A-296 Validation of a Real Time PCR Kit for the Detection and Differentiation of MRSA, MSSA and MRCoNS in Respiratory Clinical Samples

Abstract

Abstract Background Staphylococcus aureus infections are remarkable due to their high morbimortality. In addition, antibiotic resistance of these bacteria is a cause of concern since it worsens the patient prognosis and it is associated to higher morbidity, mortality and cost of treatment. The aim of this study was to assess the clinical performance of the assay VIASURE Methicillin resistant Staphylococcus aureus Real Time Detection Kit in clinical and epidemiological respiratory samples. Methods Respiratory samples were collected from patients admitted to intesive care or ward of the Hospital Royo Villanova (Zaragoza, Spain). A total of 653 respiratory samples (both clinical and epidemiological) were employed: 189 nasal swab, 103 pharyngeal, 161 bronchoalveolar aspirate (BAS), 154 bronchoalveolar lavage (BAL) and 46 sputa samples previously characterised using culture methods. Results were compared with other commercial validated molecular assay (RIDA®GENE MRSA (R-biopharm)) presenting the same molecular targets as the assay under study. The characterisation performed by VIASURE is based on the combined results of the three targets S. aureus SA 442/coA, mecA/mecC and Sccmec-orfX junction and may report the following genotypes: methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible Staphylococcus aureus (MSSA)), methicillin-resistant coagulase negative Staphylococcus (MRCoNS) and methicillin-susceptible Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus (MSSA and MRCoNS). Results VIASURE assay correctly reported MRSA/MSSA/MRCoNS genotyping results with sensitivity and specificity values over 90% in all sample matrixes (Table 1). Conclusion The diagnostic performance of the assay under study demonstrated to be suitable tool for the molecular diagnosis of coagulase negative Staphylococci, S. aureus and their methicillin resistance causing mutation when compared with reference methods.