z-logo
Premium
Evaluation of a polymyxin drop test for polymyxin resistance detection among non‐fermentative gram‐negative rods and enterobacterales resistant to carbapenems
Author(s) -
Perez Leandro Reus Rodrigues,
Carniel Eliana,
Narvaez Gabriel Azambuja,
Dias Cícero Gomes
Publication year - 2021
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/apm.13096
Subject(s) - polymyxin , polymyxin b , klebsiella pneumoniae , microbiology and biotechnology , broth microdilution , medicine , minimum inhibitory concentration , biology , antibiotics , escherichia coli , biochemistry , gene
To assess the performance of the drop test for polymyxin B resistance detection among Enterobacterales and non‐fermentative gram‐negative rods resistant to carbapenems. Seven hundred and fifteen carbapenem‐resistant isolates were tested: 628 Enterobacterales species and 87 non‐fermentative gram‐negative rods. For the polymyxin drop test, concentrations range from 0.25 to 8.0 µg/mL. Broth microdilution, as gold standard, was performed using in‐house‐prepared panels and interpreted according to the CLSI guidelines. Results were interpreted in terms of categorical agreements and discrepancies. Accuracy for a drop of polymyxin B at 2.0, 4.0 and 8.0 was calculated as better cutoff for resistance determination. No very major error was observed among all isolates, and 95.5% of agreement was observed among Enterobacterales, particularly for Klebsiella pneumoniae . A higher accuracy (95.1%) was obtained when a single drop of polymyxin B at 4.0 μg/mL was applied. Polymyxin drop test presented >95% of categorical agreement, without very major errors, for KPC‐producing K. pneumoniae isolates. An accuracy of 95.1% was obtained with a single drop at 4.0 μg/mL polymyxin B. Polymyxin B drop is an easy and feasible test and may allow a reduction on the turnaround time for polymyxin resistance detection and impacting on early implementation of accurate therapeutic interventions.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here