Culture Result Discrepancy Between Laboratories for Nontuberculous Mycobacteria in People with Cystic Fibrosis.

Nontuberculous mycobacteria (NTM) can cause severe chronic pulmonary infection, particularly in people with cystic fibrosis (CF). It is crucial for the laboratory to grow, identify to species and subspecies level, and report antimicrobial susceptibilities for the diagnosis and appropriate treatment of NTM. We suspected false negative acid-fast-bacilli (AFB) cultures or possibly reports of incorrect identification and/or antimicrobial susceptibility results from our local laboratories. We compared samples from our teaching hospital and commercial laboratories to a specialized NTM laboratory in 18 samples of sputum and/or bronchoalveolar lavage (BAL) fluid from patients with known or suspected NTM infection. We found discrepancies in all the samples that grew NTM at the specialized NTM laboratory compared to the local laboratories. These discrepancies are concerning. The commercial laboratories that are required to be used in the outpatient setting are mandated by insurance of the patient. We have no control over handling of samples in these laboratories. Our findings raise concerns about the accuracy of culture results in non-specialized laboratories, which is impacting patient care This article is protected by copyright. All rights reserved.