Performance of the cobas MRSA/SA Test for Simultaneous Detection of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus From Nasal Swabs

Abstract

The cobas MRSA/SA Test is an effective tool to simultaneously perform surveillance testing for nasal colonization of both MRSA and MSSA.

Liquid and dry swabs for culture- and PCR-based detection of colonization with methicillin-resistant Staphylococcus aureus during admission screening

“…Detection rates for MRSA ranged from 5.3 to 6.0% for the different swab collection systems and did not differ significantly between the PCR-based tests (GeneXpert, cobas, and BD MAX). Detection rates using chromogenic culture with dry, ESwab, and MSwab collection systems compared to PCR systems were markedly lower at 2.9%, 3.9%, and 1.9%, respectively; this finding of lower detection rates using culture compared to PCR-based methods has been reported in other studies [12,23]. The admission prevalence reported in our tertiary care trauma center falls within the reported ranges of 3-7% for Europe [11,14,[24][25][26][27].…”

“…Positive predictive values as an indicator of specificity ranged from 33-54% compared to direct chromogenic culture and were lowest in liquid swabs, especially in those optimized for molecular testing (MSwab: 27-28%; ESwab 37-42%; dry swabs 41-49%), but did not vary between PCR methods; the calculated positive predictive values were lower than previously described in other studies; possible reasons would be the use of direct culture in the present study vs. direct and enrichment culture in other studies, i.e., those for FDA clearance of assays [12,30]. Other reasons for this finding could be the low MRSA prevalence and the presence of nonviable organisms (which are detected by PCR but not culture methods), as well as the overall lower sensitivity of the culture method used.…”

“…The cobas MRSA/SA test on the cobas 4800 system (cobas) is validated for use with MSwabs [12]. The testing was performed according to the manufacturer's instructions with the exception of the other swab types used.…”

“…Screening of potential MRSA-positive patients has been shown to be effective in most studies in reducing the frequency of MRSA transmissions in hospitals [3,7,[9][10][11]. Over the last years, multiple medium-to-high throughput automated PCR systems have become commercially available [12][13][14]. Using these MRSA screening tests, the value of rapid detection of colonization with MRSA and SA and consequent implementation of appropriate barrier precautions have been repeatedly demonstrated [15,16].…”

An Ointment Consisting of the Phage Lysin LysGH15 and Apigenin for Decolonization of Methicillin-Resistant Staphylococcus aureus from Skin Wounds

“…Staphylococcus aureus causes an extensive range of infections, from skin to systemic infections, which cause organ failure and death [ 1 , 2 , 3 , 4 ]. When the normal skin barrier is disrupted and cell-mediated immunity is suppressed, S. aureus can colonize wounds and cause infection [ 5 , 6 , 7 , 8 ]. Damaged skin, such as that which occurs in burn wounds, shows a high risk for S. aureus colonization and infection, increasing morbidity and mortality among burn patients [ 6 , 9 , 10 , 11 ] because the host defence against bacterial infections is severely impaired after burn injury [ 12 , 13 ].…”