[False-positive cultures due to cross contamination in tuberculosis laboratories].
Fifteen episodes of Mycobacterium tuberculosis laboratory cross-contamination suspected between 1996 and 2001 at 6 laboratories in Buenos Aires City and suburbs were investigated by IS6110 RFLP. Thirteen episodes were confirmed. Even though BACTEC 460 produced the highest number of confirmed episodes in a single laboratory, the most extended one occurred while employing conventional culture procedures in solid medium. The double repetitive element-polymerase chain reaction (DRE-PCR) was applied to 8 of these episodes and produced concordant results with those of the RFLP. The DRE-PCR appears to be a valuable tool for the prompt identification of false positive cultures. The timely rectification of defects in laboratory protocols can avert false diagnoses of tuberculosis and unnecessary prolonged treatments.
Ritacco
V
V
Servicio de Micobacterias, INEI ANLIS Carlos G. Malbrán, Av. Vélez Sarsfield 563, 1281 Buenos Aires, Argentina. vivianaritacco@hotmail.com
López
B
B
Paul
R
R
Reniero
A
A
Di Lonardo
M
M
Casimir
L
L
Togneri
A
A
Kaufman
S
S
Barrera
L
L
D000336:Aerosols; D001118:Argentina; D001431:Bacteriological Techniques / Q000295:instrumentation; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis*; D004866:Equipment Contamination; D005189:False Positive Reactions; D006801:Humans; D007755:Laboratories, Hospital; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D011874:Radiometry / Q000295:instrumentation; D013048:Specimen Handling; D013242:Sterilization / Q000379:methods; D014376:Tuberculosis / Q000175:diagnosis*
D000336:Aerosols; D003470:Culture Media; D004269:DNA, Bacterial