. Courses of linezolid were retraced. Strains belonged to three spa types (t002, t045, t127) and two sequence types (ST1, ST5). Emergence of LR occurred under treatment, one year apart in both siblings, in the CC5-MRSA-I Geraldine clone harboring the toxic shock syndrome toxin-1-encoding gene. Resistance was related to a G2576T substitution present in a variable number of 23S rRNA gene copies. Susceptible and resistant strains were co-isolated within samples. Single Nucleotide Polymorphism-based analysis revealed complex colonizations by highly diversified, clonally related populations. LR remains rare in MRSA and there are very few longitudinal analyses documenting its emergence. Analyzing a large MRSA collection revealed new aspects of LR emergence: it emerges in specific subclonal lineages resulting from adaptive diversification of MRSA in the CF lung and this heterogeneity of intra-sample resistance may contribute to compromising antibiotic management.
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Bernardy EE, Petit RA, Raghuram V, Alexander AM, Read TD, Goldberg JB. Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa. mBio 2020; 11. [PMID: 32576671 DOI: 10.31234/osf.io/9whp4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023] Open
Abstract
Staphylococcus aureus has recently overtaken Pseudomonas aeruginosa as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of S. aureus in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by P. aeruginosa Less is known about the diversity of S. aureus CF patient lung isolates in terms of both their virulence and their interaction with P. aeruginosa To begin to address this gap, we recently sequenced 64 clinical S. aureus isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, spa types, agr types, and presence/absence of other known virulence factor genes of these isolates. We hypothesized that virulence phenotypes of S. aureus, namely, toxin production and the mucoid phenotype, would be lost in these isolates due to adaptation in the CF patient lung. In contrast to these expectations, we found that most isolates can lyse both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), suggesting that these phenotypes were not lost during adaptation to the CF lung. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus isolates from CF patients, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.IMPORTANCEStaphylococcus aureus is now the most frequently detected recognized pathogen in the lungs of individuals who have cystic fibrosis (CF) in the United States, followed closely by Pseudomonas aeruginosa When these pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus Here, we present an in-depth study of 64 S. aureus clinical isolates from CF patients, for which we investigated genetic diversity utilizing whole-genome sequencing, virulence phenotypes, and interactions with P. aeruginosa We found that S. aureus isolated from CF lungs are phylogenetically diverse; most retain known virulence factors and vary in their interactions with P. aeruginosa (i.e., they range from being highly sensitive to P. aeruginosa to completely tolerant to it). Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.
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Affiliation(s)
- Eryn E Bernardy
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Robert A Petit
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Vishnu Raghuram
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M Alexander
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
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Bernardy EE, Petit RA, Raghuram V, Alexander AM, Read TD, Goldberg JB. Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa. mBio 2020; 11:mBio.00735-20. [PMID: 32576671 PMCID: PMC7315118 DOI: 10.1128/mbio.00735-20] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Staphylococcus aureus has recently overtaken Pseudomonas aeruginosa as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of S. aureus in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by P. aeruginosa Less is known about the diversity of S. aureus CF patient lung isolates in terms of both their virulence and their interaction with P. aeruginosa To begin to address this gap, we recently sequenced 64 clinical S. aureus isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, spa types, agr types, and presence/absence of other known virulence factor genes of these isolates. We hypothesized that virulence phenotypes of S. aureus, namely, toxin production and the mucoid phenotype, would be lost in these isolates due to adaptation in the CF patient lung. In contrast to these expectations, we found that most isolates can lyse both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), suggesting that these phenotypes were not lost during adaptation to the CF lung. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus isolates from CF patients, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.IMPORTANCEStaphylococcus aureus is now the most frequently detected recognized pathogen in the lungs of individuals who have cystic fibrosis (CF) in the United States, followed closely by Pseudomonas aeruginosa When these pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus Here, we present an in-depth study of 64 S. aureus clinical isolates from CF patients, for which we investigated genetic diversity utilizing whole-genome sequencing, virulence phenotypes, and interactions with P. aeruginosa We found that S. aureus isolated from CF lungs are phylogenetically diverse; most retain known virulence factors and vary in their interactions with P. aeruginosa (i.e., they range from being highly sensitive to P. aeruginosa to completely tolerant to it). Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.
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Affiliation(s)
- Eryn E Bernardy
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Robert A Petit
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Vishnu Raghuram
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M Alexander
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
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Molecular characterisation of methicillin-resistant Staphylococcus aureus from chronically colonised cystic fibrosis paediatric patients in Brazil. Epidemiol Infect 2020; 148:e149. [PMID: 32450935 PMCID: PMC7374800 DOI: 10.1017/s0950268820001156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) infection in cystic fibrosis (CF) patients has been associated with a more rapid decline in lung function, increased hospitalisation and mortality. The aim of this study was to evaluate the clonal relationships among 116 MRSA isolates from 12 chronically colonised CF pediatric patients over a 6-year period in a Rio de Janeiro CF specialist centre. Isolates were characterised by antimicrobial resistance, SCCmec type, presence of Panton-Valentine Leukocidin (PVL) genes and grouped according to DNA macrorestriction profile by pulsed-field gel electrophoresis (PFGE) and spa gene type. High resistance rates were detected for erythromycin (78%) and ciprofloxacin (50%) and SCCmec IV was the most common type (72.4%). Only 8.6% of isolates were PVL positive. High genetic diversity was evident by PFGE (39 pulsotypes) and of nine that were identified spa types, t002 (53.1%) and t539 (14.8%) were the most prevalent. We conclude that the observed homogeneity of spa types within patients over the study period demonstrates the persistence of such strain lineages throughout the course of chronic lung infection.
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Lange J, Heidenreich K, Higelin K, Dyck K, Marx V, Reichel C, van Wamel W, den Reijer M, Görlich D, Kahl BC. Staphylococcus aureus Pathogenicity in Cystic Fibrosis Patients-Results from an Observational Prospective Multicenter Study Concerning Virulence Genes, Phylogeny, and Gene Plasticity. Toxins (Basel) 2020; 12:toxins12050279. [PMID: 32357453 PMCID: PMC7290773 DOI: 10.3390/toxins12050279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus and cystic fibrosis (CF) are closely interlinked. To date, however, the impact of S. aureus culture in CF airways on lung function and disease progression has only been elucidated to a limited degree. This analysis aims to identify bacterial factors associated to clinical deterioration. Data were collected during an observational prospective multi-center study following 195 patients from 17 centers. The average follow-up time was 80 weeks. S. aureus isolates (n = 3180) were scanned for the presence of 25 virulence genes and agr-types using single and multiplex PCR. The presence of specific virulence genes was not associated to clinical deterioration. For the agr-types 1 and 4, however, a link to the subjects’ clinical status became evident. Furthermore, a significant longitudinal decrease in the virulence gene quantity was observed. Analyses of the plasticity of the virulence genes revealed significantly increased plasticity rates in the presence of environmental stress. The results suggest that the phylogenetic background defines S. aureus pathogenicity rather than specific virulence genes. The longitudinal loss of virulence genes most likely reflects the adaptation process directed towards a persistent and colonizing rather than infecting lifestyle.
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Affiliation(s)
- Jonas Lange
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Kathrin Heidenreich
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Katharina Higelin
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Kristina Dyck
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Vanessa Marx
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Christian Reichel
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
| | - Willem van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (W.v.W.); (M.d.R.)
| | - Martijn den Reijer
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands; (W.v.W.); (M.d.R.)
| | - Dennis Görlich
- Institute of Biostatistics and Clinical Research, University Hospital Münster, 48149 Münster, Germany;
| | - Barbara C. Kahl
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (J.L.); (K.H.); (K.H.); (K.D.); (V.M.); (C.R.)
- Correspondence: ; Tel.: +49-251-8355358
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Izydorczyk C, Waddell B, Edwards BD, Greysson-Wong J, Surette MG, Somayaji R, Rabin HR, Conly JM, Church DL, Parkins MD. Epidemiology of E. coli in Cystic Fibrosis Airways Demonstrates the Capacity for Persistent Infection but Not Patient-Patient Transmission. Front Microbiol 2020; 11:475. [PMID: 32265892 PMCID: PMC7100150 DOI: 10.3389/fmicb.2020.00475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/04/2020] [Indexed: 11/16/2022] Open
Abstract
Escherichia coli is frequently isolated from the respiratory secretions of cystic fibrosis (CF) patients yet is not considered a classical CF pathogen. Accordingly, little is known about the natural history of this organism in the CF airways, as well as the potential for patient-to-patient transmission. Patients attending the Calgary Adult CF Clinic (CACFC) between January 1983 and December 2016 with at least one E. coli-positive sputum culture were identified by retrospective review. Annual E. coli isolates from the CACFC biobank from each patient were typed by pulsed-field gel electrophoresis (PFGE) and isolates belonging to shared pulsotypes were sequenced. Single nucleotide polymorphism (SNP) and phylogenetic analysis were used to investigate the natural history of E. coli infection and identify potential transmission events. Forty-five patients with E. coli-positive sputum cultures were identified. Most patients had a single infection episode with a single pulsotype, while replacement of an initial pulsotype with a second was observed in three patients. Twenty-four had E. coli recovered from their sputum more than once and 18 patients had persistent infections (E. coli carriage >6 months with ≥3 positive cultures). Shared pulsotypes corresponded to known extraintestinal pathogenic E. coli strains: ST-131, ST-73, and ST-1193. Phylogenetic relationships and SNP distances among isolates within shared pulsotypes were consistent with independent acquisition of E. coli by individual patients. Most recent common ancestor date estimates of isolates between patients were inconsistent with patient-to-patient transmission. E. coli infection in CF is a dynamic process that appears to be characterized by independent acquisition within our patient population and carriage of unique sets of strains over time by individual patients.
