Elution methods to evaluate colistin susceptibility of Gram-negative rods

Tanise Vendruscolo Dalmolin; Alana Mazzetti; Helena Ávila; Julia Kranich; Gabriel Ibrahim Borba Carneiro; Lavinia Nery Villa Stangler Arend; Guilherme Nardi Becker; Karin Obladen Ferreira; Daiana de Lima-Morales; Afonso Luís Barth; Marcelo Pillonetto

doi:10.1016/j.diagmicrobio.2019.114910

Elution methods to evaluate colistin susceptibility of Gram-negative rods

Diagn Microbiol Infect Dis. 2020 Jan;96(1):114910. doi: 10.1016/j.diagmicrobio.2019.114910. Epub 2019 Oct 23.

Affiliations

¹ LABRESIS - Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
² LACEN/PR - Laboratório Central do Paraná, São José dos Pinhais, - PR, Brazil.
³ LABRESIS - Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
⁴ Escola de Medicina, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil.
⁵ LABRESIS - Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address: albarth@hcpa.edu.br.

PMID: 31699544
DOI: 10.1016/j.diagmicrobio.2019.114910

Abstract

Recently it was developed the Colistin Broth Disk Elution test which uses colistin disks as a source of these antibiotics. The aim of this study was to evaluate the performance of protocols that used diminished volumes of the reagents: the Colistin Broth Microelution (CBM) (1 mL) and the Microelution-Plates Test (MPT) (200 μL), as well as the Colistin Susceptibility Test Tube (CSTT), which uses only one colistin disk added to a tube containing broth. The tests were performed with 85 Gram-negative isolates collected from surveillance studies. The CBM, MPT, and CSTT tests presented a good Categorical Agreement (CA), Essential Agreement (EA), sensitivity and specificity to Enterobacterales isolates, however the ME and VME were less satisfactory. The results for non-fermentative isolates were not satisfactory. In conclusion, the proposed methods, mainly the CSTT, can be used as screening tests to detect colistin resistant among Enterobacterales, as they are an easy and inexpensive option to the reference method.

Keywords: Antibiotic resistance; Colistin; Elution.

Publication types

Evaluation Study

MeSH terms

Anti-Bacterial Agents / pharmacology*
Chemistry Techniques, Analytical / standards*
Colistin / pharmacology*
Drug Resistance, Multiple, Bacterial
Gram-Negative Bacteria / drug effects*
Humans
Microbial Sensitivity Tests
Sensitivity and Specificity

Substances

Anti-Bacterial Agents
Colistin