05) to adhere to human alveolar (A549) and human

bronchial (BBM) epithelial cells. The XDR variant of KZN invaded A549 cells more effectively than the other isolates. These results suggest that the successful spread of the Beijing and KZN strains might be related to their interaction with alveolar epithelium Staurosporine (Ashiru et al., 2010). Examples of the locally predominant, but drug-susceptible clonal groups emerge, intriguingly, from the insular settings. In Japan, a large-scale study of the Beijing genotype revealed that the spread of its modern Beijing sublineage, which has a high transmissibility, is currently increasing, while the spread of an ancient Beijing sublineage has decreased significantly in younger generations (Iwamoto et al., 2009). In another study in Trinidad island in Caribbean, it was shown that a single major clone of an ‘evolutionary modern’ tubercle bacilli (SIT566) was responsible for more than Roxadustat purchase half of the TB cases, whereas it preferentially infected younger age groups. A comparison with genotyping data for six Caribbean countries showed that the overall lineage distribution in Trinidad was completely different from its neighbors, i.e., Trinidad was the only country harboring a unique sublineage of the LAM family, designated

LAM-10CAM (Millet et al., 2009). This sublineage is phylogeographically specific for Cameroon and neighboring countries in West Africa; it was shown to be significantly associated with clusters, suggesting its preponderant role Sclareol in recent transmission in Cameroon (Niobe-Eyangoh et al., 2004) and Burkina Faso (Godreuil et al., 2007). Interestingly,

3/4 of the patients within this group in Trinidad were African descendants (Millet et al., 2009). As mentioned above for the case of Beijing and KZN families in South Africa, the locally predominant clones may be noncompetitively cocirculating in an area. In Tunisia, >60% of the TB cases were due to a single genotype in each prevalent family, although their clustering differed: more clustered ST50/Haarlem was more predominant in the northern Tunisia, while the more widespread ST42/LAM displayed weak clustering and a low transmission rate, suggesting its stable association with the Tunisian population (Namouchi et al., 2008). Regarding interpretation of the results in our study, it should be noted, however, that ST125 was not associated either with drug resistance (Valcheva et al., 2008a) or with a higher growth rate in mouse macrophage model (N. Markova et al., unpublished data). The ability to replicate rapidly within macrophages may be considered as a proxy for increased transmissibility (Nicol & Wilkinson, 2008). Therefore, the presence of ST125 in Bulgaria cannot be attributed to the increased resistance/virulence/transmissibility properties. Instead, the specificity of ST125 in Bulgaria probably reflects its historical presence in this region, leading to a bacterium–host coadaptation.