Virtual digest identification of secondary enzymes for use in pulsed-field gel electrophoresis of Staphylococcus aureus.
Pulsed-field gel electrophoresis (PFGE) is currently the gold standard for methicillin-resistant Staphylococcus aureus (MRSA) typing but only one enzyme, SmaI, is currently used for restriction digest. We report the use of virtual digestion to identify enzymes for S. aureus PFGE. Two enzymes (EagI and SacII) were identified and successfully used to characterize two sets of S. aureus isolates, 12 USA300, and 14 additional MRSA isolates comprised of seven SmaI patterns. Phylogenetic analysis of patterns generated by all enzymes determined that the USA300 MRSAs are identical. In contrast, digestion with EagI or SacII resolved one to two band differences among three MRSA pattern sets that were not detected using SmaI. These results demonstrate that a second enzyme may detect differences in S. aureus isolates not detected by single enzyme digestion. However, because isolates differing by one to two bands are considered identical, such discrimination may not be clinically or epidemiologically relevant.
Center for Biological Defense, University of South Florida College of Public Health, Tampa, FL 33612, USA. jroberts@bt.usf.edu
Jill C
JC
Roberts
Andrew C
AC
Cannons
Philip T
PT
Amuso
Jacqueline
J
Cattani
D003198:Computer Simulation; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D006801:Humans; D016106:Methicillin Resistance; D015183:Restriction Mapping / Q000379:methods; D013211:Staphylococcus aureus / Q000145:classification*
C046751:endodeoxyribonuclease XmaIII; C025651:CCCGGG-specific type II deoxyribonucleases; C035337:CCGCGG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific