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Watkin S, Yongblah F, Burton J, Hartley JC, Cloutman-Green E. Clostridioides difficile detection and infection in children: are they just small adults? J Med Microbiol 2024; 73. [PMID: 38526913 DOI: 10.1099/jmm.0.001816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024] Open
Abstract
Clostridioides difficile is a well-recognized healthcare-associated pathogen, with its significance widely recognized in adult populations. Despite this, there is limited data on the significance of detection within paediatric populations, both for individual patient management and wider transmission risk-based considerations. High rates of colonization are understood to occur in infants, with increasing levels up to 11 months, and colonization rates similar to adults by 8 years old. Sources of C. difficile are ubiquitous, with detection in companion animals and food sources, as well as within the clinical and wider environment. Due to the close interactions that occur between children and the environment, it is understandable that increasing recognition is afforded to the community acquisition of C. difficile in children. Other risk factors for the detection of C. difficile in children are similar to those observed in adults, including prior hospitalization and underlying conditions affecting gut health and motility. Recent studies have shown rising awareness of the role of asymptomatic carriage of C. difficile in healthcare transmission. Prior to this, paediatric patient populations were less likely to be screened due to uncertainty regarding the significance of detection; however, this increased awareness has led to a review of possible carriage testing pathways. Despite this increased attention, C. difficile infection remains poorly defined in paediatric populations, with limited dedicated paediatric data sets making comparison challenging. This is further complicated by the fact that infection in children frequently self resolves without additional therapies. Due to this, C. difficile remains a management challenge in paediatric settings.
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Affiliation(s)
- Sam Watkin
- Department of Civil Environmental and Geomatic Engineering, Healthy Infrastructure Research Group, University College London, Chadwick Building, London, UK
| | - Francis Yongblah
- Great Ormond Street Hospital NHS Foundation Trust, Camelia Botnar Laboratories, Department of Microbiology, London, UK
| | - James Burton
- Great Ormond Street Hospital NHS Foundation Trust, Camelia Botnar Laboratories, Department of Microbiology, London, UK
| | - John C Hartley
- Great Ormond Street Hospital NHS Foundation Trust, Camelia Botnar Laboratories, Department of Microbiology, London, UK
| | - Elaine Cloutman-Green
- Department of Civil Environmental and Geomatic Engineering, Healthy Infrastructure Research Group, University College London, Chadwick Building, London, UK
- Great Ormond Street Hospital NHS Foundation Trust, Camelia Botnar Laboratories, Department of Microbiology, London, UK
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2
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Schubert TL, Hume EB, Willcox MD. Staphylococcus aureus ocular isolates from symptomatic adverse events: antibiotic resistance and similarity of bacteria causing adverse events. Clin Exp Optom 2021; 91:148-55. [DOI: 10.1111/j.1444-0938.2007.00219.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Tracey L Schubert
- The School of Optometry and Vision Science, University of New South Wales, NSW, Australia
- The Institute for Eye Research, Kensington, New South Wales, Australia
- Vision CRC, Kensington, New South Wales, Australia
E‐mail:
| | - Emma Bh Hume
- The Institute for Eye Research, Kensington, New South Wales, Australia
- Vision CRC, Kensington, New South Wales, Australia
E‐mail:
| | - Mark Dp Willcox
- The School of Optometry and Vision Science, University of New South Wales, NSW, Australia
- The Institute for Eye Research, Kensington, New South Wales, Australia
- Vision CRC, Kensington, New South Wales, Australia
E‐mail:
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3
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Watanabe H, Koizumi Y, Matsumoto A, Asai N, Yamagishi Y, Mikamo H. Association between Clostridioides difficile ribotypes, restriction endonuclease analysis types, and toxin gene expression. Anaerobe 2018; 54:140-143. [PMID: 30201540 DOI: 10.1016/j.anaerobe.2018.09.002] [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: 06/03/2018] [Revised: 08/16/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES Clostridioides difficile strains cause severe infection. Previous studies suggested that the virulence of C. difficile is dependent on ribotype; however, this hypothesis is still controversial. We aim to investigate the relationship between ribotypes, restriction endonuclease analysis (REA) types, and toxin gene expression in C. difficile strains. METHODS We utilized 53 clinical C. difficile strains. All strains were assigned a molecular strain type using PCR ribotyping and REA typing and classified into 17 ribotypes and six REA types. The expression of toxin genes (tcdA, tcdB, and cdtB) in C. difficile strains were quantified by real-time PCR using each specific primer set, and expression was normalized to that of the housekeeping gene rpoA. RESULTS All 53 strains expressed tcdB and four strains expressed cdtB. Five strains did not express tcdA. Most ribotype and REA type strains expressed tcdA and tcdB similar to the BAA-1870 strain. In cdtB-positive strains, the cdtB expression levels were similar to those in the BAA-1870 strain. tcdA and tcdB expression levels were similar in the cdtB-positive and cdtB-negative strains. CONCLUSION Toxin gene expression was not associated with the ribotype. Production of binary toxin C. difficile transferase was not related to tcdA and tcdB expression levels.
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Affiliation(s)
- Hiroki Watanabe
- Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan
| | - Yusuke Koizumi
- Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan
| | - Asami Matsumoto
- Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan
| | - Nobuhiro Asai
- Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan
| | - Yuka Yamagishi
- Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan
| | - Hiroshige Mikamo
- Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Infection Control and Prevention, Aichi Medical University Hospital, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan; Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1, Yazako-karimata, Nagakute, Aichi 480-1195, Japan.
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4
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Elliott B, Androga GO, Knight DR, Riley TV. Clostridium difficile infection: Evolution, phylogeny and molecular epidemiology. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2017; 49:1-11. [PMID: 28012982 DOI: 10.1016/j.meegid.2016.12.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 12/19/2016] [Accepted: 12/19/2016] [Indexed: 02/07/2023]
Abstract
Over the recent decades, Clostridium difficile infection (CDI) has emerged as a global public health threat. Despite growing attention, C. difficile remains a poorly understood pathogen, however, the exquisite sensitivity offered by next generation sequencing (NGS) technology has enabled analysis of the genome of C. difficile, giving us access to massive genomic data on factors such as virulence, evolution, and genetic relatedness within C. difficile groups. NGS has also demonstrated excellence in investigations of outbreaks and disease transmission, in both small and large-scale applications. This review summarizes the molecular epidemiology, evolution, and phylogeny of C. difficile, one of the most important pathogens worldwide in the current antibiotic resistance era.
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Affiliation(s)
- Briony Elliott
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Grace O Androga
- School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Australia
| | - Daniel R Knight
- School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Australia
| | - Thomas V Riley
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Australia; School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia; Department of Microbiology, PathWest Laboratory Medicine, Perth, Australia.
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5
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Tóth J, Urbán E, Osztie H, Benczik M, Indra A, Nagy E, Allerberger F. Distribution of PCR ribotypes among recent Clostridium difficile isolates collected in two districts of Hungary using capillary gel electrophoresis and review of changes in the circulating ribotypes over time. J Med Microbiol 2016; 65:1158-1163. [DOI: 10.1099/jmm.0.000334] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Judith Tóth
- Synlab Budapest Diagnostic Center, Microbiology Laboratory, Budapest, Hungary
| | - Edith Urbán
- Institute of Clinical Microbiology, University of Szeged, Szeged, Hungary
| | - Hilda Osztie
- Synlab Budapest Diagnostic Center, Microbiology Laboratory, Budapest, Hungary
| | - Márta Benczik
- Synlab Budapest Diagnostic Center, GenoID Molecular Diagnostic Laboratory, Budapest, Hungary
| | - Alexander Indra
- Austrian Agency for Health and Food Safety (AGES), Vienna, Austria
| | - Elisabeth Nagy
- Institute of Clinical Microbiology, University of Szeged, Szeged, Hungary
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Boakye EY, Lawson IYD, Danso SKA, Offei SK. Characterization and diversity of rhizobia nodulating selected tree legumes in Ghana. Symbiosis 2016; 69:89-99. [PMID: 27231407 PMCID: PMC4853468 DOI: 10.1007/s13199-016-0383-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 02/05/2016] [Indexed: 11/06/2022]
Abstract
The study was conducted to assess the characteristics and diversity of the rhizobia that nodulate some prominent tree legumes in three soils of Ghana. Five introduced and/or indigenous tree legumes were initially assessed for nodulation in three Ghanaian soils. After 12 weeks of growth in nursery pots the 200 rhizobial strains isolated from their nodules were characterized culturally, metabolically and phenotypically. Sixty of these isolates were selected randomly and their genotypic characteristics determined using PCR-RFLP of 16S rRNA and intergenic spacer (ITS) genes. Each tree legume was nodulated by isolates classified as fast or very fast-growers or by isolates classified as slow- or very slow-growers with 54 % of all the 200 isolates belonging to fast- or very fast-growers. Morphologically, eighty five percent of the colonies formed on yeast extract mannitol agar were wet and gummy while 70 % were acid tolerant, i.e. they were able to grow at a pH of 3.5. Combined restriction of the 16S rRNA genes of the 60 rhizobial isolates with five restriction enzymes clearly distinguished seven different clusters at 80 % similarity level. The majority of A. lebbeck isolates were distinct from those of the Acacias and L. leucocephala. The M. thonningii isolates were related to L. leucocephala isolates. Simple PCR of the ITS DNA provided several distinct band sizes indicating great variation among the isolates and restriction of the ITS with three different enzymes did not yield many further differences. Molecular techniques revealed a great diversity among the rhizobia that nodulate tree legumes in the tropics and this may explain why many introduced and/or indigenous trees are able to form nodules with indigenous rhizobia in this region.
