Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2007 Jan;45(1):154-8.
doi: 10.1128/JCM.01115-06. Epub 2006 Nov 8.

Combined use of Pastorex Staph-Plus and either of two new chromogenic agars, MRSA ID and CHROMagar MRSA, for detection of methicillin-resistant Staphylococcus aureus

Affiliations
Comparative Study

Combined use of Pastorex Staph-Plus and either of two new chromogenic agars, MRSA ID and CHROMagar MRSA, for detection of methicillin-resistant Staphylococcus aureus

Veerle Compernolle et al. J Clin Microbiol. 2007 Jan.

Abstract

We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillin-resistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h). Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination). When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl, subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates combined with Gram staining and the direct_Pastorex agglutination test; and (iv) direct inoculation of C_MRSA plates combined with Gram staining and the direct_Pastorex agglutination test. We concluded that the use of MRSA_ID in combination with Gram staining and the direct_Pastorex agglutination test is faster and more specific than the other strategies tested.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Apfalter, P., O. Assadian, A. Kalczyk, V. Lindenmann, A. Makristathis, S. Mustafa, M. Rotter, and A. M. Hirschl. 2002. Performance of a new chromogenic oxacillin resistance screen medium (Oxoid) in the detection and presumptive identification of methicillin-resistant Staphylococcus aureus. Diagn. Microbiol. Infect. Dis. 44:209-211. - PubMed
    1. Blanc, D. S., A. Wenger, and J. Bille. 2003. Evaluation of a novel medium for screening specimens from hospitalized patients to detect methicillin-resistant Staphylococcus aureus. J. Clin. Microbiol. 41:3499-3502. - PMC - PubMed
    1. Hedin, G., and H. Fang. 2005. Evaluation of two new chromogenic media, CHROMagar MRSA and S. aureus ID, for identifying Staphylococcus aureus and screening methicillin-resistant S. aureus. J. Clin. Microbiol. 43:4242-4244. - PMC - PubMed
    1. Jevons, M. P., A. W. Coe, and M. T. Parker. 1963. Methicillin resistance in staphylococci. Lancet i:904-907. - PubMed
    1. O'Brien, M., and G. H. G. Davis. 1982. Enzymatic profile of Pseudomonas maltophilia. J. Clin. Microbiol. 16:417-421. - PMC - PubMed

MeSH terms

LinkOut - more resources