Evaluation of a new chromogenic medium for the detection of methicillin-resistant Staphylococcus aureus carriage on nasal and perianal specimens.
A new chromogenic medium, denim blue (DB), was compared with methicillin-resistant Staphylococcus aureus (MRSA) Select (MRSAS) for detection of MRSA from surveillance specimens. On DB, MRSA colonies are larger (0.57-0.8 versus 0.45-0.6 mm at 18 and 24 h, respectively). Despite this, sensitivities of DB were 77% and 96% at 18 and 24 h, respectively, and those of MRSAS were 63% and 97.5%. Specificities were significantly higher for MRSAS than DB. The study demonstrates that DB and MRSA are equal for the detection of MRSA from surveillance specimens provided the plates are read after 24 h of incubation. Positive predictive values of both media were less than 95% requiring confirmation of MRSA, by another method, from all new patients.
Reyes
Romina C
RC
London Health Sciences Centre, London, Ontario, Canada.
Stoakes
Luba
L
Milburn
Sue
S
Lennox
Gwen
G
Daniel
Janis
J
Silver
Shannon N
SN
Wijnker
E
E
John
Michael A
MA
Hussain
Zafar
Z
D001003:Anal Canal / Q000382:microbiology; D001431:Bacteriological Techniques / Q000379:methods*; D002353:Carrier State / Q000382:microbiology*; D002863:Chromogenic Compounds / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D016106:Methicillin Resistance; D009666:Nose / Q000382:microbiology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D002863:Chromogenic Compounds; D003470:Culture Media