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Affiliation(s)
- Emmanuel Yaw Boakye
- College of Agriculture and Consumer Sciences, Department of Soil Science, University of Ghana Legon, P. O. Box 245, Legon, Ghana
| | - Innocent Yao Dotse Lawson
- College of Agriculture and Consumer Sciences, Department of Soil Science, University of Ghana Legon, P. O. Box 245, Legon, Ghana
| | - Seth Kofi Akyea Danso
- College of Agriculture and Consumer Sciences, Department of Soil Science, University of Ghana Legon, P. O. Box 245, Legon, Ghana
| | - Samuel Kwame Offei
- College of Agriculture and Consumer Sciences, Department of Soil Science, University of Ghana Legon, P. O. Box 245, Legon, Ghana
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7
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Genomic diversity of Clostridium difficile strains. Res Microbiol 2015; 166:353-60. [DOI: 10.1016/j.resmic.2015.02.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/15/2015] [Accepted: 02/04/2015] [Indexed: 02/04/2023]
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8
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Martinson JNV, Broadaway S, Lohman E, Johnson C, Alam MJ, Khaleduzzaman M, Garey KW, Schlackman J, Young VB, Santhosh K, Rao K, Lyons RH, Walk ST. Evaluation of portability and cost of a fluorescent PCR ribotyping protocol for Clostridium difficile epidemiology. J Clin Microbiol 2015; 53:1192-7. [PMID: 25631804 PMCID: PMC4365229 DOI: 10.1128/jcm.03591-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/22/2015] [Indexed: 11/20/2022] Open
Abstract
Clostridium difficile is the most commonly identified pathogen among health care-associated infections in the United States. There is a need for accurate and low-cost typing tools that produce comparable data across studies (i.e., portable data) to help characterize isolates during epidemiologic investigations of C. difficile outbreaks and sporadic cases of disease. The most popular C. difficile-typing technique is PCR ribotyping, and we previously developed methods using fluorescent PCR primers and amplicon sizing on a Sanger-style sequencer to generate fluorescent PCR ribotyping data. This technique has been used to characterize tens of thousands of C. difficile isolates from cases of disease. Here, we present validation of a protocol for the cost-effective generation of fluorescent PCR ribotyping data. A key component of this protocol is the ability to accurately identify PCR ribotypes against an online database (http://walklab.rcg.montana.edu) at no cost. We present results from a blinded multicenter study to address data portability across four different laboratories and three different sequencing centers. Our standardized protocol and centralized database for typing of C. difficile pathogens will increase comparability between studies so that important epidemiologic linkages between cases of disease and patterns of emergence can be rapidly identified.
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Affiliation(s)
- Jonathan N V Martinson
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Susan Broadaway
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Egan Lohman
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - Christina Johnson
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
| | - M Jahangir Alam
- College of Pharmacy, University of Houston, Houston, Texas, USA
| | | | - Kevin W Garey
- College of Pharmacy, University of Houston, Houston, Texas, USA
| | - Jessica Schlackman
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vincent B Young
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, Michigan, USA Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA Division of Infectious Diseases, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
| | - Kavitha Santhosh
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, Michigan, USA
| | - Krishna Rao
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, Michigan, USA Division of Infectious Diseases, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
| | - Robert H Lyons
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Seth T Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
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9
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Gürtler V, Grando D. Reprint of New opportunities for improved ribotyping of C. difficile clinical isolates by exploring their genomes. METHODS IN MICROBIOLOGY 2013; 95:425-40. [PMID: 24050948 DOI: 10.1016/j.mimet.2013.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 11/24/2022]
Abstract
Clostridium difficile causes outbreaks of infectious diarrhoea, most commonly occurring in healthcare institutions. Recently, concern has been raised with reports of C. difficile disease in those traditionally thought to be at low risk i.e. community acquired rather than healthcare acquired. This has increased awareness for the need to track outbreaks and PCR-ribotyping has found widespread use to elucidate epidemiologically linked isolates. PCR-ribotyping uses conserved regions of the 16S rRNA gene and 23S rRNA gene as primer binding sites to produce varying PCR products due to the intergenic spacer (ITS1) regions of the multiple operons. With the explosion of whole genome sequence data it became possible to analyse the start of the 23S rRNA gene for a more accurate selection of regions closer to the end of the ITS1. However the following questions must still be asked: (i) Does the chromosomal organisation of the rrn operon vary between C. difficile strains? and (ii) just how conserved are the primer binding regions? Eight published C. difficile genomes have been aligned to produce a detailed database of indels of the ITS1's from the rrn operon sets. An iPad Filemaker Go App has been constructed and named RiboTyping (RT). It contains detail such as sequences, ribotypes, strain numbers, GenBank numbers and genome position numbers. Access to various levels of the database is provided so that details can be printed. There are three main regions of the rrn operon that have been analysed by the database and related to each other by strain, ribotype and operon: (1) 16S gene (2) ITS1 indels (3) 23S gene. This has enabled direct intra- and inter-genomic comparisons at the strain, ribotype and operon (allele) levels in each of the three genomic regions. This is the first time that such an analysis has been done. By using the RT App with search criteria it will be possible to select probe combinations for specific strains/ribotypes/rrn operons for experiments to do with diagnostics, typing and recombination of operons. Many more incomplete C. difficile whole genome sequencing projects are recorded in GenBank as underway and the rrn operon information from these can also be added to the RT App when available. The RT App will help simplify probe selection because of the complexity of the ITS1 in C. difficile even in a single genome and because other allele-specific regions (16S and 23S genes) of variability can be relationally compared to design extra probes to increase sensitivity.
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Affiliation(s)
- Volker Gürtler
- School of Applied Sciences, Building 223, Level 1, Bundoora Campus RMIT University, PO Box 71, Bundoora 3083, Australia.
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10
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Schumann P, Pukall R. The discriminatory power of ribotyping as automatable technique for differentiation of bacteria. Syst Appl Microbiol 2013; 36:369-75. [DOI: 10.1016/j.syapm.2013.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 05/17/2013] [Accepted: 05/28/2013] [Indexed: 10/26/2022]
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11
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Genetically diverse Clostridium difficile strains harboring abundant prophages in an estuarine environment. Appl Environ Microbiol 2013; 79:6236-43. [PMID: 23913427 DOI: 10.1128/aem.01849-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Clostridium difficile is the leading cause of antibiotic-associated diarrheal disease in health care settings across the world. Despite its pathogenic capacity, it can be carried asymptomatically and has been found in terrestrial and marine ecosystems outside hospital environments. Little is known about these environmental strains, and few studies have been conducted on estuarine systems. Although prophage abundance and diversity are known to occur within clinical strains, prophage carriage within environmental strains of C. difficile has not previously been explored. In this study, we isolated C. difficile from sites sampled in two consecutive years in an English estuarine system. Isolates were characterized by PCR ribotype, antibiotic resistance, and motility. The prevalence and diversity of prophages were detected by transmission electron microscopy (TEM) and a phage-specific PCR assay. We show that a dynamic and diverse population of C. difficile exists within these sediments and that it includes isolates of ribotypes which are associated with severe clinical infections and those which are more frequently isolated from outside the hospital environment. Prophage carriage was found to be high (75%), demonstrating that phages play a role in the biology of these strains.
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12
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Gürtler V, Grando D. New opportunities for improved ribotyping of C. difficile clinical isolates by exploring their genomes. J Microbiol Methods 2013; 93:257-72. [PMID: 23545446 DOI: 10.1016/j.mimet.2013.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
Abstract
Clostridium difficile causes outbreaks of infectious diarrhoea, most commonly occurring in healthcare institutions. Recently, concern has been raised with reports of C. difficile disease in those traditionally thought to be at low risk i.e. community acquired rather than healthcare acquired. This has increased awareness for the need to track outbreaks and PCR-ribotyping has found widespread use to elucidate epidemiologically linked isolates. PCR-ribotyping uses conserved regions of the 16S rRNA gene and 23S rRNA gene as primer binding sites to produce varying PCR products due to the intergenic spacer (ITS1) regions of the multiple operons. With the explosion of whole genome sequence data it became possible to analyse the start of the 23S rRNA gene for a more accurate selection of regions closer to the end of the ITS1. However the following questions must still be asked: (i) Does the chromosomal organisation of the rrn operon vary between C. difficile strains? and (ii) just how conserved are the primer binding regions? Eight published C. difficile genomes have been aligned to produce a detailed database of indels of the ITS1's from the rrn operon sets. An iPad Filemaker Go App has been constructed and named RiboTyping (RT). It contains detail such as sequences, ribotypes, strain numbers, GenBank numbers and genome position numbers. Access to various levels of the database is provided so that details can be printed. There are three main regions of the rrn operon that have been analysed by the database and related to each other by strain, ribotype and operon: (1) 16S gene (2) ITS1 indels (3) 23S gene. This has enabled direct intra- and inter-genomic comparisons at the strain, ribotype and operon (allele) levels in each of the three genomic regions. This is the first time that such an analysis has been done. By using the RT App with search criteria it will be possible to select probe combinations for specific strains/ribotypes/rrn operons for experiments to do with diagnostics, typing and recombination of operons. Many more incomplete C. difficile whole genome sequencing projects are recorded in GenBank as underway and the rrn operon information from these can also be added to the RT App when available. The RT App will help simplify probe selection because of the complexity of the ITS1 in C. difficile even in a single genome and because other allele-specific regions (16S and 23S genes) of variability can be relationally compared to design extra probes to increase sensitivity.
