Characterisation of a Staphylococcus aureus strain with progressive loss of susceptibility to vancomycin and daptomycin during therapy.
Int J Antimicrob Agents
; 33(6): 564-8, 2009 Jun.
Article
in En
| MEDLINE
| ID: mdl-19233622
Following an initial response to vancomycin therapy, a patient with meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia developed endocarditis, failed a second course of vancomycin and then failed daptomycin therapy. An increase in the vancomycin minimum inhibitory concentrations of four consecutive MRSA blood isolates from 2 microg/mL to 8 microg/mL was shown by Etest. Population analysis of four successive blood culture isolates recovered over the 10-week period showed that the MRSA strain became progressively less susceptible to both vancomycin and daptomycin. Retrospectively, the macro Etest method using teicoplanin indicated a decrease in vancomycin susceptibility in the second blood isolate. The patient improved after treatment with various courses of trimethoprim/sulfamethoxazole, quinupristin/dalfopristin and linezolid. Early detection of vancomycin-heteroresistant S. aureus isolates, which appeared to have clinical significance in this case, continues to be a challenge for the clinical laboratory. Development of suitable practical methods for this should be given priority. Concurrent development of resistance to vancomycin and daptomycin, whilst rare, must be considered in a patient who is unresponsive to daptomycin following vancomycin therapy.
Full text:
1
Database:
MEDLINE
Therapeutic Methods and Therapies TCIM:
Plantas_medicinales
Main subject:
Staphylococcal Infections
/
Vancomycin
/
Daptomycin
/
Drug Resistance, Bacterial
/
Methicillin-Resistant Staphylococcus aureus
/
Anti-Bacterial Agents
Type of study:
Screening_studies
Language:
En
Journal:
Int J Antimicrob Agents
Year:
2009
Type:
Article
Affiliation country:
United States