title: Evaluation of BacLite Rapid MRSA, a rapid culture based screening test for the detection of ciprofloxacin and methicillin resistant S. aureus (MRSA) from screening swabs.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The need for accurate and rapid screening methods to detect MRSA carriers has been clearly established. The performance of a novel assay, BacLite Rapid MRSA (Acolyte Biomedica, UK) for the rapid detection (5 h) and identification of hospital associated ciprofloxacin resistant strains of MRSA directly from nasal swab specimens was compared to that obtained by culture on Mannitol salt agar containing Oxacillin (MSAO) after 48 h incubation.
  
  
  RESULTS
  A total of 1382 nasal screening swabs were tested by multiple operators. The BacLite Rapid MRSA test detected 142 out of the 157 confirmed MRSA that were detected on MSAO giving a diagnostic sensitivity of 90.4, diagnostic specificity of 95.7% and a negative predictive value of 98.7%. Of the 15 false negatives obtained by the BacLite Rapid MRSA test, seven grew small amounts (< 10 colonies of MRSA) on the MSAO culture plate and five isolates were ciprofloxacin sensitive. However there were 13 confirmed BacLite MRSA positive samples, which were negative by the direct culture method, probably due to overgrowth on the MSAO plate. There were 53 false positive results obtained by the BacLite Rapid MRSA test at 5 h and 115 cases where MRSA colonies were tentatively identified on the MSAO plate when read at 48 h, and which subsequently proved not to be MRSA.
  
  
  CONCLUSIONS
  The BacLite MRSA test is easy to use and provides a similar level of sensitivity to conventional culture for the detection of nasal carriage of MRSA with the advantage that the results are obtained much more rapidly.
authors.affiliation: Division of Infection, Barts and the London NHS Trust, London, UK. gljohnson@hotmail.co.uk
authors.forename: Gemma
authors.initials: G
authors.lastname: Johnson
authors.forename: Michael R
authors.initials: MR
authors.lastname: Millar
authors.forename: Stuart
authors.initials: S
authors.lastname: Matthews
authors.forename: Margaret
authors.initials: M
authors.lastname: Skyrme
authors.forename: Peter
authors.initials: P
authors.lastname: Marsh
authors.forename: Emma
authors.initials: E
authors.lastname: Barringer
authors.forename: Stephen
authors.initials: S
authors.lastname: O'Hara
authors.forename: Mark
authors.initials: M
authors.lastname: Wilks
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques / Q000191:economics / Q000379:methods*; D002353:Carrier State; D002939:Ciprofloxacin / Q000494:pharmacology*; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification* / Q000502:physiology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin