Alonso, MAlonso-Rodríguez, NGarzelli, CMartinez-Lirola, MHerranz, MSamper, SRuiz Serrano, MJBouza, EGarcía de Viedma, D2012-12-032012-12-032010-05-25Alonso M, Alonso Rodriguez N, Garzelli C, Martínez Lirola M, Herranz M, Samper S, et al. Characterization of Mycobacterium tuberculosis Beijing isolates from the Mediterranean area. BMC Microbiol. 2010 May 25;10:151.http://hdl.handle.net/10668/681BACKGROUND. The Beijing lineage of Mycobacterium tuberculosis is causing concern due to its global distribution and its involvement in severe outbreaks. Studies focused on this lineage are mainly restricted to geographical settings where its prevalence is high, whereas those in other areas are scarce. In this study, we analyze Beijing isolates in the Mediterranean area, where this lineage is not prevalent and is mainly associated with immigrant cases. RESULTS. Only 1% (N = 26) of the isolates from two population-based studies in Spain corresponded to Beijing strains, most of which were pan-susceptible and from Peruvian and Ecuadorian patients. Restriction fragment length polymorphism typing with the insertion sequence IS6110 identified three small clusters (2-3 cases). Mycobacterial interspersed repetitive unit-variable number tandem repeat typing (MIRU-15) offered low discriminatory power, requiring the introduction of five additional loci. A selection of the Beijing isolates identified in the Spanish sample, together with a sample of Beijing strains from Italy, to broaden the analysis context in the Mediterranean area, were assayed in an infection model with THP-1 cells. A wide range of intracellular growth rates was observed with only two isolates showing an increased intracellular replication, in both cases associated with contained production of TNF-alpha. No correlation was observed between virulence and the Beijing phylogenetic group, clustered/orphan status, or resistance. The Beijing strain responsible for extensive spread on Gran Canaria Island was also identified in Madrid, but did not lead to secondary cases and did not show high infectivity in the infection model. CONCLUSIONS. The Beijing lineage in our area is a non-homogeneous family, with only certain highly virulent representatives. The specific characterization of Beijing isolates in different settings could help us to accurately identify the virulent representatives before making general assumptions about this lineage.enAntituberculososFarmacorresistencia Bacteriana MúltipleGenotipoRegión MediterráneaMycobacterium tuberculosisFactores de TiempoTuberculosis PulmonarMedical Subject Headings::Chemicals and Drugs::Chemical Actions and Uses::Pharmacologic Actions::Therapeutic Uses::Anti-Infective Agents::Anti-Bacterial Agents::Antitubercular AgentsMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::GenotypeMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Geographicals::Geographic Locations::Europe::Mediterranean RegionMedical Subject Headings::Organisms::Bacteria::Gram-Positive Bacteria::Gram-Positive Rods::Gram-Positive Asporogenous Rods::Gram-Positive Asporogenous Rods, Regular::Mycobacteriaceae::Mycobacterium::Mycobacterium tuberculosisMedical Subject Headings::Phenomena and Processes::Physical Phenomena::Time::Time FactorsMedical Subject Headings::Diseases::Respiratory Tract Diseases::Respiratory Tract Infections::Tuberculosis, PulmonaryMedical Subject Headings::Geographicals::Geographic Locations::Europe::Spainresearch article20500810open access10.1186/1471-2180-10-1511471-2180PMC2894025