Methods to evaluate colistin heteroresistance in acinetobacter baumannii

• Type of Material: Article
• Authors: Edgar X. Sherman, Emory University; Jessie E. Wozniak, Emory University; David Weiss, Emory University
• Language: English
• Date: 2019-01-01
• Publisher: Humana Press
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © Springer Science+Business Media, LLC, part of Springer Nature 2019.
• Final Published Version (URL): http://dx.doi.org/10.1007/978-1-4939-9118-1_4
• Title of Journal or Parent Work: Methods in Molecular Biology
• ISSN: 1064-3745
• Volume: 1946
• Start Page: 39
• End Page: 50
• Keywords: Humans; Disk Diffusion Antimicrobial Tests; Drug Resistance, Bacterial; Heteroresistance; Resistant subpopulations; Polymyxin; Antibiotic susceptibility testing; Population analysis profile; Phenotypic antibiotic resistance; Colistin; Dose-Response Relationship, Drug; Anti-Bacterial Agents; Microbial Sensitivity Tests; Acinetobacter baumannii
• Research Categories: Biology, Microbiology; Health Sciences, Immunology

Abstract

The nosocomial pathogen Acinetobacter baumannii is a growing threat to public health due to its increasing resistance to antibiotics including the last-line polymyxin, colistin. Heteroresistance to colistin has been described in A. baumannii, wherein a resistant subpopulation of cells coexisting with a majority susceptible subpopulation actively grows in the presence of antibiotic and can cause treatment failure. The shortcomings of diagnostic tests in detecting colistin heteroresistance are especially worrisome as they may lead to clinicians unknowingly prescribing an ineffective antibiotic, leading to increased patient morbidity and mortality. Several techniques can be used to detect heteroresistance, and the purpose of this chapter is to outline effective methods for identifying, quantifying, and analyzing heteroresistance to colistin in A. baumannii. We will highlight the advantages and disadvantages of techniques including population analysis profile (PAP), Etest, and disc diffusion, as well as additional methods to distinguish heteroresistance from other forms of resistance. While the scope of this chapter will focus on colistin heteroresistance in A. baumannii, these techniques can be adapted for the study of heteroresistance to other antibiotics and in other bacteria with slight modifications.