title: Unsuspected and extensive transmission of a drug-susceptible Mycobacterium tuberculosis strain.
abstract: BACKGROUND
  A large and unsuspected tuberculosis outbreak involving 18.7% of the total of the tuberculosis cases studied, was detected in a population-based molecular epidemiological study performed in Zaragoza (Spain) from 2001 to 2004.
  
  
  METHODS
  The Mycobacterium tuberculosis drug-susceptible strain, named MTZ strain, was genetically characterized by IS6110-RFLP, Spoligotyping and by MIRU-VNTR typing and the genetic patterns obtained were compared with those included in international databases. The characteristics of the affected patients, in an attempt to understand why the MTZ strain was so highly transmitted among the population were also analyzed.
  
  
  RESULTS
  The genetic profile of the MTZ strain was rare and not widely distributed in our area or elsewhere. The patients affected did not show any notable risk factor for TB.
  
  
  CONCLUSIONS
  The M. tuberculosis strain MTZ, might have particular transmissibility or virulence properties, and we believe that greater focus should be placed on stopping its widespread dissemination.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Miguel Servet, Paseo Isabel la Católica, Zaragoza, Spain. ailopezc@aragon.es
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: López-Calleja
authors.forename: Patricia
authors.initials: P
authors.lastname: Gavín
authors.forename: Ma Antonia
authors.initials: MA
authors.lastname: Lezcano
authors.forename: Ma Asunción
authors.initials: MA
authors.lastname: Vitoria
authors.forename: Ma José
authors.initials: MJ
authors.lastname: Iglesias
authors.forename: Joaquín
authors.initials: J
authors.lastname: Guimbao
authors.forename: Ma Angeles
authors.initials: MA
authors.lastname: Lázaro
authors.forename: Nalin
authors.initials: N
authors.lastname: Rastogi
authors.forename: Ma José
authors.initials: MJ
authors.lastname: Revillo
authors.forename: Carlos
authors.initials: C
authors.lastname: Martín
authors.forename: Sofia
authors.initials: S
authors.lastname: Samper
mesh_terms: D000328:Adult; D000368:Aged; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D002675:Child, Preschool; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission*
chemical_list: D000904:Antibiotics, Antitubercular; D004269:DNA, Bacterial