scholarly journals Genome-Sequence-Based Fluorescent Amplified-Fragment Length Polymorphism Analysis ofMycobacterium tuberculosis

2000 ◽  
Vol 38 (3) ◽  
pp. 1121-1126 ◽  
Author(s):  
Jonathan N. Goulding ◽  
John Stanley ◽  
Nick Saunders ◽  
Catherine Arnold
Keyword(s):  
Genome Sequence ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Clinical Isolates ◽  
Resolving Power ◽  
Base Substitution ◽  
Polymorphism Analysis

The whole-genome fingerprinting technique, fluorescent amplified-fragment length polymorphism (FAFLP) analysis, was applied toMycobacterium tuberculosis. Sixty-five clinical isolates were analyzed to determine the value of FAFLP as a stand-alone genotyping technique and to compare it with the well-established IS6110 typing system. The genome sequence of M. tuberculosis strain H37Rv (S. T. Cole et al., Nature 393:537–544, 1998) was used to model computer-generated informative primer combination(s), and the precision and reproducibility of FAFLP were evaluated by comparing the results of in vitro and computer-generated experiments. Multiplex FAFLP was used to increase resolving power in a predictable and systematic fashion. FAFLP analysis was broadly congruent with IS6110 typing for those strains with multiple IS6110 copies. It was also able to resolve an epidemiologically unlinked group of strains with only one copy of IS6110; up to 10% of clinical isolates may fall into this category. For certain epidemiological investigations, it was concluded that a combination of FAFLP and IS6110 typing would give higher resolution than would either alone. FAFLP data were digital, precise, reproducible, and suitable for rapid electronic dissemination, manipulation, interlaboratory comparison, and storage in national or international epidemiological databases. Because FAFLP samples and analyzes base substitution across the genome as a whole, FAFLP could generate new information about the microevolution of the M. tuberculosis complex.

scholarly journals Evaluation of Amplified Fragment Length Polymorphism Analysis for Inter- and Intraspecific Differentiation ofMycobacterium bovis, M. tuberculosis, andM. ulcerans

2000 ◽  
Vol 38 (10) ◽  
pp. 3675-3680 ◽  
Author(s):  
G. Huys ◽  
L. Rigouts ◽  
K. Chemlal ◽  
F. Portaels ◽  
J. Swings
Keyword(s):  
Correlation Coefficient ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Aflp Marker ◽  
Genotypic Variation ◽  
Amplified Fragment Length Polymorphism ◽  
Resolving Power ◽  
Aflp Analysis ◽  
Polymorphism Analysis

The usefulness of amplified fragment length polymorphism (AFLP) analysis was evaluated for the discrimination of Mycobacterium bovis (17 strains), M. tuberculosis (15 strains), andM. ulcerans (12 strains) at the inter- and intraspecific level. The AFLP technique is a whole-genome coverage genotypic fingerprinting method based on the selective PCR amplification of modified restriction fragments obtained through a double enzymatic digest and subsequent ligation of double-stranded restriction site-specific adapter oligonucleotides. Selective amplification ofApaI/TaqI templates with primer combination A02-T02 (both having an additional C at their 3′ end) generated autoradiographic AFLP fingerprints that were grouped by numerical analysis in two main AFLP clusters allowing clear separation ofM. ulcerans (cluster I) from the M. tuberculosis complex members M. bovis and M. tuberculosis (cluster II). Calculation of similarities using the band-based Dice correlation coefficient instead of the Pearson product-moment correlation coefficient revealed a further subgrouping in cluster II. The two resulting subclusters corresponded with the phenotypic identity of M. bovis and M. tuberculosis, respectively, and could also be visually identified by two AFLP marker bands. Because of the relatively low degree of genotypic variation among the AFLP band patterns of the latter two taxa, no correlation could be found with previously reported molecular typing data or with geographical origin. The use of primer combination A02-T01 (the latter having an A as selective base) did not increase the resolving power within the M. tuberculosis complex but resulted in a visual subgrouping of the M. ulcerans strains that was not observed with primer combination A02-T02. Based on the presence or absence of a single AFLP marker band, the M. ulcerans isolates could be unambiguously classified in two continental types corresponding with the African and Australian origin of the strains, respectively. In conclusion, the radioactive AFLP method proved to be a reproducible and reliable taxonomic tool for the differentiation of the three mycobacterial species under study and also demonstrated its potential use for typing of M. ulceransstrains when employing multiple primer combinations.

scholarly journals High-Resolution Genotyping of Streptococcus pyogenesSerotype M1 Isolates by Fluorescent Amplified-Fragment Length Polymorphism Analysis

1999 ◽  
Vol 37 (6) ◽  
pp. 1948-1952 ◽  
Author(s):  
Meeta Desai ◽  
Androulla Efstratiou ◽  
Robert George ◽  
John Stanley
Keyword(s):  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Geographic Origin ◽  
Amplified Fragment Length Polymorphism ◽  
Discriminatory Power ◽  
Polymorphism Analysis ◽  
Worldwide Distribution ◽  
High Discriminatory Power ◽  
Typing Methods