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Affiliation(s)
- Conrad Izydorczyk
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Barbara Waddell
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Brett D. Edwards
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jasper Greysson-Wong
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Michael G. Surette
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Ranjani Somayaji
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Harvey R. Rabin
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - John M. Conly
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
| | - Deirdre L. Church
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
| | - Michael D. Parkins
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
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Goyal M, Javerliat F, Palmieri M, Mirande C, van Wamel W, Tavakol M, Verkaik NJ, van Belkum A. Genomic Evolution of Staphylococcus aureus During Artificial and Natural Colonization of the Human Nose. Front Microbiol 2019; 10:1525. [PMID: 31333626 PMCID: PMC6624446 DOI: 10.3389/fmicb.2019.01525] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/18/2019] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus can colonize the human vestibulum nasi for many years. It is unknown whether and, how S. aureus adapts to this ecological niche during colonization. We determined the short (1 and 3 months) and mid-term (36 months) genomic evolution of S. aureus in natural carriers and artificially colonized volunteers. Eighty-five S. aureus strains were collected from 6 natural carriers during 3 years and 6 artificially colonized volunteers during 1 month. Multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis based on whole-genome sequencing (WGS) were carried out. Mutation frequencies within resident bacterial populations over time were quantified using core genome SNP counts (comparing groups of genomes) and pairwise SNP divergence assessment (comparing two genomes from strains originating from one host and sharing identical MLST). SNP counts (within 1–3 months) in all naturally colonizing strains varied from 0 to 757 (median 4). These strains showed random and independent patterns of pairwise SNP divergence (0 to 44 SNPs, median 7). When the different core genome SNP counts over a period of 3 years were considered, the median SNP count was 4 (range 0–26). Host-specific pairwise SNP divergence for the same period ranged from 9 to 57 SNPs (median 20). During short term artificial colonization the mutation frequency was even lower (0–7 SNPs, median 2) and the pairwise SNP distances were 0 to 5 SNPs (median 2). Quantifying mutation frequencies is important for the longitudinal follow-up of epidemics of infections and outbreak management. Random pattern of pairwise SNP divergence between the strains isolated from single carriers suggested that the WGS of multiple colonies is necessary in this context. Over periods up to 3 years, maximum median core genome SNP counts and SNP divergence for the strains studied were 4 and 20 SNPs or lower. During artificial colonization, where median core genome SNP and pairwise SNP distance scores were 2, there is no early stage selection of different genotypes. Therefore, we suggest an epidemiological cut off value of 20 SNPs as a marker of S. aureus strain identity during studies on nasal colonization and also outbreaks of infection.
