Molecular epidemiology of enterococci with high-level resistance to aminoglycosides.
DNA-based methodologies are considerably more powerful than other phenotype-based typing systems, providing a finer level of epidemiological discrimination, differentiating both closely and distantly related independent isolates that otherwise may appear as identical. In this study, plasmid analysis and pulsed-field gel electrophoresis were used to compare 28 isolates of Enterococci (respectively 13 strains of Enterococcus faecalis and 15 strains of Enterococcus faecium) with high-level resistance to aminoglycosides, isolated in Catania (Italy). Plasmid profile analysis resolved 20 different patterns among 24 plasmid harboring strains; many isolates showed one or two plasmids of the same size, but different plasmid content. Analysis of the PFGE-based RFLP patterns after SmaI digestion of genomic DNA resolved 26 different clones from 28 isolates: particularly, it resolved two different clones from three isolates showing identical plasmid profiles, and it identified as a single clone two isolates exhibiting different plasmid profiles. Thus, on the basis of our PFGE-based RFLP analysis data, we concluded that all the strains included in the study were genetically unrelated with two exceptions.
Privitera
O
O
Institute of Microbiology, University of Catania, Italy.
Agodi
A
A
Puntorieri
M
M
Primavera
A
A
Santagati
M
M
Privitera
A
A
Mezzatesta
M L
ML
Giuffrida
E
E
Stefani
S
S
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002876:Chromosomes, Bacterial / Q000502:physiology; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial