Recent Articles

Milan SJ, Hauge KA, Kurepina NE, Lofy KH, Goldberg SV, Narita M, Nolan CM, McElroy PD, Kreiswirth BN, Cangelosi GA. (2004).
Expanded geographical distribution of the N family of Mycobacterium tuberculosis strains within the United States.
J Clin Microbiol. 2004 Mar;42(3):1064-8
PMID: 15004054

The N and W-Beijing families of Mycobacterium tuberculosis are phylogenetically closely related. The ability of the W-Beijing family to rapidly cause widespread disease is well described; however, few outbreaks involving the N family have been reported outside the New York City, N.Y., area. During 2002 to 2003, Seattle, Wash., experienced a rapidly expanding tuberculosis outbreak involving 38 persons in a 23-month period. The outbreak strain, SBRI9, exhibited the genotypic properties of the N family. Its IS6110 restriction fragment length poly-morphism pattern was identical or nearly identical to those of two N family strains that were responsible for clusters of tuberculosis cases, including a large nosocomial outbreak, in New York City and New Jersey from 1989 to 1990. It was also identical to strains involved in late 1990s tuberculosis cases in Michigan, Maryland, and Arkansas. Further monitoring of the N family may show that it shares with the W-Beijing family the propensity to spread rapidly, suggesting that this characteristic evolved prior to the divergence of the two genetic lineages.