Rapid detection of methicillin-susceptible and methicillin-resistant Staphylococcus aureus directly from positive BacT/Alert blood culture bottles using real-time polymerase chain reaction: evaluation and comparison of 4 DNA extraction methods.

Although the introduction of automated blood culture systems has dramatically reduced laboratory personnel bench time, 48 to 72 h is still required for the identification of pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) and the accurate determination of antimicrobial sensitivities for prompt optimal patient therapy and infection control initiatives. The following 4 DNA blood culture extraction methods were compared: (a) organic, (b) differential centrifugation and lysis, (c) alkali wash/lysis, and (d) Qiagen lysis/filtration (QIAGEN, West Sussex, UK).