Evaluation of CHROMagar™ LIN-R for the Screening of Linezolid Resistant Staphylococci from Positive Blood Cultures and Nasal Swab Screening Samples

• Main Authors: Delphine Girlich (Author), Liliana Mihaila (Author), Vincent Cattoir (Author), Frédéric Laurent (Author), Christine Begasse (Author), Florence David (Author), Carole-Ann Metro (Author), Laurent Dortet (Author)
• Format: Book
• Published: MDPI AG, 2022-02-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

The increasing number of nosocomial pathogens with resistances towards last resort antibiotics, like linezolid for gram positive bacteria, leads to a pressing need for screening and, consequently, suitable screening media. Some national guidelines on infection prevention (e.g., in Germany) have already recommended screening for linezolid-resistant bacteria, despite an accurate screening medium that was not available yet. In this study, we analyzed the performance and reliability of the first commercial chromogenic medium, CHOMagar™ LIN-R, for screening of linezolid-resistant gram-positive isolates. Thirty-four pure bacterial cultures, 18 positive blood cultures, and 358 nasal swab screening samples were tested. This medium efficiently detected linezolid-resistant <i>S. epidermidis</i> isolates from pure bacterial cultures and from positive blood cultures with a high sensitivity (100%) and specificity (100%). Among the 358 nasal swab screening samples prospectively tested, 10.9% were cultured with linezolid-resistant isolates (mostly <i>S. epidermidis</i>). Of note, slight growth was observed for 7.5% samples with linezolid-susceptible isolates of <i>S. epidermidis</i> (<i>n</i> = 1), <i>S. aureus</i> (<i>n</i> = 1), <i>Enterococcus faecalis</i> (<i>n</i> = 4), <i>Lactobacillus</i> spp. (<i>n</i> = 3), gram negatives (<i>n</i> = 18). Moreover, few <i>Candida</i> spp. also cultured on this medium (1.4%).

Item Description

10.3390/antibiotics11030313
2079-6382