GenomEra MRSA/SA, a fully automated homogeneous PCR assay for rapid detection ofStaphylococcus aureusand the marker of methicillin resistance in various sample matrixes

Abstract

The GenomEra MRSA/SA assay (Abacus Diagnostica, Turku, Finland) is the first commercial homogeneous PCR assay using thermally stable, intrinsically fluorescent time-resolved fluorometric (TRF) labels resistant to autofluorescence and other background effects. This fully automated closed tube PCR assay simultaneously detects Staphylococcus aureus specific DNA and the mecA gene within 50 min. It can be used for both screening and confirmation of methicillin-resistant and -sensitive S. aureus (MRSA and MSSA) directly in different specimen types or from preceding cultures. The assay has shown excellent performance in comparisons with other diagnostic methods in all the sample types tested. The GenomEra MRSA/SA assay provides rapid assistance for the detection of MRSA as well as invasive staphylococcal infections and helps the early targeting of antimicrobial therapy to patients with potential MRSA infection.

The Use of Molecular Methods for the Detection and Identification of Methicillin-Resistant Staphylococcus Aureus

“…There are two main strategies for the identification of MRSA by NATs: dual-target detection of S. aureus specific gene and the mec genes or targeting the orfX-SCCmec junction. The former approach has proven to be more suitable for the confirmation of MRSA on a selective culture, whereas the latter has allowed rapid screening of MRSA, directly in clinical specimens [43,46,52,[54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69]. However, recent developments of NAT detection technologies have enabled also the dual-target strategy to directly link the identification of S. aureus with the mecA gene detection from specimens containing mixed growth of MRSA, MRCoNS and MSSA.…”

“…Real-time PCR tests targeting S. aureus specific genes such as nuc, spa or fem in combination with the mec genes are considered as the 'gold standards' for MRSA confirmation. To date, several in-house tests and commercialized assays, utilizing this detection strategy, have been described in the literature (Table 1) [42][43][44][45][46]. One such test was described recently by Pasanen et al [43].…”

“…This new CE (Conformité Européenne)-cleared assay is the first commercially available homogeneous PCR platform, which uses thermally stable, intrinsically fluorescent time-resolved fluorometric labels resistant to aqueous quenching and other background effects [48]. In this fully automated, but low-throughput assay, cells are lysed by heat in a disposable plastic reaction vessel, in other words, the 'test chip,' which readily contains all the assay-specific PCR reagents, including the polymerase, in dry form [46]. Sample preparation time is minimal (< 5 min) and the PCR assay time is 55 min.…”

“…The detection is based on two nucleic acid targets: a sequence within the mecA gene encoding for methicillin resistance, and a highly conserved, but yet unpublished, sequence specific for S. aureus [47]. In recent future science group Molecular identification of methicillin-resistant Staphylococcus aureus Review studies, evaluating the performance of the GenomEra MRSA/SA assay for detection of MRSA, high sensitivity (99.3-100%) and specificity (100%) was observed as compared with other genotypic and phenotypic confirmatory tests [46]. However, thus far this assay has been utilized in combination with preceding cultures (selective and nonselective) only, and therefore, the total turnaround time for MRSA detection with the GenomEra assay is 16-24 h.…”

Vasoconstrictor effect of Africanized honeybee (Apis mellifera L.) venom on rat aorta

“…Among the components of the venom are biogenic amines, hyaluronidases, phospholipases A 2 (PLA 2 ) and melittin, which is its main constituent, approximately 50% of the dry weight [4,5]. This active 26-amino-acid peptide is released from its precursor, promelittin, during biosynthesis and presents hemolytic activity.…”