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Affiliation(s)
- Volker Gürtler
- School of Applied Sciences, Building 223, Level 1, Bundoora Campus RMIT University, PO Box 71, Bundoora 3083, Australia.
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13
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Clayton EM, Rea MC, Shanahan F, Quigley EMM, Kiely B, Ross RP, Hill C. Carriage of Clostridium difficile in outpatients with irritable bowel syndrome. J Med Microbiol 2012; 61:1290-1294. [PMID: 22580916 DOI: 10.1099/jmm.0.040568-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Irritable bowel syndrome (IBS) is a common, typically chronic and sometimes disabling gastrointestinal condition of uncertain aetiology. Recently, a variety of links to gastrointestinal infections have been described including the onset of IBS following exposure to enteric pathogens and an apparent predisposition to gastrointestinal infection. The prevalence of Clostridium difficile in a population of IBS outpatients (n = 87) in the absence of established risk factors for the acquisition of C. difficile infection was examined. Overall, 5.7 % of patients (n = 5) carried culturable C. difficile and 4.6 % (n = 4) of isolates were toxigenic, belonging to toxinotype group 0, compared with 1.1 % (n = 1) for the healthy control group (n = 88). These isolates were members of toxigenic PCR ribotype groups 005 and 050 (IBS group) and 062 (control group) and were identified further as three individual strains by PFGE. Although no significant difference was observed between IBS patients and healthy volunteers, these findings support the concept that a subpopulation of IBS patients may be susceptible to gastrointestinal infection.
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Affiliation(s)
- Evelyn M Clayton
- Alimentary Pharmabiotic Centre, University College, Cork, Ireland.,Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Mary C Rea
- Alimentary Pharmabiotic Centre, University College, Cork, Ireland.,Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Fergus Shanahan
- Department of Medicine, University College, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College, Cork, Ireland
| | - Eamonn M M Quigley
- Department of Medicine, University College, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College, Cork, Ireland
| | - Barry Kiely
- Alimentary Health, Cork Airport Business Park, Cork, Ireland
| | - R Paul Ross
- Alimentary Pharmabiotic Centre, University College, Cork, Ireland.,Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Colin Hill
- Department of Microbiology, University College, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College, Cork, Ireland
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14
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Rapid identification of gram-negative bacteria with and without CTX-M extended-spectrum β-lactamase from positive blood culture bottles by PCR followed by microchip gel electrophoresis. J Clin Microbiol 2011; 49:1483-8. [PMID: 21289149 DOI: 10.1128/jcm.01976-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We evaluated the usefulness of PCR analysis of the 16S-23S rRNA gene internal transcribed spacer (ITS) and the CTX-M extended-spectrum β-lactamase (ESBL) followed by microchip gel electrophoresis (MGE) for direct identification and CTX-M detection of Gram-negative bacteria (GNB) from positive blood culture bottles. Of 251 GNB isolated from blood cultures containing a single bacterium, 225 (90%) were correctly identified at the species level directly from positive blood culture bottles by comparing the ITS-PCR patterns of the sample strain with those of the control strains. There were no cases of incorrect identification. Limitations encountered included the inability to detect mixed cultures (four bottles) as well as some species (Enterobacter species and Klebsiella oxytoca) demonstrating identical ITS-PCR patterns. A total of 109 ESBL-producing isolates from various clinical materials obtained between January 2005 and December 2008 were examined for bla(CTX-M), bla(SHV), and bla(TEM) genes by PCR and sequences of PCR products. CTX-M ESBL was detected in 105 isolates, and SHV ESBL was detected in two isolates. The remaining two isolates (K. oxytoca) were shown to harbor bla(OXY.) Twenty (19%) of 104 Escherichia coli isolates from blood cultures were suspected to produce ESBL by the combination disk method, and these isolates were shown to harbor CTX-M ESBL by PCR-MGE. The results were obtained within 1.5 h at a calculated cost of $6.50 per specimen. In conclusion, simultaneous detection of ITS length polymorphisms and bla(CTX)-(M) by single PCR followed by MGE is useful for rapid, cost-effective, and reliable species-level identification of CTX-M ESBL-producing GNB responsible for bloodstream infections.
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Janezic S, Rupnik M. Molecular typing methods for Clostridium difficile: pulsed-field gel electrophoresis and PCR ribotyping. Methods Mol Biol 2010; 646:55-65. [PMID: 20597002 DOI: 10.1007/978-1-60327-365-7_4] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Molecular typing methods for Clostridium difficile are based on gel electrophoresis of restriction fragments (endonuclease restriction analysis, REA; pulsed field gel electrophoresis PFGE; toxinotyping), PCR amplification (PCR ribotyping, arbitrarily primed PCR, multilocus variable-number tandem-repeat analysis MLVA), and sequence analysis (multilocus sequence typing MLST; slpA typing, tandem repeat sequence typing). We will describe two standard methods (PCR ribotyping predominantly used throughout Europe and PFGE which is predominantly used in North America) and will discuss the difficulties of inter-laboratory comparability and unification of typing nomenclature.
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Affiliation(s)
- Sandra Janezic
- Institute of Public Health Maribor, Centre for Microbiology, Maribor, Slovenia
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16
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Abstract
Clostridium difficile is a spore-forming, toxin-producing, anaerobic bacterium abundant in soils and water. Frequent and early colonization of the human intestinal flora is common and often asymptomatic. Antimicrobials given commonly disrupt the intestinal microflora and through proliferation in colon and production of toxin A and B it precipitates C. difficile infection (CDI). The enterocytic detachment and bowel inflammation provoke C. difficile-associated diarrhoea (CDAD) sometimes developing into severe pseudomembranous colitis (PMC) and paralytic ileus. Infection is acquired from an endogenous source or from spores in the environment, most easily facilitated during hospital stay. In the elderly, comorbidity, hospitalization and antimicrobial treatment present as major risk factors and the slow recolonization of the normal flora likely responsible for single or multiple recurrences of CDI (25-50%) post therapy. The key procedure for diagnosis is toxin detection from stool specimens and sometimes in combination with culture to increase sensitivity. In mild cases stopping the offending antimicrobial will lead to resolution (25%) but standard therapy still consist of either oral metronidazole or vancomycin. Alternative agents are presently being developed and fidaxomicin, as well as nitrothiazolide are promising. Furthermore, host factors like low antitoxin A levels in serum relates to increased risk of recurrence and small numbers of patients have received immunoglobulin with good results. An immunogenic toxoid vaccine has been developed and human colostrum rich in specific secretory Ig A also support the future use of immunotherapy. Today we experience a tenfold increase of CDI incidence in the western world and both epidemics and therapeutic failure of metronidazole is contributing to morbidity and mortality. The current epidemic of the C. difficile strain NAP1/027 emerging in 2002 in Canada and the USA has now spread to most parts of Europe and virulence factors like high toxin production and sporulation challenge the therapeutic situation and cause great concern among infection control workers. Excessive use of modern fluoroquinolones is thought to play an important role in facilitating this epidemic since NAP1/027 was shown to have acquired moxifloxacin resistance compared to historical strains of the same genotype. Both the current epidemic like this and other local outbreaks from resistant or virulent strains warrant culture to be routinely performed enabling susceptibility testing and typing of the pathogen. Genotyping is most commonly done today by pulse-field gel electrophoresis (PFGE) or PCR ribotyping but multilocus variable-number tandem-repeat analysis (MLVA) seems promising. Epidemiological surveillance using all these tools will help us to better understand the global spread of C. difficile.
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Affiliation(s)
- Torbjörn Norén
- Department of Infectious Diseases, Orebro University Hospital and Orebro University, Orebro, Sweden.
