Improvement of a latex agglutination test for the evaluation of oxacillin resistance in coagulase-negative staphylococci.
The "Slidex MRSA Detection" test (Denka Seiken, Japan) is a latex agglutination assay able to detect PBP2a. We evaluated its ability to differentiate mecA-positive from mecA-negative coagulase-negative staphylococci. We included 100 coagulase-negative staphylococci clinical isolates belonging to 9 species, 54 mecA positive and 46 mecA negative, as characterized by PCR. The specificity achieved using the manufacturer's instructions was 100%, but the sensitivity was only 57%. To increase sensitivity, we introduced modifications into the standard protocol. Using either large inocula or oxacillin induction before test performance, we achieved 100% sensitivity.
Corso
A
A
Servicio Antimicrobianos, Departamento Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS Dr. Carlos G. Malbrán, Buenos Aires, Argentina. acorso@anlis.gov.ar
Soloaga
R
R
Faccone
D
D
Gagetti
P
P
Corbella
S
S
Iglesias
M
M
Galas
M
M
D007841:Latex Fixation Tests / Q000379:methods*; D010068:Oxacillin / Q000494:pharmacology*; D010403:Penicillin Resistance / Q000235:genetics; D046915:Penicillin-Binding Proteins / Q000032:analysis*; D011933:Reagent Kits, Diagnostic / Q000382:microbiology; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects* / Q000235:genetics
D046915:Penicillin-Binding Proteins; D011933:Reagent Kits, Diagnostic; D010068:Oxacillin