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Affiliation(s)
- Manisha Goyal
- Data Analytics Unit, bioMérieux, La Balme-les-Grottes, France
| | | | - Mattia Palmieri
- Data Analytics Unit, bioMérieux, La Balme-les-Grottes, France
| | | | - Willem van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Mehri Tavakol
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Nelianne J Verkaik
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Alex van Belkum
- Data Analytics Unit, bioMérieux, La Balme-les-Grottes, France
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Azarian T, Ridgway JP, Yin Z, David MZ. Long-Term Intrahost Evolution of Methicillin Resistant Staphylococcus aureus Among Cystic Fibrosis Patients With Respiratory Carriage. Front Genet 2019; 10:546. [PMID: 31244886 PMCID: PMC6581716 DOI: 10.3389/fgene.2019.00546] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/22/2019] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus is the most commonly identified airway colonizer of cystic fibrosis (CF) patients, and infections with methicillin-resistant S. aureus (MRSA) are associated with poor outcomes. Yet, little is known about the intrahost evolution of S. aureus among CF patients. We investigated convergent evolution and adaptation of MRSA among four CF patients with long-term respiratory carriage. For each patient, we performed whole-genome sequencing on an average of 21 isolates (range: 19–23) carried for a mean of 1,403 days (range: 903–1,679), including 25 pairs of isolates collected on the same day. We assessed intrahost diversity, population structure, evolutionary history, evidence of switched intergenic regions (IGRs), and signatures of adaptation in the context of patient age, antibiotic treatment, and co-colonizing microbes. Phylogenetic analysis delineated distinct multilocus sequence type ST5 (n = 3) and ST72 (n = 1) clonal populations in addition to sporadic, non-clonal isolates, and uncovered a putative transmission event. Variation in antibiotic resistance was observed within clonal populations, even among isolates collected on the same day. Rates of molecular evolution ranged from 2.21 to 8.64 nucleotide polymorphisms per year, and lineage ages were consistent with acquisition of colonization in early childhood followed by subsequent persistence of multiple sub-populations. Selection analysis of 1,622 core genes present in all four clonal populations (n = 79) found 11 genes variable in three subjects – most notably, ATP-dependent protease clpX, 2-oxoglutarate dehydrogenase odhA, fmtC, and transcription-repair coupling factor mfd. Only one gene, staphylococcal protein A (spa), was found to have evidence of gene-wide diversifying selection. We identified three instances of intrahost IGR switching events, two of which flanked genes related to quorum sensing. The complex microbial ecology of the CF airway poses challenges for management. We illustrate appreciable intrahost diversity as well as persistence of a dominant lineage. We also show that intrahost adaptation is a continual process, despite purifying selective pressure, and provide targets that should be investigated further for their function in CF adaptation.
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Affiliation(s)
- Taj Azarian
- College of Medicine, University of Central Florida, Orlando, FL, United States
| | - Jessica P Ridgway
- Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Zachary Yin
- Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Z David
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Bernardy EE, Petit RA, Moller AG, Blumenthal JA, McAdam AJ, Priebe GP, Chande AT, Rishishwar L, Jordan IK, Read TD, Goldberg JB. Whole-Genome Sequences of Staphylococcus aureus Isolates from Cystic Fibrosis Lung Infections. Microbiol Resour Announc 2019; 8:e01564-18. [PMID: 30687841 PMCID: PMC6346173 DOI: 10.1128/mra.01564-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 12/12/2018] [Indexed: 02/05/2023] Open
Abstract
Staphylococcus aureus is an early colonizer in the lungs of individuals with cystic fibrosis (CF), but surprisingly, only a limited number of genomes from CF-associated S. aureus isolates have been sequenced. Here, we present the whole-genome sequences of 65 S. aureus isolates obtained from 50 individuals with CF.
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Affiliation(s)
- Eryn E. Bernardy
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children’s Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Robert A. Petit
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Abraham G. Moller
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Jennifer A. Blumenthal
- Division of Critical Care Medicine, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts, USA
- Departments of Anaesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Alexander J. McAdam
- Department of Laboratory Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory P. Priebe
- Division of Critical Care Medicine, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts, USA
- Departments of Anaesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Aroon T. Chande
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- IHRC-Georgia Tech Applied Bioinformatics Laboratory, Atlanta, Georgia, USA
- PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia
| | - Lavanya Rishishwar
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- IHRC-Georgia Tech Applied Bioinformatics Laboratory, Atlanta, Georgia, USA
- PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia
| | - I. King Jordan
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- IHRC-Georgia Tech Applied Bioinformatics Laboratory, Atlanta, Georgia, USA
- PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia
| | - Timothy D. Read
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia, USA
| | - Joanna B. Goldberg
- Department of Pediatrics, Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis and Sleep, Emory University, Atlanta, Georgia, USA
- Emory-Children’s Center for Cystic Fibrosis Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
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Emergence and Within-Host Genetic Evolution of Methicillin-Resistant Staphylococcus aureus Resistant to Linezolid in a Cystic Fibrosis Patient. Antimicrob Agents Chemother 2018; 62:AAC.00720-18. [PMID: 30275089 DOI: 10.1128/aac.00720-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 09/22/2018] [Indexed: 12/26/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infection has increased in recent years among cystic fibrosis (CF) patients. Linezolid (LZD) is one of the antistaphylococcal antibiotics widely used in this context. Although LZD resistance is rare, it has been described as often associated with long-term treatments. Thirteen MRSA strains isolated over 5 years from one CF patient were studied for LZD resistance emergence and subjected to whole-genome sequencing (WGS). Resistance emerged after three 15-day LZD therapeutic regimens over 4 months. It was associated with the mutation of G to T at position 2576 (G2576T) in all 5 rrl copies, along with a very high MIC (>256 mg/liter) and a strong increase in the generation time. Resistant strains isolated during the ensuing LZD therapeutic regimens and until 13 months after LZD stopped harbored only 3 or 4 mutated rrl copies, associated with lower MICs (8 to 32 mg/liter) and low to moderate generation time increases. Despite these differences, whole-genome sequencing allowed us to determine that all isolates, including the susceptible one isolated before LZD treatment, belonged to the same lineage. In conclusion, LZD resistance can emerge rapidly in CF patients and persist without linezolid selective pressure in colonizing MRSA strains belonging to the same lineage.
