title: Evaluation of tuberculosis transmission in Tehran: using RFLP and spoligotyping methods.
abstract: OBJECTIVE
  To evaluate the DNA polymorphism among Mycobacterium tuberculosis (MTB) strains isolated from new smear positive tuberculosis (TB) patients residing in Tehran capital city of Iran, during the year 2001.
  
  
  METHODS
  IS6110-restriction fragment length polymorphism (RFLP) and spoligotyping analyses were performed on 129 M. tuberculosis strains. Additional patient's information was collected for further epidemiological analyses. Patients whose isolates had identical RFLP and spoligotyping patterns were considered a cluster.
  
  
  RESULTS
  The results show that the IS6110 were polymorphic and the strains with 8 or 9 IS6110 copy number were more frequently defected (42%). Out of 129 available isolates, 56 (43%) belonged to clusters and 72 (57%) did not. The risk factors like age, sex, family history or close contact and intravenous drug abuse were associated with clustering. Whereas, unemployment (61%) and poor living conditions (83%) contributed to diseases development in both groups. Spoligotyping of M. tuberculosis strains resulted in 46 different patterns, out of which 38 patterns were unique and reported for the first time. We found one M. tuberculosis strains with a pattern characteristic of the Beijing family.
  
  
  CONCLUSIONS
  In the studied time period both reactivation (57%) and recent transmission (43%) were contributing to annual new TB cases in Tehran.
authors.affiliation: Centre National de Reference des Mycobacteries, Institute Pasteur, Paris, France. pfarnia@hotmail.com
authors.forename: Parissa
authors.initials: P
authors.lastname: Farnia
authors.forename: Foorozan
authors.initials: F
authors.lastname: Mohammadi
authors.forename: Mohamad Reza
authors.initials: MR
authors.lastname: Masjedi
authors.forename: Anna
authors.initials: A
authors.lastname: Varnerot
authors.forename: Abolhasan Zia
authors.initials: AZ
authors.lastname: Zarifi
authors.forename: Javad
authors.initials: J
authors.lastname: Tabatabee
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Douraghei
authors.forename: Kumarze
authors.initials: K
authors.lastname: Ghazisaeedi
authors.forename: Davood
authors.initials: D
authors.lastname: Mansorri
authors.forename: Muslam
authors.initials: M
authors.lastname: Bahadori
authors.forename: Veronique
authors.initials: V
authors.lastname: Vincent
authors.forename: Cristina
authors.initials: C
authors.lastname: Gutierrez
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Velayati
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques; D016172:DNA Fingerprinting; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014376:Tuberculosis / Q000453:epidemiology / Q000382:microbiology*