The Laboratory Must Do More Than Report Resistance Reimagining Its Role In Antimicrobial Stewardship
Wajid Sipra
Antimicrobial resistance (AMR) is often described as a prescribing problem. Physicians prescribe antibiotics, pharmacists dispense them, and patients use them. Yet one of the most important players in antimicrobial stewardship is sometimes left at the edge of the discussion: the diagnostic laboratory. In many hospitals, the laboratory identifies the organism, performs antimicrobial susceptibility testing, releases the report and considers its job complete. In the era of AMR, this passive model is no longer enough.
The scale of the problem demands a different approach. The World Health Organization (WHO) reported that approximately one in six laboratory-confirmed bacterial infections causing common infections worldwide in 2023 was resistant to antibiotic treatment. Resistance increased in more than 40% of the pathogen-antibiotic combinations monitored between 2018 and 2023.1 The laboratory therefore sits at a critical point between the emergence of resistance and the clinical decisions that determine whether antimicrobial pressure is increased or reduced.
A susceptibility report is valuable only if it leads to the right decision. A perfectly accurate report that arrives too late, contains unnecessarily broad treatment options, or is interpreted without local resistance data may have limited influence on patient management. Laboratories should therefore move beyond simply documenting resistance to actively supporting the decisions that follow it. This begins even before a specimen reaches the laboratory. Diagnostic stewardship means ensuring that the right test is performed for the right patient, at the right time, and that its result is used appropriately. WHO has emphasized diagnostic stewardship as an integral component of both AMR surveillance and patient management.2
More recently, the WHO AMR Diagnostic Initiative has placed laboratory capacity and appropriate diagnostic use at the centre of efforts to improve antimicrobial stewardship, infection prevention and surveillance.3
Poor diagnostic practices can themselves drive inappropriate antimicrobial use. Cultures collected after antibiotic initiation, contaminated blood cultures, inappropriate urine cultures and inadequate specimens may produce misleading or uninterpretable information. The consequence may be prolonged empirical therapy or unnecessary escalation to broader-spectrum antibiotics. Laboratory professionals should therefore engage with clinical teams on specimen selection, collection and interpretation rather than functioning only as recipients of specimens.