Molecular strain typing of Mycobacterium tuberculosis to confirm cross-contamination in the mycobacteriology laboratory and modification of procedures to minimize occurrence of false-positive cultures.
Molecular strain typing by restriction fragment length polymorphism analysis was used to demonstrate that two clusters of Mycobacterium tuberculosis cultures involving six patients resulted from cross-contamination in the mycobacteriology laboratory. Contaminated cultures were processed by the decontamination procedure and were read on the BACTEC instrument following acid-fast bacillus smear-positive specimens from patients with active tuberculosis. Investigation of these episodes suggested opportunities for modification of laboratory procedures to minimize cross-contamination and confirmed the adverse medical and public health consequences of false-positive cultures. Strain-typing results were used in decisions regarding patient care, including the curtailment of unnecessary treatment in one patient. Molecular strain typing appears to be a valuable means of identifying false-positive cultures of M. tuberculosis in selected settings.
Small
P M
PM
Department of Medicine, Stanford University, California 94305.
McClenny
N B
NB
Singh
S P
SP
Schoolnik
G K
GK
Tompkins
L S
LS
Mickelsen
P A
PA
D015373:Bacterial Typing Techniques; D001431:Bacteriological Techniques; D004269:DNA, Bacterial / Q000235:genetics; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D006801:Humans; D007755:Laboratories, Hospital; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology
D004269:DNA, Bacterial