Performance of a new chromogenic oxacillin resistance screen medium (Oxoid) in the detection and presumptive identification of methicillin-resistant Staphylococcus aureus.
A new chromogenic Oxacillin Resistance Screen Agar (ORSA; Oxoid) for the presumptive detection of methicillin-resistant Staphylococcus aureus (MRSA) was compared to a phenyl-mannitol-salt-oxacillin medium (MS-Oxa), blood agar and brain heart-infusion (BHI) on 579 clinical specimens. After 24 h [48h] sensitivity and specificity for ORSA vs. MS-Oxa were 50.8% [68.2%] vs. 53.8% [65.7%] and 95.6% [94.5%] vs. 92.7% [91.8], respectively. Within 24 h, ORSA and MS-Oxa identified 51% and 54% MRSA. It is not feasible to omit BHI in MRSA-screening protocols since 33% MRSA grew in BHI only.
Apfalter
Petra
P
Division of Clinical Microbiology, Hygiene-Institute of the University of Vienna, Vienna, Austria. petra.apfalter@akh-wien.ac.at
Assadian
Ojan
O
Kalczyk
Andrea
A
Lindenmann
Verena
V
Makristathis
Athanasios
A
Mustafa
Stefan
S
Rotter
Manfred
M
Hirschl
Alexander M
AM
D017077:Culture Media, Conditioned; D005260:Female; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000494:pharmacology*; D011237:Predictive Value of Tests; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*
D017077:Culture Media, Conditioned; D010068:Oxacillin