Molecular Typing of Selected
            <i>Enterococcus faecalis</i>
            Isolates: Pilot Study Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis

Nallapareddy, Sreedhar R.; Duh, Ruay Wang; Singh, Kavindra V.; Murray, Barbara E.

doi:10.1128/jcm.40.3.868-876.2002

Cited by 82 publications

(83 citation statements)

References 53 publications

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“…Whereas ribotyping techniques accurately discriminate among species (140) and are less expensive than PFGE, the latter method has better discrimination among closely related strains (128). MLST has proven to be useful in epidemiological studies of E. faecalis and E. faecium (56,91,276), and studies have shown an accuracy equivalent to that of PFGE for the identification of organisms to the subspecies level (163,242).…”

Section: Enterococci and The Genus Enterococcusmentioning

confidence: 99%

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Enterococci in the Environment

Byappanahalli

Nevers

Korajkic

et al. 2012

Microbiol Mol Biol Rev

565

383

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SUMMARYEnterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human health risks from exposure to polluted recreational waters, they are used as surrogates for waterborne pathogens and as fecal indicator bacteria (FIB) in research and in water quality testing throughout the world. Evidence from several decades of research demonstrates, however, that enterococci may be present in high densities in the absence of obvious fecal sources and that environmental reservoirs of these FIB are important sources and sinks, with the potential to impact water quality. This review focuses on the distribution and microbial ecology of enterococci in environmental (secondary) habitats, including the effect of environmental stressors; an outline of their known and apparent sources, sinks, and fluxes; and an overview of the use of enterococci as FIB. Finally, the significance of emerging methodologies, such as microbial source tracking (MST) and empirical predictive models, as tools in water quality monitoring is addressed. The mounting evidence for widespread extraenteric sources and reservoirs of enterococci demonstrates the versatility of the genusEnterococcusand argues for the necessity of a better understanding of their ecology in natural environments, as well as their roles as opportunistic pathogens and indicators of human pathogens.

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Section: Enterococci and The Genus Enterococcusmentioning

confidence: 99%

“…and strain typing is PFGE (163,242). Whereas ribotyping techniques accurately discriminate among species (140) and are less expensive than PFGE, the latter method has better discrimination among closely related strains (128).…”

Section: Enterococci and The Genus Enterococcusmentioning

confidence: 99%

Enterococci in the Environment

Byappanahalli

Nevers

Korajkic

et al. 2012

Microbiol Mol Biol Rev

565

383

View full text Add to dashboard Cite

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“…It is therefore important to combine the use of spa typing with another locus that can be analyzed for genetic variation when microresolution of strains is sought. This approach has been successfully applied to Neisseria meningitidis (12) and Enterococcus faecalis (27). Furthermore, because spa typing has been shown to be in agreement with MLST (1,6,(31)(32)(33)(34), a typing technique that helps to resolve differences among similar spa types would also be useful in subdividing the clonal complexes identified by MLST.…”

mentioning

confidence: 99%

Comparative Sequencing of the Serine-Aspartate Repeat-Encoding Region of the Clumping Factor B Gene ( clfB ) for Resolution within Clonal Groups of Staphylococcus aureus

Koreen

Ramaswamy

Naidich³

et al. 2005

J Clin Microbiol

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Molecular techniques such as spa typing and multilocus sequence typing use DNA sequence data for differentiating Staphylococcus aureus isolates. Although spa typing is capable of detecting both genetic microand macrovariation, it has less discriminatory power than the more labor-intensive pulsed-field gel electrophoresis (PFGE) and costly genomic DNA microarray analyses. This limitation hinders strain interrogation for newly emerging clones and outbreak investigations in hospital or community settings where robust clones are endemic. To overcome this constraint, we developed a typing system using DNA sequence analysis of the serine-aspartate (SD) repeat-encoding region within the gene encoding the keratin-and fibrinogen-binding clumping factor B (clfB typing) and tested whether it is capable of discriminating within clonal groups. We analyzed 116 S. aureus strains, and the repeat region was present in all isolates, varying in sequence and in length from 420 to 804 bp. In a sample of 36 well-characterized genetically diverse isolates, clfB typing subdivided identical spa and PFGE clusters which had been discriminated by whole-genome DNA microarray mapping. The combination of spa typing and clfB typing resulted in a discriminatory power (99.5%) substantially higher than that of spa typing alone and closely approached that of the whole-genome microarray (100.0%). clfB typing also successfully resolved genetic differences among isolates differentiated by PFGE that had been collected over short periods of time from single hospitals and that belonged to the most prevalent S. aureus clone in the United States. clfB typing demonstrated in vivo, in vitro, and interpatient transmission stability yet revealed that this locus may be recombinogenic in a primarily clonal population structure. Taken together, these data show that the SD repeat-encoding region of clfB is a highly stable marker of microvariation, that in conjunction with spa typing it may serve as a DNA sequence-based alternative to PFGE for investigating genetically similar strains, and that it is useful for analyzing collections of isolates in both long-term population-based and local epidemiologic studies.Strain typing techniques for Staphylococcus aureus, the leading cause of nosocomial infections (28), have become widely used. These techniques aid in both local/short-term epidemiologic outbreak investigations and global/long-term population-based studies of methicillin-resistant and -susceptible S. aureus (MRSA and MSSA, respectively). Macrorestriction digests using pulsed-field gel electrophoresis (PFGE) have been shown to be highly effective in outbreak settings (48). Multilocus enzyme electrophoresis (MLEE), multilocus sequence typing (MLST), and sequence analysis of the repeat region within the coagulase gene, i.e., coa typing, are effective techniques for analyzing S. aureus strains in long-term study settings (10,42), and the sequence analysis of the repeat region within the protein A gene, spa typing, can effectively be used in both settings (22,41)....

