title: [False tuberculosis outbreak caused by specimen contamination in a micro-bacteriology laboratory: confirmation by molecular techniques].
abstract: BACKGROUND
  The authors describe a false outbreak of tuberculosis by contamination in sample processing.
  
  
  METHODS
  The longitudinal polymorphisms of restriction fragments (RFLPs) of 6 strains of Mycobacterium tuberculosis isolated in different patients over a three week period and which were apparently implicated in an outbreak of tuberculosis were analyzed.
  
  
  RESULTS
  Four of the strains studied presented identical restriction pattern and the remaining two presented totally different patterns. Following study of the clinical histories and the epidemiologic relationships three cases of tuberculosis were confirmed. The other three strains isolated corresponded to contamination during the sampling process.
  
  
  CONCLUSIONS
  In a possible outbreak of six cases of tuberculosis, molecular techniques have allowed identification of three true cases of tuberculosis and have demonstrated contamination during the sampling process in three other cases. The latter could not have been shown with the clinical and phenotypical data of the strains.
authors.affiliation: Departamento de Microbiología, Hospital Universitario Virgen Macarena, Universidad de Sevilla.
authors.forename: J
authors.initials: J
authors.lastname: Aznar
authors.forename: H
authors.initials: H
authors.lastname: Safi
authors.forename: J C
authors.initials: JC
authors.lastname: Palomares
mesh_terms: D000328:Adult; D001431:Bacteriological Techniques; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D004269:DNA, Bacterial / Q000302:isolation & purification; D004196:Disease Outbreaks; D004866:Equipment Contamination; D005189:False Positive Reactions; D006801:Humans; D007755:Laboratories, Hospital; D008168:Lung / Q000382:microbiology; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D013048:Specimen Handling; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial
vernacular_title: Falso brote de tuberculosis por contaminación en las muestras en un laboratorio de microbacteriología: confirmación por técnicas moleculares.