DNA restriction fragments length polymorphism of Mycobacterium tuberculosis isolates in Pisa, Italy

Eur J Epidemiol. 1997 Oct;13(7):845-51. doi: 10.1023/a:1007337319454.


A total of 60 Mycobacterium tuberculosis strains isolated in the area of Pisa, Italy, over a period from April 1993 to December 1995, were analyzed for the IS6110-based restriction fragments length polymorphism (RFLP). Isolates were found to show a great heterogeneity and only few isolates shared identical DNA banding patterns. In particular, 55 distinct IS6110 patterns were found (average number of isolates per pattern: 1.09) and only 9 strains (15%) occurred in 4 clusters of 2-3 identical clones. Computer analysis of genetic similarities among the strains revealed a family of 17 isolates including the clustered clones implicated in recently acquired infections. No correlation was found between the RFLP DNA patterns of the isolates and drug susceptibility. Of the 5 isolates from immigrants only one showed abnormal DNA fingerprinting. Our data indicate that the patterns of M. tuberculosis isolates in Pisa area are comparable to those of countries with low-prevalence TB and that a low level of TB transmission occurs in this area.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Bacterial / genetics*
  • Italy
  • Mycobacterium tuberculosis / genetics*
  • Mycobacterium tuberculosis / isolation & purification
  • Polymorphism, Restriction Fragment Length


  • DNA, Bacterial