Genotypic diversity of Mycobacterium tuberculosis in Buenos Aires, Argentina

Fil: Monteserin, Johana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Paul, Roxana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Gravina, Elida. Hospital Interzonal General de Agudos Dr. Diego Paroissien; Argentina.Fil: Reniero, Ana. Hospital Central de San Isidro; Argentina.Fil: Hernández, Teresa. Centro de Zooantroponosis de La Matanza; Argentina.Fil: Mazzeo, Eduardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Togneri, Ana. Hospital Interzonal de Agudos Evita; Argentina.Fil: Simboli, Norberto. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: López, Beatriz. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Couvin, David. Institut Pasteur de la Guadeloupe. WHO Supranational TB Reference Laboratory; Francia.Fil: Rastogi, Nalin. Institut Pasteur de la Guadeloupe. WHO Supranational TB Reference Laboratory; Francia.Fil: Ritacco, Viviana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Buenos Aires is an overpopulated port city historically inhabited by people of European descent. Together with its broader metropolitan area, the city exhibits medium tuberculosis rates, and receives migrants, mainly from tuberculosis highly endemic areas of Argentina and neighboring countries. This work was aimed to gain insight into the Mycobacterium tuberculosis population structure in two suburban districts of Buenos Aires which are illustrative of the overall situation of tuberculosis in Argentina. The Lineage 4 Euro-American accounted for >99% of the 816 isolates analyzed (one per patient). Frequencies of spoligotype families were T 35.9%, LAM 33.2%, Haarlem 19.5%, S 3.2%, X 1.5%, Ural 0.7%, BOV 0.2%, Beijing 0.2%, and Cameroon 0.2%. Unknown signatures accounted for 5.3% isolates. Of 55 spoligotypes not matching any extant shared international type (SIT) in SITVIT database, 22 fitted into 15 newly-issued SITs. Certain autochthonous South American genotypes were found to be actively evolving. LAM3, which is wild type for RDrio, was the predominant LAM subfamily in both districts and the RDrio signature was rare among autochthonous, newly created, SITs and orphan patterns. Two genotypes that are rarely observed in neighboring countries ̶ SIT2/H2 and SIT159/T1 Tuscany ̶ were conspicuously represented in Argentina. The infrequent Beijing patterns belonged to Peruvian patients. We conclude that the genotype diversity observed reflects the influence of the Hispanic colonization and more recent immigration waves from Mediterranean and neighboring countries. Unlike in Brazil, the RDrio type does not play a major role in the tuberculosis epidemic in Buenos Aires