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Antagonistic Pleiotropy in the Bifunctional Surface Protein FadL (OmpP1) during Adaptation of Haemophilus influenzae to Chronic Lung Infection Associated with Chronic Obstructive Pulmonary Disease. mBio 2018; 9:mBio.01176-18. [PMID: 30254117 PMCID: PMC6156194 DOI: 10.1128/mbio.01176-18] [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] [Indexed: 12/13/2022] Open
Abstract
Tracking bacterial evolution during chronic infection provides insights into how host selection pressures shape bacterial genomes. The human-restricted opportunistic pathogen nontypeable Haemophilus influenzae (NTHi) infects the lower airways of patients suffering chronic obstructive pulmonary disease (COPD) and contributes to disease progression. To identify bacterial genetic variation associated with bacterial adaptation to the COPD lung, we sequenced the genomes of 92 isolates collected from the sputum of 13 COPD patients over 1 to 9 years. Individuals were colonized by distinct clonal types (CTs) over time, but the same CT was often reisolated at a later time or found in different patients. Although genomes from the same CT were nearly identical, intra-CT variation due to mutation and recombination occurred. Recurrent mutations in several genes were likely involved in COPD lung adaptation. Notably, nearly a third of CTs were polymorphic for null alleles of ompP1 (also called fadL), which encodes a bifunctional membrane protein that both binds the human carcinoembryonic antigen-related cell adhesion molecule 1 (hCEACAM1) receptor and imports long-chain fatty acids (LCFAs). Our computational studies provide plausible three-dimensional models for FadL's interaction with hCEACAM1 and LCFA binding. We show that recurrent fadL mutations are likely a case of antagonistic pleiotropy, since loss of FadL reduces NTHi's ability to infect epithelia but also increases its resistance to bactericidal LCFAs enriched within the COPD lung. Supporting this interpretation, truncated fadL alleles are common in publicly available NTHi genomes isolated from the lower airway tract but rare in others. These results shed light on molecular mechanisms of bacterial pathoadaptation and guide future research toward developing novel COPD therapeutics.IMPORTANCE Nontypeable Haemophilus influenzae is an important pathogen in patients with chronic obstructive pulmonary disease (COPD). To elucidate the bacterial pathways undergoing in vivo evolutionary adaptation, we compared bacterial genomes collected over time from 13 COPD patients and identified recurrent genetic changes arising in independent bacterial lineages colonizing different patients. Besides finding changes in phase-variable genes, we found recurrent loss-of-function mutations in the ompP1 (fadL) gene. We show that loss of OmpP1/FadL function reduces this bacterium's ability to infect cells via the hCEACAM1 epithelial receptor but also increases its resistance to bactericidal fatty acids enriched within the COPD lung, suggesting a case of antagonistic pleiotropy that restricts ΔfadL strains' niche. These results show how H. influenzae adapts to host-generated inflammatory mediators in the COPD airways.
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Zhou W, Li X, Osmundson T, Shi L, Ren J, Yan H. WGS analysis of ST9-MRSA-XII isolates from live pigs in China provides insights into transmission among porcine, human and bovine hosts. J Antimicrob Chemother 2018; 73:2652-2661. [DOI: 10.1093/jac/dky245] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/27/2018] [Indexed: 12/21/2022] Open
Affiliation(s)
- Wenyuan Zhou
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Xinhui Li
- Department of Microbiology, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI, USA
| | - Todd Osmundson
- Department of Biology, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI, USA
| | - Lei Shi
- Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
- State Key Laboratory of Food Safely Technology for Meat Products, Xiamen, Fujian, China
| | - Jiaoyan Ren
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - He Yan
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- State Key Laboratory of Food Safely Technology for Meat Products, Xiamen, Fujian, China
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