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Abstract
Multilocus sequence typing (MLST), a nucleotide sequence-based characterization of allelic polymorphism of housekeeping genes, has been proposed as a new approach for population and evolutionary genetics and global epidemiology of bacterial pathogens. MLST provides unambiguous sequence data that can be generated from various laboratories and should be shared in a common web database. Here are presented most of materials, methods, and programs or software necessary to perform MLST on Clostridium difficile.We also describe an example of an MLST scheme for C. difficile based on sequence analysis of six housekeeping gene loci and use a set of 74 C. difficile isolates from various hosts, geographic sources, and PCR-toxigenic types (A+B+, A-B+, and A-B-). Thirty-two "sequence types" (ST) are defined from the combination of allelic data, which correlate well with toxigenic types. The estimation of linkage disequilibrium between loci reveals a clonal population structure. Mutational evolution of C. difficile is characterized, with point mutation generating new alleles at a frequency eightfold higher than recombinational exchange. Phylogenetic analysis shows that human and animal isolates do not cluster in distinct lineages, and that no hypervirulent lineage can be characterized within the population of toxigenic human isolates studied (strains from pseudomembranous colitis and antibiotic-associated diarrhea do not cluster in distinct lineages). However, all A-B+ variant isolates belong to a divergent but very homogeneous lineage in the population studied.An MLST database specific for this species is now hosted at the web site of the Institut Pasteur Paris. Since MLST data reflect evolutionary genetics of the species, they could be used as typing markers, possibly in combination with virulence genes data, for long-term global epidemiology of C. difficile.
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Affiliation(s)
- Ludovic Lemée
- Groupe de Recherche sur les Antimicrobiens et les Micro-organismes, Faculté de Médecine-Pharmacie, Université de Rouen, Rouen Cedex, France
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18
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The vexed relationship between Clostridium difficile and inflammatory bowel disease: an assessment of carriage in an outpatient setting among patients in remission. Am J Gastroenterol 2009; 104:1162-9. [PMID: 19319128 DOI: 10.1038/ajg.2009.4] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Comorbidity with Clostridium difficile may cause diagnostic delay in newly presenting inflammatory bowel disease (IBD) patients, trigger relapse in established disease, confound therapies, and serve as an indicator of an underlying defect in innate immunity. Retrospective analyses have suggested community acquisition; to address this we conducted a prospective analysis of C. difficile carriage in IBD patients using molecular methods specifically in an outpatient setting. METHODS Recruited participants had long-standing diagnoses of ulcerative colitis (n = 64) and Crohn's disease (n = 58), were in clinical remission, and had no recent exposure to antibiotics, corticosteroids, immunomodulatory drugs or recent hospitalization. Isolates were cultured from stools and confirmed by 16S sequencing. The antibiotic susceptibilities of the isolates were tested followed by further strain characterization by toxinotyping, ribotyping, and pulsed-field gel electrophoresis (PFGE). RESULTS The frequency of toxigenic C. difficile was higher in IBD patients than in healthy volunteers at 8.2 and 1.0%, respectively (P = 0.02 Fisher's exact test). All strains belonged to toxinotype 0 with rare subtypes of this group noted in five isolates and represented by an altered repressor genotype. Patients harbored a diverse range of toxigenic ribotype groups, including those previously associated with C. difficile-associated disease (CDAD) (R015, R005, and R020) and the rarer types R062, R050, and R003. Interestingly, common nosocomial groups were not identified. The considerable nonclonal distribution of distinct strains was further demonstrated by PFGE genomic fingerprinting. None of the study subjects experienced a clinical episode of CDAD during a 6-month period of follow-up. CONCLUSIONS Detection of C. difficile is increased in IBD outpatients in remission, and strain diversity is consistent with community acquisition from a multitude of sources.
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Kuijper EJ, van den Berg RJ, Brazier JS. Comparison of molecular typing methods applied to Clostridium difficile. Methods Mol Biol 2009; 551:159-171. [PMID: 19521874 DOI: 10.1007/978-1-60327-999-4_13] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Since the 1980s the epidemiology of Clostridium difficile infection (CDI) has been investigated by the application of many different typing or fingerprinting methods. To study the epidemiology of CDI, a typing method with a high discriminatory power, typeability, and reproducibility is required. Molecular typing methods are generally regarded as having advantages over phenotypic methods in terms of the stability of genomic markers and providing greater levels of typeability. A growing number of molecular methods have been applied to C. difficile. For the early and rapid detection of outbreak situations, methods such as restriction enzyme analysis, arbitrary primed polymerase chain reaction (PCR), and PCR ribotyping are commonly used. For long-term epidemiology, multilocus sequence typing, multilocus variable number of tandem repeats analysis, and amplified fragment length polymorphism are of interest. Currently, the PCR-ribotyping method and the library of PCR ribotypes in Cardiff are the benchmarks to which most typing studies around the world are compared. Multilocus variable number of tandem repeats analysis is the most discriminative typing method and will contribute significantly to our understanding of the epidemiology of this important nosocomial pathogen.
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Affiliation(s)
- Ed J Kuijper
- Reference Laboratory for Clostridium difficile, Medical Microbiology Department, LUMC, Leiden, The National Institute for Public Health and Environment, Bangkok, Bilthoven, The Netherlands
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20
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Sawabe E, Kato H, Osawa K, Chida T, Tojo N, Arakawa Y, Okamura N. Molecular analysis of Clostridium difficile at a university teaching hospital in Japan: a shift in the predominant type over a five-year period. Eur J Clin Microbiol Infect Dis 2007; 26:695-703. [PMID: 17647032 DOI: 10.1007/s10096-007-0355-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Clostridium difficile isolates recovered from patients admitted to a teaching hospital in Japan over a 5-year period were analyzed. Two molecular typing systems, PCR ribotyping and pulsed-field gel electrophoresis (PFGE) analysis, were used. Twenty-six PCR ribotypes were found among the 148 isolates. The predominant type at our hospital appeared to shift during the study period, from PCR ribotype a in 2000 (15/33, 45%) to PCR ribotype f in 2004 (18/28, 64%). By using PFGE with thiourea added to both the gel and running buffer, all 148 Clostridium difficile isolates were successfully classified into 37 types and 61 subtypes. The PCR ribotype f isolates were further classified into four types and 11 subtypes by PFGE. The PFGE patterns of the 11 subtypes differed from each other by only 1 to 4 bands, suggesting that these differences might reflect genetic changes during patient-to-patient transmission over the 5-year period analyzed, and that PCR ribotype f isolates might be outbreak-related. In addition, the PCR ribotype f was identical to the PCR ribotype designated smz, which is reported to have caused multiple outbreaks in Japan. These results confirmed that PCR ribotype f (type smz) has specific virulence or survival factors that make it more likely to cause nosocomial outbreaks at Japanese hospitals. PCR ribotype 027, which has been reported to have caused recent outbreaks in North America and Europe, was recovered from one patient in this study; however, this strain was community-acquired. Our findings emphasize the importance of monitoring specific strains to control and prevent nosocomial infection.
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Affiliation(s)
- E Sawabe
- Department of Clinical Laboratory, Tokyo Medical and Dental University Hospital, Faculty of Medicine, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
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21
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Sadeghifard N, Gürtler V, Beer M, Seviour RJ. The mosaic nature of intergenic 16S-23S rRNA spacer regions suggests rRNA operon copy number variation in Clostridium difficile strains. Appl Environ Microbiol 2006; 72:7311-23. [PMID: 16980415 PMCID: PMC1636144 DOI: 10.1128/aem.01179-06] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 09/07/2006] [Indexed: 11/20/2022] Open
Abstract
Clostridium difficile is a major spore-forming environmental pathogen that causes serious health problems in patients undergoing antibiotic therapy. Consequently, reliable and sensitive methods for typing individual strains are required for epidemiological and environmental studies. Ribotyping is generally considered the best method, but it fails to account for sequence diversity which might exist in intergenic 16S-23S rRNA spacer regions (ISRs) within and among strains of this organism. Therefore, this study was undertaken to compare the sequence of each individual ISR in five strains of C. difficile to explore the extent of this diversity and see whether such information might provide the basis for more sensitive and discriminatory strain typing methods. After targeted PCR amplification, cloning, and sequencing, the diversity of the ISRs was used as a measure of rRNA operon copy number. In C. difficile strains 630, ATCC 43593, A, and B, 11, 11, 7, and 8 ISR length variants, respectively, were found (containing different combinations of sequence groups [i to xiii]), suggesting 11, 11, 7, and 8 rrn copies in the respective strains. Many ISRs of the same length differed markedly in their sequences, and some of these were restricted in occurrence to a single strain. Most of these ISRs did not contain any tRNA genes, and only single copies of the tRNA(Ala) gene were found in those that did. The presence of ISR sequence groups (i to xiii) varied between strains, with some found in one, two, three, four, or all five strains. We conclude that the intergenic 16S-23S rRNA spacer regions showed a high degree of diversity, not only among the rrn operons in different strains and different rrn copies in a single strain but also among ISRs of the same length. It appears that C. difficile ISRs vary more at the inter- and intragenic levels than those of other species as determined by empirical comparison of sequences. The precise characterization of these sequences has demonstrated a high level of mosaic sequence block rearrangements that are present or absent in multiple strain-variable rrn copies within and between five different strains of C. difficile.
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Affiliation(s)
- Nourkhoda Sadeghifard
- Biotechnology Research Centre, La Trobe University, Bendigo, Victoria 3552, Australia
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22
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Voth DE, Martinez OV, Ballard JD. Variations in lethal toxin and cholesterol-dependent cytolysin production correspond to differences in cytotoxicity among strains of Clostridium sordellii. FEMS Microbiol Lett 2006; 259:295-302. [PMID: 16734793 DOI: 10.1111/j.1574-6968.2006.00287.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Clostridium sordellii is an emerging human pathogen and frequent contaminant of cadaver-derived tissue transplant material. Herein, we provide data suggesting the potential for severe C. sordellii-associated disease may be dictated by whether the specific strain produces lethal toxin (TcsL) or sordellilysin (SDL), a cholesterol-dependent cytolysin. The virulence factor profiles of 14 C. sordellii isolates were determined, and culture supernatant from six of the isolates was found to be cytotoxic to mammalian cells; yet, only one of these strains conferred cytotoxicity via production of TcsL. Cytotoxicity of TcsL- strains correlated with the production of sordellilysin, which was also recognized by an antiperfringolysin O antibody. However, supernatant from TcsL+, SDL- strains demonstrated a lower LD50 relative to TcsL-, SDL+ strains, suggesting the potential for severe C. sordellii-associated disease may be determined by the particular strain colonizing the host.
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Affiliation(s)
- Daniel E Voth
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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23
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24
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Abstract
PCR has become a widely used tool for detection, identification and differentiation of pathogenic microorganisms in diagnosis of animal and human diseases. However, quite a number of currently used protocols can be further optimized to exclude nonspecific reactions. On the one hand, target sequences as defined by primer binding sites should be checked carefully for the absence of significant homologies to other organisms in order to insure high specificity of detection. A major part of PCR assays is still based on target sequences in the ribosomal RNA operon, but, as the differentiating potential of this region is limited, genes encoding cellular proteins, such as toxins, surface antigens or enzymes, have been shown to be a viable alternative in many instances. On the other hand, various approaches are available to improve the performance of the amplification reaction itself. The kinetics of amplification is known to be heavily dependent on primer-to-template ratio, efficiency of primer annealing and enzyme-to-template ratio. In the present paper, recently published PCR detection assays for microorganisms, particularly bacterial pathogens, are reviewed and optimization strategies are explained. The practical implications and epidemiological consequences of routine use of PCR in the diagnostic laboratory are also discussed.
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Affiliation(s)
- Konrad Sachse
- Federal Research Centre for Virus Diseases of Animals (BFAV), Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07743 Jena, Germany.
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25
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Lemee L, Dhalluin A, Pestel-Caron M, Lemeland JF, Pons JL. Multilocus sequence typing analysis of human and animal Clostridium difficile isolates of various toxigenic types. J Clin Microbiol 2004; 42:2609-17. [PMID: 15184441 PMCID: PMC427854 DOI: 10.1128/jcm.42.6.2609-2617.2004] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A multilocus sequence typing (MLST) scheme was developed to study the genetic relationships and population structure of 72 Clostridium difficile isolates from various hosts, geographic sources, PCR ribotypes, and toxigenic types (determined by PCR targeting tcdA and tcdB genes). MLST was performed by DNA sequence analysis of seven housekeeping genes (aroE, ddl, dutA, tpi, recA, gmk, and sodA). The number of alleles ranged from five (dutA and ddl) to eleven (recA). Allelic profiles allowed the definition of 34 different sequence types (STs). These STs lacked correlation with geographic source but were well correlated to toxigenic type. The dendrogram generated from a matrix of pairwise genetic distances showed that animal isolates did not constitute a distinct lineage from human isolates and that there was no hypervirulent lineage within the population of toxigenic human isolates (isolates recovered from pseudomembranous colitis and antibiotic-associated diarrhea did not cluster in distinct lineages). However, A(-) B(+) variant isolates shared the same ST that appeared as a divergent lineage in the population studied, indicating a single evolutionary origin. The population structure was further examined by analysis of allelic polymorphism. The dendrogram generated from composite sequence-based analysis revealed a homogeneous population associated with three divergent lineages, one of which was restricted to A(-) B(+) variant isolates. C. difficile exhibited a clonal population structure, as revealed by the estimation of linkage disequilibrium (Ia) between loci. The analysis of alleles within clonal complexes estimated that point mutation generated new alleles at a frequency eightfold higher than recombinational exchange, and the congruence of the dendrograms generated from separate housekeeping loci confirmed the mutational evolution of this species.
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Affiliation(s)
- Ludovic Lemee
- U.F.R. Médecine-Pharmacie de Rouen, G.R.A.M. (EA 2656), 22 Boulevard Gambetta, F-76183 Rouen Cedex, France
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26
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Wullt M, Burman LG, Laurell MH, Akerlund T. Comparison of AP-PCR typing and PCR-ribotyping for estimation of nosocomial transmission of Clostridium difficile. J Hosp Infect 2003; 55:124-30. [PMID: 14529637 DOI: 10.1016/s0195-6701(03)00266-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently attempted to clarify an increased incidence of Clostridium difficile-associated diarrhoea (CDAD) in our hospital by arbitrarily primed polymerase chain reaction (AP-PCR) typing of isolates from 147 consecutive patients collected during a 12 month period (Wullt et al. J Hosp Infect 1999;43:265-273). In the present study we compared the results based on previous AP-PCR data with those based on recent PCR ribotyping of the same isolates and re-analysis of a subset of isolates by AP-PCR typing. The pattern of PCR ribotypes was similar among inpatients and outpatients. A cluster of three closely related PCR ribotypes, related to those of the serogroup H and A8 type strains, dominated and comprised 31% of inpatient and 28% of outpatient C. difficile isolates. The apparent nosocomial transmission rate among inpatients with CDAD was only 9% by AP-PCR typing compared with 18 or 36% by PCR ribotyping depending on the definition used (proportion of patients sharing C. difficile type and ward within two or 12 months). Corresponding rates for all CDAD patients were 5% by AP-PCR and 11 or 21% by PCR ribotyping. Thus, most CDAD patients apparently became ill due to their endogenous strain of C. difficile. Because of the low concordance between the two typing methods the proportion of patients fulfilling the criteria for nosocomial transmission by both methods was only 1%. Re-examination of isolates from patients with recurrences revealed a reproducibility problem with AP-PCR typing. We conclude, that of these two PCR-based options for typing of C. difficile PCR ribotyping offers a superior experimental robustness compared with AP-PCR typing.
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Affiliation(s)
- M Wullt
- Department of Infectious Diseases, University Hospital Malmö, SE-205 02 Malmö, Sweden.
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27
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Spigaglia P, Mastrantonio P. Evaluation of repetitive element sequence-based PCR as a molecular typing method for Clostridium difficile. J Clin Microbiol 2003; 41:2454-7. [PMID: 12791864 PMCID: PMC156551 DOI: 10.1128/jcm.41.6.2454-2457.2003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Repetitive element sequence-based PCR (rep-PCR) is a typing method that enables the generation of DNA fingerprinting that discriminates bacterial strains. In this study, we evaluated the applicability of rep-PCR in typing Clostridium difficile clinical isolates. The results obtained by rep-PCR were compared with those obtained by pulsed-field gel electrophoresis (PFGE) and PCR ribotyping. A high correspondence between pattern differentiations produced by rep-PCR and PFGE was observed, whereas PCR ribotyping showed a lower level of discriminatory power.
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Affiliation(s)
- Patrizia Spigaglia
- Bacteriology and Medical Mycology Laboratory, Istituto Superiore di Sanità, Rome, Italy
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28
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Fawley WN, Freeman J, Wilcox MH. Evidence to support the existence of subgroups within the UK epidemic Clostridium difficile strain (PCR ribotype 1). J Hosp Infect 2003; 54:74-7. [PMID: 12767851 DOI: 10.1016/s0195-6701(03)00079-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We used three different DNA fingerprinting techniques and clindamycin susceptibility testing to confirm that Clostridium difficile PCR ribotype I isolates can be divided into two subclones. This observation may permit a better understanding of the epidemiology and pathogenicity of C. difficile infection.
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Affiliation(s)
- W N Fawley
- Department of Microbiology, The University of Leeds and Leeds General Infirmary, Old Medical School, Leeds LS2 9JT, UK
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29
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Abstract
Clostridium difficile is primarily recognised as a nosocomially acquired pathogen manifesting in gastrointestinal disease subsequent to the patient receiving broad-spectrum antibiotics. Infection can be sporadic, but outbreaks commonly occur within a ward or hospital as a result of cross-infection. Since the 1980s, the epidemiology of C. difficile disease has been studied by the application of many different typing or fingerprinting methods; these, and the lessons learned, are reviewed herein.
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Affiliation(s)
- J S Brazier
- Anaerobe Reference Unit, Public Health Laboratory, University Hospital of Wales, Heath Park, Cardiff, UK
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30
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McFarland LV, Brandmarker SA, Guandalini S. Pediatric Clostridium difficile: a phantom menace or clinical reality? J Pediatr Gastroenterol Nutr 2000; 31:220-31. [PMID: 10997362 DOI: 10.1097/00005176-200009000-00004] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- L V McFarland
- Department of Medicinal Chemistry, University of Washington, Seattle, USA.
