Dunlap N E, Harris R H, Benjamin W H, Harden J W, Hafner D
Department of Microbiology, University of Alabama at Birmingham, USA.
Am J Respir Crit Care Med. 1995 Nov;152(5 Pt 1):1702-4. doi: 10.1164/ajrccm.152.5.7582316.
The purpose of this study was to investigate possible laboratory contamination of Mycobacterium tuberculosis cultures which resulted in the misdiagnosis of tuberculosis. We have investigated three cases in which a patient's culture was positive for M. tuberculosis but there was not a high clinical suspicion for disease. In each instance, another patient with clinically obvious pulmonary tuberculosis had specimens cultured concurrently within the same clinical laboratory. The isolates from both the obvious cases of tuberculosis and the suspect cases were obtained through the State of Alabama TB Laboratory, but these isolates originated at a commercial laboratory, a community hospital laboratory, and at a university hospital. MTB isolates were fingerprinted by probing for the insertion sequence IS6110. With each of the three pairs of isolates (case and suspicious case), identical IS6110 banding patterns were found suggesting identical MTB strains. Because the patients were geographically separated, it is strongly suspected that laboratory contamination of M. tuberculosis cultures resulted in the three suspect cases being diagnosed with tuberculosis. These findings indicate that positive M. tuberculosis cultures resulting from laboratory contamination can occur.
本研究的目的是调查结核分枝杆菌培养物可能存在的实验室污染情况，这种污染导致了结核病的误诊。我们调查了三例患者，其培养物结核分枝杆菌呈阳性，但临床对疾病的怀疑程度不高。在每一个案例中，另一位患有临床明显肺结核的患者在同一临床实验室同时进行了标本培养。来自明显肺结核病例和可疑病例的分离株均通过阿拉巴马州结核病实验室获得，但这些分离株分别来自一家商业实验室、一家社区医院实验室和一家大学医院。通过探测插入序列IS6110对结核分枝杆菌分离株进行指纹识别。在三对分离株（病例和可疑病例）中，均发现了相同的IS6110条带模式，这表明结核分枝杆菌菌株相同。由于这些患者在地理上相互隔离，因此强烈怀疑结核分枝杆菌培养物的实验室污染导致了这三例可疑病例被诊断为结核病。这些发现表明，实验室污染可能导致结核分枝杆菌培养物呈阳性。
