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Vehreschild MJGT, Schreiber S, von Müller L, Epple HJ, Weinke T, Manthey C, Oh J, Wahler S, Stallmach A. Trends in the epidemiology of Clostridioides difficile infection in Germany. Infection 2023; 51:1695-1702. [PMID: 37162717 PMCID: PMC10170422 DOI: 10.1007/s15010-023-02044-5] [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: 04/16/2023] [Accepted: 04/25/2023] [Indexed: 05/11/2023]
Abstract
PURPOSES Despite reports of a declining incidence over the last decade, Clostridioides difficile infection (CDI) is still considered the most important healthcare-associated causes of diarrhea worldwide. In Germany, several measures have been taken to observe, report, and influence this development. This report aims to analyze the development of hospital coding for CDI in Germany over the last decade and to use it to estimate the public health burden caused by CDI. METHODS Reports from the Institute for Hospital Remuneration Systems, German Federal Statistical Office (DESTATIS), the Robert-Koch-Institute (RKI), Saxonian authorities and hospital quality reports during 2010-2021 were examined for CDI coding and assessed in a structured expert consultation. Analysis was performed using 2019 versions of Microsoft Excel® and Microsoft Access®. RESULTS Peaks of 32,203 cases with a primary diagnosis (PD) of CDI and 78,648 cases with a secondary diagnosis (SD) of CDI were observed in 2015. The number of cases had decreased to 15,412 PD cases (- 52.1%) and 40,188 SD cases (- 48.9%) by 2021. These results were paralleled by a similar decline in notifiable severe cases. However, average duration of hospitalization of the cases remained constant during this period. CONCLUSIONS Hospital coding of CDI and notification to authorities has approximately halved from 2015 to 2021. Potential influential factors include hospital hygiene campaigns, implementation of antibiotic stewardship programs, social distancing due to the COVID-19 pandemic, and a decrease in more pathogenic subtypes of bacteria. Further research is necessary to validate the multiple possible drivers for this development.
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Affiliation(s)
| | - Stefan Schreiber
- Department Medicine I, University Hospital Schleswig-Holstein, Christian-Albrechts-University, Rosalind-Franklin-Str. 12, 24105 Kiel, Germany
| | - Lutz von Müller
- Christophorus-Kliniken GmbH, Südring 41, 48653 Coesfeld, Germany
| | - Hans-Jörg Epple
- Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Antibiotic Stewardship, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Thomas Weinke
- Ernst Von Bergmann Klinikum gGmbH, Charlottenstraße 72, 14467 Potsdam, Germany
| | - Carolin Manthey
- Gemeinschaftspraxis Innere Medizin (GIM), Pferdebachstr. 29, 58455 Witten, Germany
| | - Jun Oh
- Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Steffen Wahler
- St. Bernward GmbH, Friedrich-Kirsten-Str. 40, 22391 Hamburg, Germany
| | - Andreas Stallmach
- Klinik Für Innere Medizin IV, Universitätsklinikum Jena, Am Klinikum 1, 07747 Jena, Germany
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Abdrabou AMM, Bischoff M, Mellmann A, von Müller L, Margardt L, Gärtner BC, Berger FK, Haase G, Häfner H, Hoffmann R, Simon V, Stappmanns H, Hischebeth GT, Büchler C, Rößler S, Hochauf-Stange K, Pfeffer K, MacKenzie C, Kunz C, Alsalameh R, Dziobaka J, le Chapot VS, Sanabria E, Hogardt M, Komp J, Imirzalioglu C, Schmiedel J, Pararas M, Sommer F, Groß U, Bohne W, Kekulé AS, Dagwadordsch U, Löffler B, Rödel J, Walker SV, Tobys D, Weikert-Asbeck S, Hauswaldt S, Kaasch AJ, Zautner AE, Joß N, Siegel E, Kehr K, Schaumburg F, Schoeler S, Hamprecht A, Hellkamp J, Hagemann JB, Kubis J, Hering S, Warnke P. Implementation of a Clostridioides difficile sentinel surveillance system in Germany: First insights for 2019–2021. Anaerobe 2022; 77:102548. [DOI: 10.1016/j.anaerobe.2022.102548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 03/08/2022] [Accepted: 03/14/2022] [Indexed: 11/01/2022]
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3
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Molecular epidemiology and antimicrobial resistance of Clostridioides difficile in Germany, 2014-2019. Int J Med Microbiol 2021; 311:151507. [PMID: 33915347 DOI: 10.1016/j.ijmm.2021.151507] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/12/2021] [Accepted: 04/15/2021] [Indexed: 01/05/2023] Open
Abstract
Clostridioides difficile is a Gram positive spore-forming rod and mainly responsible for nosocomial diarrhea in developed nations. Molecular and antimicrobial surveillance is important for monitoring the strain composition including genotypes of high epidemiological importance such as ribotype 027 (RT027) and corresponding resistance patterns. 1535 isolates obtained from samples sent between 2014 and 2019 to the German National Reference Center (NRC) for diagnostic reasons (NRC strain set), and 1143 isolates from a Tertiary Care University Center in Saarland, Germany (non-NRC strain set), were evaluated using antibiotic susceptibility testing and ribotyping. In the NRC strain set, RT027 overtook RT001, the main RT found in the preceding studies, and dominated with 36.2%, followed by RT001 (13.3%), and RT014 (8.5%). Of note, since 2016 a constant decrease of RT027 could be noticed. In the non-NRC strain set a large strain diversity was present with RT014 (18%) and RT001 (8.9%) being most prevalent. In NRC samples, resistance towards metronidazole, vancomycin, moxifloxacin, clarithromycin and rifampicin was 2.7%, 0%, 57.1%, 53.2% and 19.2%, respectively. Metronidazole resistance was almost exclusively found in RT027 isolates. Rifampicin resistance was also observed predominantly in isolates of RT027, constituting an almost four-fold increase, when compared to preceeding studies in this region. In conclusion these data demonstrate that RT027 is a driver for rifampicin and metronidazole resistance, underlining the importance of continuous surveillance efforts.
