. Increase in IS256 transposition in invasive vancomycin heteroresistant Staphylococcus aureus isolate belonging to ST100 and its derived VISA mutants

SABRINA DI GREGORIO, ; SILVINA FERNANDEZ; BEATRIZ PERAZZI; NATALIA BELLO; ANGELA FAMIGLIETTI, ; MARTA MOLLERACH

Infection, Genetics and Evolution

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 43 p. 197 - 202

1567-1348

In Staphylococcus aureus, transposition of IS256 has been described to play an important role in biofilm formation and antibiotic resistance. This study describes the molecular characterization of two clinical MRSA hVISA isolates recovered from the same patient (before and after antibiotic treatment) and two VISA derivatives obtained by serial passages in the presence of vancomycin. Our results showed that antibiotic treatment (in vivo and in vitro) could enhance IS256 transposition, being responsible for the eventual loss of agr function. As far as we know this is the first study that reports the increase in transposition of IS256 in isogenic strains after antibiotic treatment in a clinical setting.