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Antibiotic Stewardship: The Role Medical Laboratories Play

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Antibiotic resistance (AR) and overall antimicrobial resistance (AMR) is a complex issue that has currently reached a dangerous tipping point. Although frequently associated with antibiotics, AMR is not a phenomenon exclusive to bacteria. Other pathogens including viruses, fungi and protozoa also exhibit this ability to respond to antimicrobials, further demonstrating the dangerous scope of AMR in infectious diseases. Therefore, AMR represents a massive public health concern for pathogens ranging from influenza, to Pseudomonas aeruginosa (bacteria), to Plasmodium falciparum (the malaria parasite), to Candida (fungi). This puts a tremendous burden on healthcare providers and healthcare infrastructure, particularly in developing countries where resources can already be scarce.1

Antibiotic Resistiance

Whether one is discussing AR or AMR, together they represent a slow-burning global emergency. The World Health Organization (WHO), Centers for Disease Control and Prevention, and other similar agencies have predicted that AMR could lead to an economic impact of $100 trillion dollars and cause 10 million deaths annually by 2050 if the world does not take action. If this occurs, AMR will lead the world in mortality over longtime leaders like cancer and other health related conditions.


The Misuse of Antimicrobials

The efficacy of antimicrobials, particularly antibiotics, has led to their overuse and misuse. If honest, all of us have been in a situation where we utilize an antimicrobial / antibiotic without a prescription or without a confirmatory medical laboratory test and antibiotic susceptibility test. Whenever antibiotics are used, a selective pressure is applied, and the bacteria that escape that pressure can then proliferate or transfer the resistance gene; this can occur when antibiotics are taken during a virus infection. Antibiotics are meant to target bacteria, and therefore, have little-to-no effect when it comes to viral infections. Thus, the virus pathogen will be unaffected, but the bacteria existing in the patient’s body are being put through an antibacterial bottleneck in which only the strongest survive.2 The same scenario can be true when antibiotics are incorrectly used during an allergy or for other non-bacterial agents. Examples of this could include a fungal infection (like athlete’s foot) or infection with a protozoan (like malaria). Therefore, not only can taking antibiotics select for resistant bacterial populations, but the treatment will also do nothing for the patient suffering from a non-bacterial infection. This can then lead to the rise of AMR bacterial pathogens. Ultimately, whenever it is possible, antibiotics should be prescribed only for a bacterial infection. AMR has also contributed largely to the issue of healthcare and community associated infections. It is critical that physicians and others with the authority to prescribe antibiotics should do so based on a confirmatory medical laboratory tests and antibiotic susceptibility panels.3,4


Nudging – Can Selective Reporting Help?

In an April 2021 research study, Langford et al. conclude that laboratory reporting of antibiotic susceptibility results for urine cultures is associated with empirical and directed prescribing of the reported antibiotics. Laboratories can play an important role in guiding appropriate antibiotic selection for urinary indications.5   Briefly, after a patient specimen is identified as a bacterial pathogen, the medical laboratory / clinical microbiology professional will most often perform an antibiotic susceptibility test (AST) on the pathogen. Testing determines the potential effectiveness of specific antibiotics on the bacteria and/or determines if the bacteria have developed resistance to certain antibiotics. Used properly, the AST results help select the drug(s) that will likely be most effective in treating an infection.


Three Keys for the Microbiology / Medical Laboratory in Antimicrobial Stewardship

When one boils AR / AMR down to the most common denominator, an American Association of Clinical Chemistry publication does an effective job of explaining the role of the laboratory. Three main keys are discussed:

Antibiogram Reporting – Clinical microbiology laboratories conduct surveillance on local antimicrobial resistance trends among microbial pathogens. The collection, organization, and communication of resistance data culminates in the creation of an antibiogram. Antibiograms provide critical information to ASPs and prescribing physicians on institutional susceptibility patterns.