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Marujo V, Arvand M. The largely unnoticed spread of Clostridioides difficile PCR ribotype 027 in Germany after 2010. Infect Prev Pract 2020; 2:100102. [PMID: 34368730 PMCID: PMC8336157 DOI: 10.1016/j.infpip.2020.100102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/26/2020] [Indexed: 02/04/2023] Open
Abstract
In recent decades, incidence and severity of Clostridioides difficile infection (CDI) has increased dramatically, coinciding with the emergence of hypervirulent strains such as PCR ribotype 027 (RT027). Data on prevalence of distinct C. difficile strains in random CDI cases in Germany are scarce. The aim of this review was to obtain an overview of prevalence and geographical distribution of RT027 among clinical C. difficile isolates from random cases in non-outbreak settings in hospitals in Germany. For this purpose, we performed a literature review on reported cases of C. difficile RT027 in Germany between 2007 and 2019 in three databases (PubMed, Embase and LIVIVO) and conference proceedings. Studies with selection bias for RT027 (e.g. clinical severity, outbreak reports) were excluded. A total of 304 records were screened, from which 21 were included in this analysis. The nationwide prevalence of RT027 in Germany was <1% prior to 2010 but increased continuously thereafter, reaching 21.7% in 2013. The regional prevalence varied markedly between federal states, higher prevalence was reported from North Rhine-Westphalia (37.4%) and Saxony (31.8%) in 2013-2015. However, data on C. difficile RT027 were not available from almost half of the federal states and were scarce at the national level. Our data suggest a remarkable spread of RT027 in Germany during the past decade, which has remained rather unnoticed so far. A national program for molecular surveillance of C. difficile is required to monitor the changing epidemiology of CDI and to adjust the prevention and control measures.
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Affiliation(s)
- Vanda Marujo
- Robert Koch Institute, Department of Infectious Diseases, Unit for Hospital Hygiene, Infection Prevention and Control, Berlin, Germany
| | - Mardjan Arvand
- Robert Koch Institute, Department of Infectious Diseases, Unit for Hospital Hygiene, Infection Prevention and Control, Berlin, Germany
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5
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Frentrup M, Zhou Z, Steglich M, Meier-Kolthoff JP, Göker M, Riedel T, Bunk B, Spröer C, Overmann J, Blaschitz M, Indra A, von Müller L, Kohl TA, Niemann S, Seyboldt C, Klawonn F, Kumar N, Lawley TD, García-Fernández S, Cantón R, del Campo R, Zimmermann O, Groß U, Achtman M, Nübel U. A publicly accessible database for Clostridioides difficile genome sequences supports tracing of transmission chains and epidemics. Microb Genom 2020; 6:mgen000410. [PMID: 32726198 PMCID: PMC7641423 DOI: 10.1099/mgen.0.000410] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/30/2020] [Indexed: 01/02/2023] Open
Abstract
Clostridioides difficile is the primary infectious cause of antibiotic-associated diarrhea. Local transmissions and international outbreaks of this pathogen have been previously elucidated by bacterial whole-genome sequencing, but comparative genomic analyses at the global scale were hampered by the lack of specific bioinformatic tools. Here we introduce a publicly accessible database within EnteroBase (http://enterobase.warwick.ac.uk) that automatically retrieves and assembles C. difficile short-reads from the public domain, and calls alleles for core-genome multilocus sequence typing (cgMLST). We demonstrate that comparable levels of resolution and precision are attained by EnteroBase cgMLST and single-nucleotide polymorphism analysis. EnteroBase currently contains 18 254 quality-controlled C. difficile genomes, which have been assigned to hierarchical sets of single-linkage clusters by cgMLST distances. This hierarchical clustering is used to identify and name populations of C. difficile at all epidemiological levels, from recent transmission chains through to epidemic and endemic strains. Moreover, it puts newly collected isolates into phylogenetic and epidemiological context by identifying related strains among all previously published genome data. For example, HC2 clusters (i.e. chains of genomes with pairwise distances of up to two cgMLST alleles) were statistically associated with specific hospitals (P<10-4) or single wards (P=0.01) within hospitals, indicating they represented local transmission clusters. We also detected several HC2 clusters spanning more than one hospital that by retrospective epidemiological analysis were confirmed to be associated with inter-hospital patient transfers. In contrast, clustering at level HC150 correlated with k-mer-based classification and was largely compatible with PCR ribotyping, thus enabling comparisons to earlier surveillance data. EnteroBase enables contextual interpretation of a growing collection of assembled, quality-controlled C. difficile genome sequences and their associated metadata. Hierarchical clustering rapidly identifies database entries that are related at multiple levels of genetic distance, facilitating communication among researchers, clinicians and public-health officials who are combatting disease caused by C. difficile.
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Affiliation(s)
| | - Zhemin Zhou
- Warwick Medical School, University of Warwick, UK
| | - Matthias Steglich
- Leibniz Institute DSMZ, Braunschweig, Germany
- German Center for Infection Research (DZIF), Partner site Hannover-Braunschweig, Germany
| | | | | | - Thomas Riedel
- Leibniz Institute DSMZ, Braunschweig, Germany
- German Center for Infection Research (DZIF), Partner site Hannover-Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ, Braunschweig, Germany
| | | | - Jörg Overmann
- Leibniz Institute DSMZ, Braunschweig, Germany
- German Center for Infection Research (DZIF), Partner site Hannover-Braunschweig, Germany
- Braunschweig Integrated Center of Systems Biology (BRICS), Technical University, Braunschweig, Germany
| | - Marion Blaschitz
- AGES-Austrian Agency for Health and Food Safety, Vienna, Austria
| | - Alexander Indra
- AGES-Austrian Agency for Health and Food Safety, Vienna, Austria
| | | | - Thomas A. Kohl
- Research Center Borstel, Germany
- German Center for Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel, Germany
| | - Stefan Niemann
- Research Center Borstel, Germany
- German Center for Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel, Germany
| | | | - Frank Klawonn
- Biostatistics, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Information Engineering, Ostfalia University, Wolfenbüttel, Germany
| | | | | | - Sergio García-Fernández
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Rafael Cantón
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Rosa del Campo
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | | | - Uwe Groß
- University Medical Center Göttingen, Germany
| | - Mark Achtman
- Warwick Medical School, University of Warwick, UK
| | - Ulrich Nübel
- Leibniz Institute DSMZ, Braunschweig, Germany
- German Center for Infection Research (DZIF), Partner site Hannover-Braunschweig, Germany
- Braunschweig Integrated Center of Systems Biology (BRICS), Technical University, Braunschweig, Germany
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6
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Guerrero-Araya E, Meneses C, Castro-Nallar E, Guzmán D. AM, Álvarez-Lobos M, Quesada-Gómez C, Paredes-Sabja D, Rodríguez C. Origin, genomic diversity and microevolution of the Clostridium difficile B1/NAP1/RT027/ST01 strain in Costa Rica, Chile, Honduras and Mexico. Microb Genom 2020; 6:e000355. [PMID: 32176604 PMCID: PMC7371124 DOI: 10.1099/mgen.0.000355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/28/2020] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile B1/NAP1/RT027/ST01 has been responsible for outbreaks of antibiotic-associated diarrhoea in clinical settings worldwide and is associated with severe disease presentations and increased mortality rates. Two fluoroquinolone-resistant (FQR) lineages of the epidemic B1/NAP1/RT027/ST01 strain emerged in the USA in the early 1990s and disseminated trans continentally (FQR1 and FQR2). However, it is unclear when and from where they entered Latin America (LA) and whether isolates from LA exhibit unique genomic features when compared to B1/NAP1/RT027/ST01 isolates from other regions of the world. To answer the first issue we compared whole-genome sequences (WGS) of 25 clinical isolates typed as NAP1, RT027 or ST01 in Costa Rica (n=16), Chile (n=5), Honduras (n=3) and Mexico (n=1) to WGS of 129 global isolates from the same genotype using Bayesian phylogenomics. The second question was addressed through a detailed analysis of the number and type of mutations of the LA isolates and their mobile resistome. All but two B1/NAP1/RT027/ST01 isolates from LA belong to the FQR2 lineage (n=23, 92 %), confirming its widespread distribution. As indicated by analysis of a dataset composed of 154 WGS, the B1/NAP1/RT027/ST01 strain was introduced into the four LA countries analysed between 1998 and 2005 from North America (twice) and Europe (at least four times). These events occurred soon after the emergence of the FQR lineages and more than one decade before the first report of the detection of the B1/NAP1/RT027/ST01 in LA. A total of 552 SNPs were identified across all genomes examined (3.8-4.3 Mb) in pairwise comparisons to the R20291 reference genome. Moreover, pairwise SNP distances were among the smallest distances determined in this species so far (0 to 55). Despite this high level of genomic conservation, 39 unique SNPs (7 %) in genes that play roles in the infection process (i.e. slpA) or antibiotic resistance (i.e. rpoB, fusA) distinguished the LA isolates. In addition, isolates from Chile, Honduras and Mexico had twice as many antibiotic resistance genes (ARGs, n=4) than related isolates from other regions. Their unique set of ARGs includes a cfr-like gene and tetM, which were found as part of putative mobile genetic elements whose sequences resemble undescribed integrative and conjugative elements. These results show multiple, independent introductions of B1/NAP1/RT027/ST01 isolates from the FQR1 and FQR2 lineages from different geographical sources into LA and a rather rapid accumulation of distinct mutations and acquired ARG by the LA isolates.
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Affiliation(s)
- Enzo Guerrero-Araya
- Millennium Nucleus in the Biology of Intestinal Microbiota, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
- Microbiota-Host Interactions & Clostridia Research Group, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Claudio Meneses
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
- FONDAP Center for Genome Regulation, Universidad Andrés Bello, Santiago, Chile
| | - Eduardo Castro-Nallar
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Ana M. Guzmán D.
- Department of Clinical Laboratory, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel Álvarez-Lobos
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carlos Quesada-Gómez
- Facultad de Microbiología & Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Daniel Paredes-Sabja
- Millennium Nucleus in the Biology of Intestinal Microbiota, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
- Microbiota-Host Interactions & Clostridia Research Group, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - César Rodríguez
- Facultad de Microbiología & Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
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Waker E, Ambrozkiewicz F, Kulecka M, Paziewska A, Skubisz K, Cybula P, Targoński Ł, Mikula M, Walewski J, Ostrowski J. High Prevalence of Genetically Related Clostridium Difficile Strains at a Single Hemato-Oncology Ward Over 10 Years. Front Microbiol 2020; 11:1618. [PMID: 32793147 PMCID: PMC7384382 DOI: 10.3389/fmicb.2020.01618] [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: 03/19/2020] [Accepted: 06/22/2020] [Indexed: 12/19/2022] Open
Abstract
Aims: Clostridium difficile (C. difficile) infection (CDI) is the main cause of healthcare-associated infectious diarrhea. We used whole-genome sequencing (WGS) to measure the prevalence and genetic variability of C. difficile at a single hemato-oncology ward over a 10 year period. Methods: Between 2008 and 2018, 2077 stool samples were obtained from diarrheal patients hospitalized at the Department of Lymphoma; of these, 618 were positive for toxin A/B. 140 isolates were then subjected to WGS on Ion Torrent PGM sequencer. Results: 36 and 104 isolates were recovered from 36 to 46 patients with single and multiple CDIs, respectively. Of these, 131 strains were toxigenic. Toxin gene profiles tcdA(+);tcdB(+);cdtA/cdtB(+) and tcdA(+);tcdB(+);cdtA/cdtB(-) were identified in 122 and nine strains, respectively. No isolates showed reduced susceptibility to metronidazole and vancomycin. All tested strains were resistant to ciprofloxacin, and 72.9, 42.9, and 72.9% of strains were resistant to erythromycin, clindamycin, or moxifloxacin, respectively. Multi-locus sequence typing (MLST) identified 23 distinct sequence types (STs) and two unidentified strains. Strains ST1 and ST42 represented 31 and 30.1% of all strains tested, respectively. However, while ST1 was detected across nearly all years studied, ST42 was detected only from 2009 to 2011. Conclusion: The high proportion of infected patients in 2008-2011 may be explained by the predominance of more transmissible and virulent C. difficile strains. Although this retrospective study was not designed to define outbreaks of C. difficile, the finding that most isolates exhibited high levels of genetic relatedness suggests nosocomial acquisition.
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Affiliation(s)
- Edyta Waker
- Department of Clinical Microbiology, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Filip Ambrozkiewicz
- Department of Genetics, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Maria Kulecka
- Department of Genetics, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
- Department of Gastroenterology, Hepatology and Clinical Oncology, Centre for Postgraduate Medical Education, Warsaw, Poland
| | - Agnieszka Paziewska
- Department of Genetics, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
- Department of Gastroenterology, Hepatology and Clinical Oncology, Centre for Postgraduate Medical Education, Warsaw, Poland
| | - Karolina Skubisz
- Department of Gastroenterology, Hepatology and Clinical Oncology, Centre for Postgraduate Medical Education, Warsaw, Poland
| | - Patrycja Cybula
- Department of Gastroenterology, Hepatology and Clinical Oncology, Centre for Postgraduate Medical Education, Warsaw, Poland
| | - Łukasz Targoński
- Department of Lymphoproliferative Diseases, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Michał Mikula
- Department of Genetics, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Jan Walewski
- Department of Lymphoproliferative Diseases, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Jerzy Ostrowski
- Department of Genetics, Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland
- Department of Gastroenterology, Hepatology and Clinical Oncology, Centre for Postgraduate Medical Education, Warsaw, Poland
- *Correspondence: Jerzy Ostrowski,
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8
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Van Goethem N, Descamps T, Devleesschauwer B, Roosens NHC, Boon NAM, Van Oyen H, Robert A. Status and potential of bacterial genomics for public health practice: a scoping review. Implement Sci 2019; 14:79. [PMID: 31409417 PMCID: PMC6692930 DOI: 10.1186/s13012-019-0930-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 07/26/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Next-generation sequencing (NGS) is increasingly being translated into routine public health practice, affecting the surveillance and control of many pathogens. The purpose of this scoping review is to identify and characterize the recent literature concerning the application of bacterial pathogen genomics for public health practice and to assess the added value, challenges, and needs related to its implementation from an epidemiologist's perspective. METHODS In this scoping review, a systematic PubMed search with forward and backward snowballing was performed to identify manuscripts in English published between January 2015 and September 2018. Included studies had to describe the application of NGS on bacterial isolates within a public health setting. The studied pathogen, year of publication, country, number of isolates, sampling fraction, setting, public health application, study aim, level of implementation, time orientation of the NGS analyses, and key findings were extracted from each study. Due to a large heterogeneity of settings, applications, pathogens, and study measurements, a descriptive narrative synthesis of the eligible studies was performed. RESULTS Out of the 275 included articles, 164 were outbreak investigations, 70 focused on strategy-oriented surveillance, and 41 on control-oriented surveillance. Main applications included the use of whole-genome sequencing (WGS) data for (1) source tracing, (2) early outbreak detection, (3) unraveling transmission dynamics, (4) monitoring drug resistance, (5) detecting cross-border transmission events, (6) identifying the emergence of strains with enhanced virulence or zoonotic potential, and (7) assessing the impact of prevention and control programs. The superior resolution over conventional typing methods to infer transmission routes was reported as an added value, as well as the ability to simultaneously characterize the resistome and virulome of the studied pathogen. However, the full potential of pathogen genomics can only be reached through its integration with high-quality contextual data. CONCLUSIONS For several pathogens, it is time for a shift from proof-of-concept studies to routine use of WGS during outbreak investigations and surveillance activities. However, some implementation challenges from the epidemiologist's perspective remain, such as data integration, quality of contextual data, sampling strategies, and meaningful interpretations. Interdisciplinary, inter-sectoral, and international collaborations are key for an appropriate genomics-informed surveillance.
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Affiliation(s)
- Nina Van Goethem
- Department of Epidemiology and public health, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
- Department of Epidemiology and Biostatistics, Institut de recherche expérimentale et clinique, Faculty of Public Health, Université catholique de Louvain, Clos Chapelle-aux-champs 30, 1200 Woluwe-Saint-Lambert, Belgium
| | - Tine Descamps
- Department of Epidemiology and public health, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
| | - Brecht Devleesschauwer
- Department of Epidemiology and public health, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Nancy H. C. Roosens
- Transversal Activities in Applied Genomics, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
| | - Nele A. M. Boon
- Department of Epidemiology and public health, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
| | - Herman Van Oyen
- Department of Epidemiology and public health, Sciensano, J. Wytsmanstraat 14, 1050 Brussels, Belgium
- Department of Public Health and Primary Care, Faculty of Medicine, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium
| | - Annie Robert
- Department of Epidemiology and Biostatistics, Institut de recherche expérimentale et clinique, Faculty of Public Health, Université catholique de Louvain, Clos Chapelle-aux-champs 30, 1200 Woluwe-Saint-Lambert, Belgium
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9
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García-Fernández S, Frentrup M, Steglich M, Gonzaga A, Cobo M, López-Fresneña N, Cobo J, Morosini MI, Cantón R, Del Campo R, Nübel U. Whole-genome sequencing reveals nosocomial Clostridioides difficile transmission and a previously unsuspected epidemic scenario. Sci Rep 2019; 9:6959. [PMID: 31061423 PMCID: PMC6502822 DOI: 10.1038/s41598-019-43464-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/25/2019] [Indexed: 12/19/2022] Open
Abstract
To trace the routes and frequencies of transmission of Clostridioides difficile in a tertiary-care hospital in Madrid (Spain), we sequenced the genomes from all C. difficile isolates collected over 36 months (2014-2016) that were indistinguishable from any other isolate by PCR ribotyping. From a total of 589 C. difficile infection cases, we cultivated and PCR-ribotyped 367 C. difficile isolates (62%), of which 265 were genome-sequenced. Based on close relatedness of successively collected isolates (≤2 SNPs difference in their genomes), whole-genome sequencing revealed a total of 17 independent, putative transmission clusters, caused by various C. difficile strains and each containing 2 to 18 cases, none of which had been detected previously by standard epidemiological surveillance. Proportions of linked isolates varied widely among PCR ribotypes, from 3% (1/36) for ribotype 014/020 to 60% (12/20) for ribotype 027, suggesting differential aptitudes for nosocomial spread. Remarkably, only a minority (17%) of transmission recipients had direct ward contact to their presumed donors and specific C. difficile genome types frequently went undetectable for several months before re-emerging later, suggesting reservoirs for the pathogen outside of symptomatic patients. Taken together, our analysis based on genome sequencing suggested considerable within-hospital epidemic spread of C. difficile, even though epidemiological data initially had been inconspicuous.
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Affiliation(s)
- Sergio García-Fernández
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | | | - Matthias Steglich
- Leibniz Institute DSMZ, Braunschweig, Germany.,German Center of Infection Research (DZIF), Braunschweig, Germany
| | | | - Marta Cobo
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Nieves López-Fresneña
- Servicio de Medicina Preventiva, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Javier Cobo
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain.,Servicio de Enfermedades Infecciosas, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - María-Isabel Morosini
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Rafael Cantón
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Rosa Del Campo
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Ulrich Nübel
- Leibniz Institute DSMZ, Braunschweig, Germany. .,German Center of Infection Research (DZIF), Braunschweig, Germany. .,Braunschweig Integrated Center of Systems Biology (BRICS), Technical University, Braunschweig, Germany.
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10
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Szafrańska AK, Junker V, Steglich M, Nübel U. Rapid cell division of Staphylococcus aureus during colonization of the human nose. BMC Genomics 2019; 20:229. [PMID: 30894139 PMCID: PMC6425579 DOI: 10.1186/s12864-019-5604-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/13/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Staphylococcus aureus is an important opportunistic pathogen and a commensal bacterium, thriving in the nasal cavities of 20% of the human population. Little is known about the dynamics of asymptomatic colonization and the occasional transition to infectious disease. RESULTS In this study, we inferred that S. aureus cells replicate every one to three hours on average while colonizing the human nose, based on two independent lines of genomic evidence. First, we collected nasal swab samples from human subjects, extracted and sequenced metagenomic DNA, and analyzed the distribution of sequencing coverage along the staphylococcal chromosome. Calibration of this data by comparison to a laboratory culture enabled measuring S. aureus cell division rates in nasal samples. Second, we applied mutation accumulation experiments paired with genome sequencing to measure spontaneous mutation rates at a genome scale. Relating these mutation rates to annual evolutionary rates confirmed that nasal S. aureus continuously pass several thousand cell divisions per year when averaged over large, globally distributed populations and over many years, corresponding to generation times of less than two hours. CONCLUSIONS The cell division rates we determined were higher than the fastest documented rates during fulminant disease progression (in a mouse model of systemic infection) and much higher than those previously measured in expectorated sputum from cystic fibrosis patients. This paper supplies absolute in-vivo generation times for an important bacterial commensal, indicating that colonization of the human upper respiratory tract is characterized by a highly dynamic equilibrium between bacterial growth and removal.
