The following is a summary of the “Antibiotic heteroresistance in ESKAPE pathogens, from bench to bedside,” published in the March 2023 issue of Clinical Microbiology and Infections Disease by Roch et al.

This narrative review aims to give clinical microbiologists and physicians an accessible summary of recent advances in the study of heteroresistance, with a special emphasis on ESKAPE pathogens. Using the terms “heteroresistance” (heterogeneity OR heterogeneity) and “antibiotic resistance,” a search of the scientific literature was conducted using Pubmed and Google. This review focuses on the most pertinent abstracts from 836 publications on the detection, epidemiology, and clinical impact of heteroresistance in ESKAPE pathogens.

Staphylococcus aureus strains that are intermediate in their sensitivity to the antibiotic vancomycin are the only ones for which heteroresistance can be reliably defined. They compiled a more comprehensive microbiological definition that can be used with different types of bacteria and antibiotics in a medical setting. The population analysis profile is the gold standard for detecting heteroresistance, and we summarized its most important technical aspects for you here. Multidrug-resistant gram-negative pathogens are frequently reported to be heteroresistant to polymyxins, β-lactams (carbapenems, cefiderocol), fosfomycin, tigecycline, and aminoglycosides. 

Only in the case of heteroresistance to vancomycin-intermediate S. aureus have meta-analyses confirmed the existence of treatment failure due to heteroresistance described in case reports or retrospective studies. Lastly, they discuss the possibility of using individualized antibiotic combinations to target susceptible subpopulations of resistant isolates to treat infections caused by pan-drug-resistant bacteria. There is no current recommendation for clinical laboratories to screen for heteroresistance routinely. However, they need to be aware of this phenomenon, and in certain circumstances, such as treatment failure, reference laboratories should test for heteroresistance. To better understand heteroresistance and evaluate its clinical impact, more studies employing standardized methods are required.

Source: sciencedirect.com/science/article/abs/pii/S1198743X22005328