title: Increase in IS256 transposition in invasive vancomycin heteroresistant Staphylococcus aureus isolate belonging to ST100 and its derived VISA mutants.
abstract: 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 heterogeneous vancomycin-intermediate S. aureus (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 of IS256 transposition in isogenic strains after antibiotic treatment in a clinical setting.
authors.affiliation: Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CABA, Argentina.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Di Gregorio
authors.affiliation: Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CABA, Argentina.
authors.forename: Silvina
authors.initials: S
authors.lastname: Fernandez
authors.affiliation: Laboratorio de Bacteriología Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CABA, Argentina.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Perazzi
authors.affiliation: División Infectología, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, CABA, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Bello
authors.affiliation: Laboratorio de Bacteriología Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CABA, Argentina.
authors.forename: Angela
authors.initials: A
authors.lastname: Famiglietti
authors.affiliation: Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CABA, Argentina. Electronic address: martamollerach@gmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Mollerach
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015373:Bacterial Typing Techniques; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D004251:DNA Transposable Elements; D015870:Gene Expression; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics* / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; C079011:SigB protein, Bacteria; D012808:Sigma Factor; D014640:Vancomycin; D010744:Phosphoric Monoester Hydrolases
keywords: IS256 transposition; S. aureus; hVISA/VISA