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Affiliation(s)
- Anna K Szafrańska
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, 38124, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig site, Germany
| | - Vera Junker
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, 38124, Braunschweig, Germany
| | - Matthias Steglich
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, 38124, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig site, Germany
| | - Ulrich Nübel
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Inhoffenstr. 7B, 38124, Braunschweig, Germany. .,German Center for Infection Research (DZIF), Braunschweig site, Germany. .,Braunschweig Integrated Centre of Systems Biology (BRICS), Technical University Braunschweig, Braunschweig, Germany.
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11
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Berger FK, Gfrörer S, Becker SL, Baldan R, Cirillo DM, Frentrup M, Steglich M, Engling P, Nübel U, Mellmann A, Bischoff M, Gärtner B, von Müller L. Hospital outbreak due to Clostridium difficile ribotype 018 (RT018) in Southern Germany. Int J Med Microbiol 2019; 309:189-193. [PMID: 30879971 DOI: 10.1016/j.ijmm.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/18/2019] [Accepted: 03/04/2019] [Indexed: 02/06/2023] Open
Abstract
Clostridium (Clostridioides) difficile is the main cause of nosocomial diarrhoea. Ribotype 018 (RT018) has been recognized as the predominant strain responsible for C. difficile infection (CDI) in Italy, whereas in most other European countries only sporadic RT018 cases occur. Between August and October 2015, a suspected C. difficile outbreak at two associated hospitals in Southern Germany was investigated by comprehensive molecular typing. Surprisingly, RT018 was detected in 9/82 CDI patients, which has never been described before in a German outbreak. Phenotypic analysis revealed fluoroquinolone and macrolide resistance. Genetic subtyping using multiple-locus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS) was performed and outbreak isolates were directly compared to sporadic German RT018 isolates and to epidemic ones from Milan, Northern Italy. Molecular typing confirmed a hospital outbreak with closely related RT018 isolates. Both, MLVA and WGS revealed high similarity of outbreak strains with epidemic isolates from Italy, but low similarity to other German isolates. Comparison between both typing strategies showed that ribotyping in combination with MLVA was appropriate to identify related isolates and clonal complexes, whereas WGS provided a better discrimination with more detailed information about the phylogenetic relationship of isolates. This is the first hospital outbreak in Germany presumably caused by cross-national transmission of an Italian epidemic RT018 strain.
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Affiliation(s)
- Fabian K Berger
- Institute of Medical Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Saarland University, Kirrberger Straße, Building 43, 66421 Homburg, Saar, Germany.
| | - Sabine Gfrörer
- Regionale Kliniken Holding RKH GmbH, Ludwigsburg, Germany
| | - Sören L Becker
- Institute of Medical Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Saarland University, Kirrberger Straße, Building 43, 66421 Homburg, Saar, Germany; Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Rossella Baldan
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Via Olgettina Milano 60, 20132 Italy
| | - Daniela Maria Cirillo
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Via Olgettina Milano 60, 20132 Italy
| | | | - Matthias Steglich
- Leibniz Institute DSMZ, Inhoffenstraße 7B, 38124 Braunschweig, Germany; German Centre for Infection Research (DZIF), Partner site Braunschweig-Hannover, Inhoffenstraße 7, 38124 Braunschweig, Germany
| | - Pit Engling
- Leibniz Institute DSMZ, Inhoffenstraße 7B, 38124 Braunschweig, Germany
| | - Ulrich Nübel
- Leibniz Institute DSMZ, Inhoffenstraße 7B, 38124 Braunschweig, Germany; German Centre for Infection Research (DZIF), Partner site Braunschweig-Hannover, Inhoffenstraße 7, 38124 Braunschweig, Germany; Braunschweig Integrated Centre of Systems Biology (BRICS), Technical University Braunschweig, Rebenring 56, 38106 Braunschweig, Germany
| | - Alexander Mellmann
- Institute of Hygiene, University Hospital Münster, National Reference Centre for Clostridium difficile, Robert-Koch-Straße 41, 48149 Münster, Germany
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Saarland University, Kirrberger Straße, Building 43, 66421 Homburg, Saar, Germany
| | - Barbara Gärtner
- Institute of Medical Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Saarland University, Kirrberger Straße, Building 43, 66421 Homburg, Saar, Germany
| | - Lutz von Müller
- Institute of Medical Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Saarland University, Kirrberger Straße, Building 43, 66421 Homburg, Saar, Germany; Institute for Laboratory Medicine, Microbiology and Hygiene, National Reference Centre for Clostridium difficile, Christophorus Kliniken, Südwall 22, 48653 Coesfeld, Germany
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12
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Endres BT, Begum K, Sun H, Walk ST, Memariani A, Lancaster C, Gonzales-Luna AJ, Dotson KM, Bassères E, Offiong C, Tupy S, Kuper K, Septimus E, Arafat R, Alam MJ, Zhao Z, Hurdle JG, Savidge TC, Garey KW. Epidemic Clostridioides difficile Ribotype 027 Lineages: Comparisons of Texas Versus Worldwide Strains. Open Forum Infect Dis 2019; 6:ofz013. [PMID: 30793006 PMCID: PMC6368847 DOI: 10.1093/ofid/ofz013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/25/2019] [Indexed: 12/18/2022] Open
Abstract
Background The epidemic Clostridioides difficile ribotype 027 strain resulted from the dissemination of 2 separate fluoroquinolone-resistant lineages: FQR1 and FQR2. Both lineages were reported to originate in North America; however, confirmatory large-scale investigations of C difficile ribotype 027 epidemiology using whole genome sequencing has not been undertaken in the United States. Methods Whole genome sequencing and single-nucleotide polymorphism (SNP) analysis was performed on 76 clinical ribotype 027 isolates obtained from hospitalized patients in Texas with C difficile infection and compared with 32 previously sequenced worldwide strains. Maximum-likelihood phylogeny based on a set of core genome SNPs was used to construct phylogenetic trees investigating strain macro- and microevolution. Bayesian phylogenetic and phylogeographic analyses were used to incorporate temporal and geographic variables with the SNP strain analysis. Results Whole genome sequence analysis identified 2841 SNPs including 900 nonsynonymous mutations, 1404 synonymous substitutions, and 537 intergenic changes. Phylogenetic analysis separated the strains into 2 prominent groups, which grossly differed by 28 SNPs: the FQR1 and FQR2 lineages. Five isolates were identified as pre-epidemic strains. Phylogeny demonstrated unique clustering and resistance genes in Texas strains indicating that spatiotemporal bias has defined the microevolution of ribotype 027 genetics. Conclusions Clostridioides difficile ribotype 027 lineages emerged earlier than previously reported, coinciding with increased use of fluoroquinolones. Both FQR1 and FQR2 ribotype 027 epidemic lineages are present in Texas, but they have evolved geographically to represent region-specific public health threats.
