Title
Evaluation of chromogenic media for detection of methicillin-resistant **Staphylococcus aureus**
Author
Faculty/Department
Faculty of Sciences. Mathematics and Computer Science
Faculty of Medicine and Health Sciences
Publication type
article
Publication
Washington, D.C. ,
Subject
Biology
Human medicine
Source (journal)
Journal of clinical microbiology. - Washington, D.C.
Volume/pages
48(2010) :4 , p. 1040-1046
ISSN
0095-1137
ISI
000276153200004
Carrier
E
Target language
English (eng)
Full text (Publishers DOI)
Affiliation
University of Antwerp
Abstract
Rapid laboratory diagnosis is critical for treating, managing, and preventing methicillin-resistant Staphylococcus aureus (MRSA) infections. We evaluated and compared the potential for MRSA detection of five chromogenic media - Brilliance (Oxoid), ChromID (bioMérieux), MRSASelect (Bio-Rad), CHROMagar (CHROMagar-Microbiology), and BBL-CHROMagar (BD Diagnostics). Media were tested on log serial dilutions (100-106 cfu) of pure isolates of MRSA (n=60), non-MRSA (n=27), and their defined mixtures simulating clinical samples (n=84). Further evaluations were done on pre-enriched nasal and groin screening swabs (n=213) from 165 hospitalized patients. Randomized samples were spiral-plated on each medium and independently scored by 5 investigators for characteristic colonies at 24 and 48 hours incubation. Confirmatory testing was done on upto 5 putative MRSA colonies recovered from each medium. Cumulative average sensitivity on isolates, mixtures and clinical samples was highest for Brilliance (97), and similar for the other four media (≥92%). Cumulative average specificity was highest for BBL-CHROMagar (99%), followed by MRSASelect (98%), CHROMagar (97%), ChromID (89%), and Brilliance (86%). All media detected MRSA at 10 and 1 cfu, although at these low loads, few MRSA harboring SCCmec III- or IV were misinterpreted as non-MRSA by investigators. False-positive results were mainly due to methicillin-resistant S. epidermidis. For an arbitrary MRSA prevalence of 5% and based on patient sample evaluations, positive predictive values for BBL-CHROMagar and CHROMagar ({approx}84%) were highest. Negative predictive values of all media were ≥92% for MRSA prevalence ranging from 5%30%. In conclusion, BBL-CHROMagar and CHROMagar gave best overall results for detection of MRSA, irrespective of the sample concentration, investigator, or incubation period.
Full text (open access)
https://repository.uantwerpen.be/docman/irua/98bfa9/7be16081.pdf
E-info
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000276153200004&DestLinkType=RelatedRecords&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000276153200004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000276153200004&DestLinkType=CitingArticles&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848
Handle