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31
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Fukui K, Kato N, Kato H, Watanabe K, Tatematsu N. Incidence of Prevotella intermedia and Prevotella nigrescens carriage among family members with subclinical periodontal disease. J Clin Microbiol 1999; 37:3141-5. [PMID: 10488167 PMCID: PMC85513 DOI: 10.1128/jcm.37.10.3141-3145.1999] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We established a typing system for Prevotella intermedia and Prevotella nigrescens using the combination of PCR ribotyping and arbitrarily primed PCR (AP-PCR) fingerprinting and applied this system to the study of intrafamilial incidence of these species in the oral cavity. PCR ribotyping followed by subtyping by AP-PCR fingerprinting was applied to each type strain of P. intermedia and P. nigrescens and 54 isolates (32 isolates of P. intermedia and 24 isolates of P. nigrescens) from extraoral infections, resulting in an excellent discriminatory power (discrimination index, 0.99) for both species. A total of 18 subjects from six families, with the subjects from each family comprising the mother, the father, and a child who had subclinical early-stage to moderate adult periodontitis or simple gingivitis and who carried P. intermedia or P. nigrescens, or both, were enrolled in the study of intrafamilial carriage. When 20 colonies per specimen of subgingival plaque, if available, were picked from primary culture, 115 P. intermedia and 178 P. nigrescens isolates were recovered from the 18 subjects. Among the subjects studied, family members shared the same subtype strain(s) but non-family members did not. Multiple subtypes were found in 8 (57%) of the 14 P. nigrescens-positive subjects but in only 3 (27%) of the 11 P. intermedia-positive subjects; the difference was, however, not statistically significant (P = 0.14). These results suggest that the combination of PCR ribotyping and AP-PCR fingerprinting is well suited for the epidemiological study of P. intermedia and P. nigrescens and that each family seems to carry a distinct subtype(s) of these species.
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Affiliation(s)
- K Fukui
- Institute of Anaerobic Bacteriology, Gifu University School of Medicine, Gifu 500-8705, Japan
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32
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Abstract
The intragenomic heterogeneity of the bacterial intergenic (16S-23S rDNA) spacer region (ISR) was analysed from the following species in which sequences for the complete rRNA operon (rrn) set have been determined (rrn number): Enterococcus faecalis (6) and E. faecium (6), Bacillus subtilis (10), Staphylococcus aureus (9), Vibrio cholerae (4), Haemophilus influenzae (6) and Escherichia coli (7). It was found that some spacer sequence blocks were highly conserved between operons of a genome, whereas the presence of others was variable. When these variations were analysed using the program PLATO and partial likelihood phylogenies determined by DNAml for each operon set, three regions showed significant (Z>3.3) spatial variation [Region I was 78-184 nt long (2.1<Z<49.4), Region II was 10-60 nt long (3.7<Z<23)] and Region III was 6 nt long (3.4<Z>4.4) possibly due to recombination or selection. Within Region I, there was sequence block variation in all operon sets [some operons contained tRNA genes (tRNAala, tRNAile or tRNAglu), whereas others had sequence blocks such as VS2 (S. aureus) or rsl (E. coli)]. Q Analysis of the ISR sequence from E. faecalis and E. faecium showed that there was more interspecies than intraspecies variation (both in DNA sequence and in the presence or absence of blocks). Dot matrix analysis of the sequence blocks in the nine rrn ISRs from S. aureus showed that there was significant homology between VS2 and VS5/VS6. Furthermore, repeat motifs with only A or T were present in higher copy numbers in VS5/VS6 than in VS2. Since these sequence blocks (VS2 and VS5-VS6) are related, intragenic evolution resulting in AT expansion may have occurred between these two regions. A model is proposed that postulates a role for recombination and AT-expansion in intra-genomic ISR variations. This process may represent a general mechanism of concerted evolution for bacterial ISR rearrangements.
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MESH Headings
- Bacteria/genetics
- Base Sequence
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Genetic Heterogeneity
- Molecular Sequence Data
- Mutation
- Nucleic Acid Conformation
- Operon
- Phylogeny
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- Recombination, Genetic
- Sequence Homology, Nucleic Acid
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Affiliation(s)
- V Gürtler
- Department of Microbiology, Austin & Repatriation Medical Centre, Heidelberg, Vic., Australia.
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33
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Kato H, Kato N, Katow S, Maegawa T, Nakamura S, Lyerly DM. Deletions in the repeating sequences of the toxin A gene of toxin A-negative, toxin B-positive Clostridium difficile strains. FEMS Microbiol Lett 1999; 175:197-203. [PMID: 10386368 DOI: 10.1111/j.1574-6968.1999.tb13620.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The repeating sequences of the toxin A gene from toxin A-negative, toxin B-positive (toxin A-, toxin B+) strains of Clostridium difficile which were isolated in geographically separated facilities in Japan and Indonesia were determined. All six strains tested had identical repeating sequences with two deletions (1548 and 273 nucleotides in size) in the toxin A gene. A PCR method was designed to detect the deletions and the deletions were confirmed in all 50 toxin A-, toxin B+ strains examined by this method. Western immunoblot analysis revealed that polyclonal antiserum against native toxin A did not react with the concentrated culture filtrates of the toxin A-, toxin B+ strains. These results may suggest that toxin A-, toxin B+ strains have deletions of the two thirds of the repeating regions of the toxin A gene, which encodes the epitopes fully responsible for the reaction with the polyclonal antiserum.
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Affiliation(s)
- H Kato
- Institute of Anaerobic Bacteriology, Gifu University School of Medicine, Japan
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34
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Stubbs SL, Brazier JS, O'Neill GL, Duerden BI. PCR targeted to the 16S-23S rRNA gene intergenic spacer region of Clostridium difficile and construction of a library consisting of 116 different PCR ribotypes. J Clin Microbiol 1999; 37:461-3. [PMID: 9889244 PMCID: PMC84342 DOI: 10.1128/jcm.37.2.461-463.1999] [Citation(s) in RCA: 437] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A reference library of types of Clostridium difficile has been constructed by PCR ribotyping isolates (n = 2,030) from environmental (n = 89), hospital (n = 1,386), community practitioner (n = 395), veterinary (n = 27), and reference (n = 133) sources. The library consists of 116 distinct types identified on the basis of differences in profiles generated with PCR primers designed to amplify the 16S-23S rRNA gene intergenic spacer region. Isolates from 55% of infections in hospitals in the United Kingdom belonged to one ribotype (type 1), but this type was responsible for only 7. 5% of community infections.
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Affiliation(s)
- S L Stubbs
- Anaerobe Reference Unit, Department of Medical Microbiology and Public Health Laboratory, University Hospital of Wales, Cardiff, United Kingdom
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35
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Genetic diversity and phylogeny of rhizobia that nodulate acacia spp. in morocco assessed by analysis of rRNA genes. Appl Environ Microbiol 1998; 64:4912-7. [PMID: 9835582 PMCID: PMC90942 DOI: 10.1128/aem.64.12.4912-4917.1998] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Forty rhizobia nodulating four Acacia species (A. gummifera, A. raddiana, A. cyanophylla, and A. horrida) were isolated from different sites in Morocco. These rhizobia were compared by analyzing both the 16S rRNA gene (rDNA) and the 16S-23S rRNA spacer by PCR with restriction fragment length polymorphism (RFLP) analysis. Analysis of the length of 16S-23S spacer showed a considerable diversity within these microsymbionts, but RFLP analysis of the amplified spacer revealed no additional heterogeneity. Three clusters were identified when 16S rDNA analysis was carried out. Two of these clusters include some isolates which nodulate, nonspecifically, the four Acacia species. These clusters, A and B, fit within the Sinorhizobium lineage and are closely related to S. meliloti and S. fredii, respectively. The third cluster appeared to belong to the Agrobacterium-Rhizobium galegae phylum and is more closely related to the Agrobacterium tumefaciens species. These relations were confirmed by sequencing a representative strain from each cluster.