Patient-Specific Information – Laboratories provide patient-specific information by identifying microbial pathogens and performing antimicrobial susceptibility testing. This information is necessary so that empiric antimicrobial therapy can be narrowed appropriately.

Specimen and Reporting Quality – Laboratory guidelines, policies, and procedures that ensure high-quality specimen collection and processing have an important role in limiting unnecessary antimicrobial use.

Lastly, the ongoing and growing development of rapid diagnostics (e.g. MALDI-TOF, PNA-FISH, qPCR, NGS, and other multiplex nucleic acid assays) will continue to offer powerful discriminatory methods for not only pathogen identification but also genes that may confer resistance to antimicrobial drugs. It will be critical for the experts on laboratory testing (medical laboratory professionals) to be at the table for test selection and proper interpretation to aid physicians, pharmacists, and other healthcare professionals. Another important tool for healthcare / hospitals to utilize will be the newly created Doctor of Clinical Laboratory Science (DCLS). The DCLS will be the future of Diagnostic Management Teams and laboratory test utilization at the intersection of open communication with the entire healthcare team, including physicians.


Final Thoughts

In recent publications 6-11, I have discussed the overall critical importance of the medical laboratory. Most people, including some in healthcare, do not understand who performs your medical laboratory tests for COVID-19 or any other test. If you answered “my doctor” or “my nurse” or “a robot”, you would be completely wrong.

To put it bluntly, your life is in the hands of medical laboratory professionals. We perform an estimated 13 billion laboratory tests in the United States each year; that means laboratory testing is the single highest-volume medical activity in the lives of Americans.

Why should you care? Those 13 billion tests help drive approximately two-thirds of all medical decisions made by your doctor and other health care professionals from cradle to grave. There are only 337,800 practicing medical laboratory professionals for a population of just over 330 million people in the U.S. It is critical that all healthcare professionals understand the critical role laboratory medicine plays in not only antibiotic / antimicrobial resistance and antibiotic stewardship decisions, but in all patient health decisions.



  1. Rohde, R.E. & McNamara, R.P. Globalization and Antimicrobial Resistance: A Moving Target. Clin Lab Sci, 2018; DOI:
  2. Low D. Reducing antibiotic use in influenza: challenges and rewards. Clinical Microbiology and Infection. 2008;14(4):298-306.
  3. Rohde RE, Felkner M, Reagan J, Mitchell AH, Tille P. Healthcare-Associated Infections (HAI): The Perfect Storm has Arrived. Clinical laboratory science. 2016. p. 28-31.
  4. Rohde, R.E. Two Laboratory Tests you must Demand – Advice from MRSA Survivors and a Scientist.
  5. Langford, Nick Daneman, Christina Diong, et. al. Antibiotic susceptibility reporting and association with antibiotic prescribing: a cohort study. Clinical Microbiology and Infection, Volume 27, Issue 4, 2021, pp. 568-575, ISSN 1198-743X,
  6. Rohde R.E. To Beat Covid Variants, The U.S. Must Do More To Find Them. Forbes, Coronavirus Frontlines, Healthcare, April 21, 2021.
  7. Rohde R.E. Who is doing all those COVID-19 tests? Why you should care about medical laboratory professionals. The Conversation. December 14, 2020.
  8. Rohde R.E. What Happens When Laboratory Tests Fail? Microbiologics Blog, November 4, 2020.
  9. Rohde R.E. Beating Pandemics Like COVID-19 Requires More Medical Laboratory Professionals, This Virologist Explains. Forbes, Coronavirus Frontlines, Healthcare. April 23, 2020.
  10. Rohde R.E. Celebrating Medical Laboratory Professionals – We Save Lives Every Day! American Society for Microbiology, Bugs and Drugs, Invited online article, April 23, 2020.
  11. Rohde R.E. #PublicHealth Matters ALL the time to EVERYONE – Public Health Thank You Day #PHTYD19. Invited online article for tips, November 25, 2019.