Detection of antibiotic-resistant microorganisms

Abstract

Method of detecting methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) in a nucleic acid coamplification assay. The invention advantageously reduces the incidence of false-positive MRSA determinations in real-time assays by requiring satisfaction of a threshold criterion that excludes certain co-infections from the MRSA determination. The invention further provides for determination of MSSA, even when the MSSA is present in combination with methicillin-resistant coagulase-negative (MR-CoNS) bacteria at high or low levels.

1 - 3 . (canceled) 
     
     
         4 . A composition for amplifying a nucleic acid sequence encoding methicillin resistance, comprising:
 a first oligonucleotide that has a target-complementary base sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; and   a second oligonucleotide that has a target-complementary base sequence consisting of SEQ ID NO:13, optionally including a 5′ sequence that is not complementary to the nucleic acid sequence encoding methicillin resistance.   
     
     
         5 . The composition of  claim 4 , wherein only one of the first and second oligonucleotides has a 3′ end that can be extended by a template-dependent DNA polymerase. 
     
     
         6 . The composition of  claim 5 , further comprising a detectably labeled hybridization probe. 
     
     
         7 - 53 . (canceled)