https://scholars.lib.ntu.edu.tw/handle/123456789/561155
Title: | Molecular evidence of false-positive cultures for Mycobacterium tuberculosis in a Taiwanese hospital with a high incidence of TB | Authors: | Lai C.-C. Tan C.-K. Lin S.H. Liao C.-H. Chou C.-H. YU-TSUNG HUANG PO-REN HSUEH |
Issue Date: | 2010 | Journal Volume: | 137 | Journal Issue: | 5 | Start page/Pages: | 1065-1070 | Source: | Chest | Abstract: | Background: Isolation of Mycobacterium tuberculosis (MTB) from the clinical specimens of patients with suspected TB remains the gold standard for diagnosis of TB. However, false-positive MTB cultures can occur as a result of laboratory contamination. Methods: After reviewing the medical records of 400 TB cases identified during January 2008 to January 2009 by the infection control unit of a university-affiliated hospital in Taipei, Taiwan, five patients were considered as clinically suspected false-positive cases and were referred to a mycobacteriology laboratory for confirmation. Spoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeat analyses were performed for all the suspected isolates and all other isolates cultured on the same day as the five suspected isolates. Results: Three cases were confirmed as false-positive culture cases based on the laboratory investigation. The culture from one of these cases (index case 1) grew multidrug-resistant TB. Another patient (index case 2) received an extended course of anti-TB treatment after he was considered to have failed treatment because of the false-positive MTB culture result. No anti-TB medication was given for index case 3. All three cases with false-positive cultures had only one positive culture specimen among multiple consecutive specimens submitted for cultures. In addition, specimens of the false-positive cultures were all negative for acid-fast smears. Conclusions: False-positive MTB cultures should be suspected in the following situations: when growth is observed on only one specimen among multiple specimens submitted; when it is positive in only one culture medium, especially in broth; or when there is only one specimen submitted. False-positive MTB cultures can be further confirmed with modern molecular typing techniques. ? 2010 American College of Chest Physicians. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/561155 | ISSN: | 0012-3692 | DOI: | 10.1378/chest.09-1878 | SDG/Keyword: | tuberculostatic agent; acid fast bacterium; adult; aged; article; bacterium contamination; bacterium culture; bacterium isolate; bacterium isolation; comorbidity; computer assisted tomography; controlled study; culture medium; drug treatment failure; female; human; infection control; laboratory diagnosis; major clinical study; male; medical record review; molecular epidemiology; molecular typing; morbidity; multidrug resistant tuberculosis; Mycobacterium tuberculosis; priority journal; spoligotyping; sputum culture; sputum smear; Taiwan; tandem repeat; thorax radiography; tuberculosis; university hospital |
Appears in Collections: | 醫學院附設醫院 (臺大醫院) |
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