We have used fluorescent amplified-fragment length polymorphism (FAFLP) analysis to subtype clinical isolates of Streptococcus pyogenes serotype M1. Established typing methods define most M1 isolates as members of a clone that has a worldwide distribution and that is strongly associated with invasive diseases. FAFLP analysis simultaneously sampled 90 to 120 loci throughout the M1 genome. Its discriminatory power, precision, and reproducibility were compared with those of other molecular typing methods. Irrespective of disease symptomatology or geographic origin, the majority of the clinical M1 isolates shared a single ribotype, pulsed-field gel electrophoresis macrorestriction profile, and emm1 gene sequence. Nonetheless, among these isolates, FAFLP analysis could differentiate 17 distinct profiles, including seven multi-isolate groups. The FAFLP profiles of M1 isolates reproducibly exhibited between 1 and more than 20 amplified fragment differences. The high discriminatory power of genotyping by FAFLP analysis revealed genetic microheterogeneity and differentiated otherwise “identical” M1 isolates as members of a clone complex.

scholarly journals Genomic Relatedness of ChlamydiaIsolates Determined by Amplified Fragment Length Polymorphism Analysis

1999 ◽  
Vol 181 (15) ◽  
pp. 4469-4475 ◽  
Author(s):  
Adam Meijer ◽  
Servaas A. Morré ◽  
Adriaan J. C. Van Den Brule ◽  
Paul H. M. Savelkoul ◽  
Jacobus M. Ossewaarde
Keyword(s):  
Cluster Analysis ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Chlamydia Psittaci ◽  
Rrna Genes ◽  
Aflp Analysis ◽  
Polymorphism Analysis ◽  
Genomic Relatedness

ABSTRACT The genomic relatedness of 19 Chlamydia pneumoniaeisolates (17 from respiratory origin and 2 from atherosclerotic origin), 21 Chlamydia trachomatis isolates (all serovars from the human biovar, an isolate from the mouse biovar, and a porcine isolate), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and 1 Chlamydia pecorum isolate was studied by analyzing genomic amplified fragment length polymorphism (AFLP) fingerprints. The AFLP procedure was adapted from a previously developed method for characterization of clinical C. trachomatis isolates. The fingerprints of all C. pneumoniae isolates were nearly identical, clustering together at a Dice similarity of 92.6% (± 1.6% standard deviation). The fingerprints of the C. trachomatis isolates of human, mouse, and swine origin were clearly distinct from each other. The fingerprints of the isolates from the human biovar could be divided into at least 12 different types when the presence or absence of specific bands was taken into account. The C. psittacifingerprints could be divided into a parakeet, a pigeon, and a feline type. The fingerprint of C. pecorum was clearly distinct from all others. Cluster analysis of selected isolates from all species revealed groups other than those based on sequence data from single genes (in particular, omp1 and rRNA genes) but was in agreement with available DNA-DNA hybridization data. In conclusion, cluster analysis of AFLP fingerprints of representatives of all species provided suggestions for a grouping of chlamydiae based on the analysis of the whole genome. Furthermore, genomic AFLP analysis showed that the genome of C. pneumoniae is highly conserved and that no differences exist between isolates of respiratory and atherosclerotic origins.

Predictive Fluorescent Amplified-Fragment Length Polymorphism Analysis of Escherichia coli: High-Resolution Typing Method with Phylogenetic Significance

1999 ◽  
Vol 37 (5) ◽  
pp. 1274-1279 ◽  
Author(s):  
Catherine Arnold ◽  
Lou Metherell ◽  
Geraldine Willshaw ◽  
Anthony Maggs ◽  
John Stanley
Keyword(s):  
Escherichia Coli ◽  
High Resolution ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Polymorphism Analysis ◽  
Enzyme Electrophoresis ◽  
Typing Method ◽  
E Coli

The fluorescent amplified-fragment length polymorphism (FAFLP) assay potentially amplifies a unique set of genome fragments from each bacterial clone. It uses stringently hybridizing primers which carry a fluorescent label. Precise fragment sizing is achieved by the inclusion of an internal size standard in every lane. Therefore, a unique genotype identifier(s) can be found in the form of fragments of precise size or sizes, and these can be generated reproducibly. In order to evaluate the potential of FAFLP as an epidemiological typing method with a valid phylogenetic basis, we applied it to 87 strains ofEscherichia coli. These comprised the EcoR collection, which has previously been classified by multilocus enzyme electrophoresis (MLEE) and which represents the genetic diversity of the species E. coli, plus 15 strains of the clinically important serogroup O157. FAFLP with an unlabelled nonselectiveEcoRI primer (Eco+0) and a labelled selectiveMseI primer (Mse+TA) gave strain-specific profiles. Fragments of identical sizes (in base pairs) were assumed to be identical, and the genetic distances between the strains were calculated. A phylogenetic tree derived from measure of distance correlated closely with the MLEE groupings of the EcoR collection and placed the verocytotoxin-producing O157 strains on an outlier branch. Our data indicate that FAFLP is suitable for epidemiological investigation of E. coli infection, providing well-defined and reproducible identifiers of genotype for each strain. Since FAFLP objectively samples the whole genome, each strain or isolate can be assigned a place within the broad context of the whole species and can also be subjected to a high-resolution comparison with closely related strains to investigate epidemiological clonality.

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