Molecular typing methods and their discriminatory power

Phenotypic And genotypic characteristics of Salmonella enterica serotype Typhi have been determined for 29 isolates, from Baghdad in 2007. Conventional typing methods were performed by biochemical tests, and antimicrobial susceptibility test. Molecular typing performed by analysis plasmid DNA beside using the Random Amplified Polymorphic DNA (RAPD-PCR). For the latter, two universal primers that have selected for the high discriminatory power were used for RAPD analysis. All isolates were belong one biotype according to the differention by their ability to decarboxylat lysine, 29(100%) were lysine (+). All the isolates were susceptible to the Antibiotics used. However, all the strains free of plasmids. RAPD was capable of grouping the strains in 6 genotypic patterns using primer 784, in 4 genotypic patterns using primer 787. Conventional phenotypic typing methods, as well as the DNA plasmid analysis, presented non significant discriminatory power; however, RAPD-PCR analysis showed discriminatory power, reproducibility, easy interpretation and can be considered as a promising alternative typing method for S. Typhi.

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Comparison of four molecular typing methods to assess genetic relatedness of Candida albicans clinical isolates in Taiwan

Journal of Medical Microbiology ◽

10.1099/jmm.0.45829-0 ◽

2005 ◽

Vol 54 (3) ◽

pp. 249-258 ◽

Cited By ~ 28

Author(s):

Kuo-Wei Chen ◽

Hsiu-Jung Lo ◽

Yu-Hui Lin ◽

Shu-Ying Li

Keyword(s):

Candida Albicans ◽

Molecular Typing ◽

Genetic Relatedness ◽

Geographic Origin ◽

Discriminatory Power ◽

Patient Specific ◽

High Discriminatory Power ◽

Typing Methods ◽

Pcr Method ◽

Genetic Profiles

This report describes the investigation of the genetic profiles of 53 Candida albicans isolates collected from 18 hospitals in Taiwan using three PFGE-based typing methods (PFGE karyotyping, and PFGE of SfiI and BssHII restriction fragments) and one repetitive-sequence-PCR (rep-PCR) method. All four methods were able to identify clonal related isolates from the same patients. PFGE-BssHII exhibited the highest discriminatory power by discriminating 40 genotypes, followed by PFGE-SfiI (35 genotypes) and then by rep-PCR (31 genotypes), while PFGE karyotyping exhibited the lowest discriminatory power (19 genotypes). High discriminatory power can also be achieved by combining typing methods with different typing mechanisms, such as rep-PCR and PFGE-based typing methods. The results also showed that the genotype of each isolate was patient-specific and not associated with the source of the isolation, geographic origin or antifungal resistance.

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Conventional and molecular typing of Salmonella typhi strains from Brazil

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652002000600004 ◽

2002 ◽

Vol 44 (6) ◽

pp. 315-319 ◽

Cited By ~ 2

Author(s):

Bianca R. QUINTAES ◽

Nilma C. LEAL ◽

Eliane M. F. REIS ◽

Érica L. FONSECA ◽

Ernesto HOFER

Keyword(s):

Molecular Typing ◽

Random Amplified Polymorphic Dna ◽

Salmonella Typhi ◽

Discriminatory Power ◽

Pcr Analysis ◽

Biochemical Tests ◽

Promising Alternative ◽

Phage Types ◽

Rapd Pcr ◽

Typing Methods

Phenotypic and genotypic characteristics of Salmonella Typhi were studied in 30 strains, isolated in different years, from some areas in Brazil. Conventional typing methods were performed by biochemical tests, Vi phage-typing scheme, and antimicrobial susceptibility test. Molecular typing methods were performed by analysis of plasmid DNA and by random amplified polymorphic DNA (RAPD-PCR). For the latter, an optimization step was performed to ensure the reproducibility of the process in genetic characterization of S. Typhi. The predominance of 76.7% of biotype I (xylose +, arabinose -) was noticed in all studied areas. Three phage types were recognized, with prominence for the phage types A (73.3%) and I+IV (23.3%). All the strains were susceptible to the drugs used. However, 36.7% of the strains contained plasmids, with predominance of the 105 Kb plasmid. RAPD was capable of grouping the strains in 8 genotypic patterns using primer 784, in 6, using primer 787 and in 7, using primer 797. Conventional phenotypic typing methods, as well as the DNA plasmid analysis, presented nonsignificant discriminatory power; however, RAPD-PCR analysis showed discriminatory power, reproducibility, easy interpretation and performance, being considered as a promising alternative typing method for S. Typhi.

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Outbreak ofStenotrophomonas maltophiliaBacteremia Among Patients Undergoing Bone Marrow Transplantation: Association With Faulty Replacement of Handwashing Soap

Infection Control and Hospital Epidemiology ◽

10.1086/501578 ◽

1999 ◽

Vol 20 (11) ◽

pp. 756-758 ◽

Cited By ~ 30

Author(s):

Jeffrey D. Klausner ◽

Carol Zukerman ◽

Ajit P. Limaye ◽

Lawrence Corey

Keyword(s):

Bone Marrow ◽

Bone Marrow Transplantation ◽

Healthcare Worker ◽

Molecular Typing ◽

Marrow Transplantation ◽

Stenotrophomonas Maltophilia ◽

Marrow Transplant ◽

Hand Washing ◽

Transplant Patients ◽

Typing Methods

AbstractUsing molecular typing methods, we confirmed an outbreak ofStenotrophomonas maltophiliaamong bone marrow transplant patients. The likely source was a healthcare worker who may have washed with moisturizer instead of soap between patients. Hospital epidemiologists need to go beyond antibiograms when evaluating outbreaks and be vigilant about all aspects of hand washing.

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

Journal of Clinical Microbiology ◽

10.1128/jcm.37.6.1948-1952.1999 ◽

1999 ◽

Vol 37 (6) ◽

pp. 1948-1952 ◽

Cited By ~ 7

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.

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