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36
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Kluytmans J, Berg H, Steegh P, Vandenesch F, Etienne J, van Belkum A. Outbreak of Staphylococcus schleiferi wound infections: strain characterization by randomly amplified polymorphic DNA analysis, PCR ribotyping, conventional ribotyping, and pulsed-field gel electrophoresis. J Clin Microbiol 1998; 36:2214-9. [PMID: 9665994 PMCID: PMC105016 DOI: 10.1128/jcm.36.8.2214-2219.1998] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Within a 1-year period, six surgical-site infections (SSI) caused by Staphylococcus schleiferi were observed in the department of cardiac surgery of Ignatius Hospital, Breda, The Netherlands. Since outbreaks caused by this species of coagulase-negative staphylococci have not been described before, an extensive environmental survey and a case control study were performed in combination with molecular typing of the causative microorganism in order to identify potential sources of infection. Variability, as detected by four different genotyping methods (random amplification of polymorphic DNA [RAPD], conventional and PCR-mediated ribotyping, and pulsed-field gel electrophoresis [PFGE] of DNA macro restriction fragments), appeared to be limited both among the clinical isolates and among several control strains obtained from various unrelated sources. Among unrelated strains, RAPD and PCR-mediated ribotyping identified two types only, whereas seven different types were identified in a relatively concordant manner by conventional ribotyping and PFGE. The latter two procedures proved to be the most useful tools for tracking the epidemiology of S. schleiferi. Four of the outbreak-related strains were identical by both methods, and two isolates showed limited differences. In the search for a potential source of S. schleiferi infection, two slightly different PFGE types were encountered on several occasions in the nose of a single surgeon. These strains were, however, clearly different from the outbreak type. In contrast, S. schleiferi cultures remained negative for two persons identified on the basis of case control analysis. It was demonstrated that SSI caused by S. schleiferi had a clinical impact for patients comparable to that of a wound infection caused by Staphylococcus aureus. This report describes the first well-documented outbreak of S. schleiferi infection. A source of the outbreak was not detected.
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Affiliation(s)
- J Kluytmans
- Department of Clinical Microbiology, Ignatius Hospital Breda, The Netherlands.
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37
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Nour M. 16S-23S and 23S-5S intergenic spacer regions of lactobacilli: nucleotide sequence, secondary structure and comparative analysis. Res Microbiol 1998; 149:433-48. [PMID: 9766243 DOI: 10.1016/s0923-2508(98)80326-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Lactobacilli have been used as industrial starters for a long time, but in several cases their identification was, and still is, neither easy nor reliable. The aim of the present work was to examine whether the intergenic spacer regions could be of value in the identification of Lactobacillus species. For that purpose, the polymerase chain reaction (PCR) was used to amplify 16S-23S and 23S-5S spacer regions of Lactobacillus (L.) acidophilus, L. delbrueckii subsp. bulgaricus, L. casei, L. helveticus and L. curvatus. The PCR products were directly sequenced, and two forms of ribosomal RNA (rrn) operons were identified in each species studied: one with tandem tRNA(Ile)/tRNA(Ala) genes and the other one without tRNA genes. Our study revealed that the rrn operons of Lactobacillus species studied comprise the genes of 16S, 23S and 5S rRNA, in that order. Only the tRNA genes and the rRNA processing stems are highly conserved in spacer regions of lactobacilli. The divergence between the lactobacilli spacer region sequences arises from insertions and deletions of short sequences. These sequences could be interesting candidates for the development of species-specific probes. Theoretical RNA/RNA secondary structure models of the interaction between the two spacer region sequences were constructed. In conclusion, the two spacer region sequences may prove to be a useful alternative to 16S and 23S rDNA sequencing for designing species-specific probes and for establishing phylogenetic relationships between closely related species such as L. curvatus and L. casei or L. acidophilus and L. helveticus.
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MESH Headings
- Base Sequence
- Fermentation/genetics
- Lactobacillus/genetics
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phylogeny
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5S/genetics
- RNA, Transfer, Ala/genetics
- RNA, Transfer, Ile/genetics
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Affiliation(s)
- M Nour
- Département des Sciences Biologiques (Microbiologie), Faculté des Sciences de Monastir, Tunisia
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Leszczynski P, van Belkum A, Pituch H, Verbrugh H, Meisel-Mikolajczyk F. Vaginal carriage of enterotoxigenic Bacteroides fragilis in pregnant women. J Clin Microbiol 1997; 35:2899-903. [PMID: 9350755 PMCID: PMC230083 DOI: 10.1128/jcm.35.11.2899-2903.1997] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Bacteroides fragilis is an anaerobic bacterial species that is involved in gynecological infections and pathology. The incidence of vaginal carriage is largely unknown, and in order to study this, 120 pregnant women attending a general hospital for delivery were examined. Cultures were positive for eight of these women (6.6%). Interestingly, potential clonal relatedness could be demonstrated among several of the nonenterotoxigenic B. fragilis strains. Among the strains, only one produced metalloprotease enterotoxin. The presence of the gene for the metalloprotease, giving rise to the pathogenic effect on cultured eukaryotic HT29/C1 cells, was confirmed by a newly designed specific PCR assay. The enterotoxigenic B. fragilis (ETBF) strain was analyzed with the help of arbitrarily primed PCR (AP-PCR) and PCR-mediated ribotyping. The ETBF strain was shown to be genetically different compared to several other strains obtained from diverse sources. Our data indicate a relatively high vaginal B. fragilis carriage rate among pregnant women in Warsaw, Poland. Although neither ETBF nor B. fragilis colonization presented a clinical problem, the possible genetic relatedness among the colonizing B. fragilis strains indicates the need for additional research in the field of ETBF transmission and molecular epidemiology.
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Affiliation(s)
- P Leszczynski
- Department of Clinical Bacteriology, Warsaw Medical Academy, Poland
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Abstract
BACKGROUND There has been a marked increase in the number of surgical patients developing Clostridium difficile colitis. The epidemiology, pathogenesis, diagnosis and management of C. difficile infection were reviewed from a surgical perspective. METHODS A literature review was carried out based primarily on a Medline search of all English language publications containing the term C. difficile. RESULTS The recent dramatic increase in diagnosis of C. difficile infection amongst surgical patients results from heightened awareness of the condition, better methods of diagnosis, more widespread use of antibiotics for treatment and prophylaxis, and the increasing numbers of elderly and immunocompromised patients with malignancy, sepsis, and (multiple) organ failure being cared for within intensive therapy and high-dependency units. In addition to morbidity and mortality, the economic burden of C. difficile infection in terms of delayed discharge and other hospital costs is considerable. CONCLUSION Appropriate use of antibiotics, isolation of affected patients and meticulous hygiene measures on the part of staff are vital if the morbidity, mortality and economic consequences of this nosocomial infection are to be minimized.
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Affiliation(s)
- A W Bradbury
- University Department of Surgery, Royal Infirmary, Edinburgh, UK
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40
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van Dijck P, Avesani V, Delmée M. Genotyping of outbreak-related and sporadic isolates of Clostridium difficile belonging to serogroup C. J Clin Microbiol 1996; 34:3049-55. [PMID: 8940447 PMCID: PMC229458 DOI: 10.1128/jcm.34.12.3049-3055.1996] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Serogroup C of Clostridium difficile is the serogroup most frequently related to outbreaks. Fifty-six toxigenic serogroup C isolates of C. difficile were genotyped by ribotyping PCR (ribo-PCR), random amplified polymorphic DNA (RAPD) assay, and pulsed-field gel electrophoresis (PFGE). Thirty-five of the 56 isolates were recovered from four unrelated outbreaks (Belgium, 1987, 1992, and 1995; France, 1992 to 1993) 7 derived from a spatiotemporal cluster in Cotonou, Benin (1992), and 14 were sporadic isolates. The serogroup C reference strain, also isolated during an outbreak (Belgium, 1983), was genotyped too. Ribo-PCR, the RAPD assay, and PFGE generated 2, 5, and 11 major genotypes, respectively. Combination of the three methods finally yielded 13 general types, although ribo-PCR did not play any role in enhancing resolution. Three general types were recovered from all the isolates from the five outbreaks and the cluster, with two types being predominant. The 14 sporadic serogroup C isolates were divided into 11 overall genotypes. These results indicate that genotyping methods, and more particularly the combination of the RAPD assay and PFGE, can resolve genetic diversity within toxigenic, serogroup C C. difficile strains. Also, this study suggests that outbreak-related serogroup C strains are limited to a few genetically stable and apparently very widely (internationally and intercontinentally) distributed genotypes.
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Affiliation(s)
- P van Dijck
- Microbiology Unit, Catholic University of Louvain, Brussels, Belgium
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41
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Vaneechoutte M. DNA fingerprinting techniques for microorganisms. A proposal for classification and nomenclature. Mol Biotechnol 1996; 6:115-42. [PMID: 8970167 DOI: 10.1007/bf02740768] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A whole array of DNA-fingerprinting techniques, which provide indirect access to DNA sequence polymorphism in order to assess species or clonal identity of bacterial organisms or in order to study bacterial genome composition, have been described during past decades. Nomenclature has been sometimes erroneous and/or confusing, also because of hybrid techniques that combine different approaches. It can be shown that most techniques study the sequence polymorphism of only the chromosome, or only the plasmid(s) or only a gene or gene fragment and that the sequence polymorphism is revealed by AFLP (amplified fragment length polymorphism) or by RFLP (restriction fragment length polymorphism) or by special electrophoresis techniques. Starting from these considerations, some taxonomy of techniques, which enables more appropriate nomenclature, can be developed.
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Affiliation(s)
- M Vaneechoutte
- Department of Clinical Chemistry, Microbiology & Immunology Blok A, University Hospital, Ghent, Belgium.
