A method and an apparatus are provided for enriching pathogen DNA. The method includes adding a selective lysis buffer to a sample, incubating the mixture formed thereby, and filtering the mixture. The apparatus for enriching pathogen DNA includes: a lysis chamber; a reservoir containing selective lysis buffer, connected to the lysis chamber; and a filter connected to the lysis chamber; that achieves a limit of detection of pathogens of 500 cfu/ml or less.