Antimicrobial heteroresistance: an emerging field in need of clarity

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Heteroresistance describes bacterial subpopulations with varied antibiotic susceptibility.
• This phenomenon occurs in both Gram-positive and Gram-negative bacteria.
• Current nonstandard detection methods are costly and labor-intensive, hindering clinical evaluation.

Purpose of the Study:

• To review the literature on antibiotic heteroresistance.
• To propose standardized definitions and determination criteria for heteroresistant bacteria.
• To facilitate assessment of the clinical impact of heteroresistance.

Main Methods:

• Literature review of antibiotic heteroresistance.
• Analysis of existing definitions and determination methods.
• Development of recommendations for standardized criteria.

Main Results:

• Heteroresistance has been recognized since 1947.
• Lack of standardized methods leads to the term's inappropriate use.
• Clinical relevance is significant due to potential selection of resistant subpopulations during therapy.

Conclusions:

• Standardized methods are crucial for defining and detecting heteroresistance.
• Uniform guidelines are needed for accurate clinical assessment and improved therapeutic outcomes.
• Addressing heteroresistance can enhance antimicrobial stewardship and patient care.