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42
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Collier MC, Stock F, DeGirolami PC, Samore MH, Cartwright CP. Comparison of PCR-based approaches to molecular epidemiologic analysis of Clostridium difficile. J Clin Microbiol 1996; 34:1153-7. [PMID: 8727893 PMCID: PMC228972 DOI: 10.1128/jcm.34.5.1153-1157.1996] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Representative isolates of the 10 serogroups of Clostridium difficile and 39 clinical isolates (30 toxigenic and 9 nontoxigenic), including 5 isolates from a confirmed nosocomial outbreak, were analyzed by using two previously described arbitrary-primer PCR (AP-PCR) molecular typing methodologies (AP-PG05 and AP-ARB11) and PCR ribotyping. The two AP-PCR methods investigated gave comparable results; AP-PG05 and AP-ARB11 identified 8 and 7 groups among the serogroup isolates and classified the clinical isolates into 21 and 20 distinct groups, respectively. PCR ribotyping also identified 8 unique groups among the serogroup isolates but classified the clinical isolates into 23 groups. In addition, when results obtained by the PCR methods were compared with typing data generated by pulsed-field gel electrophoresis (PFGE), PCR ribotyping and PFGE were found to be in agreement for 83% (29 of 35) of isolates typeable by both techniques while AP-PG05 was in agreement with PFGE for 60% (20 of 33) and AP-ARB11 was in agreement with PFGE for only 44% (17 of 36). These results indicate that PCR ribotyping is a more discriminatory approach than AP-PCR for typing C. difficile and, furthermore, that this technique generates results that are in higher concordance with those obtained by using an established method for differentiating isolates of this organism on a molecular level than are results generated by using AP-PCR.
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Affiliation(s)
- M C Collier
- Clinical Pathology Department Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland
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Leenders A, van Belkum A, Janssen S, de Marie S, Kluytmans J, Wielenga J, Löwenberg B, Verbrugh H. Molecular epidemiology of apparent outbreak of invasive aspergillosis in a hematology ward. J Clin Microbiol 1996; 34:345-51. [PMID: 8789013 PMCID: PMC228795 DOI: 10.1128/jcm.34.2.345-351.1996] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
During a 2-month period, five patients suffering from invasive infections caused by Aspergillus flavus or Aspergillus fumigatus were identified in the Hematology Department of the University Hospital Dijkzigt (Rotterdam, The Netherlands). To study the epidemiological aspects of invasive aspergillosis, strains from these patients and from the hospital environment, isolated during extensive microbiological screening, were subjected to genotyping. A novel DNA extraction technique, involving freezing, grinding, and direct lysis in guanidium isothiocyanate-containing buffers of mycelial material, was applied. DNA isolation was followed by typing by random amplification of polymorphic DNA (RAPD) analysis. This showed that strains isolated from all patients infected with the same fungal species were genotypically distinct, thus providing evidence against the possibility of an ongoing, single-source nosocomial outbreak. Strains could also be differentiated from strains of geographically diverse origins. However, an A. flavus strain from one of the patients was also frequently encountered in the hospital environment. As all environmental strains were collected after this patient had been diagnosed with invasive disease, the epidemiological value of this observation could not be ascertained. Intensive investigations showed no single source of A. flavus or other aspergilli. RAPD genotyping proved that the outbreak of invasive aspergillosis in the hematology ward consisted of a series of unrelated events and was not due to a common source within the hospital. RAPD fingerprinting of aspergilli may greatly facilitate future investigations of the epidemiology of invasive disease caused by these pathogens.
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Affiliation(s)
- A Leenders
- Department of Bacteriology, University Hospital Dijkzigt, Rotterdam, Netherlands
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Gürtler V, Stanisich VA. New approaches to typing and identification of bacteria using the 16S-23S rDNA spacer region. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 1):3-16. [PMID: 8581168 DOI: 10.1099/13500872-142-1-3] [Citation(s) in RCA: 560] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Volker Gürtler
- Department of Microbiology, Austin and Repatriation Medical Centre (Repatriation Campus), Heidelberg West 3081, Victoria, Australia
| | - Vilma A Stanisich
- School of Microbiology, La Trobe University, Bundoora 3083, Victoria, Australia
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45
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Abstract
The spore-forming anaerobe Clostridium difficile has become a serious enteropathogen. Changes in the composition of natural intestinal flora, mainly due to antibiotic therapy, permit its colonization of, and multiplication in, the colon. The disease is caused by (entero)toxin A and (cyto)toxin B, and infection ranges from asymptomatic carrier state and mild diarrhea to pseudomembranous colitis. The clinical diagnosis is made by observing inflammatory, sometimes bloody, diarrhea and by the colonoscopic detection of epithelial necrosis, ulceration, and, in the advanced state, pseudomembrane formation. The laboratory supports the diagnosis by detecting toxin A and/or B by an enzyme-linked immunoassay with high specificity, but sometimes less sensitivity than with the cytotoxin assay in tissue culture cells. Fecal leukocytes or fecal lactoferrin may be found. Culture for the isolation and identification of toxigenic C. difficile is time consuming but necessary for epidemiological studies. Polymerase chain reaction (PCR) tests have been tested for detection of the toxin B gene directly in stool. Therapy consists of stopping all systemic antibiotic treatment and the use of oral metronidazole or vancomycin. There may be more relapses after vancomycin therapy, and the increasing vancomycin resistance of Enterococcus is worrisome. Prevention, especially of nosocomial spread, requires isolation and enforced handwashing. For epidemiological studies, the bacteria can be typed by molecular DNA analyses, including PCR, protein electrophoresis, and immunological tests.
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Affiliation(s)
- D H Gröschel
- Department of Pathology, University of Virginia School of Medicine, Charlottesville 22908, USA
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46
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Martirosian G, Kuipers S, Verbrugh H, van Belkum A, Meisel-Mikolajczyk F. PCR ribotyping and arbitrarily primed PCR for typing strains of Clostridium difficile from a Polish maternity hospital. J Clin Microbiol 1995; 33:2016-21. [PMID: 7559940 PMCID: PMC228327 DOI: 10.1128/jcm.33.8.2016-2021.1995] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Detection of the source of Clostridium difficile strains is of importance for the control of the nosocomial spread of this microorganism. For this purpose, vaginal and rectal swabs from 183 mothers, duplicate fecal samples (taken on days 1 and 4 after birth) from 183 neonates, and 94 environmental samples were cultured for C. difficile. The microorganism was never detected in the meconium obtained on day 1 after birth. On the other hand, an incidence of 17% C. difficile positivity was noted in the fecal samples obtained on day 4 after birth. Forty-two percent of the 31 colonized neonates had been delivered with complications. The bacteria were never encountered in the rectal swabs of the mothers, and C. difficile was identified in only one vaginal swab. In contrast, 13% of the environmental samples were positive for C. difficile. No major difference was encountered between patient and environmental isolates with respect to toxigenicity (58 to 65% toxigenic isolates). All strains were subsequently typed by PCR amplification of the 16S-23S ribosomal intergenic spacer regions and by arbitrarily primed PCR (AP-PCR) with different primers and combinations thereof. All environmental isolates and 11 of 31 neonatal strains were of a single type. The vaginal strain was unique, and among the maternity ward- and neonate-related isolates, only two additional AP-PCR types were identified. When a collection of C. difficile strains from patients hospitalized in other institutions and suffering from antibiotic-associated diarrhea or pseudomembranous colitis was analyzed in a similar manner, it appeared that the strain from the maternity ward was unique. The other strain commonly encountered among the neonates was also identified frequently among the isolates from patients with antibiotic-associated diarrhea or pseudomembranous colitis, indicating its general occurrence. On the basis of both epidemiological studies and PCR-mediated genotyping, it was shown that the environment and not the birth canal is the major source of C. difficile acquisition by neonates in this maternity hospital setting. Furthermore, AP-PCR appears to be a fast and useful method for epidemiologically relevant typing of C. difficile isolates.
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Affiliation(s)
- G Martirosian
- Department of Clinical Bacteriology, Medical Academy, Warsaw, Poland
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47
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Cartwright CP, Stock F, Fahle GA, Gill VJ. Comparison of pigment production and motility tests with PCR for reliable identification of intrinsically vancomycin-resistant enterococci. J Clin Microbiol 1995; 33:1931-3. [PMID: 7665675 PMCID: PMC228304 DOI: 10.1128/jcm.33.7.1931-1933.1995] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Forty-eight clinical isolates identified as either Enterococcus faecium or Enterococcus faecalis with the MicroScan system (Dade International, MicroScan Inc., West Sacramento, Calif.) were further characterized by two supplementary biochemical tests (pigment production and motility). Twenty isolates (42%), all initially identified as E. faecium, were motile. Of these 20, 8 isolates (17%) produced yellow pigment and were identified as Enterococcus casseliflavus and the remaining 12 (25%) were nonpigmented and were identified as Enterococcus gallinarum. Identical identification results were obtained when PCR amplification of regions of the vanC gene was used as a technique for differentiating these organisms. The results of this study indicate that motility and pigment production tests together with commercial test systems are sufficient for reliable identifications of E. faecium, E. casseliflavus, and E. gallinarum.
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Affiliation(s)
- C P Cartwright
- Clinical Pathology Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA
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