Detection of polymyxins resistance among Enterobacterales: evaluation of available methods and proposal of a new rapid and feasible methodology

• Main Authors: Gabriela da Silva Collar (Author), Natália Kehl Moreira (Author), Priscila Lamb Wink (Author), Afonso Luís Barth (Author), Otávio Hallal Ferreira Raro (Author), Cícero Dias (Author), Adriano de Lima Machado (Author), Mariana Preussler Mott (Author), Juliana Caierão (Author)
• Format: Book
• Published: BMC, 2023-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Abstract Background Fast and accurate detection of polymyxins resistance is necessary as they remain the last resources to treat infections caused by Carbapenem-resistant Enterobacterales in many regions. We evaluated the rapid colorimetric polymyxin B elution (RCPE) and developed its miniaturized version, RCPE microelution (RCPEm), aiming to detect polymyxins resistance among Enterobacterales. Methods The methodologies consist of exposing the bacterial population in a solution (NP solution) where polymyxin B disks were previously eluted to obtain a concentration of 2 µg/mL for RCPE and 3 µg/mL for RCPEm. Results Two hundred sixty-seven Enterobacterales were evaluated, 90 (33.7%) resistant to polymyxin B by broth microdilution. It was observed 0.6% of major error (ME) by RCPE, with a specificity of 99.4%. The miniaturized version (RCPEm) presented the same ME and specificity values, but slightly higher sensitivity (97.8% vs. 95.6%) with 2.2% of very major error (VME). Conclusions RCPE and RCPEm proved to be useful alternatives to determine polymyxin B susceptibility in clinical microbiology laboratories, presenting low cost, being easy to perform, and demanding short incubation time.

Item Description

10.1186/s12941-023-00618-7
1476-0711