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Affiliation(s)
- Bradley T Endres
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Khurshida Begum
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Hua Sun
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston
| | - Seth T Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman
| | - Ali Memariani
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Chris Lancaster
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Kierra M Dotson
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Eugénie Bassères
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | | | - Shawn Tupy
- Texas Department of State Health Services, Austin
| | - Kristi Kuper
- Center for Pharmacy Practice Excellence, Vizient, Houston, Texas
| | - Edward Septimus
- Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts
| | | | - M Jahangir Alam
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston
| | - Julian G Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston
| | - Tor C Savidge
- Texas Children's Microbiome Center, Texas Children's Hospital, Houston.,Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Texas
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13
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Hidalgo-Villeda F, Tzoc E, Torres L, Bu E, Rodríguez C, Quesada-Gómez C. Diversity of multidrug-resistant epidemic Clostridium difficile NAP1/RT027/ST01 strains in tertiary hospitals from Honduras. Anaerobe 2018; 52:75-78. [PMID: 29890209 DOI: 10.1016/j.anaerobe.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/31/2018] [Accepted: 06/03/2018] [Indexed: 12/16/2022]
Abstract
In recent years, reports of NAP1/RT027/ST01 epidemic strains of Clostridium difficile producing outbreaks of healthcare-associated diarrhea have increased in America and Europe. We cultivated multidrug-resistant NAP1/RT027/ST01 strains from the FQR2 linage from TcdA/TcdB+ stool samples obtained from patients in two Honduran hospitals. The PFGE macrorestriction patterns of two of the isolates were new. These bacteria were toxigenic and induced with different magnitude classical cytopathic effects on HeLa cells. Besides their resistance to twelve antibiotics, including to clindamycin, fluoroquinolones, linezolid and tigecycline. In this regard, they show the gyrA mutation that typifies epidemic C. difficile genotypes and carry cfr-like genes in different molecular contexts, respectively. These results confirm the spread of multidrug-resistant NAP1/RT027/ST01 strains in Central America with potential idiosyncratic adaptations.
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Affiliation(s)
- Fanny Hidalgo-Villeda
- Programa de Maestría en Enfermedades Infecciosas y Zoonóticas and Escuela de Microbiología, Universidad Autónoma Nacional de Honduras, Tegucigalpa, Honduras
| | - Edgardo Tzoc
- Programa de Maestría en Enfermedades Infecciosas y Zoonóticas and Escuela de Microbiología, Universidad Autónoma Nacional de Honduras, Tegucigalpa, Honduras
| | - Luque Torres
- Servicio de Infectología, Hospital Escuela, Universidad Autónoma Nacional de Honduras, Tegucigalpa, Honduras
| | - Efraín Bu
- Instituto Hondureño de Seguridad Social, Tegucigalpa, Honduras
| | - César Rodríguez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Quesada-Gómez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales, Universidad de Costa Rica, San José, Costa Rica.
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14
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Steglich M, Hofmann JD, Helmecke J, Sikorski J, Spröer C, Riedel T, Bunk B, Overmann J, Neumann-Schaal M, Nübel U. Convergent Loss of ABC Transporter Genes From Clostridioides difficile Genomes Is Associated With Impaired Tyrosine Uptake and p-Cresol Production. Front Microbiol 2018; 9:901. [PMID: 29867812 PMCID: PMC5951980 DOI: 10.3389/fmicb.2018.00901] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/18/2018] [Indexed: 11/13/2022] Open
Abstract
We report the frequent, convergent loss of two genes encoding the substrate-binding protein and the ATP-binding protein of an ATP-binding cassette (ABC) transporter from the genomes of unrelated Clostridioides difficile strains. This specific genomic deletion was strongly associated with the reduced uptake of tyrosine and phenylalanine and production of derived Stickland fermentation products, including p-cresol, suggesting that the affected ABC transporter had been responsible for the import of aromatic amino acids. In contrast, the transporter gene loss did not measurably affect bacterial growth or production of enterotoxins. Phylogenomic analysis of publically available genome sequences indicated that this transporter gene deletion had occurred multiple times in diverse clonal lineages of C. difficile, with a particularly high prevalence in ribotype 027 isolates, where 48 of 195 genomes (25%) were affected. The transporter gene deletion likely was facilitated by the repetitive structure of its genomic location. While at least some of the observed transporter gene deletions are likely to have occurred during the natural life cycle of C. difficile, we also provide evidence for the emergence of this mutation during long-term laboratory cultivation of reference strain R20291.
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Affiliation(s)
- Matthias Steglich
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Julia D Hofmann
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Julia Helmecke
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Johannes Sikorski
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Thomas Riedel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Meina Neumann-Schaal
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Ulrich Nübel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
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15
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Groß U, Brzuszkiewicz E, Gunka K, Starke J, Riedel T, Bunk B, Spröer C, Wetzel D, Poehlein A, Chibani C, Bohne W, Overmann J, Zimmermann O, Daniel R, Liesegang H. Comparative genome and phenotypic analysis of three Clostridioides difficile strains isolated from a single patient provide insight into multiple infection of C. difficile. BMC Genomics 2018; 19:1. [PMID: 29291715 PMCID: PMC5749029 DOI: 10.1186/s12864-017-4368-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/06/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Clostridioides difficile infections (CDI) have emerged over the past decade causing symptoms that
range from mild, antibiotic-associated diarrhea (AAD) to life-threatening toxic megacolon. In this study, we describe a multiple and isochronal (mixed) CDI caused by the isolates DSM 27638, DSM 27639 and DSM 27640 that already initially showed different morphotypes on solid media. RESULTS The three isolates belonging to the ribotypes (RT) 012 (DSM 27639) and 027 (DSM 27638 and DSM 27640)
were phenotypically characterized and high quality closed genome sequences were generated. The genomes were compared with seven reference strains including three strains of the RT 027, two of the RT 017, and one of the RT 078 as well as a multi-resistant RT 012 strain. The analysis of horizontal gene transfer events revealed gene acquisition incidents that sort the strains within the time line of the spread of their RTs within Germany. We could show as well that horizontal gene transfer between the members of different RTs occurred within this multiple infection. In addition, acquisition and exchange of virulence-related features including antibiotic resistance genes were observed. Analysis of the two genomes assigned to RT 027 revealed three single nucleotide polymorphisms (SNPs) and apparently a regional genome modification within the flagellar switch that regulates the fli operon. CONCLUSION Our findings show that (i) evolutionary events based on horizontal gene transfer occur within an ongoing
CDI and contribute to the adaptation of the species by the introduction of new genes into the genomes, (ii) within a multiple infection of a single patient the exchange of genetic material was responsible for a much higher genome variation than the observed SNPs.
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Affiliation(s)
- Uwe Groß
- Institute for Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Elzbieta Brzuszkiewicz
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Katrin Gunka
- Institute for Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Jessica Starke
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Thomas Riedel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Daniela Wetzel
- Institute for Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Cynthia Chibani
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Wolfgang Bohne
- Institute for Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Ortrud Zimmermann
- Institute for Medical Microbiology, University Medical Center Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany
| | - Heiko Liesegang
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University, Göttingen, Germany.
