Multilocus Variable-Number Tandem Repeat Analysis Distinguishes Outbreak and Sporadic Escherichia coli O157:H7 Isolates
AUTOR(ES)
Noller, Anna C.
FONTE
American Society for Microbiology
RESUMO
Escherichia coli O157:H7 is a major cause of food-borne illness in the United States. Outbreak detection involves traditional epidemiological methods and routine molecular subtyping by pulsed-field gel electrophoresis (PFGE). PFGE is labor-intensive, and the results are difficult to analyze and not easily transferable between laboratories. Multilocus variable-number tandem repeat (VNTR) analysis (MLVA) is a fast, portable method that analyzes multiple VNTR loci, which are areas of the bacterial genome that evolve quickly. Eighty isolates, including 21 isolates from five epidemiologically well-characterized outbreaks from Pennsylvania and Minnesota, were analyzed by PFGE and MLVA. Strains in PFGE clusters were defined as strains that differed by less than or equal to one band by using XbaI and the confirmatory enzyme SpeI. MLVA was performed by comparing the number of tandem repeats at seven loci. From 6 to 30 alleles were found at the seven loci, resulting in 64 MLVA types among the 80 isolates. MLVA correctly identified the isolates from all five outbreaks if only a single-locus variant was allowed. MLVA differentiated strains with unique PFGE types. Additionally, MLVA discriminated strains within PFGE-defined clusters that were not known to be part of an outbreak. In addition to being a simple and validated method for E. coli O157:H7 outbreak detection, MLVA appears to have a sensitivity equal to that of PFGE and a specificity superior to that of PFGE.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=308975Documentos Relacionados
- Multilocus Variable-Number Tandem Repeat Analysis Distinguishes Outbreak and Sporadic Escherichia coli O157:H7 Isolates
- Genotyping Primers for Fully Automated Multilocus Variable-Number Tandem Repeat Analysis of Escherichia coli O157:H7
- Multilocus Variable-Number Tandem-Repeat Polymorphism among Brazilian Enterococcus faecalis Strains
- Use of Multilocus Variable-Number Tandem-Repeat Analysis for Typing Mycobacterium avium subsp. paratuberculosis
- DNA fingerprinting of Shiga-toxin producing Escherichia coli O157 based on Multiple-Locus Variable-Number Tandem-Repeats Analysis (MLVA)