title: Impact of Xpert MRSA/SA blood culture PCR assay on management of positive blood cultures in obstetric patients: a retrospective audit.
abstract: BACKGROUND
  The Xpert MRSA/SA blood culture assay (Cepheid, USA) is a rapid PCR test which can be used for positive blood cultures where Gram-positive cocci in clusters are seen. It can detect Staphylococcus aureus and also the mecA gene, which encodes for β-lactam resistance. The assay was introduced into the Rotunda Hospital for positive blood cultures to allow earlier detection of MRSA and methicillin susceptible S. aureus.
  
  
  OBJECTIVE
  To assess the impact of the Xpert MRSA/SA blood culture assay on the management of obstetric patients with a positive blood culture where Gram-positive cocci in clusters were seen. The main outcome measures were duration of intravenous antimicrobials and length of admission.
  
  
  METHODS
  Pre-intervention and post-intervention groups were identified relating to whether or not the test was in use at the time. A standardised form was used to retrospectively review the medical notes and laboratory results.
  
  
  RESULTS
  There were 35 obstetric patients with positive blood cultures with Gram-positive cocci in clusters in the pre-intervention group and 22 cases in the post-intervention group. All 22 positive blood cultures in the post-intervention period were correctly identified. The antimicrobial duration was reduced from a median of 55.5-43.5 h and length of admission reduced from a median of 66.5-56 h (Mann-Whitney U value = 161, p = 0.46 and U value = 256, p = 0.15, respectively).
  
  
  CONCLUSIONS
  This study has shown a reduction in the median duration of intravenous antimicrobials and admission; however, larger multi-centre studies are needed to evaluate this potential benefit further.
authors.affiliation: Trinity College, University of Dublin, Dublin 2, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Page
authors.affiliation: Department of Microbiology, Temple St Children's University Hospital, Dublin 7, Ireland.
authors.forename: S
authors.initials: S
authors.lastname: O'Rourke
authors.affiliation: Department of Midwifery, Rotunda Hospital, Dublin 1, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Brennan
authors.affiliation: Pharmacy Department, Rotunda Hospital, Dublin 1, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Clooney
authors.affiliation: Department of Microbiology, Rotunda Hospital, Dublin 1, Ireland.
authors.forename: D
authors.initials: D
authors.lastname: Le Blanc
authors.affiliation: Department of Research, Rotunda Hospital, Dublin 1, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Griffin
authors.affiliation: Department of Obstetrics, Rotunda Hospital, Dublin 1, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Eogan
authors.affiliation: Department of Microbiology, Temple St Children's University Hospital, Dublin 7, Ireland. rdrew@rotunda.ie.|Department of Microbiology, Rotunda Hospital, Dublin 1, Ireland. rdrew@rotunda.ie.|Department of Microbiology, Royal College of Surgeons in Ireland, Dublin 2, Ireland. rdrew@rotunda.ie.
authors.forename: R J
authors.initials: RJ
authors.lastname: Drew
mesh_terms: D000071997:Blood Culture / Q000379:methods*; D005260:Female; D006801:Humans; D008485:Medical Audit; D055624:Methicillin-Resistant Staphylococcus aureus / Q000472:pathogenicity*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D012189:Retrospective Studies
keywords: Bacteraemia; Blood cultures; GeneXpert; Obstetrics; PCR