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“…MLST has already been used to characterize a number of pathogenic bacteria, including Neisseria meningitidis, Enterococcus spp., Staphylococcus aureus, and Campylobacter spp. (3,4,7,21). In studies comparing MLST to PFGE among Salmonella spp., Vibrio cholerae, Enterococcus faecalis, and S. aureus isolates, MLST has been found to have similar or greater discriminatory ability than PFGE (17,18,21,27).…”

mentioning

confidence: 99%

“…(3,4,7,21). In studies comparing MLST to PFGE among Salmonella spp., Vibrio cholerae, Enterococcus faecalis, and S. aureus isolates, MLST has been found to have similar or greater discriminatory ability than PFGE (17,18,21,27). However, these results may not be generalizable to all species, since a study comparing MLST to PFGE in Escherichia coli O157:H7 found that PFGE had a greater discriminatory ability than MLST did (26).…”

mentioning

confidence: 99%

Multilocus Sequence Typing versus Pulsed-Field Gel Electrophoresis for Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates

Nemoy

Kotetishvili²,

Tigno

et al. 2005

J Clin Microbiol

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Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains are emerging pathogens. Molecular typing of ESBL-producing E. coli is useful for surveillance purposes, to monitor outbreaks and track nosocomial spread. Although pulsed-field gel electrophoresis (PFGE) is the current "gold standard" for bacterial molecular typing, multilocus sequence typing (MLST) may offer advantages. Forty ESBL-producing E. coli isolates were selected at random from a cohort of intensive care unit patients who had active surveillance perirectal cultures done. PFGE identified 19 unique PFGE types (PT) among the 40 isolates; MLST identified 22 unique sequence types. MLST had greater discriminatory ability than PFGE for ESBL-producing E. coli. Simpson's indices of diversity for PFGE and MLST were 0.895 and 0.956, respectively. There were five clonal complexes (CCs) (isolates with differences of no more than two loci) that each contained multiple PT, but each PT was found in only one CC, indicating genetic consistency within a CC. MLST has clear utility in studies of ESBL-producing E. coli, based on a greater discriminatory ability and reproducibility than PFGE and the ability to a priori define genetically related bacterial strains.Pulsed-field gel electrophoresis (PFGE) is the most widely used tool for molecular typing of bacterial strains (1), but new DNA fingerprinting techniques, including multilocus sequence typing (MLST), are emerging as alternatives, particularly when information regarding evolutionary history is needed (30). MLST is a relatively new technique where multiple genes (loci) are sequenced to measure genetic relatedness and analyze sequence variation between alleles from many strains (20). MLST has already been used to characterize a number of pathogenic bacteria, including Neisseria meningitidis, Enterococcus spp., Staphylococcus aureus, and Campylobacter spp. (3,4,7,21). In studies comparing MLST to PFGE among Salmonella spp., Vibrio cholerae, Enterococcus faecalis, and S. aureus isolates, MLST has been found to have similar or greater discriminatory ability than PFGE (17,18,21,27). However, these results may not be generalizable to all species, since a study comparing MLST to PFGE in Escherichia coli O157:H7 found that PFGE had a greater discriminatory ability than MLST did (26).MLST has not yet been used to characterize extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates. ESBL production, which confers resistance to all penicillins and cephalosporins, is found in E. coli and other members of the family Enterobacteriaceae. In the United States, the prevalence of ESBL carriage ranges between 0 and 25%, with a national average of approximately 6%, and these numbers are increasing (2, 24). ESBL-producing E. coli bacteria cause nosocomial infections, including bloodstream infections, urinary tract infections, and pneumonias, and are associated with increased patient morbidity and mortality (29). Molecular typing of ESBL-producing E. coli is useful as a framework for hospital epidemiologist...

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Molecular Typing of Selected Enterococcus faecalis Isolates: Pilot Study Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis

Cited by 82 publications

References 53 publications

Enterococci in the Environment

Enterococci in the Environment

Comparative Sequencing of the Serine-Aspartate Repeat-Encoding Region of the Clumping Factor B Gene ( clfB ) for Resolution within Clonal Groups of Staphylococcus aureus

Multilocus Sequence Typing versus Pulsed-Field Gel Electrophoresis for Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates

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