American Society for Microbiology

View all recommendations from this society

August 5 2020

Do not order urine cultures unless patients have symptoms consistent with urinary tract infection (UTI).

Urine cultures should only be requested on patients who have clinical signs of UTI. Routine culture of urine in asymptomatic individuals may detect asymptomatic bacteriuria (ASB) which is commonly found in certain populations. Screening for ASB has no clinical benefit and may result in harm (1, 2).

Testing for ASB should only be pursued in specific populations such as pregnant women and individuals who are about to undergo urologic procedures that involve mucosal disruption (2).

These items are provided solely for informational purposes and are not intended as a substitute for consultation with a medical professional. Patients with any specific questions about the items on this list or their individual situation should consult their physician.
American Society of Microbiology in partnership with the Five Things Physicians and Patients Should Question

How The List Was Created

The American Society for Microbiology’s (ASM) list was developed under the leadership of the ASM’s Clinical and Public Health Microbiology Committee. The subject matter experts who identified the list and formulated the recommendations are laboratory directors at academic, commercial and public health laboratories and test utilization experts across the fields of microbiology and laboratory medicine. They worked together to identify a list of diagnostic and management decisions that have resulted in misuse of laboratory studies and resources. The five experts independently ranked the recommendations in order of priority and identified tests or procedures commonly used whose necessity should be questioned and discussed with patients. The experts formulated recommendations based on laboratory practice, evidence and an extensive review of the literature.

Five recommendations to address the most common clinical microbiology laboratory test misconceptions were written. They consist of diagnostic tests or treatments that are commonly ordered, expensive and have no evidence to illustrate its value and in some cases, may be potentially harmful to the patient. The recommendations, if instituted, would result in higher quality care, lower costs, and more effective use of our laboratory resources and personnel. The experts involved in this project are Sheldon Campbell, Marc Couturier, Omai Garner, Duane Newton, Preeti Pancholi and Linoj Samuel.

The recommendations were vetted and approved by ASM’s Clinical and Public Health Microbiology Committee.

The list has also been reviewed and approved by the ASCP Effective Test Utilization Committee.


Weiskopf J, Scott S. 2015. Asymptomatic bacteriuria, what are you treating? JAMA Intern Med 175:344-5.

Nicolle LE, Gupta K, Bradley SF, Colgan R, DeMuri GP, Drekonja D, Eckert LO, Geerlings SE, Koves B, Hooton TM, Juthani-Mehta M, Knight SL, Saint S, Schaeffer AJ, Trautner B, Wullt B, Siemieniuk R. 2019. Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America. Clin Infect Dis 68:e83-e110.