Latex agglutination for rapid identification of methicillin-resistant Staphylococcus aureus recovered from selective media.
The accuracy of combining latex agglutination with selective media for the identification of methicillin-resistant Staphylococcus aureus (MRSA) was determined. Test strains were identified by latex agglutination on blood agar, the heat-stable thermonuclease test and broth microdilution MICs of oxacillin and included 97 MRSA, 56 methicillin-susceptible Staphylococcus aureus, 52 methicillin resistant, and 49 methicillin-susceptible Staphylococcus species. Isolates were grown on trypticase-soy agar with 5% sheep red blood cells (TSAB), Mueller-Hinton agar (MHA), mannitol-salt agar (MSA), and four media designed for the selective growth of MRSA:TSAB with clindamycin and gentamicin, MHA with oxacillin, MSA with oxacillin, and lipovitellin-salt-mannitol agar (LVSM) with 1 microgram oxacillin disks applied. The mean sensitivity, specificity, and positive predictive value for the combination of latex agglutination with selective media for the identification of MRSA was 96%, 99% and 98% respectively.
University of Texas Medical School, Department of Pathology, Houston 77030.
A R
AR
Wanger
D G
DG
Moore
M T
MT
LaRocco
D003470:Culture Media; D007841:Latex Fixation Tests; D016106:Methicillin Resistance; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D003470:Culture Media