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The Beijing genotype is a globally spread lineage of Mycobacterium tuberculosis. In Russia, these strains constitute half of the local population of M. tuberculosis; they are associated with multidrug resistance and show increased transmissibility. Here, we analyzed traditional and new markers for the rapid and simple genotyping of the Beijing strains. A representative sample of 120 Beijing genotype strains was selected from a local IS6110-restriction fragment length (RFLP) database at the St. Petersburg Pasteur Institute. These strains were subjected to variablenumber tandem-repeat (VNTR) typing using 24 loci of a newly proposed format and three hypervariable (HV) loci (QUB-3232, VNTR-3820, and VNTR-4120). Ten of the 27 VNTR loci were monomorphic, while five loci, MIRU26, QUB-26, QUB-3232, VNTR-3820, and VNTR-4120, were the most polymorphic (Hunter Gaston index, >0.5). VNTR typing allowed us to differentiate between two large IS6110-RFLP clusters known to be prevalent across the entire country (clusters B0/W148 and A0) and identified in 27 and 23% of strains, respectively, in the Beijing genotype database. The B0/W148 strains were grouped closely in the VNTR dendrogram and could be distinguished by a characteristic signature of the loci MIRU26 and QUB-26. Consequently, this clinically important IS6110-RFLP variant, B0/W148, likely presents a successful clonal group within the M. tuberculosis Beijing lineage that is widespread in Russia. To conclude, the IS6110-RFLP method and VNTR typing using a reduced set of the most polymorphic loci complement each other for the high-resolution epidemiological typing of the M. tuberculosis Beijing genotype strains circulating in or imported from Russia.

Mycobacterium tuberculosis strains from 349 patients were isolated in western Sweden during the years 2001-2005. Only 26% of the tuberculosis (TB) patients were born in Sweden. All the others were born in any of 42 different countries; 17% in other European countries, 28% in Africa, 16% in Asia, 11% in the Middle East, and 2% in South America. The mean age of the Swedish-born patients was 67 years, while the mean age among the foreign-born patients was 37 years. The male/female ratio was 1.6 among the Swedes and 0.9 among those born abroad. Extrapulmonary manifestations of TB were most common among patients born in Africa while lung infections without extrapulmonary manifestations were most common in patients born in Europe, including Sweden. Spoligotyping showed that patients with T or Beijing strains had more pulmonary TB than extrapulmonary TB, while patients with EAI and CAS strains had a high proportion of extrapulmonary TB. The ancestral and/or evolutionary older PGG1 strains were more often isolated from the foreign-born patients than from the Swedish-born patients, who had strains generally being of the evolutionary recent genogroups PGG2/PGG3. We conclude that immigration from countries with a high incidence of TB has a strong impact on the TB epidemiology in western Sweden, a finding that should be taken into account by TB control strategists when developing programmes for eradication of TB in low prevalence settings.

The present investigation focused on genetic diversity and drug resistance of 101 Mycobacterium tuberculosis strains isolated between July 2003 and February 2005 in the Okinawa prefecture, Ryukyu Islands, Japan. A high rate of clustering (87%, eight clusters, 2 to 69 strains/cluster) was observed upon spoligotyping; most of it was due to the lower discriminatory power of this method for the Beijing lineage (n ‫؍‬ 72; 71.3% of the isolates). The remaining diversity was limited to seven clusters (two to five isolates/cluster), with the following distribution of major lineages: ill-defined T (n ‫؍‬ 13; 12.8%), ancestral East African-Indian (n ‫؍‬ 6; 5.9%), Haarlem (n ‫؍‬ 4; 4%), Latin American-Mediterranean (n ‫؍‬ 2; 2%), X1 (n ‫؍‬ 1; 1%), and a total absence of the central Asian clade. Three remaining strains could not be classified on the basis of their spoligotype pattern and were labeled "unknown." Subtyping with mycobacterial interspersed repetitive units (MIRUs) in association with additional QUB minisatellites was performed to discriminate among the Beijing strains. Based on an "in-house" spoligotyping/MIRU database (n ‫؍‬ 694 Beijing strains), eight highly discriminative MIRU loci for Beijing strains were selected (loci numbered 10, 16, 23, 26, 27, 31, 39, and 40). The highest discriminatory power (h) observed in our sample (n ‫؍‬ 72; M-26, 0.385; M-10, 0.38; M-31, 0.255; M-16, 0.238) was too low, and 73.6% of the Beijing strains from Okinawa remained clustered. Typing of Beijing strains with additional QUB loci (with the exception of "one-copy" QUB-1451) resulted in higher discriminatory powers: QUB-11b, 0.68; QUB-11a, 0.656; QUB-26, 0.644; QUB-18, 0.553; QUB-4156, 0.5; and QUB-1895, 0.453. A definitive algorithm on the use of QUB markers to subtype Beijing isolates in expanded studies would shed light on their hypervariability, which may sometimes blur recognition between epidemiologically linked Beijing isolates. The total absence of multiple drug resistance among Beijing isolates from Okinawa, as well as the relatively older ages of the patients (majority above 60 years), shows that tuberculosis (TB) is a declining disease in Okinawa, and an adequate TB control program has successfully avoided both the emergence and the spread of multidrug-resistant TB in this insular setting.Understanding the population structure and transmission dynamics of circulating Mycobacterium tuberculosis clades provides a unique insight into crucial public health issues, such as the appearance and persistence of variants escaping human immune response or the emergence of resistance to antibiotics. PCR-based methods, such as spoligotyping (17), may be a good indicator of strain identity by providing information about epidemiologically important clones, particularly when used in a new setting (17,30,40). Although spoligotyping may correctly identify "outbreak" episodes as well as reflect the spread of the disease due to human migratory movements, it is not suitable when used alone for purely epidemiological investigations as it ...

BackgroundTuberculosis (TB) remains a major health problem in Morocco. Characterization of circulating Mycobacterium tuberculosis genotypic lineages, important to understand the dynamic of the disease, was hereby addressed for the first time at a national level.Methodology/Principal FindingsSpoligotyping was performed on a panel of 592 M. tuberculosis complex strains covering a 2-year period (2004–2006). It identified 129 patterns: 105 (n = 568 strains) corresponded to a SIT number in the SITVIT2 database, while 24 patterns were labeled as orphan. A total of 523 (88.3%) strains were clustered vs. 69 or 11.7% unclustered. Classification of strains within 3 large phylogenetical groups was as follows: group 1– ancestral/TbD1+/PGG1 (EAI, Bovis, Africanum), group 2– modern/TbD1−/PGG1 group (Beijing, CAS), group 3– evolutionary recent/TbD1−/PGG2/3 (Haarlem, X, S, T, LAM; alternatively designated as the Euro-American lineage). As opposed to group 3 strains (namely LAM, Haarlem, and T) that predominated (86.5% of all isolates), 6 strains belonged to group 2 (Beijing n = 5, CAS n = 1), and 3 strains (BOV_1 n = 2, BOV_4-CAPRAE) belonged to ancestral group 1 (EAI and AFRI lineage strains were absent). 12-loci MIRU-VNTR typing of the Casablanca subgroup (n = 114 strains) identified 71 patterns: 48 MITs and 23 orphan patterns; it allowed to reduce the clustering rate from 72.8% to 29.8% and the recent transmission rate from 64% to 20.2%.ConclusionThe M. tuberculosis population structure in Morocco is highly homogeneous, and is characterized by the predominance of the Euro-American lineages, namely LAM, Haarlem, and T, which belong to the “evolutionary recent” TbD1−/PGG2/3 phylogenetic group. The combination of spoligotyping and MIRUs decreased the clustering rate significantly, and should now be systematically applied in larger studies. The methods used in this study appear well suited to monitor the M. tuberculosis population structure for an enhanced TB management program in Morocco.

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The ability of four 9,10-dihydroethanoanthracene derivatives (BG920, BG932, BG958, and BG996), as well as verapamil and promethazine, to reverse chloroquine resistance was assessed against 24 chloroquine-resistant and 10 chloroquine-susceptible strains of Plasmodium falciparum from different countries. The 9,10-dihydroethanoanthracene derivatives clearly increase chloroquine susceptibility only in chloroquine-resistant isolates

dMycobacterium tuberculosis Beijing genotype strains are rapidly disseminating, frequently hypervirulent, and multidrug resistant. Here, we describe a method for their rapid detection by real-time PCR that targets the specific IS6110 insertion in the dnaAdnaN genome region. The method was evaluated with a geographically and genetically diverse collection representing areas in East Asia and the former Soviet Union in which the Beijing genotype is endemic and epidemic (i.e., major foci of its global propagation) and with clinical specimens.