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16
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Gerlach RG, Walter S, McClelland M, Schmidt C, Steglich M, Prager R, Bender JK, Fuchs S, Schoerner C, Rabsch W, Lang W, Jantsch J. Comparative whole genome analysis of three consecutive Salmonella diarizonae isolates. Int J Med Microbiol 2017; 307:542-551. [PMID: 28939438 DOI: 10.1016/j.ijmm.2017.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/03/2017] [Accepted: 09/03/2017] [Indexed: 10/18/2022] Open
Abstract
Infections of very young children or immunocompromised people with Salmonella of higher subspecies are a well-known phenomenon often associated with contact to cold-blooded animals. We describe the molecular characterization of three S. enterica subsp. diarizonae strains, isolated consecutively over a period of several months from a hospital patient suffering from diarrhea and sepsis with fatal outcome. With the initial isolate the first complete genome sequence of a member of subsp. diarizonae is provided and based on this reference we revealed the genomic differences between the three isolates by use of next-generation sequencing and confirmed by phenotypical tests. Genome comparisons revealed mutations within gpt, hfq and purK in the first isolate as a sign of clonal variation rather than host-directed evolution. Furthermore, our work demonstrates that S. enterica subsp. diarizonae possess, besides a conserved set of known Salmonella Pathogenicity Islands, a variable portfolio of additional genomic islands of unknown function.
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Affiliation(s)
- Roman G Gerlach
- Project Group 5, Robert Koch Institute, Wernigerode, Germany.
| | - Steffi Walter
- Project Group 5, Robert Koch Institute, Wernigerode, Germany
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, CA, USA
| | | | - Matthias Steglich
- Division of Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Rita Prager
- National Reference Centre for Salmonella and other Enteric Bacterial Pathogens and Division of Enteropathogenic Bacteria and Legionella, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Jennifer K Bender
- Division of Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Stephan Fuchs
- Division of Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Christoph Schoerner
- Institute of Microbiology - Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen and Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany
| | - Wolfgang Rabsch
- National Reference Centre for Salmonella and other Enteric Bacterial Pathogens and Division of Enteropathogenic Bacteria and Legionella, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
| | - Werner Lang
- Department of Vascular Surgery, University Hospital Erlangen and Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, Regensburg, Germany
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17
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Nyc O, Tejkalova R, Kriz Z, Ruzicka F, Kubicek L, Matejkova J, Kuijper E, Krutova M. Two Clusters of Fluoroquinolone and Clindamycin-ResistantClostridium difficilePCR Ribotype 001 Strain Recognized by Capillary Electrophoresis Ribotyping and Multilocus Variable Tandem Repeat Analysis. Microb Drug Resist 2017; 23:609-615. [DOI: 10.1089/mdr.2016.0159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Otakar Nyc
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Praha, Czech Republic
| | - Renata Tejkalova
- Department of Medical Microbiology, St. Anne's University Hospital, and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Zdenek Kriz
- 2nd Department of Surgery, St. Anne's University Hospital, and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Filip Ruzicka
- Department of Medical Microbiology, St. Anne's University Hospital, and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lubos Kubicek
- 2nd Department of Surgery, St. Anne's University Hospital, and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Jana Matejkova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Praha, Czech Republic
| | - Ed Kuijper
- Leiden University Medical Centre, Leiden, the Netherlands
| | - Marcela Krutova
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Praha, Czech Republic
- DNA Laboratory, Department of Pediatric Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Praha, Czech Republic
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18
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Steglich M, Nübel U. The challenge of detecting indels in bacterial genomes from short-read sequencing data. J Biotechnol 2017; 250:11-15. [PMID: 28267569 DOI: 10.1016/j.jbiotec.2017.02.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/24/2017] [Accepted: 02/26/2017] [Indexed: 10/20/2022]
Abstract
We tested the capabilities of four different software tools to detect insertions and deletions (indels) in a bacterial genome on the basis of short sequencing reads. We included tools applying the gapped-alignment (VarScan, FreeBayes) or split-read (Pindel) methods, respectively, and a combinatorial approach with local de-novo assembly (ScanIndel). Tests were performed with 151-basepair, paired-end sequencing reads simulated from a bacterial (Clostridioides difficile R20291) genome sequence with predefined indels (indel length, 1-2321bp). Results achieved with the different tools varied widely, and the specific sensitivity and false-discovery rates strongly depended on indel size. All tools tested were able to detect short indels (≤29 basepairs) at sensitivities close to 100%, albeit Pindel reported up to 20% false calls. In contrast, gapped-alignment and split-read tools failed to recover large proportions of long indels (>29bp) even at 120-fold coverage, and again, Pindel produced significant numbers of false-positive calls. Outstandingly, ScanIndel detected and reconstructed 97% of long indels on average (95% confidence intervals, 88%-99%) and, at the same time, produced negligible amounts of false calls. Hence, the combinatorial approach implemented in ScanIndel was able to recover the positions, types and sequences of indels with excellent sensitivity and false-discovery rate, by encompassing the full indel length spectrum present in the datasets.
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Affiliation(s)
| | - Ulrich Nübel
- Leibniz Institute DSMZ, Braunschweig, Germany; German Center for Infection Research (DZIF), Partner Site, Hannover-Braunschweig, Germany
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19
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Hoffmann S, Schmidt C, Walter S, Bender JK, Gerlach RG. Scarless deletion of up to seven methyl-accepting chemotaxis genes with an optimized method highlights key function of CheM in Salmonella Typhimurium. PLoS One 2017; 12:e0172630. [PMID: 28212413 PMCID: PMC5315404 DOI: 10.1371/journal.pone.0172630] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/07/2017] [Indexed: 11/19/2022] Open
Abstract
Site-directed scarless mutagenesis is an essential tool of modern pathogenesis research. We describe an optimized two-step protocol for genome editing in Salmonella enterica serovar Typhimurium to enable multiple sequential mutagenesis steps in a single strain. The system is based on the λ Red recombinase-catalyzed integration of a selectable antibiotics resistance marker followed by replacement of this cassette. Markerless mutants are selected by expressing the meganuclease I-SceI which induces double-strand breaks in bacteria still harboring the resistance locus. Our new dual-functional plasmid pWRG730 allows for heat-inducible expression of the λ Red recombinase and tet-inducible production of I-SceI. Methyl-accepting chemotaxis proteins (MCP) are transmembrane chemoreceptors for a vast set of environmental signals including amino acids, sugars, ions and oxygen. Based on the sensory input of MCPs, chemotaxis is a key component for Salmonella virulence. To determine the contribution of individual MCPs we sequentially deleted seven MCP genes. The individual mutations were validated by PCR and genetic integrity of the final seven MCP mutant WRG279 was confirmed by whole genome sequencing. The successive MCP mutants were functionally tested in a HeLa cell infection model which revealed increased invasion rates for non-chemotactic mutants and strains lacking the MCP CheM (Tar). The phenotype of WRG279 was reversed with plasmid-based expression of CheM. The complemented WRG279 mutant showed also partially restored chemotaxis in swarming assays on semi-solid agar. Our optimized scarless deletion protocol enables efficient and precise manipulation of the Salmonella genome. As demonstrated with whole genome sequencing, multiple subsequent mutagenesis steps can be realized without the introduction of unwanted mutations. The sequential deletion of seven MCP genes revealed a significant role of CheM for the interaction of S. Typhimurium with host cells which might give new insights into mechanisms of Salmonella host cell sensing.
