Heteroresistance is a

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...

in which a

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

isolate Isolate may refer to: Arts, entertainment, and media * ''Isolate'' (film), a 2013 Australian film * ''Isolate'' (Circus Maximus album), 2007 * ''Isolate'' (Gary Numan album), 1992 Language * Isolating language, with near-unity morpheme/word ...

contains sub-populations of cells with increased

antibiotic resistance Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...

when compared with the susceptible main population. This phenomenon is known to be highly prevalent among several antibiotic classes and bacterial isolates and associated with treatment failure through the enrichment of low frequencies of resistant subpopulations in the presence of antibiotics. Heteroresistance is known to be highly unstable, meaning that the resistance sub-population can revert to susceptibility within a limited number of generations of growth in the absence of antibiotic. Regarding the instability and the transient characteristic of heteroresistance subpopulations, the detection of this subpopulation often face difficulties by the conventional minimum inhibitory concentration methods. Hence, there is a significant demand for clinical microbiology laboratories to use rapid standardized methods to identify heteroresistance in pathologic specimen to prescribe a proper antibiotic treatment for patients.

Mechanisms

The enrichment of resistance sub-populations can be due to the acquisition of resistant mutations that are genetically stable but have high fitness cost or due to the enrichment of sub-population with increased copy number of resistance-conferring tandem gene amplifications.

References

{{reflist Bacteria