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Affiliation(s)
| | | | - Steffi Walter
- Project Group 5, Robert Koch Institute, Wernigerode, Germany
| | - Jennifer K. Bender
- Division of Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
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20
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Advances in the Microbiome: Applications to Clostridium difficile Infection. J Clin Med 2016; 5:jcm5090083. [PMID: 27657145 PMCID: PMC5039486 DOI: 10.3390/jcm5090083] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/02/2016] [Accepted: 09/13/2016] [Indexed: 12/14/2022] Open
Abstract
Clostridium difficile is a major cause of morbidity and mortality worldwide, causing over 400,000 infections and approximately 29,000 deaths in the United States alone each year. C. difficile is the most common cause of nosocomial diarrhoea in the developed world, and, in recent years, the emergence of hyper-virulent (mainly ribotypes 027 and 078, sometimes characterised by increased toxin production), epidemic strains and an increase in the number of community-acquired infections has caused further concern. Antibiotic therapy with metronidazole, vancomycin or fidaxomicin is the primary treatment for C. difficile infection (CDI). However, CDI is unique, in that, antibiotic use is also a major risk factor for acquiring CDI or recurrent CDI due to disruption of the normal gut microbiota. Therefore, there is an urgent need for alternative, non-antibiotic therapeutics to treat or prevent CDI. Here, we review a number of such potential treatments which have emerged from advances in the field of microbiome research.
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21
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Andersen JM, Shoup M, Robinson C, Britton R, Olsen KEP, Barrangou R. CRISPR Diversity and Microevolution in Clostridium difficile. Genome Biol Evol 2016; 8:2841-55. [PMID: 27576538 PMCID: PMC5630864 DOI: 10.1093/gbe/evw203] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2016] [Indexed: 12/20/2022] Open
Abstract
Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes.
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Affiliation(s)
- Joakim M Andersen
- Department of Food, Processing and Nutritional Sciences, North Carolina State University, NC
| | - Madelyn Shoup
- Department of Microbiology and Molecular Genetics, Michigan State University, MI
| | - Cathy Robinson
- Department of Microbiology and Molecular Genetics, Michigan State University, MI
| | - Robert Britton
- Department of Molecular Virology and Microbiology, Center for Metagenomics and Microbiome Research, Baylor College of Medicine, TX
| | - Katharina E P Olsen
- Microbial Competence Centre, Novo Nordisk, Bagsværd, Denmark (Former Employment: Department of Microbiology & Infection Control, Statens Serum Institut, Copenhagen, Denmark)
| | - Rodolphe Barrangou
- Department of Food, Processing and Nutritional Sciences, North Carolina State University, NC
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22
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Arvand M, Bettge-Weller G. Clostridium difficile ribotype 027 is not evenly distributed in Hesse, Germany. Anaerobe 2016; 40:1-4. [DOI: 10.1016/j.anaerobe.2016.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 01/05/2023]
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23
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Hegarty JP, Krzeminski J, Sharma AK, Guzman-Villanueva D, Weissig V, Stewart DB. Bolaamphiphile-based nanocomplex delivery of phosphorothioate gapmer antisense oligonucleotides as a treatment for Clostridium difficile. Int J Nanomedicine 2016; 11:3607-19. [PMID: 27536102 PMCID: PMC4975145 DOI: 10.2147/ijn.s109600] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Despite being a conceptually appealing alternative to conventional antibiotics, a major challenge toward the successful implementation of antisense treatments for bacterial infections is the development of efficient oligonucleotide delivery systems. Cationic vesicles (bolasomes) composed of dequalinium chloride ("DQAsomes") have been used to deliver plasmid DNA across the cardiolipin-rich inner membrane of mitochondria. As cardiolipin is also a component of many bacterial membranes, we investigated the application of cationic bolasomes to bacteria as an oligonucleotide delivery system. Antisense sequences designed in silico to target the expression of essential genes of the bacterial pathogen, Clostridium difficile, were synthesized as 2'-O-methyl phosphorothioate gapmer antisense oligonucleotides (ASO). These antisense gapmers were quantitatively assessed for their ability to block mRNA translation using luciferase reporter and C. difficile protein expression plasmid constructs in a coupled transcription-translation system. Cationic bolaamphiphile compounds (dequalinium derivatives) of varying alkyl chain length were synthesized and bolasomes were prepared via probe sonication of an aqueous suspension. Bolasomes were characterized by particle size distribution, zeta potential, and binding capacities for anionic oligonucleotide. Bolasomes and antisense gapmers were combined to form antisense nanocomplexes. Anaerobic C. difficile log phase cultures were treated with serial doses of gapmer nanocomplexes or equivalent amounts of empty bolasomes for 24 hours. Antisense gapmers for four gene targets achieved nanomolar minimum inhibitory concentrations for C. difficile, with the lowest values observed for oligonucleotides targeting polymerase genes rpoB and dnaE. No inhibition of bacterial growth was observed from treatments at matched dosages of scrambled gapmer nanocomplexes or plain, oligonucleotide-free bolasomes compared to untreated control cultures. We describe the novel application of cationic bolasomes to deliver ASOs into bacteria. We also report the first successful in vitro antisense treatment to inhibit the growth of C. difficile.
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Affiliation(s)
- John P Hegarty
- Deparment of Surgery, Pennsylvania State University College of Medicine Hershey, PA, USA
| | - Jacek Krzeminski
- Department of Pharmacology, Penn State Hershey Cancer Institute, Hershey, PA, USA
| | - Arun K Sharma
- Department of Pharmacology, Penn State Hershey Cancer Institute, Hershey, PA, USA
| | - Diana Guzman-Villanueva
- Department of Pharmaceutical Sciences, College of Pharmacy, Nanomedicine Center of Excellence in Translational Research, Midwestern University, Glendale, AZ, USA
| | - Volkmar Weissig
- Department of Pharmaceutical Sciences, College of Pharmacy, Nanomedicine Center of Excellence in Translational Research, Midwestern University, Glendale, AZ, USA
| | - David B Stewart
- Deparment of Surgery, Pennsylvania State University College of Medicine Hershey, PA, USA
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